Detection of Legionella pneumophila serogroup 1 antigen in bronchoalveolar lavage fluid by an immunochromatographic assay.

of centrifuged BAL fluids, while culture yielded no Legionella spp. Conventional microbiological methods did reveal other microorganisms: e.g., H. influenzae, Serratia marcescens, Pseudo- monas aeruginosa, Corynebacterium spp., coagulase-negative staphylococci, Candida spp., and Pneumocystis carinii. The NOW Legionella urinary antigen test detected L. pneu- mophila serogroup 1 antigen in BAL fluid from an HIV-in- fected patient with culture-proven Legionnaires' disease. Ap- plication of the test to specimens other than urine might prove useful for rapid diagnosis of Legionnaires' disease. This may be especially true for anuric patients. End-stage renal disease is identified as risk factor for legionellosis, and acute renal failure is a known complication of Legionnaires' disease (1-3). The test might also prove useful for patients with extrapulmonary manifestations of L. pneumophila serogroup 1 infection—e.g., pericarditis, which often presents without overt pneumonia (4). While our observation seems promising, additional clinical ob- servations are needed to evaluate the sensitivity and specificity of the test with specimens other than urine.