The objective of the study was to evaluate risk factors for
pulmonary tuberculosis in
systemic lupus erythematosus (SLE). Clinical/laboratorial features of 1283 SLE patients (ACR criteria) followed at the Lupus Clinic were obtained from the electronic register database from 2001 to 2009.
Pulmonary tuberculosis was diagnosed in 20 patients (1.6%) (TB+ group). As control group (TB-), 40 patients without
tuberculosis matched for age, gender, ethnicity, age at SLE diagnosis, and disease duration were arbitrarily selected. All 20 patients of the TB+ group presented confirmed
pulmonary tuberculosis from 1 to 23 years after SLE diagnosis (7.6 ± 8.1 years). Frequencies of previous SLE involvements (cutaneous, articular, hematological, renal,
pericarditis,
pneumonitis, and central nervous system) were alike in TB+ and TB- groups (p > 0.05). In contrast, prior
pleuritis was more frequent in the TB+ group (40% vs. 5%, p = 0.001). In fact,
pulmonary tuberculosis was diagnosed in 8/10 patients with previous
pleuritis. Immunosuppressive and
corticosteroid therapies at the moment of
tuberculosis diagnosis were also similar in both groups (p > 0.05). We have identified
pleuritis as a relevant risk factor for
pulmonary tuberculosis, suggesting that previous pleural injury is a critical part of the complex interplay between altered immune system, socio-economic conditions, and increased susceptibility to this mycobacterial
infection.