MACROPROLACTINAEMIA IN A 33-YEAR OLD PREMENOPAUSAL NIGERIAN WOMAN: A CASE REPORT

Okpara H.C, Agan T.U, Ekanem E.C, Akpan U.B, Enang O.E

Available online Jul 18, 2018.

[ Report ] Volume 25, Issue 4, 2016, Pages 391-394


Abstract

BACKGROUND: Macroprolactin is a 150-170kDa heteropolymeric complex of monomeric prolactin and
immunoglobulin G (IgG) that contributes less than 1% of circulating prolactin concentration in plasma. It exerts
little or no biological action in vivo. Its elevated plasma concentration (macroprolactinaemia) is a notable cause of
frequent misdiagnosis, unnecessary investigation, and inappropriate treatment in patients with biochemical
hyperprolactinaemia.
OBJECTIVE: To highlight the need for macroprolactin screening in premenopausal women with biochemical
hyperprolactinaemia.
METHOD: We report an investigated case of macroprolactinaemia in a 33-year old premenopausal nulliparons
woman with sustained hyperprolactinaemia, normoovulatory and regular menstrual cycles, and no radiological
evidence of pituitary tumour (prolactinoma).
RESULT: The patient had persistent hyperprolactinaemia even after treatment with bromocriptine for 1month.
The menstrual cycle remained regular with clinical and biochemical presumptive evidence of ovulation.
CONCLUSION: Macroprolactinaemia is a potential cause of (pseudo) hyperprolactinaemia in women of
childbearing age. Its occurrence should be suspected and investigated especially in patients with
hyperprolactinaemia and regular normoovulatory cycles. The polyethyleneglycol (PEG) precipitation test is a
simple and cost-effective screening test for macroprolactinaemia.


Keywords

Prolactin, hyperprolactinaemia, macroprolactin, macroprolactinaemia,