Diagnosis of Penicillium marneffei infection by quantitation of urinary antigen by using an enzyme immunoassay.
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.
Desakorn
V
V
Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.
Smith
M D
MD
Walsh
A L
AL
Simpson
A J
AJ
Sahassananda
D
D
Rajanuwong
A
A
Wuthiekanun
V
V
Howe
P
P
Angus
B J
BJ
Suntharasamai
P
P
White
N J
NJ
D000328:Adult; D000946:Antigens, Fungal / Q000652:urine*; D019353:Endemic Diseases; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005069:Evaluation Studies as Topic; D016650:Fluorescein-5-isothiocyanate; D006801:Humans; D007118:Immunoassay; D008828:Microbiological Techniques; D009181:Mycoses / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology / Q000652:urine; D010407:Penicillium / Q000276:immunology / Q000302:isolation & purification*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013785:Thailand / Q000453:epidemiology
D000946:Antigens, Fungal; D016650:Fluorescein-5-isothiocyanate