Experience with MDA5 positive myositis

ABSTRACT

Introduction and Objective: Idiopathic inflammatory myopathies(IIMs) is a group of autoimmune disease characterized by muscular and extra-muscular manifestation. IIMs with anti-MDA5 antibody positivity carries poor prognosis due to rapid progressive interstitial lung disease (RP-ILD). We report clinical course of patients cared in our centre. Method(s) Patients medical record were reviewed for data collection. Result(s) Four patients with MDA5 antibody positive IIMs following up in our clinic (Table 1). None has reported Covid infection. Two has respiratory disease responded to induction therapy. One still undergoing titration of immunosuppressant. One female patient presented unwell with pleural effusion and acute pneumonitis. Patient later developed rapid progression of interstitial lung inflammation with refractory supraventricular tachycardia. IVIG was initiated, however she succumbed to adult respiratory distress syndrome (ARDS) due to pneumonia. Plasma exchange was not carried out due to source limitation at that time of period. Conclusion(s) Prevalence of anti MDA-5 positive is 30%-50% in Asians patients with IIMs particularly the east. However, it is likely under-reported in Malaysia due to lack of understanding of the pattern of disease in our multiracial population as well as lack of myositis serology tests availability especially in government hospitals. Research and registry should be instituted to allow better study of this disease in our population, to better the treatment and reduce morbidity and mortality due to rapid progressing interstitial lung disease. (Table Presented).