Included were 94 prepubertal cryptorchid boys 0.5–13.1 years with measurements of serum-inhibin-B, Anti-Müllerian-Hormone (AMH), Luteinizing Hormone (LH) and Follicle Stimulation Hormone (FSH). The serum values were measured using commercially available kits. The hormonal values were related to age-matched normal values. Testicular biopsy was taken at orchiopexy.
Inhibin-B positively correlated to AMH for 1–13 year-old patients (p < 0.0001), but not for 0.5–1 year-old patients (p = 0.439). For 0.5–1 year-old patients inhibin-B-values tended to decrease (p = 0.055), in contrast to AMH-values (p = 0.852).
LH was elevated more often than FSH (p = 0.014). FSH and LH were positively associated in patients both 0.5–1 year (p = 0.042) and 1–13 years of age (p < 0.0001). LH correlated positively to inhibin- B (p = 0.001). In contrast, FSH did not correlate to inhibin-B or AMH (p = 0.755 and p = 0.528). The number of A-dark spermatogonia per tubular transverse section was positively correlated to inhibin-B serum level.
Our new finding of an association between LH and inhibin-B in infancy of cryptorchid boys may be essential for the transformation of gonocytes to A-dark spermatogonia. Previously, LH associated to inhibin-B was described in early puberty only. During the first year of life inhibin-B values decreased faster than AMH. The AMH-levels may just reflect the increased Sertoli cell number that occurs during the first 3 months of life.