Incidence and Risk of Infection in Egyptian Patients with Systemic Lupus Erythematosus

BACKGROUND: Infection in systemic lupus erythematosus (SLE) is common and is one of the leading causes of morbidity and mortality. OBJECTIVE: To study the risk and occurrence of infection in Egyptian SLE patients and to determine its characteristics. METHODS: A total of 200 SLE patients were followed up for 1 year at monthly intervals, undergoing clinical and laboratory evaluation. Disease activity was assessed by SLE disease activity measurement (SLAM) score. Infections were diagnosed on basis of clinical findings, medical opinion, positive blood and urine cultures, Gram stain results, and specific serological assays as measurement of CMV and EBV antibodies. RESULTS: A total of 55% of patients developed infection, 45% had one infection, and the rest had multiple infection episodes. Total number of infections was 233 infections/year, 47.2% were major and 52.8% were minor infections. Urinary tract was the most commonly involved site with bacterial infection being the commonest isolated organism (46.4%), and E. coli the commonest isolated bacteria (14.2%). There were 51 episodes caused by systemic viral infection (CMV in 25, EBV in 22, HCV in 3, and 1 in HBV). CONCLUSION: There is a high rate of infection among SLE patients. Disease activity, leukopenia, high CRP level, positive anti-dsDNA, consumed C3, and cyclophosphamide therapy are independent risk factors for infection in SLE.