To investigate the characteristics and associated factors for Mycobacterium tuberculosis (TB) infection in patients with systemic lupus erythematosus (SLE) from Southern China. A retrospective study of 1108 patients admitted to the First Affiliated Hospital of Sun Yat-Sen University from January 2007 to December 2017 was performed. Demographic and clinical characteristics, laboratory data, and radiographic manifestations were recorded. A total of 59 (5.3%) lupus patients with active TB were included. Pulmonary TB occurred in 41 (69.5%) patients. Single lobe involvement was showed in 14 (34.1%) patients. Multi-lobar involvement, including miliary TB (36.6%), was presented in 27 (65.8%) patients. Lower lobe involvement accounted for 31 (75.6%) of the cases. Extrapulmonary TB occurred in 18 (30.5%) patients. Nearly one-third (35.6%) of the patients developed disseminated TB. T-SPOT.TB assay was performed in 23 patients and positive in 18 patients (78.3%). Nineteen patients (32.2%) had co-infection with TB and other pathogens, most of which were bacterial-associated (52.6%). Lymphopenia was predominant in TB-infected patients, especially in those with disseminated TB. Multivariate logistic regression analysis found that lymphopenia [odds ratio (OR) = 2.19, 95% confidence interval (CI) 1.03-4.63, P = 0.04] and the accumulated doses of glucocorticoid (GC) (OR = 2.32, 95% CI 1.69-3.20, P < 0.001) were associated with TB. TB infection is a common comorbidity in patients with SLE. Manifestations of pulmonary computed tomography (CT) scan are relatively atypical. Co-infection with TB and other pathogens is not rare. Lymphopenia and the accumulated doses of GC are associated with TB infection in lupus patients.
Keywords: Co-infection; Disseminated tuberculosis; Lymphopenia; Mycobacterium tuberculosis; Systemic lupus erythematosus.