Tuberculosis in Patients with Systemic Lupus Erythematosus: Single Center Retrospective Study

Kim, Choong Hyun; Kim, Wan Uk; Yang, Chul Woo; Jung, Young Ok; Do, Ju Ho; Ko, Hyeok Jae; Kim, Hae Rim; Youn, Chong Hyeon; Lee, Sang Heon; Park, Sung Hwan; Bang, Byung Kee; Kim, Ho Youn

Abstract

OBJECTIVE
To compare the incidence and clinical characteristics of tuberculosis (tbc) between patients with systemic lupus erythematosus (SLE) and kidney transplantation (KT) recipients.
METHODS
Six hundreds and twenty-two patients who were diagnosed as SLE from 1990 to 2001 in Kang-Nam St. Mary's hospital were reviewed, retrospectively. As a control group, 347 kidney transplant recipients in the same center were evaluated. The extent of tbc was categorized into two groups: (1) limited disease (2) extensive disease. Cumulative steroid dosage and disease activity index including SLEDAI, serum complement levels, and anti-dsDNA titers were compared between the two groups.
RESULTS
The cumulative incidence rate of tbc was similar in both groups (37 cases and 5.7% in SLE versus 17 cases and 4.9% in KT). Mean interval from SLE diagnosis or KT to tbc development was not different between the two groups. The most common site of tbc was lung/pleura, and the others included lymph nodes (2 cases), knee joint (1), bone marrow (1), central nervous system (1), kidney (1), colon (1), liver (1), and skin (1) in SLE. In contrast, most of tbc (16/17) developed exclusively in the lung and pleura in KT recipients. Cumulative doses of prednisolone 1 or 6 months before tbc diagnosis were not different between the two groups. Interestingly, extensive disease tended to be more frequent in SLE patients than in KT recipients although immuno-suppressants such as cyclosporine and azathioprine were more frequently administered in KT recipients. There were no differences in disease activity index including SLEDAI, complement levels, and anti-ds DNA titers at the time of tbc diagnosis as well as in the cumulative doses of steroid between extensive and limited diseases of tbc in SLE.
CONCLUSION
The cumulative incidence rate of tbc was higher in SLE patients than in general population. The patterns of tbc tended to be more extensive in SLE compared to KT recipients in whom a stronger immuno-suppression was required, suggesting that immune dysfunction implicated by SLE itself may play an important role in determining the incidence and patterns of tbc infection.