Tuberculosis in patients with systemic lupus erythematosus-a 37-year longitudinal survey-based study

BACKGROUND: Infections are one of the most common causes of morbidity and mortality in patients with systemic lupus erythematosus (SLE). SLE patients have a higher risk of tuberculosis (TB) infection due to impaired immune defence. OBJECTIVES: To investigate the demographics, clinical characteristics and outcomes of patients with SLE and concomitant TB. METHODS: Medical records of SLE patients with TB who were admitted to Peking Union Medical College (PUMC) Hospital in 1983-2019 were retrospectively reviewed. Age- and sex-matched SLE inpatients without TB were randomly selected as controls. Clinical and laboratory features and treatment were analysed and compared, and subjects were followed up to assess their outcome. RESULTS: Of the 10 469 SLE inpatients, 249 (2.4%) were diagnosed with TB. Compared with controls, SLE/TB + patients exhibited higher frequency of prior haematologic, mucocutaneous and musculoskeletal system involvement, and prior treatment with potent glucocorticoid/immunosuppressive agents (GC/ISA). Arthritis and alopecia, positive T-SPOT.TB test and lymphocytopenia were more common in SLE/TB + patients. SLE/TB + patients with lupus before TB (SLE –> TB) had higher risk of miliary TB (22.8%) and intracranial TB (16.5%) than SLE/TB + patients with lupus after TB (TB –> SLE). SLE/TB + patients exhibited shorter long-term survival than SLE/TB- patients; those with poorer in-hospital outcomes had more severe lymphocytopenia and had received less treatment with ISAs. CONCLUSION: Systemic lupus erythematosus patients treated vigorously with GC/ISA should be alerted of increased risk of TB infection, especially miliary and intracranial TB. Positive T-SPOT.TB and lymphocytopenia served as discriminatory variables between SLE/TB + and SLE/TB- patients. Lymphocytopenia was associated with poorer outcomes in SLE/TB + patients.