Systemic sclerosis …

Neuroimmunology

Updated 06.06.2024
Released 04.01.1997
Expires For CME 06.06.2027

Systemic sclerosis

Authors: Richard M Keating MD, Kavitta B Allem MD, Samuel Ng

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Editor: Francesc Graus MD PhD

Systemic sclerosis

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Introduction

Overview

In 1945 Goetz, emphasizing the widespread and generally worsening visceral involvement seen in some individuals with scleroderma, proposed the term “progressive systemic sclerosis.” Today we recognize that progressive systemic sclerosis, a whole-body disease, can have both diffuse cutaneous involvement and limited cutaneous involvement, with each still being a systemic disease. Either form has the potential to cause major morbidity. Progressive systemic sclerosis occurs more frequently in females, especially during the peak incidence years of 30 to 55, where the female-to-male ratio may be as high as 12 to 1. Major mechanisms accounting for the pathological changes in progressive systemic sclerosis include generalized fibrosis, systemic microangiopathy, and immunoregulatory abnormalities. Pain may result from more frequent episodes of Raynaud phenomenon leading to cutaneous ulcers. Painful joint synovitis may also occur. Among the various concepts entertained for the pathophysiology of scleroderma, the role of hypoxia, cellular stress, and a concert of interacting cytokines has been highlighted. Tyrosine kinases are involved in transforming growth factor-beta and platelet-derived growth factor, which play a central role in the pathophysiology of systemic sclerosis. A clear understanding of these mechanisms might pave the way for novel therapies for systemic sclerosis.

Key points

	• The development of new Raynaud phenomenon, especially after the teen years, should raise concern for incipient scleroderma.
	• Pulmonary artery hypertension is a complication of scleroderma and may be seen in both limited and diffuse cutaneous disease.
	• Scleroderma renal crisis can be seen in up to 10% of patients with scleroderma and should be immediately managed with an ACE inhibitor.
	• Antinuclear antibodies are seen in excess of 95% of scleroderma patients.
	• Bone marrow transplant is increasingly a treatment option, but careful patient selection is paramount.

Historical note and terminology

The earliest description of scleroderma (skleros, hard; derma, skin) may have been made by Hippocrates around 400 BCE (Aphorism V:71). He noted, "In those persons in whom the skin is stretched, parched, and hard, the disease terminates without sweats." More definitive, early descriptions are attributed to Curzio (1753), Chowne (1842), Startin (1846), and Gintrac (1847), who suggested the descriptive term sclerodermie. In 1863 Raynaud commented on the occurrence of peripheral vasospastic events in an individual with scleroderma. Reports of occasional visceral (lung, kidney, gastrointestinal, and cardiac) involvement in some cases of scleroderma were made in the late 1800s and early 1900s. In 1942 Thomas noted the association of calcinosis, Raynaud phenomenon, esophageal dysfunction, and telangiectasias in an individual with scleroderma. Later, in 1964 Winterbauer applied the CRST (CREST) acronym to this limited cutaneous syndrome. After it became clear that patients with CRST also had esophageal dysmotility, Velayos and colleagues added the “E,” thus, coining the term CREST (44). CREST is an acronym for calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasias. Recognized subsets of scleroderma include diffuse systemic sclerosis, limited cutaneous systemic sclerosis (CREST), localized (morphea and linear scleroderma), overlap syndromes, and undefined connective tissue disease (32). Formal classification criteria for systemic sclerosis were put forth by the American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) in 2013. The classification system is based on a scoring system with different weight given to various clinical features and the presence of antibodies associated with scleroderma. Important exclusion criteria include patients who have scleroderma-like disorders or patients with skin thickening that spares the fingers. Skin thickening of the fingers of both hands extending proximally to the metacarpal phalangeal joints carries the most weight in the classification criteria. Other clinical criteria include skin thickening of the fingers only, fingertip lesions, telangiectasia, abnormal nailfold capillaries, pulmonary arterial hypertension or interstitial lung disease, and Raynaud phenomenon. Serologic antibodies account for only one numerical score given for anti-centromere, anti-topoisomerase I (anti-Scl 70), and anti-RNA polymerase III (47).

Table 1. ACR/EULAR Criteria for the Classification of Systemic Sclerosis

Item	Sub-item	Weight/Score
Skin thickening of the fingers of both hands extending proximal to the metacarpal phalangeal joints		9
Skin thickening of the fingers (only count the higher score)	• Puffy fingers • Sclerodactyly of the fingers (distal to the MCP joints but proximal to the PIP joints)	2 4
Fingertip lesions (only count the higher score)	• Distal tip ulcers • Fingertip pitting ulcers	2 3
Telangiectasia		2
Abnormal nail-fold capillaries		2
Pulmonary arterial hypertension and/or ILD (maximum score 2)	• Pulmonary arterial hypertension • ILD	2 2
Raynaud’s phenomenon		3
SSc-related autoantibodies (anti-centromere, anti-topoisomerase I (anti-Scl-70), anti-RNA polymerase III (maximum score 3)	• Anticentromere • Anti-topoisomerase I • Anti-RNA polymerase III	3
Patients with a total score of 9 or higher are classified as having definite systemic sclerosis.
Abbreviations: ILD, interstitial lung disease

Clinical manifestations

Presentation and course

Progressive systemic sclerosis occurs more frequently in females, especially during the peak incidence years of 30 to 55, where the female:male ratio may be as high as 12:1 (11). African American patients are affected at nearly twice the rate of Caucasian patients with disease often occurring at a younger age and more severe disease manifestations resulting in increased mortality (35). Initial symptoms can be vague and include Raynaud phenomena, malaise, and myalgias. For diffuse cutaneous systemic sclerosis, after the appearance of inflammatory and edematous changes, progressive skin fibrosis can occur, resulting in tight and painful skin involving fingers, proximal extremities, trunk, neck, and face. Painful tendon friction rubs are frequently seen and are a poor prognostic indicator for risk of disease progression. The degree of skin thickening may vary over 2 to 3 years. In some proximal locations, skin remodeling may occur and return towards normal as time progresses. Residual and severe skin fibrosis can cause permanent atrophic digit changes, joint immobility, and limited mouth opening. Subclinical visceral involvement may also be present at disease onset, suggested by esophageal reflux and radiographic pulmonary abnormalities. More widespread visceral involvement often occurs within the initial 10 years, including prominent pulmonary, gastrointestinal, cardiac, and renal complications. Motility dysfunction is the most prevalent esophageal pathology in patients with scleroderma (16). A generalized small vessel vasculopathy affecting small arteries, arterioles, and capillaries is characteristically proliferative and obliterative, thus, contributing to organ dysfunction. Cardiopulmonary complications are the leading causes of death. Prior to the availability of angiotensin-converting enzyme inhibitors, scleroderma renal crisis was a major cause of mortality associated with rapidly progressive hypertension and renal failure. Reviews have emphasized the multisystem nature and clinical complexity of this disease (33).

Skeletal muscle involvement in scleroderma is common; however, the prevalence can vary widely in published studies due in part to an absence of an established diagnostic criteria as well as overlap of scleroderma with the inflammatory myopathies (30). Objective muscle weakness is present sometime during systemic sclerosis in at least 80% and is usually multifactorial. Disuse and deconditioning are responsible in part. Over half demonstrate a mild, nonprogressive myopathy with slight elevations of serum creatine kinase and aldolase levels. Approximately 12% have a more progressive inflammatory myopathy. Inclusion body myositis has been reported rarely.

Patients may complain of muscle pain along with weakness, particularly if a scleroderma-myositis overlap is present. Autoantibodies such as the Anti-PM-Scl can help support the diagnoses of a myositis overlap. In a database of 9,165 scleroderma patients, muscle weakness reported by a treating physician was 18.9% in patients with limited cutaneous scleroderma and 33.5% in patients with diffuse cutaneous scleroderma (30). However, studies have varied widely in prevalence of abnormal manual muscle testing.

The scleroderma-myositis overlap is often part of the antisynthetase syndrome involving scleroderma-like changes in the lung as well as overlap with polymyositis and inclusion body myositis.

Clinically apparent neurologic involvement in progressive systemic sclerosis, exclusive of muscular involvement, is infrequent (probably less than 10%). In a systematic review of neurologic involvement in scleroderma, patients with limited cutaneous scleroderma were found to have epilepsy as the most frequent reported neurologic alteration (04). Cranial nerve involvement has been described, with third, sixth, and seventh nerve palsies having been described along with trigeminal neuralgia. Trigeminal sensory neuropathy is found in about 4% and is the most frequently observed focal neurologic problem (31). Trigeminal divisions II and III are involved in 65%, with bilateral distribution in 63%. Trigeminal neuropathy generally occurs later in the disease but may precede or occur simultaneously with other presenting features. The presentation of trigeminal neuropathy in association with Raynaud phenomenon may predict subsequent development of systemic sclerosis. Trigeminal neuralgia may rarely accompany the more common sensory deficits; trigeminal motor function is usually spared (31). In patients with diffuse cutaneous scleroderma, headache was the most prevalent neurologic symptom followed by cognitive impairment (04). Migraine headaches are more common than in rheumatoid arthritis or normal control populations and may be present in at least 30%.

Peripheral neuropathy has been noted in less than 5% (04), but most occur at a higher frequency that previously reported. Reduced vibration sense, reduced pinprick, focal atrophy, muscle weakness and decreased deep tendon reflexes are often seen. Comprehensive electrophysiological testing using electromyography (EMG) and nerve conduction studies shows distal sensory impairment in as many as 50%, usually subclinical. Both symptomatic and asymptomatic carpal tunnel syndrome has been identified, with incidence up to 67% for asymptomatic median nerve abnormalities on ultrasound imaging suggestive of carpal tunnel syndrome (04). Nerve entrapment has been detected, notably ulnar nerve entrapment and manifests as large and small fiber abnormalities in a non-length dependent fashion (04). Clinically evident sensorimotor axonal polyneuropathies occur infrequently, usually later in the disease, but may occur early or precede development of other symptoms (03). Brachial plexopathy has also been reported and thought to be a result of the scleroderma vasculopathy. A systematic review of the published cases with peripheral neuropathy and systemic sclerosis identified main risk factors as diffuse systemic disease, calcinosis cutis, and anticentromere antibodies (03).

Autonomic neuropathy may rarely cause symptomatic postural hypotension and gastrointestinal disturbances with features of dysautonomia. Electrophysiological testing has shown frequent autonomic abnormalities, usually subclinical, in up to 80%. Autonomic dysfunction probably contributes significantly to esophageal, cardiovascular, gastrointestinal dysmotility, and bladder abnormalities, and may also contribute to impotence (01).

Cerebral blood flow hypoperfusion abnormalities have been found in the majority of neurologically asymptomatic individuals. These findings probably relate to intracerebral microangiopathic processes, including cerebrovascular calcinosis, and correlate well to focal or diffuse abnormalities noted on cranial MRI, which are observed in over 50% of cases. These findings may also be related to mild cognitive abnormalities noted on neuropsychometric testing.

A rare, localized form of scleroderma involving the head (scleroderma "en coup de sabre") may be associated with symptoms such as headaches, seizures, or hemiparesis; it may demonstrate focal cerebral MRI abnormalities, including vasculopathy (28). In a retrospective review, cutaneous severity did not correlate with the severity of neurologic symptoms and imaging findings (08). Scleroderma “en coup de sabre” has been associated with orbital and intracerebral involvement leading to epilepsy and impaired vision (22).

Other limited forms or localized forms of scleroderma demonstrate neurologic involvement even less commonly. Isolated case reports have reported describing intracerebral hemorrhage; ischemic stroke; optic neuropathy; impaired eye movements; hearing loss; facial weakness; vocal cord paresis; tongue fasciculations; subacute combined degeneration from malabsorption and B12 deficiency; multiple sclerosis; myasthenia gravis; acute transverse myelopathy; compressive myelopathy from fibrosis, calcinosis, or atlantoaxial subluxation; compressive radiculopathy or mononeuropathy (ulnar, lateral femoral cutaneous, saphenous); mononeuritis multiplex; brachial and lumbosacral plexopathy; and lumbar radiculopathy (04). Whether these rare clinical events are direct consequences of the underlying pathological processes, indirect consequences, or coincidental associations remains unresolved.

Descriptive studies of pain in systemic sclerosis are very limited. Schieir and colleagues report that the pain symptoms were common in their study of patients with systemic sclerosis and were independently associated with more frequent episodes of Raynaud phenomenon, active ulcers, and worsening synovitis (40).

Neuro-psychiatric manifestations are all common in scleroderma. Patients complain of chronic pain and symptoms of depression and anxiety (04) and may exhibit behaviors not unlike patients with other forms of chronic facial or dental pain. They are often depressed about pain and disfigurement, physical function and social function, and may be candidates for psychologic intervention should be considered.

Neurologic and muscular complications of progressive systemic sclerosis are summarized in Table 2.

Table 2. Neurologic and Muscular Abnormalities Seen in Progressive Systemic Sclerosis

Clinical	Percentage of patients
Muscle weakness Mild nonprogressive myopathy Migraine Inflammatory myopathy Peripheral neuropathy Trigeminal sensory neuropathy Psychologic dysfunction	80% more than 50% 30% 12% less than 5% 4% more than 50%
Subclinical
Quantitative autonomic abnormalities Abnormal (diffuse or focal) brain MRI Quantitative sensory abnormalities Motor nerve conduction abnormalities	80% more than 50% 50% 44%

Prognosis and complications

The course of systemic sclerosis in an individual can be variable, ranging from minimal symptoms to death. Age-adjusted mortality for progressive systemic sclerosis is approximately 3 in 1 million; rates for women are two to four times higher than for men (33). Black women are more severely affected and have a higher mortality than Caucasian women. For all populations, 5- and 10-year survival rates vary from 60% to 70% and 40% to 50%, respectively. Factors adversely influencing prognosis include female gender; Black race; skin thickening of the trunk; cardiac, renal, or pulmonary involvement at time of diagnosis; heavy alcohol use in Caucasians; heavy cigarette smoking in the first year; and anemia, elevated erythrocyte sedimentation rate, proteinuria, or hypoproteinemia at the time of initial diagnosis. The absence of proteinuria, elevated sedimentation rate, and low carbon monoxide diffusing capacity has been associated with a 93% survival rate at 5 years. Patients with systemic sclerosis generally have a worse prognosis than those with limited scleroderma. Severe organ involvement, in those which it occurs, is usually within the first 3 years; the 9-year cumulative survival rate was 38% in those with severe organ involvement versus 72% in those without such involvement (33). Complications arising from renal, cardiac, and pulmonary involvement are the leading causes of death.

Pulmonary arterial hypertension, in particular, is an important cause of mortality in systemic sclerosis. Patients with interstitial lung disease and pulmonary arterial hypertension are associated with a high rate of morbidity and mortality (12). Although echocardiography is used as a screen for pulmonary arterial hypertension, right heart catheterization remains the diagnostic gold standard. Earlier treatment with new agents is associated with better treatment outcomes. Patients with simple myopathy have a relatively benign muscular course, characterized by minimal progression and waxing and waning symptoms. The muscle weakness of polymyositis progresses rapidly. The course of inclusion-body myositis is more indolent.

Scleroderma renal crisis is one of the most feared complications and can affect patients with both diffuse cutaneous and limited cutaneous scleroderma. However, prevalence has been decreasing with 10% of diffuse patients and 2% of limited cutaneous patients affected (43). Scleroderma renal crisis typically manifests as acute onset of moderate to severe “accelerated” hypertension and oliguric renal failure. Some patients may exhibit hypertensive encephalopathy and retinopathy.

Several studies have reported the association of systemic sclerosis with thyroid autoimmune disorders and thyroid function abnormalities; antithyroid peroxidase autoantibodies and ultrasonography should be tested as part of the clinical profile in systemic sclerosis patients. Females, subjects with positive antithyroid peroxidase and hypoechoic and small thyroid should have thyroid function follow-up and appropriate treatment in due course.

Clinical vignette

A 48-year-old woman was in good health until six months prior to her first evaluation when she began to notice excessive tiredness, general but mild muscle aches, and intermittent hand discomfort with mild purplish discoloration on cold exposure. Two weeks before evaluation she developed painless right face numbness.

At the time of the first evaluation, the general physical exam, including vital signs, was normal. In particular, no skin, joint, or vascular abnormalities were detected. Neurologic exam was also normal except for mildly decreased pin sensation in the second and third divisions of the right trigeminal nerve.

Initial laboratory evaluation of routine serum chemistries, complete blood count with differential, thyroid function tests, and serum creatine kinase were normal. Sedimentation rate was mildly elevated at 45. Testing for rheumatoid factor was negative; antinuclear antibodies were present at 1:160. Cranial MRI demonstrated a few punctate white matter T2 hyperintense foci bilaterally that were nonenhancing after gadolinium infusion. Magnetic resonance angiography of the extra- and intra-cranial vasculature was normal. Cerebrospinal fluid analysis was normal.

Over the next nine months the facial numbness improved, but her other mild symptoms continued. In addition, her Raynaud worsened, and sclerodactyly developed involving both hands followed by similar skin tightening of the proximal arms. Repeat antinuclear antibody testing was positive at 1:2560. Anti-RNA polymerase III and anti-topoisomerase I antibodies were present; anti-centromere antibodies were absent.

A diagnosis of systemic sclerosis was made.

Comment. Neurologic complaints, especially at the time of presentation, are uncommon in systemic sclerosis. However, trigeminal sensory neuropathy is the most common focal neurologic event that is seen. In addition, the early presentation of trigeminal sensory neuropathy and Raynaud phenomenon together strongly suggests the subsequent development of typical systemic sclerosis (31).

Biological basis

Etiology and pathogenesis

The pathogenesis of systemic sclerosis is not entirely understood, but it is presumed to be autoimmune. Distinct immune profiles are found in patients with the limited cutaneous and progressive forms. An increasing body of work has been focused on the genetic role in the presentation of disease including insulin-like growth factor binding protein 7 and others (12). Environmental or occupational factors such as exposure to silica dust, organic solvents, biogenic amines, vinyl chloride, or urea formaldehyde have been implicated although only silica and solvent exposure has been consistently associated with diffuse cutaneous scleroderma (15). A scleroderma-like condition may also occur after exposure to bleomycin, tainted rapeseed oil, and L-tryptophan. This exposure may alter cytokine production and T cell responses. No clear association between silicone breast implants and systemic sclerosis has been found.

Major mechanisms accounting for the pathological changes in progressive systemic sclerosis include generalized fibrosis, systemic vasculopathy, and cellular/humoral autoimmunity. The three pathologic processes may occur and progress independently. Fibrosis appears to be the consequence of increased synthesis and deposition of collagen, fibronectin, and glycosaminoglycans by fibroblasts activated by products of microangiopathic endothelial cell damage and immune activation. Perivascular mononuclear cell infiltrates consist predominantly of T lymphocytes. They and their pro-inflammatory products can be directly damaging to skin, vasculature, and viscera. The causes of immunologic activation or the identity of the inciting autoantigens remains unresolved. The role of infectious agents as instigators is intriguing with the possibility of molecular mimicry and autoimmune disease. Given these environmental factors, it appears that both extrinsic and intrinsic events are necessary for the manifestation of disease.

A general immunoregulatory abnormality may set the stage for the development of scleroderma. Transforming growth factor-beta as well as connective tissue growth factor locally induce cytokines within the cellular infiltrate, which promotes fibrosis and angiogenesis. Blockade of these actions may provide a potential therapeutic benefit. This approach has successfully prevented pathological fibrosis in a graft-versus-host murine model of scleroderma. There is increasing evidence that IFN pathways in SSc play a pivotal pathogenic role (12). Serum levels of tumor necrosis factor and interleukin 13 are elevated in patients with localized scleroderma. Moreover, persistent fetal microchimerism after pregnancy in a majority of women with systemic sclerosis suggests that a graft-versus-host mechanism may contribute in some instances to the development of this illness (05).

The pathogenesis of scleroderma also involves a complex genetic relationship. Microchimeric cells, which can be passed from one individual to another during gestation, between twin fetuses, or via blood transfusions, organ donation, have been implicated in the pathogenesis of scleroderma; as noted above, this may be a spectrum of graft verus host disease. It is uncertain if these microchimeric cells are integrally associated with scleroderma or a source of immunologic dysregulation that results in scleroderma. Other genetic factors may be responsible for an increase in cases in families (05). To date, only one study has been published analyzing 42 twin pairs. This study demonstrated a poor correlation between clinical expression of disease, suggesting genetic predisposition alone is not sufficient to manifest disease expression (15). Patients of African American ancestry have a higher predominance of HLA-DRB1*08:04, which has been strongly related to antifibrallin auto antibodies, which could partially explain the increase prevalence among African American patients (12).

The mechanisms underlying the neurologic complications of progressive systemic sclerosis are likely not specific to the central nervous system, peripheral nervous system, or muscular system. Rather, they are similar to those involved in organ damage elsewhere in the body. Pathological reports of epineurial and perineurial thickening suggest that the neuropathy of progressive systemic sclerosis is related to excessive collagen deposition causing compression of myelinated fibers. Interstitial and perivascular fibrosis are the most common pathological findings in patients with progressive systemic sclerosis and uncomplicated myopathy. The paucity of connective tissue in the central nervous system may account for the relative rarity of clinically apparent central nervous system involvement. Immune-mediated vascular endothelial cell damage induces platelet aggregation and subsequent tissue ischemia, predisposing to ischemic neuropathy and presumed cerebral blood flow abnormalities and strokes. A study comparing vascular retinopathy with capillary nail fold findings demonstrated that retinal changes may reflect vascular damage from scleroderma and does not always correlate with the nailfold capillaroscopic patterns (46). Another study reported that the elastic properties of larger vessels in scleroderma are altered. Inflammatory vascular disease may cause some forms of cerebrovascular complications but is an unlikely basis of peripheral neuropathy. Increased endothelial growth factor levels are an early marker for subsequent vascular disease. There is also concern about defective protective mechanisms of nitric oxide in patients with scleroderma. Immune-mediated inflammatory muscle damage underlies the rare cases of aggressive myositis and progressive systemic sclerosis.

Epidemiology

There has been a gradual increase in the prevalence of scleroderma as improved care has allowed for those affected to live longer. Prevalence varies in reports but is estimated at between 38 and 341 cases per million. Disease definition and ascertainment bias leads to varying estimates. Systemic sclerosis is, however, the systemic autoimmune disease with the highest mortality, with interstitial lung disease, pulmonary hypertension, heart failure, gastrointestinal tract involvement, and scleroderma renal crisis contributing. Systematic reviews of cohort studies and meta-analyses put the standardized mortality ratio at 2.3 to 3.5 in SSc, with a cumulative survival from diagnosis of 75% at 5 years and 62.5% at 10 years (23).

Distribution is worldwide and appears to be noncontagious but affected by environmental and genetic factors. Female preponderance is noted in all studies. Female to male ratios vary from 5:1 to 12:1 (during mid to late childbearing years) with symptom onset highest in the fourth and fifth decades (33). Age-specific incidence rates are higher in African American women than in white women, especially in women younger than 54 years old. Diffuse disease is more common in black women, and this makes survival lower for African-American women (33).

Women are often younger at presentation than men and more often have overlap with another systemic autoimmune rheumatic disease (SARD), such as systemic lupus erythematosus, than men (36). Men, in contrast, more frequently present with dcSSc and in overlap with myositis. Men with systemic sclerosis are more frequently smokers than women. Finally, men more often have associated interstitial lung disease. Serologically, women are more frequently found to be anti-centromere antibody positive, and males are more often anti-topoisomerase I (anti-Scl-70) and anti-U3RNP positive. Men more often die of interstitial lung disease and women of pulmonary hypertension.

Diagnostic workup

The clinical diagnosis of progressive systemic sclerosis rests on the demonstration of the typical skin and digit changes in patients with a history of Raynaud phenomenon and positive antinuclear antibodies. Microangiopathic changes can be seen under magnified examination of the nail fold capillaries and careful retinal examination (46). About half will have an elevated sedimentation rate. Serum creatine kinase levels are usually near normal but may be markedly elevated in association with rarely accompanying inflammatory myositis.

Serological studies demonstrate high-titer antinuclear antibodies in 90% of patients. Patterns of organ involvement may be based on the type of autoantibodies detected, and their titers. The absence of antibodies may also occur in a patient otherwise meeting clinical criteria for scleroderma. The association of scleroderma with antibodies other than antinuclear antibodies is under investigation.

Autoantibody profiles are particularly helpful in the diagnosis. Antinuclear antibodies are detectable in greater than 90% of patients with scleroderma (07). Anti-RNA polymerase III antibodies are found in 45% of patients with systemic sclerosis but rarely in limited cutaneous scleroderma. They are associated with increased risk of cardiac or renal disease. Anti-topoisomerase I (Scl70) antibodies are detected in 30% of patients with systemic sclerosis and 15% in limited cutaneous scleroderma. The presence of anti-topoisomerase I antibodies and anti-U1 RNA protein complex antibodies may be associated with higher likelihood of neurologic complications in some patients with systemic sclerosis, as well as increased risk for pulmonary disease. Anti-PM-Scl antibodies are found in systemic sclerosis patients with associated inflammatory myopathy (42). Anti-centromere antibodies are found in over 70% of patients with limited scleroderma and CREST syndrome but infrequently in those with systemic sclerosis; they strongly correlate with esophageal involvement in systemic sclerosis. Localized scleroderma also demonstrates a high incidence of antinuclear antibodies (73%), prominently directed at histones, but low incidence of anti-centromere and anti-topoisomerase I antibodies.

Table 3. Disease Manifestations Associated with Autoantibodies

Biomarker	Clinical Association
Anti-Scl-70 (anti-topoisomerase) Anti-centromere Anti-Th/To Anti-RNA polymerase Anti-RNP (ribonucleoprotein complexes) Anti-Pm-Scl (polymyositis-scleroderma) Anti-U 1/U12 RNP	Diffuse systemic sclerosis (SSc); Interstitial lung disease, scleroderma renal crisis Limited SSc; Pulmonary arterial hypertension Limited SSc; SSc- Interstitial lung disease SSc renal crisis, severe diffuse SSc Skeletal muscle involvement; pulmonary arterial hypertension Scleroderma with myositis overlap SSc- Interstitial lung disease
Adapted from (07)

EMG studies demonstrate myopathic features in some muscles in the majority of individuals with systemic sclerosis, particularly with long-standing disease. Nerve conduction studies may indicate a mild distal axonal neuropathy or evidence of nerve entrapment.

Muscle biopsy is abnormal in over 50% of patients but is generally heterogenous and non-specific (30). Specimens generally show mild changes with mononuclear inflammation, microangiopathy, increased collagen deposition, nonspecific type II muscle fiber atrophy, and intimal proliferation within endomysial and perimysial vessels. Perivascular cellular infiltrates may be rarely seen and raise the possibility of coexisting inflammatory myopathy. Infrequent reports of nerve biopsies demonstrate intimal thickening, adventitial edema, a reduced number of myelinated fibers, evidence of axonal degeneration, and the relative absence of active inflammatory changes. Muscle weakness is likely multifactorial with scleroderma-related heart and lung damage leading to muscle atrophy as well. Patients with a skeletal myopathy do not appear to have a worse prognosis, but there does appear to be an increased risk of myocardial involvement (30).

An ongoing challenge of systemic sclerosis is early diagnosis before end-organ damage. Progression of nailfold patterns on videocapillaroscopy is indicative of microvascular damage and disease and may have utility for monitoring the efficacy of therapeutic interventions (38).

In patients with systemic sclerosis-related interstitial lung disease, pericardial abnormalities are commonly seen on high-resolution CT, and their presence is strongly associated with echocardiographically defined pulmonary arterial hypertension, with abnormal total pericardial score as the best individual predictor. Significantly decreased parasympathetic tone and parasympathetic reactivity had been observed in systemic sclerosis patients than the controls.

In patients with progressive systemic sclerosis, high-resolution CT of the chest may reveal numerous signs of scleroderma, such as ground-glass opacities, consolidation, reticulation, nodules, bronchiectasis, and honeycombing. Recognizing and understanding the pulmonary findings of scleroderma on CT is important because these findings may indicate the level of disease involvement and dictate whether treatment is indicated. On initial high-resolution CT of the chest, interstitial lung disease is present in more than 50% of patients, including in some patients without symptoms (26).

Hachulla and colleagues in their study show that MRI is a very dependable technique to diagnose heart involvement in systemic sclerosis, including its inflammatory, microvascular, and fibrotic components, by visualizing the myocardial fibrosis and inflammation (19). Furthermore, cardiac diastolic dysfunction is an independent risk factor associated with an increased risk of mortality (21).

Neuroimaging by CT and MRI has noted abnormalities in the absence of clear neurologic pathology (04). Imaging by CT has noted cerebral calcifications, extracranial atrophy, and cortical depression. MRI abnormalities include hyperintense white matter lesions and abnormal gyral pattern (41).

Men with systemic sclerosis present an increased risk of erectile dysfunction. Penile thermal abnormalities occur in almost all sclerodermic patients. Non-contact thermal imaging not only identifies thermal alterations but also clearly distinguishes between systemic sclerosis patients and healthy controls. Hence, this imaging could be valuable in identifying early erectile dysfunction in systemic sclerosis patients.

Management

The morbidity and mortality of progressive systemic sclerosis are primarily related to the excess accumulation of collagen in various tissues with the ensuing complications, including organ failure. As a general rule, treatment is directed at specific organ involvement. Progressive systemic sclerosis currently has no universally effective treatment and immunosuppression response is disappointing. Management is directed toward staging the severity of the disease and treating its complications.

Progressive skin disease without visceral involvement is very often approached with either methotrexate or mycophenolate mofetil. The European League Against Rheumatism supports the use of methotrexate for skin disease. Mycophenolate mofetil is often used when there is both skin and visceral involvement (29). Reports indicate that tocilizumab may benefit refractory joint and skin involvement, especially in early disease (34). IVIG may improve skin involvement in refractory cases (02).

Pulmonary complications of scleroderma, including interstitial lung disease and pulmonary hypertension, are major causes of morbidity and mortality. Cyclophosphamide and rituximab have both shown efficacy in controlling scleroderma interstitial lung disease, at least as measured by pulmonary function testing: cyclophosphamide shows impact on FVC and rituximab on DLCO (49).

Nintedanib has been used for interstitial lung disease in scleroderma with evidence of a modest impact on the decline of forced vital capacity (14). Mycophenolate mofetil can also be considered for interstitial lung disease as there was an even slower progression of forced vital capacity in combination with nintedanib (17).

The effect of tocilizumab in skin fibrosis and systemic sclerosis–associated interstitial lung disease was assessed in a multicenter, randomized, double-blind, placebo-controlled phase 3 trial. Tocilizumab was ineffective in improving skin fibrosis, but those patients on tocilizumab had significantly less worsening of the percentage of predicted forced vital capacity compared to placebo. Tocilizumab is now FDA approved for systemic sclerosis associated interstitial lung disease (25; 17).

Tocilizumab is now FDA approved for the treatment of scleroderma-associated interstitial lung disease due to a phase 3 trial (focuSSced) showing preservation of lung function via forced vital capacity that was maintained during its subsequent open-label extension at 96 weeks (37; 27).

Pulmonary artery hypertension is often responsive to endothelin receptor agonists (ambrisentan, bosentan, macitentan), PDE-5 inhibitors (sildenafil, tadalafil), and riociguat. Prostacyclin analogues (iloprost, treprostinil) have been successfully employed, too.

Renal disease in the form of scleroderma renal crisis is heralded by rapid skin involvement, autoantibodies to RNA polymerase III, rising blood pressure, and proteinuria. Glucocorticoids are traditionally used for complications such as arthritis and inflammatory myopathy, but enthusiasm for their use has been limited because they potentially precipitate scleroderma renal crisis when used at higher doses. Renal crisis can be significantly ameliorated through the use of angiotensin-converting enzyme inhibitors.

Progressive systemic sclerosis involves the gastrointestinal tract from the mouth to the anus, causing significant morbidity. Involvement of the gastrointestinal tract in progressive systemic sclerosis may occur in two stages, a neuropathic disorder followed by a myopathy. Gastric emptying is delayed and compliance of the fundus is increased, causing myoelectric abnormalities that result in reduced or absent migrating motor complexes predisposing to bacterial overgrowth. Malabsorption may also be due to pancreatic insufficiency. Pancolonic involvement occurs in 10% to 50% of patients with progressive systemic sclerosis with wide-mouthed diverticula, involving all layers of the intestinal wall, in addition to pseudoobstruction, pneumatosis cystoides intestinalis, stercoral ulcerations, and perforation. Fecal incontinence may be due to dysfunction of the internal anal sphincter. Treatments include biofeedback, sacral nerve stimulation, and surgery. Treatments for gastroparesis include metoclopramide, cisapride, and erythromycin. Bleeding from telangiectasias and watermelon stomach is treated endoscopically. Pseudoobstruction may respond to octreotide or prucalopride therapy. Treatments for rectal incontinence might include biofeedback, sacral nerve stimulation, and surgery.

Christopeit and colleagues describe marked improvement of severe progressive systemic sclerosis after transplantation of mesenchymal stem cells from an allogeneic haploidentical-related donor mediated by ligation of CD137L (09).

Autologous hematopoietic stem cell transplantation has evolved as a therapeutic option for patients with early diffuse cutaneous systemic sclerosis (13). Systemic sclerosis is the most common autoimmune disorder treated with autologous hematopoietic stem cell transplantation, accounting for 20% of all transplants done in autoimmune diseases. An open-access position statement has been published to provide plainly worded guidance for patients and nonspecialist clinicians considering hematopoietic stem cell transplantation for an autoimmune disease (24). There is a definite treatment-related mortality increase in the first year of therapy but a significant survival and quality-of-life benefit (48). Careful patient selection is key to outcome. In a randomized study, adult patients with severe scleroderma were assigned to undergo myeloablative autologous stem-cell transplantation (36 participants) or to receive cyclophosphamide (39 participants). The rate of event-free survival at 54 months was 79% in the transplantation group and 50% in the cyclophosphamide group (P=0.02). At 72 months, Kaplan-Meier estimates of event-free survival (74% vs. 47%) and overall survival (86% vs. 51%) also favored transplantation (P=0.03 and 0.02, respectively). As expected, treatment-related mortality in the transplantation group was 3% at 54 months and 6% at 72 months, as compared with 0% in the cyclophosphamide group (45). In a European Society for Blood and Marrow Transplantation multicenter, prospective, noninterventional study between December 2012 and February 2016, 80 patients underwent autologous stem cell transplantation. At two years, progression-free survival was 81.8%, and overall survival was 90%. Five (6.25%) patients died from complications in the first 100 days post transplantation (20).

An expert opinion consensus paper suggesting treatment algorithms for various clinical manifestations of systemic sclerosis has been published (18).

Raynaud phenomenon may respond to calcium channel blockers, but they may also aggravate esophageal reflux.

The treatment of existing digital ulcers includes hydrocolloid occlusion, wound care, pain control, antibiotics, and the use of vasodilating medications, and possibly digital or cervical sympathectomy.

References

01: Adler BL, Russell JW, Hummers LK, McMahan ZH. Symptoms of autonomic dysfunction in systemic sclerosis assessed by the COMPASS-31 questionnaire. J Rheumatol 2018;45(8):1145-52. PMID 29907667
02: Agostini E, De Luca G, Bruni C, et al. Intravenous immunoglobulins reduce skin thickness in systemic sclerosis: evidence from systematic literature review and from real life experience. Autoimmun Rev 2023;22(1):103198. PMID 34718166
03: AlMehmadi BA, To FZ, Anderson MA, Johnson SR. Epidemiology and treatment of peripheral neuropathy in systemic sclerosis. J Rheumatol 2021;48:1839-49. PMID 34210833
04: Amaral TN, Peres FA, Lapa AT, Marques-Neto JF, Appenzeller S. Neurologic involvement in scleroderma: a systematic review. Semin Arthritis Rheum 2013;43(3):335-47. PMID 23827688
05: Artlett CM. Microchimerism and scleroderma: an update. Curr Rheumatol Rep 2003;5(2):154-9. PMID 12628047
06: Carr ZJ, Klick J, et al. An update on systemic sclerosis and its perioperative management. Curr Anesthesiol Rep 2020;10(4):512-21. PMID 32904358
07: Castelino FV, Varga J. Current status of systemic sclerosis biomarkers: applications for diagnosis, management and drug development. Expert Rev Clin Immunol 2013;9(11):1077-90. PMID 24168414
08: Chiu YE, Vora S, Kwon EK, Maheshwari M. A significant proportion of children with morphea en coup de sabre and parry-romberg syndrome have neuroimaging findings. Pediatr Dermatol 2012;29(6):738-48. PMID 23106674
09: Christopeit M, Schendel M, Foll J, Muller LP, Keysser G, Behre G. Marked improvement of severe progressive systemic sclerosis after transplantation of mesenchymal stem cells from an allogeneic haploidentical-related donor mediated by ligation of CD137L. Leukemia 2008;22(5):1062-4. PMID 17972956
10: Clark KE, Etomi O, Ong VH. Systemic sclerosis in pregnancy. Obstet Med. 2020;13(3):105-11. PMID 33093861
11: Denton CP, Khanna D. Systemic sclerosis. Lancet 2017;390(10103):1685-99. PMID 28413064
12: Di Battista M, Barsotti S, Orlandi M, et al. One year in review 2021: systemic sclerosis. Clin Exp Rheumatol 2021;39(4):S3-S12. PMID 34251323
13: Di Benedetto P, Ruscitti P, Cipriani P, Giacomelli R. Haematopoietic stem cell transplantation in systemic sclerosis: challenges and perspectives. Autoimmun Rev 2020;19(11):102662. PMID 32942028
14: Distler O, Highland KB, Gahlemann M, et al. Nintedanib for systemic sclerosis-associated interstitial lung disease. N Engl J Med 2019;380(26):2518-28. PMID 31112379
15: Dumoitier N, Lofek S, Mouthon L. Pathophysiology of systemic sclerosis: state of the art in 2014. Presse Med 2014;43(10 Pt 2):e267-78. PMID 25179277
16: Duraj V, Tafai A, Roshi E, Burazeri G, Zoto A. Esophageal damages in systemic scleroderma. Med Arh 2007;61(1):47-8. PMID 17582977
17: Ebata S, Yoshizaki-Ogawa A, Sato S, Yoshizaki A. New era in systemic sclerosis treatment: recently approved therapeutics. J Clin Med 2022;11(15):4631. PMID 35956246
18: Fernandez-Codina A, Walker KM, Pope JE, et al. Treatment algorithms for systemic sclerosis according to experts. Arthritis Rheum 2018;70(11):1820-8. PMID 29781586
19: Hachulla AL, Launay D, Gaxotte V, et al. Cardiac magnetic resonance imaging in systemic sclerosis: a cross-sectional observational study of 52 patients. Ann Rheum Dis 2009;68(12):1878-84. PMID 19054830
20: Henes J, Oliveira MC, Labopin M, et al. Autologous stem cell transplantation for progressive systemic sclerosis: a prospective non-interventional study from the European Society for Blood and Marrow Transplantation Autoimmune Disease Working Party. Haematologica 2021;106(2):375-83. PMID 31949011
21: Hinze A, Perin J, Woods A, et al. Diastolic dysfunction in systemic sclerosis: risk factors and impact on mortality. Arthritis Rheumatol 2022; 74(5):849-59. PMID 34927390
22: Hixon AM, Christensen E, Hamilton R, Drees C. Epilepsy in Parry-Romberg syndrome and linear scleroderma en coup de sabre: case series and systematic review including 140 patients. Epilepsy Behav 2021;121(Pt A):108068. PMID 34052630
23: Ingegnoli F, Ughi N, Mihai C. Update on the epidemiology, risk factors, and disease outcomes of systemic sclerosis. Best Pract Res Clin Rheumatol 2018;32(2):223-40. PMID 30527428
24: Jessop H, Farge D, Saccardi R, et al. General information for patients and carers considering haematopoietic stem cell transplantation (HSCT) for severe autoimmune diseases (ADs): a position statement from the EBMT Autoimmune Diseases Working Party (ADWP), the EBMT Nurses Group, the EBMT Patient, Family and Donor Committee and the Joint Accreditation Committee of ISCT and EBMT (JACIE). Bone Marrow Transplant 2019;54(7):933-42. PMID 30705338
25: Khanna D, Lin CJF, Furst DE, et al. Tocilizumab in systemic sclerosis: a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Respir Med 2020;8(10):963-74. PMID 32866440
26: Khanna D, Distler O, Cottin V, et al. Diagnosis and monitoring of systemic sclerosis-associated interstitial lung disease using high-resolution computed tomography. J Scleroderma Relat Disord 2022a;7(3):168-78. PMID 36211204
27: Khanna D, Lin CJF, Furst DE, Wagner B, et al. Long-term safety and efficacy of tocilizumab in early systemic sclerosis-interstitial lung disease: Open-Label extension of a phase 3 randomized controlled trial. Am J Respire Crit Care Med 2022b;205(6):674-84. PMID 34851799
28: Knights H, Minas E, Khan F, et al. Magnetic resonance imaging findings in children with Parry-Romberg syndrome and en coup de sabre. Pediatr Rheumatol Online J 2021;19(1):42. PMID 33757522
29: Kowal-Bielecka O, Fransen J, Avouac J, et al. Update of EULAR recommendations for the treatment of systemic sclerosis. Ann Rheum Dis 2017;76(8):1327-39. PMID 27941129
30: Lorand V, Czirjak L, Minier T. Musculoskeletal involvement in systemic sclerosis. Presse Med 2014;43(10 Pt 2):e315-28. PMID 25179276
31: Maltez N, Choi MY, Troyanov Y, et al. Trigeminal neuralgia in systemic sclerosis. Semin Arthritis Rheum 2021;51(1):318-23. PMID 33461050
32: Mayes MD. Classification and epidemiology of scleroderma. Semin Cutan Med Surg 1998;17:22-6. PMID 9512103
33: Mayes MD, Lacey JV Jr, Beebe-Dimmer J, et al. Prevalence, incidence, survival, and disease characteristics of systemic sclerosis in a large US population. Arthritis Rheum 2003;48(8):2246-55. PMID 12905479
34: Panopoulos S, Tektonidou M, Bournia VK, Arida A, Sfikakis P. Anti-interleukin 6 therapy effect for refractory joint and skin involvement in systemic sclerosis: a real-world, single-center experience. J Rheumatol 2022;49(1):68-73. PMID 34393104
35: Pearson D, Werth V, Pappas-Taffer L. Systemic sclerosis - Current concepts of skin and systemic manifestations. Clin Dermatol 2018;36(4):459-74. PMID 30047430
36: Peoples C, Medsger TA, Lucas M, Rosario BL, Feghali-Bostwick CA. Gender differences in systemic sclerosis: relationship to clinical features, serologic status and outcomes. J Scleroderma Relat Disord 2016;1(2):204-12. PMID 2924839
37: Roofeh D, Lin CJ, Goldin J, et al. Tocilizumab prevents progression of early systemic sclerosis associated interstitial lung disease. Arthritis Rheumatol 2021. PMID 33538094
38: Ruaro B, Sulli A, Smith V, et al. Advances in nailfold capillaroscopic analysis in systemic sclerosis. J Scleroderma Relat Disord 2018;3(2):122-31. PMID 35382238
39: Sampaio-Barros PD, Samara AM, Marques Neto JF. Gynaecologic history in systemic sclerosis. Clin Rheumatol 2000;19:184-7. PMID 10870650
40: Schieir O, Thombs BD, Hudson M, et al; Canadian Scleroderma Research Group. Prevalence, severity, and clinical correlates of pain in patients with systemic sclerosis. Arthritis Care Res (Hoboken) 2010;62(3):409-17. PMID 20391488
41: Seese RR, Glaser D, Furtado A, Thakkar K, Torok KS. Unilateral neuroimaging findings in pediatric craniofacial scleroderma: Parry-Romberg syndrome and En Coup de Sabre. J Child Neurol 2020;35:753-762. PMID 32527172
42: Selva-O'Callaghan A, Mijares-Boeckh-Behrens T, Labrador-Horrillos M, Solans-Laque R, Ma Grau-Junyent J, Vilardell-Tarres M. Anti-PM-Scl antibodies in a patient with inclusion body myositis. Rheumatology (Oxford) 2003;42(8):1016-8. PMID 12869677
43: Shanmugam V, Steen VD. Renal disease in scleroderma: an update on evaluation, risk stratification, pathogenesis and management. Curr Opin Rheumatol 2012;24(6):669-76. PMID 22955019
44: Steen VD. The many faces of scleroderma. Rheum Dis Clin North Am 2008;34(1):1-15; v. PMID 18329529
45: Sullivan KM, Goldmuntz EA, Keyes-Elstein L, et al. Myeloablative autologous stem-cell transplantation for severe scleroderma. N Engl J Med 2018;378(1):35-47. PMID 29298160
46: Ushiyama O, Ushiyama K, Yamada T, et al. Retinal findings in systemic sclerosis: a comparison with nailfold capillaroscopic patterns. Ann Rheum Dis 2003;62(3):204-7. PMID 12594103
47: van den Hoogen F, Khanna D, Fransen J, et al. 2013 classification criteria for systemic sclerosis: an American college of rheumatology/European league against rheumatism collaborative initiative. Ann Rheum Dis 2013;72(11):1747-55. PMID 24092682
48: van Laar JM, Farge D, Sont JK, et al. Autologous hematopoietic stem cell transplantation vs intravenous pulse cyclophosphamide in diffuse cutaneous systemic sclerosis. JAMA 2014;311(24):2490-8. PMID 25058083
49: Yilmaz DD, Borekci S, Musellim B. Comparison of the effectiveness of cyclophosphamide and rituximab treatment in patients with systemic sclerosis-related interstitial lung diseases: a retrospective, observational cohort study. Clin Rheumatol 2021;40(10):4071-9. PMID 34056665

Contributors

All contributors' financial relationships have been reviewed and mitigated to ensure that this and every other article is free from commercial bias.

Authors

Richard M Keating MD

Dr. Keating of Scripps Clinic/Scripps Green Hospital has no relevant financial relationships to disclose.
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Kavitta B Allem MD

Dr. Allem of Scripps Clinic has no relevant financial relationships to disclose.
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Samuel Ng

Mr. Ng of Scripps Health has no relevant financial relationships to disclose.
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Editor

Francesc Graus MD PhD

Dr. Graus, Emeritus Professor, Laboratory Clinical and Experimental Neuroimmunology, Institut D’Investigacions Biomédiques August Pi I Sunyer, Hospital Clinic, Spain, has no relevant financial relationships to disclose.
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Former Authors

Nabih M Ramadan MD
J Theodore Phillips MD PhD
Lori B Siegel MD
Tarakad S Ramachandran MD

Patient Profile

Age range of presentation: 13 to 65+ years
Sex preponderance: female>male, >2:1
Heredity: heredity may be a factor
Population groups selectively affected: none selectively affected
Occupation groups selectively affected: none selectively affected

ICD & OMIM codes

ICD-10: Progressive systemic sclerosis: M34.0
ICD-11: Paediatric onset systemic sclerosis: 4A42.0

Diffuse systemic sclerosis: 4A42.1

Limited systemic sclerosis: 4A42.2

Systemic sclerosis, unspecified: 4A42.Z
OMIM: Susceptibility to systemic sclerosis: %181750

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Systemic sclerosis

Differential Diagnosis

scleredema
scleromyxedema
endocrine disorders
POEMS
hypothyroid myxedema
- sclerodactyly from diabetes mellitus
- amyloidosis
- eosinophilic fasciitis
- chronic graft versus host disease (GVHD)
- nephrogenic systemic fibrosis secondary to gadolinium-containing contrast media
- exposure to adulterated rapeseed cooking oil or L-tryptophan, petroleum byproducts, and organic solvents

Systemic sclerosis

Introduction

Overview

Key points

Historical note and terminology

Table 1. ACR/EULAR Criteria for the Classification of Systemic Sclerosis

Clinical manifestations

Presentation and course

Table 2. Neurologic and Muscular Abnormalities Seen in Progressive Systemic Sclerosis

Prognosis and complications

Clinical vignette

Biological basis

Etiology and pathogenesis

Epidemiology

Prevention

Differential diagnosis

Associated or underlying disorders

Diagnostic workup

Table 3. Disease Manifestations Associated with Autoantibodies

Management

Special considerations

Pregnancy

Anesthesia

References

Contributors

Authors

Editor

Former Authors

Patient Profile

ICD & OMIM codes

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