ESPE Abstracts (2022) 95 P1-342

ESPE2022 Poster Category 1 Pituitary, Neuroendocrinology and Puberty (77 abstracts)

Redefinition of LH Cut-Off to Earlier Diagnose Evolutive Precocious Puberty After Triptorelin Stimulation Test

Paolo Cavarzere 1 , Marta Arrigoni 1 , Chiara Guardo 1 , Rossella Gaudino 2 & Franco Antoniazzi 2

1Pediatric Division, Department of Pediatrics, University Hospital of Verona, Verona, Italy; 2Pediatric Section, Department Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, Verona, Italy

Introduction: Precocious puberty (PP) is defined as the appearance of thelarche before the age of 8 years, in girls. The gold standard for the diagnosis is represented by the increase of LH level after stimulation with native GnRH, but a feasible alternative involves the administration of GnRH analogues. This test is poorly standardised and currently literature lacks of defined values to confirm the activation of the hypothalamic-gonadal axis, since they depend on the type of stimulus and on the methods used. Since 2002, in Verona, Italy, triptorelin has been used as analogous, with a LH cut-off of 15 IU/l measured 4 hours after the stimulus. Nevertheless, many girls have recently presented LH values below the cut-off despite signs of pubertal progression.

Aims: To identify a new threshold of LH post triptorelin stimulation to allow an earlier diagnosis of PP in girls with pubertal progression; to verify whether other parameters, such as the longitudinal diameter of the uterus, the bone age progression and estradiol levels after the assay, can be considered a valuable method to refine the diagnostic process.

Methods: We enrolled 186 females meeting the following criteria: thelarche onset between 4-8 years and GnRH analogue assay performed between 2015-2019 without showing any activation of the axis. 62 patients of this cohort repeated a triptorelin test due to a rapid clinical progression of puberty. The GnRH analogue assay was performed by injecting 100 mg/m2 of triptorelin and measuring LH, FSH and estradiol levels before and four hours after the stimulus. All females underwent clinical evaluation, pelvic ultrasonography, and bone age.

Results: Patients presenting an activation of the axis at the second assay showed retrospectively significantly higher levels of post-stimulus LH at the first test when compared to those whose LH was inferior than 15 IU/l at the second test. They had significantly higher basal levels of LH, LH/FSH ratio and growth velocity. Statistical analysis led us to the identification of a new threshold for post-stimulus LH of 8.5 U/l (sensitivity: 83%, specificity: 76%, negative predictive value: 98%).

Conclusions: A post-stimulus LH value of 8.5 IU/l after triptorelin administration has been identified as the new cut-off to allow a diagnosis of PP in the early stages of hypothalamic-gonadal axis activation avoiding the repetition of the test for the progression of pubertal clinical signs. On the contrary, the other parameters analysed did not result conclusive for the diagnosis.

Volume 95

60th Annual ESPE (ESPE 2022)

Rome, Italy
15 Sep 2022 - 17 Sep 2022

European Society for Paediatric Endocrinology 

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