ESPE Abstracts

Background: Central precocious puberty (CPP) in girls is characterized by an activation of the hypothalamic–pituitary–ovarian (HPO) axis before 8 years of age. Given the gradual awakening of the GnRH pulse generator, a spectrum of presentations has been found among girls with premature sexual development. CPP are not easily distinguished from idiopathic precocious thelarche (PT) or other intermediate positions along this spectrum. The GnRH test is the gold standard to confirm the diagnosis of CPP. However, this test is not available in our department.

Objective and hypotheses: To evaluate the diagnostic accuracy of Triptorelin test in girls with suspicion of CPP.

Method: A prospective randomized clinical trial about 14 girls with premature breast development was performed. All patients underwent s.c. Triptorelin acetate test (0.1 mg/m², to a maximum of 0.1 mg) with blood sampling at 0, 3, and 24 h for LH, FSH, and estradiol ascertainment. CPP or PT was diagnosed according to maximal LH response to Triptorelin test and clinical characteristics during follow-up.

Results: Clinical features were similar between CPP (n=8) and PT (n=6) groups. Maximal LH response (LH, 3 h) under Triptorelin test ≥8 IU/l by ECLIA confirmed the diagnosis of CPP in all cases.

Conclusion: Triptorelin acetate is a therapeutic regimen to suppress the gonadotrophic axis. I has an acute stimulatory effect on the gonadotrophs when given as single dose, with gonadotrophins reaching maximum levels 3 h after administration. Owing to its longer half-life, this effect lasts at least 24 h, making possible to additionally evaluate the sex-hormone secretion by the gonads. The Triptorelin test had high accuracy for the differential diagnosis of CPP vs PT providing a valid alternative to the classical GnRH test.