Infections in 96 cases of systemic lupus erythematosus

The incidence, localization, etiology and predisposing factors of infections were evaluated in 96 cases of systemic lupus erythematosus (SLE) (15 males and 81 females) with a mean age of 40 years. Fifty-three patients (55%) had overall 102 infections (incidence 0.17 per year). 31% had urinary tract infections. In these, Escherichia coli was the most common causative organism (56%). 25% had respiratory infections (pneumonia in 14, pulmonary tuberculosis in 8, infections by opportunistic organisms in 4). 17% had skin infections, of which one half were due to Staphylococcus aureus. 16% had bacteremia, due to Staphylococcus spp in 5, to Salmonella spp in 4, and to Pseudomonas aeruginosa in 3. There was a higher incidence of infections in patients with active SLE, in those with nephropathy, and in those with previous immunosuppressant and/or corticosteroid therapy, Leukopenia was not associated to a higher number of infections. In 6 of the 12 patients who died, death was directly related with the infection; in one half of them, infections were due to an opportunistic organism (cytomegalovirus in 2 cases, disseminated candidiasis in one) and were not identified until necropsy. The need to rule out an opportunistic infection in any patient with SLE and fever is emphasized, particularly when there is pulmonary involvement and the patients have undergone aggressive diagnostic and/therapeutic interventions (immunosuppressants, plasmapheresis, renal dialysis).