title: High diagnostic accuracy of subcutaneous Triptorelin test compared with GnRH test for diagnosing central precocious puberty in girls.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  METHODS
  Forty-six girls with premature breast development randomly underwent two tests: (i) intravenous GnRH 100 μg, (ii) subcutaneous Triptorelin acetate (0.1 mg/m(2), to a maximum of 0.1 mg) with blood sampling at 0, 3 and 24 h for LH, FSH and estradiol ascertainment.
  
  
  METHODS
  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 1.00 (95% CI: 0.75-1.00) and sensitivity 0.76 (95% CI: 0.58-0.89). Considering either LH-3 h or maximal estradiol response at 24 h (cut-off value, 295 pm), maintaining the specificity at 1.00, the test sensitivity increased to 0.94 (95% CI: 0.80-0.99) and the diagnostic efficiency to 96%.
  
  
  CONCLUSIONS
  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.
authors: Hospital de Niños Dr. Ricardo Gutiérrez, División de Endocrinología, Centro de Investigaciones Endocrinológicas (CEDIE), Buenos Aires, Argentina.
authors: Analía Verónica
authors: AV
authors: Freire
authors: María Eugenia
authors: ME
authors: Escobar
authors: Mirta Graciela
authors: MG
authors: Gryngarten
authors: Andrea Josefina
authors: AJ
authors: Arcari
authors: María Gabriela
authors: MG
authors: Ballerini
authors: Ignacio
authors: I
authors: Bergadá
authors: María Gabriela
authors: MG
authors: Ropelato
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives; D006801:Humans; D011629:Puberty, Precocious / Q000097:blood / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D017329:Triptorelin Pamoate
chemical_list: D017329:Triptorelin Pamoate; D007987:Gonadotropin-Releasing Hormone