PR92 antigen in human prostate fluid: Elevated levels in prostate cancer

In this preliminary study, we report that an enzyme‐linked immunofluorescence assay (EFLA) was developed for the determination of PR92 antigen in prostatic fluid, utilizing anti‐PR92 monoclonal antibody. Fluid samples from 64 patients were assayed. PR92 antigen was expressed as unit per microgram (U/μg) of prostatic fluid proteins. One hundred percent of men (7 out of 7) less than 50 years of age demonstrated concentrations less than 25 U/μg; 91% of men (10 out of 11) with documented carcinoma, and only 9.5% of men (2 out of 21) with benign prostatic hyperplasia, demonstrated concentrations above 230 U/μg. The mean concentration of PR92 antigen in prostatic fluid of a group of patients suspected of having prostate cancer (high‐risk group; 227 ± 42 U/μg) was significantly greater than that of those with benign prostatic hyperplasia (87 ± 23 U/μg; P = 0.05). Further evaluation of this potential marker and of other antigens within the prostatic fluid is warranted. © 1994 Wiley‐Liss, Inc.