Diagnostic value of the total antioxidant capacity (TAC) in human seminal plasma.

OBJECTIVE To establish cutoff value, sensitivity, specificity and intra- and interobserver variability of total antioxidant capacity (TAC) in seminal plasma from healthy donors (controls) and infertile patients. DESIGN Seminal plasma from proven fertile donors (n = 55), nonproven fertile donors (n = 45), and infertile patients (n = 42) were examined for TAC level. SETTING Reproductive research center in a tertiary care hospital. PATIENT(S) Infertile patients from male infertility clinic of various diagnoses. INTERVENTION(S) Seminal plasma TAC measurement by a colorimetric assay using the TAC assay kit, receiver operating characteristics curve. MAIN OUTCOME MEASURE(S) Seminal plasma TAC levels, cutoff value, sensitivity, and specificity. RESULT(S) Proven fertile donors showed higher TAC values (median and range): 1700 (1440-2290 microM); compared with the infertile patients: 1310 (1040-1600 microM). The best cutoff to distinguish between fertile controls and infertile men was 1420 microM. At this threshold, specificity was 64% and sensitivity 76%. CONCLUSION(S) Total antioxidant capacity of the seminal plasma as measured by the colorimetric assay is a reliable and simple test for the diagnosis and management of male infertility.