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.