Evaluation of total PSA assay on Vitros ECi and correlation with Kryptor-PSA assay

Background: An increasing number of multiparametric immuno-analysers for PS A assays are available. As different immuno-assays may vary in their analyt ical quality and their accuracy for the follow-up of patients, expertise is necessary for each new assay. Methods: The PSA assay on the Vitros-ECi ana lyser has been evaluated and compared with the PSA assay from the Kryptor a nalyser. Results: Variation coefficients were 0.91 to 1.98% for within-run assays, and 4.2% to 5.4% for inter-assay (PSA levels = 0.8 mug/L to 33.6 mu g/L). Dilution tests showed 93 to 136% recovery until 70 mug/L PSA. Functio nal sensitivity was estimated at 0.03 mug/L. Equimolarity of the test was c onfirmed. Correlation of PSA levels measured with Vitros-ECi and Kryptor an alysers displayed a correlation coefficient r(2) of 0.9716. The half-lives and doubling times of PSA were similar using both methods. Conclusion: Vitr os-ECi PSA assay meets the major criteria for the management of prostate ca ncer patients.