[Prostate specific antigen in patients with prostatic cancer--clinical usefulness of its measurement with sensitive enzyme immunoassay, TOSOH II PA assay].
The TOSOH II PA (AIA-PACK PA in the U.S.A.) monoclonal immunoenzyme assay was used and the clinical usefulness of prostate specific antigen (PSA) was evaluated in 39 men with prostatic cancer and 32 men with benign prostatic hyperplasia (BPH) confirmed pathologically. We evaluated the lower limit of detection in this assay by the mean PSA level plue 3 standard deviations in 5 separate experiments with a zero control sera as well as the mean PSA level minus 3 standard deviations in 5 separate experiments with serial dilutions of a known concentration of PSA. PSA concentrations of 0 to 0.25 ng/ml could not be distinguished from the zero control. Therefore, we set the lower limit of detection for the assay as 0.25 ng/ml. At our laboratory, the normal standard value was determined by the mean PSA level plus 3 standard deviations in 79 healthy men as 2.3 ng/ml. Of patients that underwent radical cystoprostatectomy for bladder cancer, all had PSA levels less than 0.25 ng/ml, while only 6% had PAP levels less than 0.11 ng/ml, the lower limit of detection in the TOSOH II PAP assay. We compared TOSOH II PA with Markit PA, a commonly used assay in Japan. Although there was a close linear correlation (r = 0.90) between the TOSOH II PA and Markit PA, the difference of slope in the linear regression lines was great, it was thought due to anti-PSA antibodies in each assay recognizing different epitopes of PSA in the blood.(ABSTRACT TRUNCATED AT 250 WORDS)
Shinka
T
T
Department of Urology, Wakayama Medical College.
Miyai
M
M
Sawada
Y
Y
Ohkawa
T
T
D000328:Adult; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood*; D011470:Prostatic Hyperplasia / Q000175:diagnosis; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000276:immunology; D011933:Reagent Kits, Diagnostic
D011933:Reagent Kits, Diagnostic; D017430:Prostate-Specific Antigen