Circulating anti-prolactin auto-antibodies must be considered in the differential diagnosis of hyperprolactinaemia in adolescents.
In four adolescents (two girls and two boys), who were investigated for galactorrhoea or short stature, we found moderately elevated serum prolactin (PRL) levels, but without a decreased gonadotropin and sex hormone production. Serum PRL levels were not responding to the intravenous injection of thyrotropin releasing hormone. Magnetic resonance imaging of the hypothalamic-pituitary region revealed no abnormality. Initial diagnoses were idiopathic and drug-induced hyperprolactinaemia. The presence of anti-prolactin auto-antibodies was suspected because of low recovery of PRL after precipitation with polyethylene glycol and confirmed by immunoprecipitation with anti-human IgG-agarose.


CONCLUSIONS
anti-prolactin auto-antibodies causing high prolactin values in some immunoassays can cause hyperprolactinaemia in adolescents without other signs of hormonal disturbances or auto-immune disease.
Vanbesien
Jesse
J
Department of Paediatrics, Academic Hospital VUB, Laarbeeklaan 101, 1090 Brussels, Belgium.
Schiettecatte
Johan
J
Anckaert
Ellen
E
Smitz
Johan
J
Velkeniers
Brigitte
B
De Schepper
Jean
J
D000293:Adolescent; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D015415:Biomarkers / Q000032:analysis; D005260:Female; D006801:Humans; D006966:Hyperprolactinemia / Q000175:diagnosis* / Q000276:immunology*; D008297:Male; D011388:Prolactin / Q000097:blood* / Q000276:immunology; D011863:Radioimmunoassay; D012494:Sampling Studies; D012680:Sensitivity and Specificity
D001323:Autoantibodies; D015415:Biomarkers; D011388:Prolactin