A Case of Palmoplantar Keratoderma in the Constellation of Connective Tissue Diseases.

Overlap syndrome is a clinical challenge and brings together a wide range of treatment options for the treating physician. Addressing each and every complaint of the patient is crucial. A 50-year-old female patient presented with skin thickening, blackening, and hyperkeratosis; dysphagia; joint pain; features of myopathy; Raynaud's phenomenon; and dry mouth. Inflammatory markers were raised along with a positive antinuclear antibody (ANA) with Golgi apparatus pattern, anti-Sjögren's-syndrome-related antigen A (anti-SSA)/Ro60 3+, anti-SSA/Ro52 3+, and anti-PM/Scl 2+ antibodies that suggested overlap syndrome. Although the patient had no respiratory complaints, a unique interstitial lung disease (ILD) pattern was noted during the evaluation. Skin manifestations were puzzling, but the histopathology analyses of skin biopsies taken from two different sites revealed distinguishing features of cutaneous lupus and dermatomyositis. Treatment with hydroxychloroquine, pilocarpine, nifedipine, methotrexate, and topical tacrolimus produced a dramatic improvement in the clinical features. This case highlights subtle and florid features of different autoimmune diseases. The hyperkeratotic skin changes were the most striking feature, but the whole evaluation process unveiled many rare presentations of known autoimmune conditions that can open doors to new areas of our understanding toward connective tissue diseases (CTDs). Our case report demonstrates significant heterogeneity in the ANA patterns, ILD patterns, clinical manifestations, and treatment approaches.

Cumulative disease damage and anti-PM/Scl antibodies are associated with a heavy burden of calcinosis in systemic sclerosis.

OBJECTIVES: Ectopic calcification (calcinosis) is a common complication of SSc, but a subset of SSc patients has a heavy burden of calcinosis. We examined whether there are unique risk factors for a heavy burden of calcinosis, as compared with a light burden or no calcinosis. METHODS: We reviewed the medical records of all patients in the Johns Hopkins Scleroderma Center Research Registry with calcinosis to quantify calcinosis burden using pre-specified definitions. We performed latent class analysis to identify SSc phenotypic classes. We used multinomial logistic regression to determine whether latent phenotypic classes and autoantibodies were independent risk factors for calcinosis burden. RESULTS: Of all patients, 29.4% (997/3388) had calcinosis, and 13.5% (130/963) of those with calcinosis had a heavy burden. The latent phenotypic class with predominantly diffuse skin disease and higher disease severity (characterized by pulmonary hypertension, interstitial lung disease, cardiomyopathy, severe RP, gastrointestinal involvement, renal crisis, myopathy and/or tendon friction rubs) was associated with an increased risk of both a heavy burden [odds ratio (OR) 6.92, 95% CI 3.66, 13.08; P < 0.001] and a light burden (OR 2.88, 95% CI 2.11, 3.95; P < 0.001) of calcinosis compared with the phenotypic class with predominantly limited skin disease. Autoantibodies to PM/Scl were strongly associated with a heavy burden of calcinosis (OR 17.31, 95% CI 7.72, 38.81; P < 0.001) and to a lesser degree a light burden of calcinosis (OR 3.59, 95% CI 1.84, 7.00; P < 0.001). CONCLUSIONS: Calcinosis burden is associated with cumulative SSc-related tissue damage. Independent of disease severity, autoantibodies to PM/Scl are also associated with a heavy burden of calcinosis.

Anti-PM-Scl antibodies-positive patients encompass three different groups with distinct prognoses.

OBJECTIVE: To help identify homogeneous subgroups among patients with anti-PM-scleroderma-antibodies (PM-Scl-Abs) positive auto-immune diseases regardless of diagnostic classifications. MATERIAL AND METHODS: This multicentric (four hospitals) retrospective study collected all consecutive patients (from 2011 to 2021) with positive testing for anti-PM-Scl-Abs in a context of CTD. Subgroups of patients with similar clinico-biological phenotypes were defined using unsupervised multiple correspondence analysis and hierarchical clustering analysis of the features recorded in the first year of follow-up. RESULTS: One hundred and forty-two patients with anti-PM-Scl-Abs were evaluated and 129 patients were included in the clustering analysis and divided into three clusters. Cluster 1 (n = 47) included patients with frequent skin thickening, digestive involvement and interstitial lung disease (ILD) with non-specific interstitial pneumonia (NSIP). They were more likely to develop progressive fibrosing ILD. Cluster 2 (n = 36) included patients who all featured NSIP with frequent organizing pneumonia-associated pattern and mechanic's hands. This subgroup had increased risk of relapse and ILD was characterized by a good functional outcome. Cluster 3 (n = 46) was characterized by predominant or isolated musculoskeletal involvement and frequently matched UCTD criteria. Although very frequent among anti-PM-Scl-Abs positive patients, muscle involvement was less discriminating compared with skin thickening and ILD pattern to classify patients into subgroups. CONCLUSION: Anti-PM-Scl-Abs associated auto-immune diseases are segregated into three subgroups with distinct clinical phenotype and outcomes. Skin thickening and NSIP are determinant predictors in segregation of theses populations.

Clinical Significance of Antinucleolar Antibodies: Biomarkers for Autoimmune Diseases, Malignancies, and others.

Nucleolar staining is one of the standard patterns in immunofluorescence antinuclear antibodies (ANA), seen in 5-9% of ANA in various conditions. Antinucleolar antibodies (ANoA) are classified into 3 patterns in the International Consensus on ANA Patterns (ICAP) classification; AC-8 homogeneous pattern, AC-9 clumpy pattern, and AC-10 punctate pattern. Specificities known to show AC-8 include anti-Th/To, -PM-Scl, -nucleophosmin/B23, -nucleolin/C23, -No55, and others. AC-9 is seen by anti-fibrillarin/U3RNP and AC-10 by anti-RNA polymerase I and hUBF/NOR-90. ANoA has been classically known to be associated with scleroderma (SSc) and the characterization of nucleolar antigens identified several autoantigens recognized by SSc autoantibodies. The clinical association of anti-Th/To, PM-Scl, fibrillarin/U3RNP, and RNA polymerase I with SSc or SSc-overlap syndrome is well established, and commercial assays are developed. Anti-hUBF/NOR90, nucleophosmin/B23, and nucleolin/C23 are known for decades and reported in systemic autoimmune rheumatic diseases (SARDs), malignancies, graft versus host disease (GVHD), and others; however, their clinical significance remains to be established.

A Japanese patient with anti-PM/Scl and centromere antibody-positive scleroderma-amyopathic dermatomyositis overlap syndrome who developed renal crisis.

Anti-PM/Scl antibodies are associated with the overlap syndrome of systemic sclerosis and dermatomyositis/polymyositis (SSc-DM/PM), and are found in 50% of SSc-DM/PM cases in Europe and the USA, whereas they are rare in Japan. We report a case of an 80-year-old Japanese female with SSc-amyopathic dermatomyositis overlap syndrome, who developed scleroderma renal crisis, a complication of SSc. She had positive antinuclear antibodies in a discrete-speckled and nucleolar pattern and anti-centromere antibodies and anti-PM/Scl antibodies were confirmed by enzyme-linked immunosorbent assay and immunoprecipitation, respectively. The incidence rate of SRC in SSc patients varies significantly depending on the specificity of autoantibodies, with the highest incidence of ∼50% in anti-RNA polymerase III antibody positive patients, followed by ∼10% in anti-PM/Scl and lower incidence of 0.45% in anti-centromere antibody-positive cases. Anti-PM/Scl antibodies are uncommon in Japanese patients presumably due to its strong association with certain human leucocyte antigen haplotype that is rare in Japanese. Clinical significance of anti-PM/Scl antibodies in Japanese patients will need to be clarified with accumulation of cases in future studies.

Joint contractures responsive to immunosuppressive therapy in a girl with childhood-onset systemic sclerosis double-seropositive for rare anti-nucleolar autoantibodies: a case report.

BACKGROUND: Systemic sclerosis (SSc; scleroderma) is an autoimmune connective tissue disease that affects the skin and subcutaneous tissue, in addition to the internal organs of the whole body. Onset in childhood is uncommon; however, both patients with childhood-onset and adult-onset SSc are positive for anti-nuclear antibodies (ANAs).Detection of SSc-related anti-nuclear antibodies is often useful for predicting clinical features, disease course, and outcomes. CASE PRESENTATION: A 5-year-old Japanese female manifested gradually progressive abnormal gait disturbance, regression of motor development, Raynaud's phenomenon, and the shiny appearance of the skin of the face and extremities at age 2. On admission, she presented a mask-like appearance, loss of wrinkles and skin folds, puffy fingers, moderate diffuse scleroderma (18/51 of the modified Rodnan total skin thickness score), and contracture in the ankle and proximal interphalangeal joints. Grossly visible capillary hemorrhage on nail fold and severe abnormal capillaroscopy findings including bleeding, giant loop and disappearance of capillaryconsistent with the late phase in SSc. A skin biopsy showed fibrous thickening of the dermis, entrapment of an eccrine sweat glands, and thickened fiber. Chest high-resolution computed tomographic scanning demonstrated patchy areas of ill-defined air-space opacity and consolidation predominantly involving the posterior basilar aspects of the lower lobes presenting withinterstitial lung disease. Positive ANA (1:160 nucleolar and homogeneous nuclear staining by indirect fluorescent antibody technique) and double-seropositive for anti-Th/To and anti-PM-Scl antibodies were identified. She was diagnosed with diffuse cutaneous SSc based on the Pediatric Rheumatology European Society/American College of Rheumatology/European League Against Rheumatism Provisional Classification Criteria for Juvenile Systemic Sclerosis and was successfully treated with immunosuppressive agents, including methylprednisolone pulses and intravenous cyclophosphamide. CONCLUSIONS: We experienced the first case of juvenile SSc with anti-PM-Scl and anti-Th/To antibodies. ILD was identified as a typical feature of patients with these autoantibodies; however, diffuse cutaneous SSc and joint contraction were uncharacteristically associated. The case showed unexpected clinical findings though the existence of SSc-related autoantibodies aids in determining possible organ involvement and to estimate the children's outcome.

The prevalence and significance of anti-PM/Scl antibodies in systemic sclerosis.

INTRODUCTION: Anti-PM/Scl (a-PM/Scl) antibodies are found in different systemic autoimmune diseases such as polymyositis, dermatomyositis, systemic sclerosis (SSc) and overlap syndromes. According to literature, they are detected in approx. 2% of SSc patients, but their presence is more common in SSc with myositis overlap. OBJECTIVE: The aim of the study was to assess the prevalence of a-PM/Scl in patients with SSc and to identify differences in the clinical profile of the disease in patients with the presence of a-PM/Scl. MATERIAL AND METHODS: The study was performed on 126 European Caucasian SSc patients (98 females and 28 males) hospitalized consecutively in the Department of Rheumatology and Connective Tissue Diseases. The study group was analyzed for the potential presence of a-PM/Scl using a commercial test - EUROLINE Systemic Sclerosis Profile. The detection and interpretation were carried out electronically using the specific Euroimmun - EUROLineScan programme. The subtype of SSc, incidence of internal organ involvement and serological profile were determined in the entire group. Due to the presence of a-PM/Scl, patients were divided into two groups: a-PM/Scl (+) SSc - 22 patients and a-PM/Scl (-) SSc - 104 patients. RESULTS: A-PM/Scl was detected in 22/126 patients with SSc (17.5%). A strong correlation was found between a-PM/Scl and myalgia or myositis (p = 0.0379), hand joints contractures (p = 0.0002) and the prevalence of overlap syndrome (p = 0.0142). There were no relationships between the presence of a-PM/Scl and subtypes of SSc, other organ involvement, digital ulcers or calcinosis. CONCLUSIONS: Anti-PM/Scl antibodies are fairly common in patients with systemic sclerosis. In SSc, anti-PM/Scl antibodies are frequently associated with myalgia or myositis, hand joint contractures and an overlap syndrome.

Interstitial Lung Disease Is a Major Characteristic of Patients Who Test Positive for Anti-PM/Scl Antibody.

OBJECTIVE: This study aimed to analyze the clinical features of anti-PM/Scl antibodies in Chinese patients. METHOD: We reviewed the clinical data of anti-PM/Scl antibody-positive patients, including their long-term follow-up. RESULTS: A total of 30 patients carried anti-PM/Scl antibodies, 21 (70%) were females, and the mean age was 55.4 years, 15 (50%) and 10 (33.3%) patients were positive for anti-PM/Scl-75 and anti-PM/Scl-100, respectively. Fifteen cases (50%) were diagnosed as inflammatory myopathy, namely, 11 dermatomyositis (DM) and 4 polymyositis (PM). Five (16.7%) patients were diagnosed with overlap syndrome, and only one (3.3%) was diagnosed as systemic sclerosis. The other 9 (30%) patients were classified as undifferentiated connective tissue disease. Twenty-six (86.7%) had interstitial lung disease (ILD) and was the sole manifestation in 8 (26.7%) patients, 15 (58.0%) showed non-specific interstitial pneumonia based on high-resolution CT or lung biopsy. The majority of patients (95%) with mild and moderate groups on basis of pulmonary function tests. Compared to the anti-PM/Scl-100 group, the occurrence of clinical characteristics was not significantly different from the anti-PM/Scl-75 group, except the levels of C-reactive protein and erythrocyte sedimentation rate in the anti-PM/Scl-75 antibody-positive group were higher (p < 0.05). All patients with positive Ro-52 antibodies had ILD and were more likely to develop skin rash in the group with Ro-52 (p = 0.024). With a follow-up of the present cohort, 70.8% improved with treatment, but 16.7% of patients are easy to relapse. CONCLUSION: The anti-PM/Scl antibody occurred frequently in DM/PM patients, ILD was the major clinical feature, especially in patients combined with Ro-52. Some patients may complicate with ILD alone without extrapulmonary manifestations. Anti-PM/Scl antibodies positive patients were responsive to treatment.

Anti-PM/Scl Antibody-positive Systemic Sclerosis Complicated by Multiple Organ Involvement.

A 40-year-old Japanese woman developed malignant-phase hypertension complicated by thrombotic microangiopathy, progressing to end-stage renal disease. Five years later, she was diagnosed with pulmonary arterial hypertension and interstitial pneumonia. Despite a lack of overt skin sclerosis, nucleolar staining in our indirect immunofluorescence analysis and nailfold capillaroscopy facilitated the diagnosis of anti-PM/Scl antibody-positive systemic sclerosis. We observed the persistent presence of anti-PM/Scl antibodies throughout the clinical course, suggesting that her kidney disease was scleroderma renal crisis. Anti-PM/Scl antibodies can be associated with multiple organ diseases. Careful attention to a patient's antinuclear antibody pattern and dermatological findings may help clarify the etiology of undiagnosed diseases.

Concurrent anti-PM-Scl antibody-associated systemic sclerosis and inclusion body myositis - report of two cases and review of the literature.

OBJECTIVES: To describe two cases of anti-PM-Scl antibody-associated systemic sclerosis with evidence of inclusion body myositis on muscle biopsy. METHODS: Two female patients with anti-PM-Scl antibody-associated systemic sclerosis developed progressive proximal myopathy. Both patients had profound muscle weakness that was refractory to treatment with glucocorticoids with or without other oral immunosuppressive agents. Quadriceps muscle biopsy in both cases indicated inclusion body myositis (IBM). Monthly intravenous immunoglobulin (IVIG) infusions were added to the treatment regimen. RESULTS: One patient's myopathy appears to have temporarily stabilized with IVIG infusions (2 g/Kg) every four weeks, though severe residual muscle weakness has persisted. The other patient's myopathy continues to progress slowly, despite being on 4-weekly IVIG infusions, along with weekly oral methotrexate and 6-monthly rituximab infusions. In this report, we compare these two patients with two similar cases that were previously reported and hypothesize a possible pathomechanism of this association. CONCLUSION: This extremely rare association of IBM and anti-PM-Scl antibody-associated scleromyositis sheds new light on the possible pathogenesis of IBM. It strengthens the hypothesis that autoimmune muscle disease can potentially trigger myodegeneration. Whether early intervention with aggressive immunosuppressive therapy can prevent progression to treatment-refractory IBM, should be a subject of future research.

An Anti-PM/Scl-75 Antibody-positive Japanese Woman Who Developed Inflammatory Myopathy.

A 69-year-old Japanese woman presented with mild muscle weakness of the neck and symmetrical proximal parts of the upper and lower limbs. Laboratory tests, needle electromyography, and a muscle biopsy revealed inflammatory myopathy with an apparent clinical classification of polymyositis and positive findings for anti-PM/Scl-75 antibody. This antibody is rare among Japanese populations, and most Japanese patients with the antibody are not classified with the inflammatory myopathy seen in polymyositis. The muscle biopsy also showed marked necrotic and regenerative fibers. We need to collectively investigate patients with the potential to develop this disease, and to identify any unique characteristics for Asian populations, including Japanese.

Performance evaluation of a line blot assay system for detection of anti-PM-Scl antibody in Japanese patients with systemic sclerosis.

OBJECTIVE: To evaluate the performance of a line blot (LB) assay for identifying anti-PM-Scl antibody (Ab). METHODS: We screened 56 serum samples from systemic sclerosis patients using a protein immunoprecipitation (IP) assay and an LB assay (Systemic Sclerosis Profile Euroline® Blot test kit) to detect anti-PM-Scl Ab. We compared the results obtained by the IP and LB assays. RESULTS: Among the 56 serum samples of SSc patients, 9 sera were positive for anti-PM-Scl75 Ab and 1 for anti-PM-Scl100 Ab by the LB assay. The protein IP assay revealed that none of the samples precipitated 75 or 100 kDa proteins identical to the anti-PM-Scl Ab reference serum, regardless of the positive or negative results obtained in the LB assay. Therefore, the false-positive rates for both anti-PM-Scl75 Ab and anti-PM-Scl100 Ab by the LB assay were 100%. CONCLUSION: Detection of anti-PM-Scl Ab assessed with a commercial LB assay requires extreme caution since it may yield false-positive data.

Optimización del algoritmo diagnóstico de anticuerpos antinucleares / Optimization of the diagnostic algorithm of antinuclear antibodies

Introducción: La prueba de anticuerpos antinucleares es una poderosa herramienta en el diagnóstico de las enfermedades reumáticas. Los anticuerpos antinucleares se determinan en el laboratorio por un algoritmo o secuencia que se inicia con prueba de cribado y sigue con la identificación de las especificidades antinucleares más comunes. Pero, ¿cómo interpretar los resultados discordantes entre los dos niveles de estudio de anticuerpos antinucleares? Objetivo: Determinar las especificidades antinucleares menos frecuentes en pacientes positivos de cribado de ANA y negativos de las especificidades más comunes. Métodos: Estudio prospectivo de 88 pacientes consecutivos remitidos para la detección rutinaria de ANA con resultado positivo de cribado por ensayo inmuno-adsorbente ligado a enzima (ELISA) pero negativo de anticuerpos anti-ADN de doble cadena (dc, IgG) y anti-antígenos nucleares extraíbles comunes (ENAc). Las muestras séricas correspondientes fueron evaluadas por inmunofluorescencia indirecta sobre células de carcinoma epidermoide laríngeo humano (IFI-HEp-2) y por ELISA para la detección individual de ANA específicos. Resultados: La prueba de ANA por IFI/HEp-2 resultó positiva en 56/88 (63,6 por ciento) y las especificidades antinucleares se detectaron en 57/88 (64,8 por ciento) muestras, en el orden decreciente de Anti-Nucs: 16/88 (18,2 por ciento); anti-centrómero (CENP-B): 15/88 (17,0 por ciento); -histona: 15/88 (17 por ciento); -PM/Scl: 13/88 (14,8 por ciento); -ADNsc: 11/88 (12,5 por ciento) y -ENAc individuales: 8/88 (9,1 por ciento). La sensibilidad de la IFI-HEp-2 para las especificidades antinucleares fue de 0,83 (IC95 por ciento: 0,72-0,93). De los pacientes negativos de subserología (26/31), 83,9 por ciento no tenían antecedentes de enfermedad reumática asociada a ANA. Conclusiones: La mayoría de los pacientes con resultados discordantes entre el primer y segundo nivel de ANA fueron positivos de especificidades antinucleares menos comunes, pero de reconocido valor diagnóstico(AU)

Introduction: The antinuclear antibody test is a powerful tool for diagnosing rheumatic diseases. Antinuclear antibodies are determined in the laboratory by an algorithm or sequence that starts with a screening test and continues with the identification of the most common antinuclear specificities. But how to interpret the discordant results between the two levels of study of antinuclear antibodies? Objective: To determine the less frequent antinuclear specificities in positive patients of ANA screening and negative of the most common specificities. Methods: A prospective study was done on 88 consecutive patients referred for the routine ANA screening with a positive result of screening by enzyme-linked immunosorbent assay (ELISA) but negative for anti-double-stranded DNA (dc, IgG) and common extractable anti-nuclear antigens (ENAc). The corresponding serum samples were evaluated by indirect immunofluorescence on human laryngeal epidermoid carcinoma cells (IFI-HEp-2) and by ELISA for the individual detection of specific ANA. Results: The ANA test by IFI / HEp-2 was positive in 56/88 (63.6 percent) and the antinuclear specificities were detected in 57/88 (64.8 percent) samples, in decreasing Anti-Nucs order: 16/88 (18.2 percent); anti-centromere (CENP-B): 15/88 (17.0 percent); -histona: 15/88 (17 percent); -PM / Scl: 13/88 (14.8 percent); -ADNsc: 11/88 (12.5 percent) and -ENAc individual: 8/88 (9.1 percent). The sensitivity of IFI-HEp-2 for antinuclear specificities was 0.83 (95 percent CI: 0.72-0.93). No history of rheumatic disease associated with ANA was read in (26/31) 83.9 percent patients with negative subserology. Conclusions: The majority of patients with discordant results between the first and second level of ANA were positive of less common antinuclear specificities, but of recognized diagnostic value(AU)

Novel risk factors related to cancer in scleroderma.

OBJECTIVE: Emerging data have shown an increased risk of malignancy among patients diagnosed with systemic sclerosis (SSc) so identification of risk factors linking both disorders might have prognostic implications. The aim of this study was to assess the clinical and treatment-related risk factors for cancer in a single-center cohort of patients with SSc. METHODS: Demographic, clinical, capillaroscopic, immunological and treatment-related data from 432 consecutive SSc patients were retrospectively analyzed. Variables that reached significant association in the univariate analysis were entered into a logistic regression in order to identify independent risk factors for cancer. RESULTS: Malignancy was diagnosed in 53 patients (12.2%). Fifty-eight neoplasms were identified, among which breast (n=15), lung (n=10) and hematologic (n=9) malignancies were the most prevalent. In 19 patients the diagnosis of both scleroderma and tumour was made in <3years apart. Cancer significantly decreased the probability of survival (OR=2.61; 95%CI 1.46-4.69; p=0.001). No association with age, sex, smoking, cutaneous subset or RNA polymerase-III antibodies was found. However, risk of cancer was directly associated with the presence of anti-PM/Scl antibodies (OR=3.90; 95%CI 1.31-11.61; p=0.014), and inversely related to aspirin use (OR=0.33; 95%CI 0.12-0.90; p=0.031), which remained as independent risk factors for cancer on multivariate analysis. CONCLUSIONS: PM/Scl antibodies seem to be associated with a higher risk of cancer in scleroderma. In contrast, the use of aspirin is related to a lower risk of cancer in our series. More studies are needed to ascertain the role of anti PM/Scl antibodies and aspirin in the development of malignancy among patients with SSc.

Autoantibodies in children with juvenile dermatomyositis: A single centre experience from North-West India.

The objective of this study is to determine autoantibody profile in children with juvenile dermatomyositis (JDM). Children who were diagnosed with JDM (either recently diagnosed during the study period or follow-up patients) were included in the study. Autoantibodies were detected with commercially available Immunodot kit. Thirty patients were included in the study. Nine out of thirty patients (30%) were positive for one of the 12 autoantibodies tested. Anti-SRP antibody was most common antibody detected in 3 patients followed by anti-MDA-5 antibody in 2 patients; while anti-Jo1 antibody, anti-TIF1-γ antibody, anti-Mi-2 antibody, and anti-PM-Scl antibody were positive in 1 patient each. A different disease phenotype was observed with each autoantibody. The patient with anti-Jo1 antibody had a severe systemic disease in the form of interstitial lung disease; patients with anti-MDA-5 antibody and anti-Mi2 antibody had more severe skin disease with mild muscle disease and patients with anti-SRP antibody had significant skin and muscle disease. Anti-TIF1-γ and anti-PM-Scl antibodies were seen in patients with features of overlap syndrome (myositis-scleroderma). Estimation of autoantibodies may serve as an adjunct tool in delineating and defining distinct clinical phenotypes in children diagnosed with juvenile dermatomyositis. They may also help in prognostication.

Clinical correlates of monospecific anti-PM75 and anti-PM100 antibodies in a tri-nation cohort of 1574 systemic sclerosis subjects.

OBJECTIVE: Autoantibodies directed against the two principal antigens of the human exosome complex, PM75 and PM100, are present in systemic sclerosis (SSc) sera and have been associated with myositis and calcinosis. However, there is a paucity of data on the clinical correlates of these autoantibodies separately and in the absence of other SSc-specific antibodies. The aim of this study was to assess the clinical correlates of monospecific anti-PM75 and anti-PM100 in SSc. METHODS: A tri-nation cohort of 1574 SSc subjects was formed, clinical variables were harmonized and sera were tested for anti-PM75 and anti-PM100 antibodies using a line immunoassay. RESULTS: Forty-eight (3.0%) subjects had antibodies against PM75 and 18 (1.1%) against PM100. However, only 16 (1%) had monospecific anti-PM75 antibodies and 11 (0.7%) monospecific anti-PM100 antibodies (i.e. in isolation of each other and other SSc-specific antibodies). Monospecific profiles of each autoantibody included more calcinosis. An increased frequency of myositis was only seen in subjects positive for both anti-PM75 and anti-PM100 antibodies. Lung disease was only associated with anti-PM75 and subjects with anti-PM100 antibodies had better survival compared to other antibody subsets. CONCLUSION: The prevalence of monospecific anti-PM75 and anti-PM100 antibodies in this large SSc cohort was low. Disease features associated with anti-PM/Scl antibodies may depend on particular and possibly multiple antigen specificities. However, due to the small samples, these results need to be interpreted with caution. International collaborations are key to understanding the clinical correlates of uncommon serological profiles in SSc.

Good outcome of interstitial lung disease in patients with scleroderma associated to anti-PM/Scl antibody.

OBJECTIVE: The objective of this article was to establish the clinical course of interstitial lung disease (ILD) in scleroderma related to the presence of anti-PM/Scl antibody compared with anti-Scl-70 in a Spanish cohort. Furthermore, no study has thoroughly investigated the outcome of pulmonary function test in the first group of patients. METHODS: A total of 63 Spanish patients with scleroderma and ILD were selected in a retrospective observational study. Among them, 14 were positive for anti-PM/Scl antibodies and 49 for anti-Scl-70. Clinical assessments, including pulmonary function test, were collected. Variations equal or greater than 10% in forced vital capacity (FVC) were considered significant. Progression-free survival of disease was defined as the period of stable illness since pulmonary fibrosis diagnosis. RESULTS: Anti-Scl-70 patients had a higher frequency of diffuse SSc subset, peripheral vasculopathy, and gastrointestinal involvement. Inflammatory myopathy was associated to anti-PM/Scl antibody. Anti-PM/Scl patients presented more improvement in FVC during follow-up, 30.8% compared to a 7.1% in Scl-70 group (P = 0.04), with less worsening of this parameter (15.4% vs 52.4% in Scl-70 patients, P = 0.01), and secondary less frequency of severe restrictive pattern (FVC < 50%) (7.7% compared to 42.9% in the other group, P = 0.02). Regarding treatment, more anticalcineurinics were used in anti-PM/Scl patients, while cyclophosphamide and mycophenolate were mainly used in anti-Scl-70 patients. The progression-free survival of disease was higher in anti-PM/Scl patients, with 76% at 10 years from diagnosis of ILD against a 29% in the Scl-70 group. CONCLUSIONS: Several features and prognosis of ILD in SSc may be modified depending on the identified immunological profile.