Tumoral versus non-tumoral hyperprolactinemia in children and adolescents: possible usefulness of the domperidone test.

UNLABELLED: The aim of this study was to evaluate the usefulness of the domperidone test for the difficult diagnosis between functional and tumoral hyperprolactinemia. We evaluated 36 patients, aged 5-18 years, 14 (12 F, 2 M) with hyperprolactinemia (non-tumoral: 10; pituitary adenoma: 4) and 22 individuals as a control group (prepubertal: 5 F, 8 M; pubertal: 4 F, 5 M). Basal prolactin (PRL) (IRMA-DPC), T4 and TSH and PRL 30 min post-domperidone (0.2 mg/kg b. wt i.v.) were measured. Non-tumoral hyperprolactinemic females showed basal PRL: 45 (29-80) (median and range) ng/ml; post-domperidone: 208 (116-290) ng/ml; delta PRL (PRL 30' - PRL 0'): 167 (77-252) ng/ml; and PRL ratio (PRL 30'/PRL 0'): 3.9 (2.3-7.6). Females with pituitary adenoma showed basal PRL: 129 (125-660) ng/ml; post-domperidone: 202 (150-535) ng/ml; delta PRL: 73 (25-135) ng/ml; and ratio: 1.2 (0.8-1.6). Two males, one with a non-tumoral hyperprolactinemia and the other one with a pituitary adenoma, presented, respectively, PRL 0':45, 160; PRL 30':130, 173; delta: 85, 13; ratio: 2.9, 1.1. All non-tumoral patients showed a PRL ratio (30'/0') > 2.3, while no patient with pituitary adenoma had a ratio > 1.6. CONCLUSIONS: PRL response to domperidone allowed us to characterize hyperprolactinemias, although the presence of a blunted response should be confirmed in a larger number of patients with tumors with 'low' PRL levels (dependence on etiology or basal PRL level?).

Basal ultrasensitive LH assay: a useful tool in the early diagnosis of male pubertal delay?

The aim of this study was to evaluate the usefulness of basal measurements of gonadotropins in distinguishing between constitutionally delayed puberty (DP) and hypogonadotropic hypogonadism (HH), comparing its diagnostic efficiency with that of the dynamic GnRH infusion test (0.83 microg/min during 120 min). We studied 20 males, chronological age (CA) 14-18 years, with a final diagnosis of DP (n = 8), partial HH (n = 5) and complete HH (n = 7), confirmed by follow-up. We also evaluated basal samples of ultrasensitive LH and FSH in 117 healthy control males (CA 2-19 yr), classified according to Tanner stage. In the control group, ROC plot analysis showed a cutoff to differentiate prepuberty from puberty of 0.65 IU/l for LH (sensitivity: 91%, specificity: 98%). Differences were found (p < 0.05) in basal LH and in maximal responses to GnRH in complete HH in relation to DP and partial HH. The diagnostic efficiency of the GnRH infusion test was 85%. For basal LH, a cut-off limit of 0.65 IU/l showed a diagnostic efficiency of 85% for complete HH and 100% for partial HH and DP. We conclude that, in our experience, basal LH levels above 0.65 IU/l measured by ultrasensitive assay would rule out a complete deficiency. It was not possible to differentiate DP from partial HH, either in basal samples or with the infusion test.