Seminal plasma lipocalin-type prostaglandin D synthase: A potential new marker for the diagnosis of obstructive azoospermia

Purpose: We examined the relationship between L-PGDS (lipocalin-type prostaglandin D synthase) levels in seminal plasma and the presence or absence of obstruction in the male seminal tract. Materials and Methods: Semen samples were collected and analyzed from 1) 10 patients with normal semen parameters, 2) 9 with obstructive azoospermia, 3) 20 after vasectomy and 4) 14 with nonobstructive azoospermia. Seminal L-PGDS was measured using an enzyme-linked immunosorbent assay technique. Results: We found that seminal plasma L-PGDS in the groups with obstruction was significantly lower than in any of the other groups (p < 0.001). Using a cutoff of 100 mu g/l all men with obstructive azoospermia had L-PGDS less than 100 mu g/l, while none with normal sperm parameters did. Men with nonobstructive azoospermia had less homogeneity of L-PGDS levels, including 29.6% with L-PGDS more than 100 mu g/l. Conclusions: Our results suggest that seminal L-PGDS level can potentially be a biomarker for assessing patency in the seminal tract in men with azoospermia. In men with azoospermia and high seminal L-PGDS (more than 100 mu g/l) the diagnosis of nonobstructive azoospermia can be potentially made without biopsy. Our study shows that using semen L-PGDS levels provides a diagnosis of nonobstructive azoospermia in almost 30% of these men.