THE ANALYTICAL AND CLINICAL-PERFORMANCE OF THE NEW BOEHRINGER-MANNHEIM ENZYMUN-TEST(R) PSA ASSAY FOR PROSTATE-SPECIFIC ANTIGEN

A combined evaluation effort of the Boehringer Mannheim Research and D evelopment and Evaluation Departments and the University Hospital Rott erdam is described regarding the new, fully automated Enzymun-Test(R) PSA assay for prostate-specific antigen. The study consisted of an ana lytical and a clinical part. At both sites, the vast majority of intra -assay coefficients of variation ranged from 2 to 3% above prostate-sp ecific antigen = 1 mu g/l. Below that concentration higher coefficient s of variation were measured. Comparable results were obtained for the interassay imprecision. The analytical sensitivity (lower limit of de tection) was found to be 0.02 mu g/l at both sites. Regarding the line arity of the assay no systematic drift to either elevated or lower val ues which increasing dilution was found. Deviations remained well in t he range between 100 +/- 10%. The correlation with the Abbott IMx PSA assay as performed with a large set of clinical specimens revealed: y (= Enzymun) = 1.16x (= IMx) + 0.0; r = 0.985; n = 245. In this compari son study small differences between benign prostatic hyperplasia patie nts and prostate cancer patients were detected, perhaps partly based o n the differences in recognition patterns of various molecular prostat e-specific antigen forms in both assays. A follow-up after radical pro statectomy with 17 patients (50 serum samples) also showed a good comp arability between the Enzymun-Test(R) and the IMx assay. The limited c heck of the reference range resulted in data comparable to what can be found in the literature: out of 100 samples originating from healthy males, aged 20-60 years, 99 had prostate-specific antigen values lower than 4 mu g/l. Based on our findings it can be concluded that the new Enzymun-Test(R) PSA assay meets the current state-of-the-art criteria in prostate-specific antigen methodology.