CONICET | Buscador de Institutos y Recursos Humanos

Although rare in boys, CPP is an interesting model to evaluate the regulation of Sertoli cells. To date, only one study has partially characterized Sertoli cell function in CPP (Rey et al. 1993). To further characterize Sertoli cell function in CPP, five boys (4.3 ±1.2 yr) with CPP were included in this retrospective, observational study. Measurements of LH, FSH, inhibin B [InhB], AMH and testosterone [T] were performed before, during, and after monthly GnRHa treatment discontinuation (triptorelin acetate 110-190 mcg/kg). Pre-treatment testis volume (TV) was 6.6 ± 1.0 ml, and LH 3.8 ± 1.4 IU/l, FSH 1.5 ± 0.4 IU/l, T 357 ± 99 ng/dl. Sertoli cells function was assessed by measuring serum InhB and AMH. Pre-treatment InhB was elevated (396 ± 57 pg/ml) and AMH was low (87 ± 27 pmol/l) for chronological age. During treatment, LH, FSH and T returned to prepubertal values. TV persisted moderately increased (4.5 ± 0.8 ml), and InhB decreased to the upper normal prepubertal range (201 ± 37 pg/ml). AMH increased and remained at prepubertal levels (618 ± 78 pmol/l) throughout treatment. After treatment discontinuation, LH, FSH, T and InhB increased again to pubertal levels while AMH decreased, as expected. In summary, like in normal puberty, CPP induces pubertal Sertoli cell maturation (increase in InhB and decrease in AMH). GnRHa treatment curtails FSH, LH and T secretion, resulting in AMH normalization. However, InhB remains in the upper normal range, in correlation with the persistence of moderately elevated TV, probably reflecting an increased mass of Sertoli cells that is not restored to prepubertal values. In conclusion, this clinical model supports the hypothesis that peripheral InhB levels represent the result of two pools, one regulated by gonadotropins and the second to the mass effect of the prepubertal Sertoli cell population.