Sertoli cell only syndrome: Status of sertoli cell maturation and function

Mature and functional Sertoli cells are essential for the survival of germ cells in testes. In Sertoli cell only syndrome (SCOS), there is no germ cells. Then, question arises whether absence of germ cells in SCOS secondary to Sertoli cells immaturity or mal function. Sertoli cells maturational and functional status is unclear in SCOS. This study investigated status of maturation and function of Sertoli cells in patients with SCOS.

The present study was comprised of 37 cases of SCOS and 50 normal control males. Detailed clinical examination and investigation were carried out as per pre-determined proforma. Semen analysis, hormonal analysis (FSH, LH, testosterone, etc.), and fine needle aspiration cytology (FNAC) of testes (bilateral) were performed. Fluorescence in situ hybridization (FISH) with XY probes was carried out in addition to conventional chromosome analysis to find out chromosomal abnormalities, in particular sex chromosome aneuploidy, including mosaicism. Yq microdeletion status was also investigated. The anti-mullerian hormone (AMH), inhibin B, and seminal lactate were estimated by ELISA methods.

The study did not find any case of high AMH. About 78% cases had low inhibin B, and 60% had low AMH. FSH was high in about 78% cases. Low level of lactate was found in 49% cases. There was one case of high level of inhibin B. There were 6 (16.2%) cases of chromosomal abnormality (2 mosaic Klinefelter and 4 Klinefelter syndrome) and 4 (10.8%) cases of Yq microdeletion.

We conclude that Sertoli cell immaturity does not play any role in SCOS (no case of high AMH). It seems, in majority cases, Sertoli cells are functionally- and/or numerically-deficient (low inhibin B, AMH and lactate). However, in about 22% cases, Sertoli cell function and/or number remains normal (normal inhibin B, AMH). Inhibin B and FSH seems best predictor/marker of Sertoli cell function.