Clinical spectrum of active tuberculosis in patients with systemic lupus erythematosus

There is paucity of data on tuberculosis in Indian patients with systemic lupus erythematosus (SLE). We retrospectively studied clinical features and outcome of tuberculosis in SLE.

Medical records of patients who developed tuberculosis simultaneous or after the diagnosis of SLE were retrospectively reviewed. All patients fulfilled 1997 ACR and/or SLICC 2012 classification criteria for SLE. A diagnosis of tuberculosis required bacteriological, histopathological or CT/MRI suggestive of tuberculosis and initiation of four drug antituberculous therapy. Baseline parameters were compared with the rest of cohort to identify predictors of tuberculosis.

In our cohort of 1335 SLE patients, 48 (3.6%) developed tuberculosis. Incidence of tuberculosis was calculated to be 733 per 100,000 patient years and occurred after a mean disease duration of 3.0 ± 4.1 years. Extrapulmonary tuberculosis (n = 37) was commoner than pulmonary tuberculosis (n =11). Most common radiological pattern in pulmonary tuberculosis was miliary and musculoskeletal TB was most common extrapulmonary TB. A microbiological diagnosis was obtained in 52.1% patients. Male gender was associated with higher risk of tuberculosis [OR 3.30 (1.55-7.05)]. Mortality was 14.5% and all patients who died had either disseminated (n = 5) or central nervous system (CNS) tuberculosis (n = 2).

Incidence of tuberculosis in SLE is higher than general population and is associated with different phenotype and higher mortality. Male gender was associated with increased risk of tuberculosis in SLE.