High diagnostic accurency of subcutaneous Triptorelin test with GnRH test for diagnosing central precocious puberty in girls

FREIRE, ANALÍA; ESCOBAR, MARÍA EUGENIA; GRYNGARTEN, MIRTA; ARCARI, ANDREA; BALLERINI MG; BERGADÁ, IGNACIO; ROPELATO MARIA GABRIELA

CLINICAL ENDOCRINOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2013 vol. 78 p. 398 - 404

0300-0664

Context The GnRH test is the gold standard to confirm the diagnosis of central precocious puberty (CPP); however, this compound is not always readily available. Diagnostic accuracy of subcutaneous GnRH analogues tests compared to classical GnRH test has not been reported. Objective To evaluate the diagnostic accuracy of Triptorelin test (index test) compared to the GnRH test (reference test) in girls with suspicion of CPP. Design A prospective, case?control, randomized clinical trial was performed. CPP or precocious thelarche (PT) was diagnosed according to maximal LH response to GnRH test and clinical characteristics during follow-up. Patients and Interventions Forty-six girls with premature breast development randomly underwent two tests: (i) intravenous GnRH 100 lg, (ii) subcutaneous Triptorelin acetate (01 mg/m2, to a maximum of 01 mg) with blood sampling at 0, 3 and 24 h for LH, FSH and estradiol ascertainment. Measurements Gonadotrophins and estradiol responses to Triptorelin test were measured by ultrasensitive assays. Results Clinical features were similar between CPP (n = 33) and PT (n = 13) groups. Using receiver operating characteristic curves, maximal LH response (LH-3 h) under Triptorelin test 7 IU/l by immunofluorometric assay (IFMA) or 8 IU/l by electrochemiluminescence immunoassay (ECLIA) confirmed the diagnosis of CPP with specificity of 100 (95% CI: 075?100) and sensitivity 076 (95% CI: 058?089). Considering either LH- 3 h or maximal estradiol response at 24 h (cut-off value, 295 pM), maintaining the specificity at 100, the test sensitivity increased to 094 (95% CI: 080?099) and the diagnostic efficiency to 96%.Conclusion The Triptorelin test had high accuracy for the differential diagnosis of CPP vs PT in girls providing a valid alternative to the classical GnRH test. This test also allowed a comprehensive evaluation of the pituitary?ovarian axis.