Diagnostic Accuracy of Morning Salivary Cortisol in the Assessment of the Hypothalamic-Pituitary-Adrenal Axis Recovery after Prolonged Corticosteroid Therapy in Children.

INTRODUCTION: Assessment of the hypothalamic-pituitary-adrenal (HPA) axis is necessary after prolonged glucocorticoid therapy withdrawal. Salivary cortisol reflects 65% of the free circulating cortisol fraction. Saliva collection is non-invasive and child friendly. OBJECTIVE: We aimed to evaluate the diagnostic accuracy of morning salivary cortisol (mSAF) to determine HPA recovery after prolonged corticosteroid therapy in children. METHODS: We conducted a prospective, validation study in 171 paediatric patients (mean ± SD age: 13.0 ± 4.4 years) who received glucocorticoids for >4 weeks (median and interquartile range: 11 [7-14] months) and were referred for therapy withdrawal. Serum and saliva samples were collected between 8 and 9 a.m. on the same day. Cortisol was measured by an electrochemiluminescence immunoassay (ECLIA) 48 h after cessation of glucocorticoid therapy. Serum cortisol ≥193 nmol/L was used as the reference cut-off value for HPA recovery after glucocorticoid withdrawal and mSAF as the index test. RESULTS: The cut-off concentration obtained by ROC for mSAF was ≥5.0 nmol/L. True positive and true negative results were observed in 85/171 and 40/171 children, respectively. The false-positive rate was low (3/171, 1.7%); however, false-negative results were observed in 43/171 (25%) children. The main ROC results (95% CI) were area under curve: 0.98 (0.96-0.99), sensitivity: 0.66 (0.57-0.75), specificity: 0.93 (0.81-0.99), positive predictive value: 0.97 (0.90-0.99), negative predictive value: 0.48 (0.37-0.59), LR+: 9.5, and diagnostic accuracy: 73.1%. CONCLUSION: The present study supports that mSAF ≥5.0 nmol/L by ECLIA is a non-invasive biomarker for the assessment of HPA recovery after prolonged glucocorticoid therapy in paediatric patients, with a positive predictive value of 97%. This proposed cut-off should be further validated using gold standard techniques for steroid quantification such as liquid chromatography-tandem mass spectrometry.

Prevalence of Polycystic Ovarian Syndrome in Girls with a History of Idiopathic Central Precocious Puberty.

INTRODUCTION: The prevalence of polycystic ovarian syndrome (PCOS) in adolescent girls is between 1 and 4.3%. It remains controversial whether women with a history of idiopathic central precocious puberty (ICPP) are at increased risk for PCOS. Our objective was to assess the prevalence of PCOS in adolescents with a history of ICPP compared with healthy adolescents and the prevalence of PCOS among ICPP girls who have received or not gonadotropin-releasing hormone analogue (GnRHa) treatment. METHODS: We assessed post-menarcheal girls with a history of ICPP. Girls were evaluated at gynecological age ≥2.5 years. Data collected were age at menarche, menstrual cycle characteristics, BMI, clinical hyperandrogenism (HA), total and free testosterone levels. PCOS diagnosis was defined by criteria for adolescents. Subjects were also analyzed regarding whether or not they had received GnRHa treatment. RESULTS: Ninety-four subjects were assessed, and 63 had been treated with GnRHa. Menstrual disorders were found in 29%, clinical HA in 36%, and biochemical HA in 23%. Twelve percent met the diagnostic criteria for PCOS. There was no difference in BMI or in the incidence of menstrual dysfunction or hyperandrogenemia between treated and untreated patients. A higher proportion of clinical HA was found in untreated patients when compared to treated girls. The relative risk (RR) of developing PCOS in ICPP girls was 2.5 compared to a population of healthy adolescents. This RR was not higher in patients who received treatment with GnRHa than in those who did not. CONCLUSION: Adolescent girls with a history of ICPP have an increased risk of PCOS. This risk seems not to be related to GnRHa treatment.

Circulating IGF-I, IGFBP-3 and the IGF-I/IGFBP-3 Molar Ratio Concentration and Height Outcome in Prepubertal Short Children on rhGH Treatment over Two Years of Therapy.

OBJECTIVE: To investigate the occurrence of abnormally elevated values of biomarkers of growth hormone (GH) action in short children on recombinant human GH (rhGH) therapy. METHODS: Sixty-three prepubertal short children were examined: 31 with GH deficiency (GHD), 25 small for gestational age (SGA), and 9 with Turner syndrome (TS). The main outcomes were the following: standard deviation score (SDS) values of IGF-I, IGFBP-3, and IGF-I/IGFBP-3 molar ratio before, at the 1st and at the 2nd year on rhGH and Δheight (Ht)-SDS to evaluate GH treatment efficacy (adequate 1st-year ΔHt SDS: >0.4 SDS for GHD and >0.3 SDS for non-GHD). RESULTS: Seventy-eight percent of GHD, 78% of SGA and 55% of TS children had adequate 1st-year ΔHt SDS. In GHD, 88% of IGF-I SDS and IGFBP-3 SDS that were ≤-2.0 SDS at baseline normalized on treatment. Abnormal IGF-I values >+2.0 SDS were observed in 52% of SGA and in 55% of TS patients on rhGH. Within each group, the IGF-I/IGFBP-3 molar ratio increased significantly from pretreatment and throughout therapy, remaining within normal range for most patients. ΔIGF-I/IGFBP-3 molar ratio SDS were significantly higher in children with an adequate response (p < 0.01). CONCLUSION: Non-GHD groups presented markedly elevated concentrations of GH biomarkers on rhGH and normal IGF-I/IGFBP-3 molar ratio in most patients. Since there is a lack of consensus regarding the molar ratio usefulness, we think that interventions towards a more physiological IGF-I serum profile should be implemented.

Assessment of Estradiol Response after Depot Triptorelin Administration in Girls with Central Precocious Puberty.

BACKGROUND: Estradiol at baseline or after a classical gonadotropin-releasing hormone test did not reflect ovarian steroidogenesis in central precocious puberty (CPP) girls. AIMS: To evaluate estradiol response to depot triptorelin, both at start and during therapy to determine how active ovarian steroidogenesis is at pubertal stage and under therapy. METHODS: A prospective study was performed in 43 CPP girls. Serum luteinizing hormone and follicle-stimulating hormone at 3 h (LH-3h, FSH-3h) and estradiol at 24 h (E2-24h) after injection of depot triptorelin 3.75 mg were measured, at first dose and at 3, 6, 12, 18 and 24 months of treatment. RESULTS: E2-24h after depot triptorelin was >100 pg/ml after the first dose. Estradiol response (E2-24h) fell to levels <14 pg/ml in 78 out of 82 follow-up visits along 2 years of therapy. Concomitantly, LH-3h and FSH-3h were <4.0 and <6.3 IU/l, respectively. In 4 patients with inadequate treatment, E2-24h, LH-3h and FSH-3h rose to pubertal values similar to those observed at first dose. CONCLUSION: Estradiol (<14 pg/ml) assessment 24 h after depot triptorelin administration is a reliable and simple manner to confirm ovarian suppression in CPP girls during treatment.

Predicting hypocalcemia after thyroidectomy in children.

BACKGROUND AND AIMS: Hypocalcemia after thyroidectomy is caused by parathyroid trauma. There are no studies regarding the usefulness of intact parathyroid hormone (PTH) as a monitor of postoperative hypoparathyroidism tool in pediatrics. We evaluated the diagnostic accuracy of intra- and postoperative PTH to predict the risk of developing post thyroidectomy hypocalcemia in children. METHODS: A prospective longitudinal cohort study was conducted in 32 pediatric patients (3.2-17.6 years old) undergoing total thyroidectomy. Intact PTH measured by the assays (Immulite Immunoassay System [ICMA] or electrochemioluminescence assay [ECLIA]) at 5 (PTH-5) and 60 (PTH-60) minutes after thyroid removal were considered as predicting variables. The postoperative outcome was hypocalcemia (endpoint variable). Patients were clinically and biochemically monitored regularly for 48 hours after surgery. RESULTS: Of the patients, 47% developed hypocalcemia (15% symptomatic). An ICMA PTH-5 of ≤14 pg/mL or an ECLIA PTH-5 of ≤16 pg/mL predicted hypocalcemia with a sensitivity of 80%, specificity of 100%, positive predictive value (PPV) of 100%, and diagnostic efficiency (DE) of 91%. Using the same cutoff values, PTH-60 presented a sensitivity of 93%, specificity of 82%, PPV of 81%, and DE of 87%. Adjusting for variation in the assays and combining intra- and postoperative PTH determinations, we developed an algorithm that improved sensitivity, specificity, and DE. CONCLUSION: PTH is useful for predicting hypocalcemia after total thyroidectomy in children. The use of our proposed strategy should be considered to (a) initiate preventive treatment in patients identified at high risk for hypocalcemia, (b) shorten the duration of hospitalization, and (c) reduce the clinical and biochemical controls in those who remained normocalcemic.

High diagnostic accuracy of subcutaneous Triptorelin test compared with GnRH test for diagnosing central precocious puberty in girls.

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 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. 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 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%. 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.