Prevalence and reactivity of anti-melanoma differentiation-associated gene 5 (anti-MDA-5) autoantibody in Brazilian patients with dermatomyositis

Abstract: Background: There have been no studies to date on the frequency and reactivity of aanti-melanoma differentiation-associated gene 5 (anti-MDA-5) in samples from the Brazilian population with dermatomyositis. Objectives: To analyze this autoantibody in the Brazilian population. Methods: This was a single-center cross-sectional study in which 131 consecutive adult patients (109 dermatomyositis and 22 clinically amyopathic dermatomyositis) with active disease were evaluated from 2000 to 2016. Analysis of the anti-MDA-5 autoantibody was performed by ELISA. Results: The presence of this autoantibody was observed in 14.7% and 22.7% of patients with dermatomyositis and clinically amyopathic dermatomyositis, respectively. In the case of dermatomyositis, the autoantibody was associated less frequently with Raynaud's phenomenon and periungual hyperemia (P<0.05). In clinically amyopathic dermatomyositis, the presence of this autoantibody was not associated statistically with any demographic, clinical, laboratory, or imaging characteristics. Study limitations: The cross-sectional study design did not allow establishing a temporal correlation between anti-MDA-5 autoantibody and various study variables. In addition, pulmonary function tests were not performed in the patients. Conclusions: The frequency of anti-MDA-5 autoantibody was comparable to that of other populations with dermatomyositis, but with a different reactivity than described in the literature. In addition, there was a phenotypic variability between our patients with clinically amyopathic dermatomyositis and those described in the literature. Further studies are needed to confirm the current study's findings and elucidate this autoantibody's reactivity in Brazilians with idiopathic inflammatory myopathies.

Hyaluronic acid in dermatomyositis and polymyositis: relationship with disease and cutaneous lesions

Abstract: Background: There are scarce studies in the literature about hyaluronic acid in systemic autoimmune myopathies. Objectives: To analyze the serum level of hyaluronic acid in patients with dermatomyositis and polymyositis. Methods: Cross-sectional study, single-center, that evaluated hyaluronic acid in 18 dermatomyositis and 15 polymyositis (Bohan and Peter criteria), newly diagnosed, with clinical and laboratory activity, with no previous drug treatment. The patients were also age-, gender- and ethnicity-matched to 36 healthy individuals. The hyaluronic acid was analyzed by ELISA/EIA kit anti-hyaluronic acid. Results: There was a higher serum level of hyaluronic acid in patients with autoimmune myopathies, in relation to control group (P<0.05). Moreover, the serum level of this glycosaminoglycan was higher in dermatomyositis, when compared to polymyositis. Both groups were comparable with regard to demographic, clinical and laboratory data, except for the presence of skin lesions in the first group. Study limitations. The presence of hyaluronic acid in cutaneous lesions, particularly of patients with dermatomyositis, was not analyzed neither quantified. In addition, due to disease rarity and the establishment of strict inclusion and exclusion criteria, there was a small sample in the present study. Conclusions: As an example of others systemic autoimmune diseases, it is possible that the hyaluronic acid is involved in the pathogenesis of autoimmune myopathies, and particularly when associated with cutaneous lesions.

Patients with pure dermatomyositis/polymyositis and anti-PM/Scl autoantibody resembling anti-synthetase syndrome / Pacientes com dermatomiosite/polimiosite pura e autoanticorpo anti-pm/scl sememlhante à síndrome anti-sintetase

OBJECTIVE: The anti-PM/Scl autoantibody has been described in patients with scleromyositis. However, there are scant studies evaluating its prevalence and reactivity in dermatomyositis and polymyositis. METHOD: A cross-sectional, single center study evaluating the anti-PM/Scl autoantibody in 85 dermatomyositis and 32 polymyositis patients, without overlapping syndrome, was conducted between 2000 and 2016. Clinical data and complementary examinations were reviewed from electronic medical records with pre-parameterized information. RESULTS: The mean age of dermatomyositis and polymyositis patients was 41.1 and 42.8 years, respectively. The presence of anti-PM/Scl was observed in 5 (5.9%) dermatomyositis and 2 (6.3%) polymyositis patients. Two of these patients also had the anti-Ku antibody. The relevant clinical manifestations of these 7 patients were constitutional symptoms (100% of cases), muscular (100%), pulmonary (85.7%) and joint (71.4%) involvement, "mechanic hands" (85.7%), Raynaud phenomenon (85.7%) and plantar hyperkeratosis (85.7%). The 7 patients had relapses of disease activity, but at conclusion of the present study, 5 had complete clinical response and 2 complete remission of the disease. CONCLUSION: There is a low frequency of the anti-PM/Scl autoantibody in dermatomyositis and polymyositis patients. In addition, patients with this autoantibody exhibit a similar pattern of manifestations to that of antisynthetase syndrome.

OBJETIVO: O autoanticorpo anti-PM/Scl foi descrito em pacientes com escleromiosite. No entanto, há escassos estudos avaliando sua prevalência e reatividade em dermatomiosite (DM) e polimiosite (PM). MÉTODOS: Estudo transversal, num único centro, que avaliou o autoanticorpo anti-PM/Scl em 85 DM e 32 PM, sem síndrome de sobreposição, no período entre 2000 e 2016. Os dados clínicos e os exames complementares foram revisados a partir de registros médicos eletrônicos com informações pré-parametrizadas. RESULTADOS: A média de idade dos pacientes com DM e PM foi, respectivamente, de 41,1 e 42,8 anos. A presença de anti-PM/Scl foi observada em 5 (5,9%) DM e 2 (6,3%) pacientes com PM. Dois desses pacientes também possuíam o anticorpo anti-Ku. As manifestações clínicas relevantes desses 7 pacientes foram sintomas constitucionais (100% dos casos), envolvimento muscular (100%), pulmonar (85,7%) e articular (71,4%), "mãos mecânicas" (85,7%), fenômeno de Raynaud (85,7 %) e hiperqueratose plantar (85,7%). Os 7 pacientes apresentaram recidivas da atividade da doença, mas, no final do presente estudo, 5 apresentaram resposta clínica completa e 2 remissões completas da doença. CONCLUSÃO: Há uma baixa freqüência do autoanticorpo anti-PM/Scl em pacientes com DM e PM. Além disso, os pacientes com este autoanticorpo apresentam um padrão semelhante de manifestações para a síndrome da antisintetase.

Serum adipocytokine profile and metabolic syndrome in young adult female dermatomyositis patients

OBJECTIVES: To analyse the frequency of metabolic syndrome in young adult female dermatomyositis patients and its possible association with clinical and laboratory dermatomyositis-related features and serum adipocytokines. METHOD: This cross-sectional study included 35 dermatomyositis patients and 48 healthy controls. Metabolic syndrome was defined according to the 2009 Joint Interim Statement. RESULTS: Patient age was comparable in the dermatomyositis and control groups, and the median disease duration was 1.0 year. An increased prevalence of metabolic syndrome was detected in the dermatomyositis group (34.3% vs. 6.3%; p=0.001). In addition, increased serum adiponectin and resistin levels were noted in contrast to lower leptin levels. In dermatomyositis patients, adipocytokine levels were correlated with the levels of total cholesterol, low-density cholesterol, triglycerides and muscle enzymes. A comparison of dermatomyositis patients with (n=12) and without (n=23) syndrome metabolic revealed that adipocytokine levels were also correlated with age, and that dermatomyositis patients with metabolic syndrome tended to have more disease activity despite similar adipocytokine levels. CONCLUSIONS: Metabolic syndrome is highly prevalent in young adult female dermatomyositis patients and is related to age and disease activity. Moreover, increased serum adiponectin and resistin levels were detected in dermatomyositis patients, but lower serum leptin levels were observed.