title: Seminal plasma lipocalin-type prostaglandin D synthase: a potential new marker for the diagnosis of obstructive azoospermia.
abstract: OBJECTIVE
  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.
  
  
  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 microg/l all men with obstructive azoospermia had L-PGDS less than 100 microg/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 microg/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 microg/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.
authors.affiliation: Department of Surgery (Division of Urology), Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Samy M
authors.initials: SM
authors.lastname: Heshmat
authors.forename: J Brendan
authors.initials: JB
authors.lastname: Mullen
authors.forename: Keith A
authors.initials: KA
authors.lastname: Jarvi
authors.forename: Antoninus
authors.initials: A
authors.lastname: Soosaipillai
authors.forename: Eleftherios P
authors.initials: EP
authors.lastname: Diamandis
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Hamilton
authors.forename: Kirk C
authors.initials: KC
authors.lastname: Lo
mesh_terms: D053713:Azoospermia / Q000175:diagnosis* / Q000209:etiology; D015415:Biomarkers / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000032:analysis*; D054834:Lipocalins / Q000032:analysis*; D008297:Male; D012661:Semen / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D054834:Lipocalins; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase