Opportunistic infections in polymyositis and dermatomyositis.

OBJECTIVE: To assess prevalence and characteristics of opportunistic infections in patients with polymyositis/dermatomyositis (PM/DM). To determine the predictive values for opportunistic infections on clinical presentation, biochemical findings, and paraclinical features of PM/DM to detect patients at risk of opportunistic infections.

METHODS: The medical records of 156 consecutive PM/DM patients in 3 medical centers were reviewed.

RESULTS: Eighteen PM/DM patients (11.5%) developed opportunistic infections. The majority of patients exhibited an opportunistic infection after the onset of PM/DM (89% of cases). Opportunistic infections occurred most frequently during the first year following PM/DM diagnosis (62.5%). The pathogen microorganisms responsible for opportunistic infections were various, i.e., Candida albicans, Pneumocystis carinii, Aspergillus fumigatus, Geotrichum capitatum, Mycobacterium avium-intracellulare complex, M. xenopi, M. marinum, M. tuberculosis, Helicobacter heilmanii, cytomegalovirus, and herpes simplex virus. Mortality rates were as high as 27.7% in these PM/DM patients. Higher mean daily doses of steroids, lymphopenia, and lower serum total protein levels were significantly more frequent in the group of PM/DM patients with opportunistic infections.

CONCLUSION: Our study underscores the high frequency of opportunistic infections in PM/DM, resulting in an increased mortality rate. It also indicates that a great variety of microorganisms are responsible for opportunistic infections, although they were more often due to fungi (>50% of cases). Our series highlights a predominance of both lung and digestive opportunistic infections (89% of cases). In addition, our results suggest that PM/DM patients presenting with factors predictive of opportunistic infection may require closer monitoring.