Serum FSH levels and testicular histology in infertile men with non obstructive azoospermia and Y chromosome microdeletions

Abstract

Objectives: Men with nonobstructive azoospermia may father a child through intracytoplasmic injection of testicular sperms. This can result in transmission of genetic defects such as Y chromosome microdeletions which primarily caused the infertility and occur in up to 55% such men. It may not be feasible to screen all patients for Y chromosome microdeletions due to the cost and technical difficulty. A correlation with existing markers such as follicle stimulating hormone (FSH) and testicular histology may help identify a subgroup for screening. We therefore studied the association between regions of azoospermia factor (AZF) deletion, testicular histology and serum FSH level in men with nonobstructive azoospermia. Materials and Methods: One hundred and nine men presenting with primary infertility and diagnosed as nonobstructive azoospermia based on standard guidelines were included in the study. Fasting blood sugar, serum FSH, testosterone and prolactin estimation was done and testicular fine needle aspiration biopsy was performed where clinically indicated. Patients with normal karyotype on standard Q banding (n=82) were evaluated for microdeletions in the Y chromosome. Eight AZF loci which mapped to interval 5 and 6 of the Y chromosome were evaluated. Results: Microdeletions were found in seven of 82 men with normal karyotype (8.5%). Three patients had deletions in both AZFa and AZFb regions with Sertoli cell only (SCO) histology. Two had AZFc deletion with hypospermatogenesis and maturation arrest in one each. Two patients had cryptorchidism. FSH levels were higher (mean 38.77 mIU/ml) in patients with deletions in the AZFa and AZFb regions than in those with AZFc deletions (mean 5.86 mIU/ml). In patients without a deletion, FSH was higher in the group with SCO (mean 18.28 mIU/ml) compared to those with hypospermatogenesis or maturation arrest (mean 6.83 mIU/ml). Conclusions: Serum FSH is raised in patients with severely depleted germ cell function, irrespective of the presence or absence of a microdeletion. The levels may correlate with the region of deletion in that the patients with AZFa and AZFb deletion had a sertoli cell only picture on histology and raised FSH.