Autoantibody to human prolactin in patients with idiopathic hyperprolactinemia.
We have demonstrated the presence of anti-PRL autoantibody in 5 patients with idiopathic hyperprolactinemia. The clinical features were suggestive of a weak biological activity of PRL, such as regular menses and no galactorrhea. Total PRL levels were markedly elevated (685 +/- 386 micrograms/L) (mean +/- SD) and the proportion of the bound form was 90.7 +/- 7.1%. Scatchard analysis revealed a low-affinity, high-capacity antibody: the association constant was 0.73 +/- 0.56 x 10(7) mol-1 and the maximal binding capacity was 2139 +/- 1792 micrograms/L. Gel filtration study showed that a substantial amount of PRL (64.6 +/- 19.5%) was eluted at the position of 150,000-170,000 mol wt PRL (big-big PRL). Immunoprecipitation study using the chain-specific antibodies showed that the anti-PRL autoantibody belonged to kappa-type immunoglobulin G. These results may indicate that there exists autoantibody-related hyperprolactinemia, especially in those with particularly high serum PRL levels, who had previously been diagnosed as "idiopathic" hyperprolactinemia.
Hattori
N
N
Department of Endocrinology, Kobe City General Hospital, Japan.
Ishihara
T
T
Ikekubo
K
K
Moridera
K
K
Hino
M
M
Kurahachi
H
H
D000328:Adult; D001323:Autoantibodies / Q000032:analysis* / Q000276:immunology; D002850:Chromatography, Gel; D005260:Female; D006801:Humans; D006966:Hyperprolactinemia / Q000276:immunology*; D011233:Precipitin Tests; D011388:Prolactin / Q000276:immunology*; D012016:Reference Values
D001323:Autoantibodies; D011388:Prolactin