Ultrastructural analysis of chromatin defects in testicular spermatids in azoospermic men submitted to TESE-ICSI

BACKGROUND: Testicular sperm extraction (TESE) combined with intracytoplasm ic sperm injection (ICSI) is offered to treat obstructive and non-obstructi ve azoospermia, but factors that influence the outcome of ICSI are not well defined. METHODS AND RESULTS: The percentage of elongated spermatids with normal chromatin condensation in azoospermic patients submitted for TESE-IC SI was determined. The quantitative analysis could be applied to nine of 19 biopsies classified as incomplete late maturation arrest (LMA) and compare d with 10 biopsies with normal spermatogenesis. The percentage of elongated spermatids with normal chromatin was lower in LMA than in normal histology (mean 4.4%, range 0-20, and mean 52.9%, range 40-70 respectively; P = 0.00 01), The percentage of elongated spermatids with normal chromatin was negat ively correlated with the serum concentration of FSH (r = -0.86, P < 0.0001 ) and the number of degenerated germ cells per 100 Sertoli cells nuclei (r = -0.68; P < 0.0001), while it was positively correlated with the number of elongating spermatids per 100 Sertoli cell nuclei (r = 0.81; P < 0.0001), The percentage of elongated spermatids with normal chromatin was not correl ated with the rate of oocyte fertilization, while the delivery rate/cycle w as higher in cases with normal histology compared with cases of LMA. CONCLU SIONS: These preliminary data suggest that an altered chromatin condensatio n is a ubiquitous defect in spermatids of non-obstructed azoospermic men su bmitted for TESE-ICSI.