Immunopathogenesis and spectrum of infections in systemic lupus erythematosus

Objective: This study reviews the pertinent immunopathologic mechanisms that contribute to increased susceptibility to infection in patients with systemic lupus erythematosus (SLE) and the spectrum of infections in patients with SLE. It assesses the impact on patient care, morbidity, and mortality. Methods: The authors performed an extensive search of the literature through MEDLINE, using appropriate keywords and manual search of bibliography cited by retrieved papers. Results: Infection is a leading cause of morbidity and mortality in SLE and may change the natural course of the disease. Patients with SLE display numerous cellular and humoral abnormalities that are expressed in a heterogeneous pattern and contribute in varying degrees to susceptibility to infectious agents. The use of corticosteroid and immunosuppressive drugs is only partially responsible for the high infection rate in lupus patients, Common as well as opportunistic pathogens are frequently encountered among patients with SLE. The susceptibility that SLE patients exhibit to certain bacteria is now better recognized, and a broadening spectrum of pathogens is being reported. The immunization of patients against influenza and pneumococcus and the administration of prophylactic therapy against Pneumocystis carinii infection in certain patients have recently been proposed. Conclusion: Disease activity and treatment are responsible for the extensive defects of the immune defense system in lupus patients that increase their susceptibility to an extensive range of infections. Infection imposes a serious burden on lupus patients and on the caring physician. (C) 1996 by W.B. Saunders Company