Evaluation of the L-CLONE Legionella pneumophila Serogroup 1 Urine Antigen Latex Test.
The purpose of this study was to evaluate the L-CLONE Legionella pneumophila Serogroup 1 Urine Antigen Latex Test (Access Medical Systems, Inc., Branford, Conn.) for detection of Legionella antigen in urine. A total of 481 frozen urine samples previously tested by an in-house solid-phase radioimmunoassay (RIA) was thawed and retested by using L-CLONE. Included in this sample were 140 RIA-positive samples from culture-positive or serologically confirmed cases of legionellosis and 341 RIA-negative samples from patients with non-Legionella respiratory disease or bacteriuria. The original RIA test result was accepted as the true value. L-CLONE correctly identified 76 of 140 (54%) known positive samples. False-negative results could not be attributed to a low Legionella antigen concentration or to a Legionella antigen subgroup. L-CLONE correctly identified 252 of 341 (74%) known negative samples. False-positive results were experienced in all groups of negative samples, regardless of the patients' underlying diseases. A total of 141 fresh urine samples was tested; all were Legionella antigen negative by RIA. L-CLONE provided 86% specificity. The sensitivity of the L-CLONE in testing fresh urine samples could not be evaluated because of the lack of Legionella antigen RIA-positive samples.
Leland
D S
DS
Department of Pathology, Indiana University Medical Center, Indianapolis 46202.
Kohler
R B
RB
D000942:Antigens, Bacterial / Q000652:urine*; D003951:Diagnostic Errors; D005069:Evaluation Studies as Topic; D006801:Humans; D007124:Immunoenzyme Techniques; D007841:Latex Fixation Tests / Q000379:methods* / Q000706:statistics & numerical data; D016952:Legionella pneumophila / Q000145:classification / Q000276:immunology*; D007877:Legionnaires' Disease / Q000175:diagnosis*; D011863:Radioimmunoassay; D012680:Sensitivity and Specificity; D012703:Serotyping
D000942:Antigens, Bacterial