[Comparative assessment of the characteristics in various assay kits for prostate specific antigen]

Six kinds of assay kits based on different detecting principle for PSA were evaluated. Polyclonal antibody was used in 2 kits (Eiken, Markit-F) and monoclonal antibody in 4 kits (Ball Elsa, Delfia, Markit-M, Tandem-R). To evaluate their characteristics, sera of 12 female patients, 5 prostatectomized patients and 2 high stage prostate cancer patients were measured by these kits. On the female sera the polyclonal assay kits yielded values higher than the defined minimal sensitive value, but the kits of monoclonal antibody detected nothing. Dilution test of sera with high PSA level showed satisfactory results in every kit but the values of 6 assays were different to each other. For monitoring the recurrence or recrudescence of the prostatic cancer, the monoclonal antibody kits may be preferable to the polyclonal antibody kits. These results showed that we must understand the characteristics of every assay kit which is used clinically.