Opportunistic infections in patients with idiopathic inflammatory myopathies

Aim To describe the prevalence, clinical characteristics and risk factors of opportunistic infection (OI) in a cohort of patients with inflammatory myopathies, and compare mortality rates between those with and without OIs. Methods In total, 204 patients from our myositis cohort were reviewed to identify patients who had experienced an OI during the period 1986–2014. The patients’ clinical characteristics, treatments received, and outcomes were systematically recorded. Disease activity at the OI diagnosis and the cumulative doses of immunosuppressive drugs were analyzed, as well as the specific pathogens involved and affected organs. Results The prevalence of OI in the total cohort was 6.4%: viruses, 44.4% (varicella‐zoster virus, cytomegalovirus); bacteria, 22.2% (Salmonella sp., Mycobacterium tuberculosis, M. chelonae); fungi, 16.7% (Candida albicans, Pneumocystis jirovecii); and parasites, 16.7% (Toxoplasmosis gondii, Leishmania spp.). Lung and skin/soft tissues were the organs most commonly affected (27.8%). Overall, 55.6% of OIs developed during the first year after the myositis diagnosis and OI was significantly associated with administration of high‐dose glucocorticoids (P = 0.0148). Fever at onset of myositis (P = 0.0317), biological therapy (P