Performance of the 2017 European Alliance of Associations for Rheumatology/American College of Rheumatology Classification Criteria in Patients With Idiopathic Inflammatory Myopathy and Anti-Melanoma Differentiation-Associated Protein 5 Positivity.

Objective: This study aimed to evaluate whether the 2017 European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) classification criteria for adult and juvenile idiopathic inflammatory myopathies (IIMs) could appropriately classify the diagnosis in adult patients with anti-melanoma differentiation-associated protein 5 (anti-MDA-5)-positive IIM. In addition, this study sought to determine whether a status of anti-MDA-5 positivity could be incorporated into the EULAR/ACR IIM classification criteria set and whether the recently modified criteria based on the presence of myositis-specific autoantibodies (MSAs) could be used to appropriately classify the diagnosis in patients with anti-MDA-5-positive IIM.

Methods: Consecutive adult patients clinically diagnosed as having anti-MDA-5-positive IIM from 10 hospitals in Hong Kong were retrospectively recruited; patient characteristics were obtained from electronic medical records.

Seasonal Effect on Disease Onset and Presentation in Anti-MDA5 Positive Dermatomyositis.

Objective: To investigate the seasonal variation of disease onset and presentation in an ethno-geographically homogeneous cohort of patients with anti-MDA5 positive dermatomyositis (DM).

Methods: This was a multi-centered, retrospective cohort study. Adult Chinese anti-MDA5 positive DM patients were identified from the Hong Kong Myositis Registry and the Clinical Data Analysis and Reporting System from 2015 to 2020.

Predictors of rapidly progressive interstitial lung disease and mortality in patients with autoantibodies against melanoma differentiation-associated protein 5 dermatomyositis.

Objective: Anti-melanoma differentiation-associated protein 5 (MDA5)-positive DM is associated with rapidly progressive interstitial lung disease (RP-ILD) and high mortality. This multicentre retrospective study aimed to identify predictors of mortality and RP-ILD.

Methods: Anti-MDA5-positive DM patients were identified from the Hong Kong Myositis Registry and the Clinical Data Analysis and Reporting System.

Myositis-specific autoantibodies and their clinical associations in idiopathic inflammatory myopathies.

Background: Myositis-specific autoantibodies (MSAs) have been found to be present predominantly in patients with idiopathic inflammatory myopathies (IIMs). This study aimed to investigate the prevalence of MSAs and their associated complications in a cohort of patients with IIMs.

Methods: This was a multicentered prospective study.

Rituximab for refractory rapidly progressive interstitial lung disease related to anti-MDA5 antibody-positive amyopathic dermatomyositis.

To report our experience in using rituximab (RTX) for treating refractory rapidly progressive interstitial lung disease (RP-ILD) complicating anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab)-positive amyopathic dermatomyositis (ADM). Medical records of four ADM patients with refractory RP-ILD treated with RTX therapy were reviewed retrospectively. All four patients were tested positive for anti-MDA5 Ab and failed to respond to high-dose systemic steroid and other intensive immunosuppressive therapies.