Clinical Significance and Pathogenesis of Macroprolactinemia

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SAT 498-531-Female Repro Endocrinology & Case Reports
Saturday, June 15, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SAT-527
Osamu Hiraike*1, Haruko Hiraike2, Kohzo Aisaka2, Hiroe Hyodo2, Seiichiro Obata2, Hironobu Hyodo3 and Naoki Hattori4
1The University of Tokyo, Tokyo, Japan, 2Hamada Hospital, Tokyo, Tokyo, Japan, 3St. Luke's International Hospital, Tokyo, Tokyo, Japan, 4College of Pharmaceutical Scie, Kusatsu-City, Shiga, Japan
Objectives: Macroprolactin, which comprises immunoglobulin G (IgG) or anti-prolactin (PRL) autoantibody-bound PRL, is one of the causes of hyperprolactinemia. The present study was performed to elucidate the prevalence and clinical significance of macroprolactinemia in patients with ovarian dysfunction.

 Methods: Six hundred and sixty-two patients with ovarian dysfunction (age: 36.3±7.9 years old) were subjected under the enough informed consent. Macroprolactinemia was defined by PEG-precipitable PRL ratio greater than 60% (recovery less than 40%). IgG-bound PRL ratios were evaluated by protein G column method. PRL concentrations were measured by enzyme immunoassay.

 Results: Plasma PRL levels ranged from 0.5 to 133.2ng/ml (12.3±8.6ng/ml). There were 15 patients (2.3%) of macroprolactinemia as diagnosed by PEG-precipitation and protein G methods. None of the patients of macroprolactinemia had previous histories of amenorrhea or galactorrhea, however, two patients had the previous history of abortion. Hyperprolactinemia occurred more frequently in macroprolactinemic subjects (9/15, 60.0%) than non-macroprolactinemic ones (46/647, 5.17%, Chi-square=53.83, p<0.0001). The treatment of dopamine agonists was much effective in the patients of hyperprolactinemia by decreasing their plasma PRL levels, however, they were not effective in the patients of macroprolactinemia without hyperprolactinemia.

 Conclusions: This study showed that there were some patients with macroprolactinemia at a constant rate in patients with ovarian dysfunction, and also showed that dopamine agonists were not effective to the patients without hyperprolactinemia. Plasma PRL levels should be evaluated with PEG-precipitable PRL ratio and IgG-bound PRL levels to avoid the useless administration of dopamine agonists.

(1) Hattori N et al., Eur J Endocrinol. 2012; 166:625. (2) Hattori N et al., Clin Endocrinol (Oxf). 2010; 73:792. (3) Hattori N et al., Clin Endocrinol (Oxf). 2009; 71:702. (4) Hattori N et al., Clin Endocrinol (Oxf). 2008; 68:72.

Nothing to Disclose: OH, HH, KA, HH, SO, HH, NH

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