A Study to Validate the Relevance of Semen F(2)-Isoprostanes on Human Male Infertility

F(2)-isoprostanes (F(2)-IsoPs), byproducts of arachidonic acid oxidation, are one of the most reliable indices for assessing lipid peroxidation in vivo. This study aimed at evaluating the seminal F(2)-IsoP level in 147 patients with different reproductive conditions (varicocele, urogenital infection, idiopathic infertility) and 45 fertile controls to establish a cut-off value discriminating physiological and pathological ranges. Semen analyses were performed following WHO guidelines; F(2)-IsoP levels were measured by gas chromatography/negative-ion chemical ionization tandem mass spectrometry. Considering the whole group of patients, F(2)-IsoPs correlated negatively with normal morphology (r = −0.283, p < 0.01), viability (r = −0.245, p < 0.01), total progressive motility (r = −0.309, p < 0.01) and rapid motility (r = −0.535, p < 0.01). The area under the ROC curve for F(2)-IsoP levels was 0.839, indicating a good performance of the test; the Youden index showed a cut-off value of 29.96 ng/mL. Fertile men (except one) were distributed in the group of patients with F(2)-IsoP level < 29.96 ng/mL. Varicocele and urogenital infection groups showed the highest levels of F(2)-IsoPs in semen. For the first time, a cut-off for F(2)-IsoPs is identified in human semen. It allows discriminating different male infertility conditions by the semen F(2)-IsoP amounts, as an additional parameter for clinical evaluation.