Diagnosis of Penicillium marneffei infection by quantitation of urinary antigen by using an enzyme immunoassay.

摘要

Penicillium marneffei is a major cause of opportunistic infection in patients with AIDS in north and northeastern Thailand. A method for the quantitation of P. marneffei antigen in urine was developed by using fluorescein isothiocyanate-labelled purified rabbit hyperimmune immunoglobulin G in an enzyme-linked immunosorbent assay. This method was evaluated with 33 patients with culture-proven penicilliosis and 300 controls (52 healthy subjects, 248 hospitalized patients without penicilliosis) from the same area in which penicilliosis is endemic. Urinary antigen was found in all 33 (100) patients with penicilliosis, with a median titer of 1:20,480. With undiluted samples, 67 (27) of 248 hospital patients and 3 (6) of 52 healthy controls were reactive. At a cutoff titer of 1:40, the urine antigen detection assay had a diagnostic sensitivity of 97 and specificity of 98 (positive predictive value, 84; negative predictive value, 99.7). This test offers a valuable and rapid method for the diagnosis of penicilliosis in patients with AIDS and could be a useful addition to conventional diagnostic methods in areas in which penicilliosis is endemic.