ABSTRACT
Objective: With scant studies in the literature, little is known about the risk factors for tuberculosis in patients with dermatomyositis/polymyositis. Therefore, the aim of the present study was to analyze the predictive factors for tuberculosis development in dermatomyositis/polymyositis. Methods: This single-center, retrospective, cohort study initially included 290 patients with dermatomyositis/polymyositis, from 2002 to 2016. Tuberculosis (pulmonary and/or extra-pulmonary) was confirmed after dermatomyositis/polymyositis diagnosis in 12 patients (4.1%) (Tuberculosis+ group). For the control group (Tuberculosis−), 24 patients without tuberculosis were arbitrarily selected in the same period and matched for age, ethnicity, gender, age at disease diagnosis, disease duration and type (dermatomyositis or polymyositis). Results: Tuberculosis occurred for a median of 16 months after dermatomyositis/polymyositis diagnosis. Clinical, laboratory and treatment features were similar in Tuberculosis+ and Tuberculosis− groups (P > 0.05). However, previous pulmonary fibrosis in dermatomyositis/polymyositis was more prevalent in the Tuberculosis+ group (41.7 vs. 8.3%; P = 0.029). Moreover, on a multivariate logistic regression model, pulmonary fibrosis was significantly associated with Tuberculosis (Odds ratio: 9.59, 95% confidence interval: 1.17 - 78.82). Tuberculosis affected 3 dermatomyositis cases for every 1 polymyositis case, with predominantly pulmonary followed by extra-pulmonary involvement (pleura, cutaneous, muscular, joint, soft tissue and hematologic). Two or more sites were affected in 41.7% of cases. Conclusions: Previous pulmonary fibrosis in dermatomyositis/polymyositis was a predictive factor associated with tuberculosis development. Further studies are needed to confirm these results.