In-vitro spermatogenesis resumption in men with maturation arrest: relationship with in-vivo blocking stage and serum FSH

We have shown previously that germ cells recovered from some men with matur ation arrest can resume spermatogenesis in vitro and give rise to late elon gated spermatids. This study relates the ability of germ cells to different iate in vitro to the stage at which spermatogenesis is blocked in vivo and to the patient's serum FSH concentration. The presence of germ cells at dif ferent stages of spermatogenesis was assessed, before and after culture, by classical cytology, by fluorescence in-situ hybridization and by immunocyt ochemistry with a germline-specific marker. The proportion of eases of matu ration arrest at the primary spermatocyte, secondary spermatocyte and sperm atid stage in which in-vitro resumption of meiosis was achieved was 24.3% ( 9/37), 100% (3/3) and 51.1% (23/45) respectively. Serum FSH concentrations were higher than normal in most cases, However, lower values were measured in patients in whom in-vitro spermatogenesis was achieved compared with tho se in whom no progression was detected. These data show that, under the con ditions of this study, germ cells from men with very high serum FSH concent rations (>20 IU/l) are less likely to resume spermatogenesis in vitro than those coming from men with only moderate increase (10-20 IC/l).