Characterization of Patients With Dermatomyositis According to Anti–Melanoma Differentiation-Associated Gene-5 Autoantibodies in Centers from 3 Latin American Countries

Abstract

Background/Objective: The anti-melanoma differentiation-associated protein 5 (MDA5) autoantibodies have been associated with a high frequency of interstitial lung disease (ILD) and rapidly progressive ILD (RP-ILD) in dermatomyositis (DM) patients, mainly in Asian subjects. However, there is scarce information about these parameters in Latin American patients.Method: This was a medical records review cohort study that included classic DM (CDM) and clinically amyopathic DM (CADM) patients from 3 Latin American countries (Argentina, Brazil, and Mexico).Results: A total of 270 DM patients were evaluated: 25.9% with CADM and 74.1% with CDM. The overall prevalence of ILD and RP-ILD, respectively, was 70 (25.9%) and 4 (1.5%) of the 270 patients, and the distributions were comparable between patients with CDM and CADM. The anti-MDA5 was present in 31 (25.4%) of 122 CDM patients and in 17 (48.6%) of 35 CADM patients; it was not associated with presence of ILD and RP-ILD. However, anti-MDA5-positive CDM patients had significantly high frequency of "mechanic's hands," arthralgia, arthritis, and lower serum levels of creatine phosphokinase, whereas anti-MDA5-positive CADM patients had significantly high frequency of arthritis. Pulmonary infection and ILD are main causes of death in DM patients. Conclusions:In the present study, the prevalence of ILD in DM patients is comparable to that described in the literature, in contrast to the very low frequency of RP-ILD. In addition, the anti-MDA5 is not associated with ILD and RP-ILD, but anti-MDA5-positive DM patients present conditions that mimic antisynthetase syndrome. Pulmonary infection and ILD were the main causes of death in our sample.

Different clinical phenotypes in anti-melanoma differentiation-associated protein 5-associated positive dermatomyositis

“…The risk of RP-ILD in patients with dermatomyositis may be associated with positive anti-MDA-5 autoantibodies (2-7). However, Yang et al (7) and our studies (8) show that other factors may influence in RP-ILD prevalence in patients with dermatomyositis. Therefore, more studies are needed that characterise the relevance of anti-MDA-5 in patients with dermatomyositis -mainly an international study involving patients with different ethnicities and from different geographic areas.…”

“…Therefore, this study reinforces the idea that not all patients with anti-MDA-5-positive dermatomyositis have RP-ILD. Herein, we share our experience of 270 patients with dermatomyositis from three Latin American centres (8). The prevalence of the anti-MDA-5 autoantibody was 25.4% and 48.6% in patients with dermatomyositis and clinically amyopathic dermatomyositis, respectively.…”

Clinical manifestations, outcomes, and antibody profile of Brazilian adult patients with dermatomyositis: a single-center longitudinal study

“…Those that are most relevant for DM are anti-Jo-1, anti-Mi-2, anti-MDA-5, anti-TIF1-γ, anti-SAE, and anti-NXP-2 [4,5]. Detection of these autoantibodies allows for better characterization of DM's phenotypic pattern of DM and establishes associations with clinical manifestations and prognosis [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. The autoantibody profile and associations with DM manifestations vary according to the geographic area.…”

“…Only a few epidemiological studies of patients with DM have been conducted [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The majority of these studies were limited to cross-sectional [7,9,11,16,17] or retrospective studies [6,12,14,15,18,20,22], with a small number of patients with DM [13,18,23] or heterogeneous cohorts, consisting of patients with probable or possible DM diagnosis [9,11,13,18,23]. Furthermore, only five studies analyzing myositis-specific autoantibodies have been performed in a Brazilian population with DM [6,7,14,15,17].…”

“…The majority of these studies were limited to cross-sectional [7,9,11,16,17] or retrospective studies [6,12,14,15,18,20,22], with a small number of patients with DM [13,18,23] or heterogeneous cohorts, consisting of patients with probable or possible DM diagnosis [9,11,13,18,23]. Furthermore, only five studies analyzing myositis-specific autoantibodies have been performed in a Brazilian population with DM [6,7,14,15,17].…”