Comorbidities in idiopathic inflammatory myopathies: Data from the MyoCite cohort

Abstract

Idiopathic inflammatory myopathies (IIMs) are a group of heterogeneous and rare disorders affecting multisystems in addition to muscles, often leading to substantial impairment in quality of life. 1 Ethnic and geographic variations influence the autoantibody patterns and clinical spectrum among IIM patients. 2 Patients affected by IIM may suffer from several comorbidities, such as cancer or cardiovascular disease, which may complicate the course of the disease. Certain comorbidities are associated with worse outcomes and increased mortality. 3 Moreover, the presence of comorbidities may impact treatment choices.Previous studies have highlighted an elevated risk of coexisting malignancy 4,5 and cardiovascular disease 6 in the literature. However, the exact prevalence of other comorbidities and their correlation with autoantibodies remains largely unexplored. Our primary objective was to investigate the spectrum of comorbidities among Indian patients diagnosed with IIM in a tertiary care center, to establish the MyoCite Cohort, and to evaluate their potential associations with disease subtypes and antibodies.The MyoCite dataset represents a repository of longitudinal data, encompassing adults and children diagnosed with IIM who received or are currently receiving treatment at a tertiary care hospital in India. A comprehensive account of the methodology has been previously published, incorporating details on patient selection and definitions of disease subsets. 7,8 Through a thorough screening process, both adults and children presenting with myositis were meticulously evaluated. 9 From the MyoCite dataset, we extracted essential demographic information, such as age, gender, disease subtypes, comorbidities, and autoantibodies, to facilitate our investigation.Comorbidities were classified as autoimmune, cardiovascular, cancer, infections, and others. In addition, autoantibodies were classified into myositis-specific antibodies (MSAs), myositis-associated antibodies (MAAs), anti-aminoacyl tRNA synthetase antibodies (ARAs), and anti-nuclear antibodies (ANAs) as well as individual