Association between seminal plasma neopterin and oxidative stress in male infertility: A case-control study

Neopterin is a significant and sensitive marker in estimating the activity of cellular immune system. Oxidative stress plays a role in the etiology of male infertility. Increased reactive oxygen species is accompanied with increase in neopterin level. Hence neopterin may be involved in male infertility.

The objective of this case-control study was to determine neopterin level in idiopathic infertile and normospermic men; furthermore, to identify its relationship with oxidative stress markers including total oxidant, malondialdehyde, sperm DNA fragmentation, and total antioxidant capacity of seminal plasma.

Forty seven infertile and forty three normospermic males were selected according to WHO criteria. Their semen and blood samples were taken; subsequently, the levels of neopterin, total oxidant, total antioxidant, malondialdehyde, and sperm DNA fragmentation were measured.

The levels of neopterin, total oxidant, and malondialdehyde in seminal plasma of infertile males were significantly higher than those of normospermic group (p=0.038, 0.018, and 0.028, respectively). Furthermore, sperm DNA fragmentation in infertile men was higher than that of control group (p<0.001). Moreover, total antioxidant capacity of seminal plasma in infertile males was significantly lower than that of normospermic subjects (p=0.002). No significant difference was observed in serum neopterin, total oxidant, and malondialdehyde between the infertile and normospermic groups.

The significant inverse correlation between seminal plasma neopterin and total antioxidant in the infertile males supports a possible role of neopterin in male infertility. Neopterin can be suggested as a marker in monitoring and diagnosis of idiopathic male infertility.