Scleroderma-polymyositis overlap syndrome. Clinical and serologic aspects

Scleromyositis: A distinct novel entity within the systemic sclerosis and autoimmune myositis spectrum. Implications for care and pathogenesis

Systemic sclerosis and autoimmune myositis are both associated with decreased quality of life and increased mortality. Their prognosis and management largely depend on the disease subgroups. Indeed, systemic sclerosis is a heterogeneous disease, the two predominant forms of the disease being limited and diffuse scleroderma. Autoimmune myositis is also a heterogeneous group of myopathies that classically encompass necrotizing myopathy, antisynthetase syndrome, dermatomyositis and inclusion body myositis. Recent data revealed that an additional disease subset, denominated "scleromyositis", should be recognized within both the systemic sclerosis and the autoimmune myositis spectrum. We performed an in-depth review of the literature with the aim of better delineating scleromyositis. Our review highlights that this concept is supported by recent clinical, serological and histopathological findings that have important implications for patient management and understanding of the disease pathophysiology. As compared with other subsets of systemic sclerosis and autoimmune myositis, scleromyositis patients can present with a characteristic pattern of muscle involvement (i.e. distribution of muscle weakness) along with multisystemic involvement, and some of these extra-muscular complications are associated with poor prognosis. Several autoantibodies have been specifically associated with scleromyositis, but they are not currently integrated in diagnostic and classification criteria for systemic sclerosis and autoimmune myositis. Finally, striking vasculopathic lesions at muscle biopsy have been shown to be hallmarks of scleromyositis, providing a strong anatomopathological substratum for the concept of scleromyositis. These findings bring new insights into the pathogenesis of scleromyositis and help to diagnose this condition, in patients with subtle SSc features and/or no autoantibodies (i.e. "seronegative" scleromyositis). No guidelines are available for the management of these patients, but recent data are showing the way towards a new therapeutic approach dedicated to these patients.

Recent Advances in Research Regarding Autoantibodies in Connective Tissue Diseases and Related Disorders

Connective tissue diseases (CTDs), also known as systemic autoimmune diseases, involve a variety of autoantibodies against cellular components. An important factor regarding these autoantibodies is that each antibody is exclusively related to a certain clinical feature of the disease type, which may prove useful in clinical practice. Thus far, more than 100 types of autoantibodies have been found in CTDs, and most of their target antigens have been identified. Many of these autoantigens are enzymes or regulators involved in important cellular functions, such as gene replication, transcription, repair/recombination, RNA processing, and protein synthesis, as well as proteins that form complexes with RNA and DNA. This article reviews the autoantibodies for each CTD, along with an assessment of their clinical significance, and provides suggestions regarding their utilization for clinical practice.

Muscle involvement in systemic sclerosis: points to consider in clinical trials

SSc is clinically and pathogenetically heterogeneous. Consensus standards for trial design and outcome measures are needed. International experts experienced in SSc clinical trial design and a researcher experienced in systematic literature review screened the PubMed and Cochrane Central Register of Controlled Trials in order to develop points to consider when planning a clinical trial for muscle involvement in SSc. The experts conclude that SSc-associated muscle involvement is heterogeneous and lacks a universally accepted gold-standard for measuring therapeutic response. Although outcome studies are currently limited by the inability to clearly distinguish active, reversible muscle inflammation from irreversible muscle damage and extramuscular organ involvement, strong consideration should be given to enrolling patients with a myopathy that features several elements of likely reversibility such as muscle weakness, biopsy-proven active inflammation, an MRI indicating muscle inflammation and a baseline serum creatinine kinase above three times the upper limit of normal to prevent floor effect. Randomized controlled trials are preferred, with a duration of at least 24 weeks. Outcome measures should include a combination of elements that are likely to be reversible, such as muscle weakness, biopsy-proven active inflammation, creatinine kinase/aldolase and a quality of life questionnaire. The individual measurements might require a short pre-study for further validation. A biological sample repository is recommended.

Musculoskeletal Involvement in Systemic Sclerosis: An Unexplored Aspect of the Disease

Musculoskeletal (MSK) symptoms in patients with systemic sclerosis (SSc) include articular involvement (arthralgia, synovitis, contractures), which is often an early phenomenon and significantly contributes to the disability. Predominantly the hands are affected. Consensus in outcome measures of articular involvement is missing. Health Assessment Questionnaire Disability Index (HAQ-DI), Cochin Hand Function Scale (CHFS), Hand Mobility Index in Scleroderma (HAMIS), and Disease Activity Score of 28 Joints (DAS28) may be used for the assessment of different aspects of joint involvement. There is an unmet need for therapies confirmed by randomized controlled clinical trials (RCTs) to treat both synovitis and non-inflammatory joint involvement. The few rehabilitation studies that have been conducted have shown some promising efficacy.

Muscle involvement may be an early symptom. The presence of clinically meaningful muscle involvement often heralds an unfavourable prognosis. The histology of muscle biopsy shows a variable picture including inflammation and necrosis. Besides, signs of acute neurogenic atrophy have been recently described as a previously underestimated contributor to muscle weakness. Similar to articular involvement, the lack of classification criteria on inflammatory and non-inflammatory SSc-associated myopathies, and the lack of validated core set of outcome measures makes it difficult to perform RCTs.

The SSc-specific fibrinous tenosynovitis (tendon-friction rubs /TFRs/) is a frequent finding in SSc. Patients with TFR are at increased risk of developing renal, vascular, cardiac and gastrointestinal involvement and have reduced survival rates. Changes of fibrinous tenosynovitis can be objectively detected by ultrasound and may be used as an outcome measure in the treatment of MSK involvement.

Patients with Systemic Sclerosis/polymyositis Overlap Have a Worse Survival Rate Than Patients Without It

OBJECTIVE

Studies on mortality associated with patients with systemic sclerosis (SSc) and myopathy have been limited by heterogeneous definitions of muscle involvement. The objective of this study is to determine whether homogeneous-defined SSc/polymyositis overlap (SSc-PM overlap) is associated with a worse survival rate compared with SSc without PM.

METHODS

Data from the Nijmegen Systemic Sclerosis cohort were used. Incidence rates were calculated from the observed number of deaths and followup time. Survival analysis using Cox proportional hazard modeling was performed to compare survival among patients with SSc and patients with SSc-PM overlap, including controlling for confounders. All patients with SSc-PM fulfilled the Bohan and Peter criteria for PM.

RESULTS

There were 24 patients with SSc-PM (5.7%) and 396 patients with SSc (94.2%). The 5- and 10-year cumulative survival rates from diagnosis were 82% and 68% for the SSc-PM group and 93% and 87% for the SSc group, respectively. Multivariate survival analysis revealed an adjusted HR of 2.34 (95% CI 1.09-5.02) for SSc-PM compared with SSc, with age at diagnosis, modified Rodnan skin score, diffuse cutaneous subtype, and male sex included as confounders. The most common cause of death among patients with SSc-PM overlap was cardiopulmonary involvement (63%), which was similar to the patients with SSc (51%).

CONCLUSION

Patients with SSc-PM overlap have a worse survival rate compared with patients with SSc.

High grade serous ovarian carcinoma with serous tubal intraepithelial carcinoma in a case presented with atypical glandular cell favor neoplasm cervical cytology and dermatomyositis

OBJECTIVE

This report describes a case of serous ovarian carcinoma with occult serous tubal intraepithelial carcinoma (STIC), which presented as atypical glandular cells favor neoplasia (AGC-FN) with Pap cytology and dermatomyositis.

CASE REPORT

A 48-year-old woman presented with symptoms of dermatomyositis. An AGC-FN result from a Pap smear, with an absence of a cervical or endometrial lesion was noted. After cancer surveillance, ovarian high grade serous carcinoma associated with serous tubal intraepithelial carcinoma was diagnosed. Two weeks following surgical excision of the carcinoma, dramatic remission of the dermatomyositis symptoms was evident.

CONCLUSION

The patient had serous carcinoma of the ovary with tubal STIC, which presented as dermatomyositis. The AGC-FN identified from a Pap smear hinted at a diagnosis of ovarian carcinoma. These presentations point to an occult malignancy in the genital tract and demand careful diagnostic workup.

Genetic association study of TNFAIP3, IFIH1, IRF5 polymorphisms with polymyositis/dermatomyositis in Chinese Han population

Background

Single-nucleotide polymorphisms (SNPs) in the TNFAIP3, IFIH1, and IRF5 genes have been associated with several auto-inflammation diseases, while the susceptibility between these genes and idiopathic inflammatory myopathies (IIMs) were not reported. This study aimed to investigate whether TNFAIP3, IFIH1, and IRF5 gene polymorphisms confer susceptibility for the IIMs in Chinese Han population.

Methods

A large case–control study of Chinese subjects with polymyositis (PM) (n = 298) and dermatomyositis (DM) (n = 530) was accomplished. 968 healthy and ethnically matched controls were available for comparison. Six SNPs in the TNFAIP3 region (rs2230926 and rs5029939), the IFIH1 gene (rs1990760 and rs3747517) and the IRF5 region (rs4728142 and rs729302) were assessed and genotyped using the Sequenom MassArray iPLEX platform.

Results

Our study indicated a strong allele association was observed in PM/DM and PM patients for rs2230926 (OR: 1.61, 95%CI: 1.20–2.16, P_c = 7.5×10⁻³; OR: 1.88, 95%CI: 1.30–2.74, P_c = 4.0×10⁻³, respectively) and rs5029939 (OR: 1.64, 95%CI: 1.21–2.21, P_c = 6.0×10⁻³; OR: 1.88, 95%CI: 1.28–2.76, P_c = 5.5×10⁻³,respectively). And rs2230926 and rs5029939 were significantly associated with interstitial lung disease (ILD) in PM/DM and PM patients (P_c = 0.04 and P_c = 0.016; P_c = 0.02 and P_c = 0.03, respectively). In addition, rs4728142 allele and genotype had significant association with PM/DM patients (P_c = 0.026 and P_c = 0.048, respectively). Further analysis with three logistic regression genetic models revealed statistically significant difference in the genotypic distribution in the PM/DM, PM or DM patients when the additive and dominant models were used.

Conclusions

This was the first study to reveal TNFAIP3 and IRF5 polymorphisms were associated with PM/DM patients or these patients with ILD, indicating that TNFAIP3 and IRF5 might be the susceptibility gene for PM/DM patients in Chinese Han population.

Musculoskeletal involvement in systemic sclerosis

Musculoskeletal (MSK) involvement is a very frequent manifestation of patients with systemic sclerosis (SSc). There are several reports about clinical trials assessing musculoskeletal involvement in SSc. However, only few controlled studies have been conducted. The prevalence of musculoskeletal symptoms, clinical and radiographic findings has been assessed. The most important articular (arthralgia, synovitis, contractures), tendon (tendon friction rubs, tenosynovitis) and muscular manifestations (myalgia, muscle weakness, myositis) should be carefully evaluated during the assessment of SSc patients, because these are not only common, but substantially influence the quality of life and some of them also have predictive value concerning disease activity and severity.

Scleroderma-polymyositis overlap syndrome versus idiopathic polymyositis and systemic sclerosis: a descriptive study on clinical features and myopathology

INTRODUCTION

The objective was to characterize the clinical and myopathologic features of patients with scleroderma-polymyositis (SSc-PM) overlap compared with a population of patients with systemic sclerosis (SSc) and polymyositis (PM).

METHODS

A three-way comparison of patients with SSc-PM overlap (n = 25) with patients with SSc (n = 397) and PM (n = 40) on clinical and myopathologic features and causes of death. One neuropathologist blinded for the diagnosis evaluated all recent available muscle biopsies. Biopsies were scored for presence of inflammation, necrotic muscle fibers, rimmed vacuoles, fibrosis, and immunohistochemical staining. Clinical or myopathologic characteristics were compared by using the χ(2) test or one-way analysis of variance (ANOVA).

RESULTS

The prevalence of SSc-PM overlap in the Nijmegen Systemic Sclerosis cohort was 5.9%. The mortality was 32% (eight of 25) in SSc-PM, of which half was related to cardiac diseases. The prevalence of pulmonary fibrosis was significantly increased in SSc-PM (83%) (P = 0.04) compared with SSc (49%) and PM (53%). SSc or myositis-specific antibodies were nearly absent in the SSc-PM group. In almost all biopsies (96%) of SSc-PM patients, necrotic muscle fibers were present, which was significantly increased compared with PM patients (P = 0.02).

CONCLUSIONS

Patients with SSc-PM have increased prevalence of pulmonary fibrosis and cardiac disease as the cause of death compared with patients with SSc and PM . In addition, we found that necrotizing muscle fibers with inflammation characterize SSc-PM overlap in muscle biopsies. Further research should focus on underlying mechanisms causing necrosis, inflammation, and fibrosis and their relation to pulmonary involvement and mortality in patients with SSc-PM overlap.

Cutaneous lesions of dermatomyositis with supervening fibrosis

BACKGROUND

Dermatomyositis (DM) is a distinctive systemic connective tissue disease whereby the skin defines a cardinal site of involvement. There exists a body of literature, which suggests that a significant component of its clinical manifestations may be related to endothelial cell injury. We have postulated in the past that anti-endothelial cell antibodies may be the defining trigger leading to endothelial cell dysfunction. The primary organs affected by DM are the skin and muscle. A significant albeit rare complication is pulmonary fibrosis, which our recent study postulated to be attributable to an autoimmune endothelialitis.

DESIGN

We describe six patients, four women and two men who ranged in age from 3 to 60 years, and had classic clinical presentations and cutaneous lesions of DM without any supervening clinical changes indicative of cutaneous sclerosis.

RESULTS

Skin biopsies showed cell-poor interface dermatitis with variable dermal mucin and C5b-9 within the cutaneous vasculature. However, at variance with classic DM was the presence of a sclerodermoid tissue reaction, which was of variable depth. All of these patients had severe muscle involvement. One pediatric patient had concomitant significant cutaneous, central nervous system and oral mucosal ischemic infarcts. Significant pulmonary disease ensued in the four adult patients, manifesting as pulmonary fibrosis in two, diffuse alveolar damage in one and diaphragmatic failure in one. In three patients, direct immunofluorescent studies were corroborative of immune-based microvascular injury while Western blot and/or indirect immunofluorescent studies showed anti-endothelial cell antibody activity within the serum of three patients.

CONCLUSIONS

The identification of sclerosis in biopsies of skin lesions typical clinically for DM may be a harbinger for more severe autoimmune-based endothelial cell injury phenomenon. One could speculate that its basis may be attributable to elevated serum levels of the natural fibrogenic factor, transforming growth factor beta, which in turn is released from damaged endothelium.

Progression of interstitial lung disease upon overlapping of systemic sclerosis with polymyositis

We describe a 73-year-old woman with systemic sclerosis (SSc)-polymyositis (PM) overlap syndrome, primarily SSc followed by PM. She had suffered from SSc and had interstitial pneumonia (IP), which was stable. Eight years after the initial diagnosis of SSc, proximal muscle weakness, myalgia, and dyspnea on effort developed. A chest computed tomography (CT) showed reticular shadows, and serum markers of IP such as KL-6 and surfactant protein-D were elevated at 1,170 U/mL and 176 ng/mL, respectively. Bronchoalveolar lavage fluid showed a remarkably increased number of lymphocytes. Exacerbation of SSc-IP 8 years after the initial diagnosis of SSc is not usual, and a marked increase in the number of lymphocytes in bronchoalveolar lavage fluid is also uncommon in SSc-IP, indicating overlap of another connective tissue disease. The diagnostic criteria for PM were satisfied; thus, SSc-PM overlap syndrome was diagnosed. We emphasize the need to investigate whether another connective tissue disease has developed when symptoms or laboratory findings cannot be explained by the usual clinical course of an existing connective tissue disease.

Polymyositis and dermatomyositis

The inflammatory myopathies, commonly described as idiopathic, are the largest group of acquired and potentially treatable myopathies. On the basis of unique clinical, histopathological, immunological, and demographic features, they can be differentiated into three major and distinct subsets: dermatomyositis, polymyositis, and inclusion-body myositis. Use of new diagnostic criteria is essential to discriminate between them and to exclude other disorders. Dermatomyositis is a microangiopathy affecting skin and muscle; activation and deposition of complement causes lysis of endomysial capillaries and muscle ischaemia. In polymyositis and inclusion-body myositis, clonally expanded CD8-positive cytotoxic T cells invade muscle fibres that express MHC class I antigens, which leads to fibre necrosis via the perforin pathway. In inclusion-body myositis, vacuolar formation with amyloid deposits coexists with the immunological features. The causative autoantigen has not yet been identified. Upregulated vascular-cell adhesion molecule, intercellular adhesion molecule, chemokines, and their receptors promote T-cell transgression, and various cytokines increase the immunopathological process. Early initiation of therapy is essential, since both polymyositis and dermatomyositis respond to immunotherapeutic agents. New immunomodulatory agents currently being tested in controlled trials may prove promising for difficult cases.

Increased prevalence of autoantibodies to ku antigen in African American versus white patients with systemic lupus erythematosus

OBJECTIVE

To investigate whether the widely varying estimates of the prevalence of anti-Ku autoantibodies are explained by racial/ethnic differences.

METHODS

Consecutive African American or white patients who met the 1982 criteria for systemic lupus erythematosus (SLE) and who were evaluated over 10 years in North Carolina, Florida, and New York were tested by immunoprecipitation of K562 cell extract for anti-Ku as well as anti-nuclear RNP (nRNP)/Sm, anti-Ro/SSA, and anti-La/SSB autoantibodies.

RESULTS

Anti-Ku autoantibodies were detected in sera from 18 of 155 African American patients with SLE (12%) versus 0 of 126 white patients (P < 0.0001, by Fisher's exact test). Anti-nRNP (63% versus 16%; P < 0.0001) and anti-Sm (23% versus 7%; P < 0.0004) autoantibodies were also more common in the African American subset. The 2 groups had comparable frequencies of anti-Ro/SSA and anti-La/SSB autoantibodies.

CONCLUSION

Anti-Ku antibodies are common in African American patients with SLE but rare in whites, probably explaining the different estimates of their prevalence. In African Americans, the frequency is comparable with that of anti-La/SSB. Along with anti-Ku, anti-nRNP and anti-Sm autoantibodies are also overrepresented in African Americans, suggesting that a group of specificities is characteristically associated with SLE in African Americans.

A localised morphoea/idiopathic polymyositis overlap

A 54-year-old female presented with a three-year history of proximal muscle weakness and arthralgia. EMG, muscle enzymes and biopsy and other tests were consistent with idiopathic polymyositis. At a later stage, she developed plaques of morphoea involving the dorsum of hands and forearms. There was no evidence of systemic sclerosis throughout the course of the disease. In our opinion, such association appeared as an unusual overlap syndrome that provided a new constellation of features in connective tissue disease.

Scleroderma renal crisis as a presenting feature in the absence of skin involvement

A 56-year-old man was admitted to the nephrology unit with a short (6-week) history of severe hypertension that necessitated renal replacement therapy within 7 days after admission. Renal biopsy showed features of thrombotic microangiopathy in arterioles and small arteries with occluding thrombi. The skin was unremarkable at the time of admission. Progressive skin lesions with scleroderma, telangiectasia, sclerodactyly, and generalized cutaneous sclerosis developed within 4 weeks and the specific skin changes were found on skin biopsy. On admission antinuclear antibody titers were high (1:10, 240) with a nucleolar pattern, and PM-Scl antibodies (1:5, 120) were present. In the present case the diagnosis of scleroderma renal crisis was made in vivo by renal biopsy. Renal and skin biopsies documented that renal lesions may precede the clinically manifest skin lesions of progressive systemic sclerosis.

Autoantibodies in scleroderma

Autoantibodies directed against nuclear, nucleolar, and a number of cytoplasmic components are described in the sera of scleroderma patients. Early studies of autoantibodies that relied on cryopreserved sections of rodent organ substrates showed that approximately 50% of scleroderma patients had anti-nuclear antibodies (ANA). More recent studies that have used tissue culture cell substrates have shown that up to 98% of scleroderma patients have a positive ANA. In all of these studies, the presence of different patterns of staining have suggested that scleroderma sera reacted with a variety of intracellular antigens. The use of molecular and immunochemical techniques has now shown that over 20 intracellular autoantigens are targets of autoantibodies in scleroderma sera. Clinical studies have shown that these autoantibodies are important diagnostic and prognostic markers in scleroderma. In the future, autoantibody testing may be used to monitor the patient's response to immunological therapies.

Humoral immunity in polymyositis/dermatomyositis

Autoantibodies are found in most patients with polymyositis (PM) or dermatomyositis (DM) and 35-40% of these patients have myositis-specific antibodies. Twenty-five to thirty percent have anti-aminoacyl-tRNA synthetases, of which anti-Jo-1, directed at histidyl-tRNA synthetase, is by far the most common. Patients with anti-synthetases have a high frequency of myositis, interstitial lung disease, Raynaud's phenomenon, and other features constituting an "anti-synthetase syndrome." Anti-synthetases tend to react with conformational epitopes and to inhibit enzymatic activity, suggesting reaction with conserved regions. Sera with antibodies to alanyl-tRNA synthetase (anti-PL-12) also have antibodies to tRNA(ala), whereas most sera with other anti-synthetases do not react directly with tRNA. Production of the antibodies appears to be antigen-driven, and is influenced by HLA genes, although an initiating factor, possibly a viral infection, may be important. Antibodies to other cytoplasmic antigens, most notably the signal recognition particle (anti-SRP), are seen in a small percentage of patients. Patients with anti-SRP do not tend to develop the anti-synthetase syndrome, but may have very severe disease. Antibodies to the nuclear antigen Mi-2 are also specific for myositis, and are strongly associated with DM. Several autoantibodies, including anti-PM-Scl, anti-Ku, and anti-U1 and U2 RNP, have been associated with scleroderma-PM overlap. The role of humoral immunity in the myositis of PM and DM has not yet been clarified. Capillary loss and ischemic damage are important in DM, and seem to be mediated by humoral mechanisms, whereas cell-mediated attack on muscle fibers is important in PM. The mechanism of skin injury in cutaneous lesions is not known, but antibody deposition is inconsistent and uncommon. Whether the myositis-specific antibodies are involved in disease pathogenesis is not yet known, although there is no direct evidence for this. An understanding of the reasons for production of these antibodies, however, should provide insight into the etiology and pathogenesis of PM and DM.

Malignancy and interstitial pneumonitis as fatal complications in dermatomyositis

By sending questionnaires to the major dermatological clinics in Japan, we examined the outcome and causes of death in 182 cases of dermatomyositis (DM) observed between 1983 and 1987. The mortality rate in adults was 26.7%. Associated malignancy occurred in 47 cases (25.8% of adults), and 16 of them died of neoplasms. In contrast to 43 carcinomas, only 1 patient died of lymphoma. Associated interstitial pneumonitis (IP) appeared in 31 cases. IP started simultaneously or within 6 months after the diagnosis of DM in the majority of these cases. Of the 13 fatal cases due to IP, 8 died of respiratory failure within two months of the onset of lung disease. In the malignancy group, periungual erythema was noted in a higher proportion. Raynaud's phenomenon was more frequently noted in the IP group. DM overlapped with other collagen diseases in 14 cases.

Childhood scleromyositis: an overlap syndrome associated with PM-Scl antibody

Fourteen patients with childhood scleromyositis followed from 1 to more than 10 years experienced concomitant sclerodermoid and dermatomyositis features, variably expressed at one time or another during the course of the disease. The most characteristic features were myalgia-myositis, arthralgia-arthritis, puffy, atrophic, sclerotic fingers, and Raynaud's phenomenon. This overlap syndrome was the most frequent sclerodermoid condition in children, differing from both systemic scleroderma and dermatomyositis. The course of the disease was protracted and rather benign, and PM-Scl antibody was an important diagnostic and prognostic marker. We present criteria for diagnosis of scleromyositis and its differentiation from systemic scleroderma, dermatomyositis, and Sharp overlap syndrome.

Dermatomyositis as a systemic disease

Dermatomyositis is a classic example of a disease that has both cutaneous and systemic manifestations. The skin and muscle disease are described as well as the possible systemic manifestations including overlap syndromes, joint symptoms, pulmonary disease, and other internal organ involvement. The association with pregnancy is also discussed.