MDA Evaluation of Five Free

Résumé du livre

During 1998/99, the MDA Kit Evaluation Unit, Sheffield, performed a series of five evaluations of kits for the determination of free prostate specific antigen (PSA). To permit calculation of diagnostic sensitivity and specificity the assays were evaluated in conjunction with the matched total PSA kit. Assays were performed in strict accordance with the manufacturer's instructions and the distributors were given the opportunity to train the operators prior to the commencement of the evaluation. The evaluations included an assessment of the presentation of the kits, ease of use and performance characteristics. This report presents comparative data for the five assays. All kits were found to be well presented and packaged and all complied reasonably well with IFCC guidelines on packaging and labelling. The most frequent omission was quality control material, available as a separate item in most cases. Imprecision was acceptable for most kits evaluated. CVs for total PSA ranged from 2.9 to 20.2% between assay and 1.5 to 8.6% within assay. CVs for free PSA ranged from 2.3 to 14.4% between assay and 0.6 to 7.8% within-assay. As may be expected, the automated assays gave the better results. Linearity of dose response was acceptable for all the kits evaluated. No high dose hook was seen up to a level of 5,000 ng/ml for total and free PSA assays in all the kits evaluated with the exception of the ELECSYS free PSA assay where a spurious result was observed at a level of 500 ng/ml. Clinical sensitivity for prostate cancer (CaP) (total PSA 20 ng/ml) varied considerably throughout the series of kits evaluated. Sensitivity ranged from an unacceptable 3% for the LIAISON free/total PSA assays to 91% for the IMMULITE free/total PSA assays. Clinical specificity for prostate cancer (CaP) (total PSA