The high frequency of infections in SLE is probably caused by secondary immunodeficiency due to immunological abnormalities participating in the immunopathogenesis of the disease. Immunosuppressive therapy can intensify the immunodeficiency, concerning especially cell mediated and non-specific immunity. Thus the risk of opportune infection increases in immuno-suppressed condition including tuberculosis. A change in the prevalence and transmission of tuberculosis has been observed in recent years. In addition, the treatment of systemic rheumatic disease includes better immunosuppressive agents, and patients with systemic rheumatic diseases are more likely to survive longer. These patients have thus become more susceptible to infections such as tuberculosis, either by the disease it self or its treatment mainly steroids.