ABSTRACT
BACKGROUND: Serum prostate specific antigen (PSA) is used as a marker for early diagnosis, monitoring of therapy, and detection of recurrence of the prostatic tumor or benign prostatic hyperplasia (BPH). In Korea, over 15 instruments have been used for measuring PSA. In this study, chemiluminescence microparticle immunoassay Architect total PSA (Abbott Lab., Abbott Park, IL, USA) was evaluated for analytical performance and diagnostic usefulness as a marker for prostate cancer. METHODS: The within-run and between-run precision, lower detection limits, correlation with AxSYM total PSA (Abbott Lab., Abbott Park, IL, USA) and clinical investigation were evaluated. Three level control serums (0.5, 4.0, and 23.0 ng/mL) were used for a precision test. The linearity was evaluated using a patient serum sample with a PSA concentration of 100 ng/mL. Functional and analytical sensitivities were tested using a patient serum sample with a PSA concentration of less than 0.1 ng/ mL and saline. A correlation study with AxSYM total PSA was done with 42 serum samples. Clinical evaluation was done with 230 patients of whom 17 had prostate cancer. RESULTS: The total PSA showed a good precision result with less than 5 % of CV and showed linearity to 100 ng/mL. The functional sensitivity was 0.025 ng/mL and analytical sensitivity 0.001 ng/mL. The correlation evaluation showed Y (Architect)=1.0575X(AxSYM)+0.1895, r=0.9960. A Cut-off value of 8.35 ng/mL showed 88.2% sensitivity, 80.3% specificity as a diagnostic marker for prostate cancer. CONCLUSIONS: Architect total PSA showed an acceptable analytical performance with its high sensitivity and could be a useful marker for early detection and recurrence of prostate cancer.