Background Systemic Lupus Erythematosus (SLE) is an autoimmune disease caused by disturbance in immune tolerance to self-antigens, leading to multiorgan inflammation. SLE causes a high risk of tuberculosis (TB) infection in SLE. In SLE pathogenesis, T cells play a major role to amplify inflammation by secreting pro-inflammatory cytokines. Interferon-γ release assay (IGRA) is commonly used to diagnose latent TB infection (LTBI). Many immunosuppressive agents are potent inhibitors of T cells and may impair the interferon-γ response. This study was aimed to determine the effect of steroid therapy on the performance of IGRA in SLE.

Methods This experimental study included 50 female SLE. Data such as age, disease duration, SLE disease activity index (SLEDAI), steroid therapy doses, and Body Mass Index (BMI) were obtained. Steroid therapy doses were categorized as high-dose (≥7.50 mg) and low-dose steroids (<7.50 mg). Patients were excluded if they had history of TB or current active TB. Each group underwent IGRA testing using the QuantiFERON-TB Gold Plus kit. Data analysis was performed using SPSS.

Results There were 50 (100%) female SLE with average age 32.64 (±8.16) years old, mean disease duration 5.78 (±3.99) years, mean SLEDAI score 2.64 (±3.19), mean steroid therapy doses 8.47 (±8.35) mg/day, and median of BMI 21.7 (16.4–36.0). In high-dose steroids group (n=20), IGRA result was 5% positive, 15% indeterminate, and 80% negative. In low-dose steroids group, 3.3% was positive and 96.7% was negative. There was no significant association between steroid therapies and IGRA results (p=0.084).

Conclusions Steroid therapy causes dysregulation of immune response and has tendency to influence IGRA result in SLE. In our study steroid therapy is not associated with IGRA result. Further study to explore latent tuberculosis infection and steroid therapy in SLE is of great interest.