Background Systemic Lupus Erythematosus (SLE) is an autoimmune disease of unknown etiology affecting different organs and systems, and requiring the use of immunosuppressors (IS), which increases the risk of infections such as tuberculosis (TB) and its deliberate search is mandatory. Patients with SLE are prone to infections as a consequence of either intrinsic immunologic defects or the IS mainly steroids. The prevalence of TB is higher in SLE patients compared with the general population and has been reported in endemic areas up to 5%.

Objectives To determine the prevalence of pulmonary TB - extrapulmonary and associated factor in SLE patients.

Methods we performed a retrospective study in a cohort of 328 SLE patients between 2010–2015 in tertiary level hospital. We included SLE patients with TB diagnosis which was made by PCR, culture, histopathology (HP), acid fast bacillus (AFB) and therapeutic trial (TT). We investigated associated factors for TB: IS drugs 6 months prior diagnosis of Tb (steroids, cyclophosphamide pulse (CY), azathioprine, mycophenolate mophetil (MM) and rituximab), comorbidities (diabetes mellitus, chronic renal disease, arterial hypertension). We also investigated previous exposure and vaccination for TB, type of TB: pulmonary and extra pulmonary. Time evolution, organ involved and SLEDAI at time of diagnosis of Tb were analyzed. Descriptive statistics were performed descriptive statistical.

Results We found 13 SLE patients with TB (mean age 43.5± 9.06 years, mean disease evolution of SLE: 6.6±3.2 years). SLE organ involvement: Renal: 7, hematological: 4 Neuropsychiatric: 2; joint -mucocutaneous 6. Active SLE: 9 (SLEDAI 11.5±4.9), inactive SLE: 4. Use of IS: MM 6, Azathioprine: 7, Cy: 5, steroid: 13 (prednisone: median 2.5, range 2.5 to 50 mg/day and methylprednisolone pulse 3g bimonthly in 2 patients), Rituximab: 3. Prevalence of TB was 13 of 328 (4%) patients, extrapulmonary:10 (77%) renal: 4, meningeal: 3, cerebral tuberculoma: 1 peritoneal: 1 disseminated: 1, and pulmonary TB: 3 (23%). Manifestation associated with TB: Fever 12 (92%) appetite loss: 3 (23%), weight loss 5 (38%), asthenia 8 (61%) headache: 3 (23%), hematuria: 2 (15%). TB diagnosis: AFB: 9 (69%), HP: 1 (7.5%), culture and PCR: 2 (15%), TT: one patients with miliary TB who died.

Conclusions The prevalence of TB in SLE patients was about 4% and its main form was extrapulmonary. The presence of tuberculosis in patients LES constitute a chalence and should be identified in promptly in order to initiate an adequate treatment. TB diagnosis in patients with active SLE is difficult because both diseases share clinical and laboratory manifestations.

1. Lu MC, Lai CL, Tsai CC et al. Increased risk of pulmonary and extra-pulmonary tuberculosis in patients with rheumatic diseases. Int J Tuberc Lung Dis. 2015;19:1500–6. doi: 10.5588/ijtld.15.0087.

Disclosure of Interest None declared