Prevalence of Macroprolactinemia by Polyethyleneglycol Precipitation Method: A Cross-sectional Study
Introduction: Macroprolactin, an immunoreactive molecule resulting from association of monomeric Prolactin (mPRL) and immunoglobulin G is a significant cause of misdiagnosis, unnecessary radiological investigation and treatment for hyperprolactinaemia. Data on its prevalence and clinical manife...
Main Authors: | , , , , |
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Format: | Article |
Language: | English |
Published: |
JCDR Research and Publications Pvt. Ltd.
2021-07-01
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Series: | National Journal of Laboratory Medicine |
Subjects: | |
Online Access: | http://www.njlm.net/articles/PDF/2515/48777_CE[Ra1]_F(SHU)_PF1(SY_SL)_PFA(SY_KM)_PN(KM).pdf |
Summary: | Introduction: Macroprolactin, an immunoreactive molecule
resulting from association of monomeric Prolactin (mPRL)
and immunoglobulin G is a significant cause of misdiagnosis,
unnecessary radiological investigation and treatment for
hyperprolactinaemia. Data on its prevalence and clinical
manifestation varies regionally. Case presentation can vary with
assymptomatic cases to those with galactorrhea and irregular
menses.
Aim: The study aimed to find the prevalence and clinical features
associated with macroprolactin in cases of hyperprolactinaemia
in hospital patients.
Materials and Methods: A cross-sectional study was conducted
in the Department of Biochemistry, Institute of Post Graduate
Medical Education and Research and SSKM hospital, Kolkata
from November 2018 to April 2019. Serum samples were assayed
for serum PRL levels in 1400 subjects by Chemiluminescence
immunoassay (Immulite 1000 Siemens) based on presenting
symptoms of galactorrhoea, amenorrhoea and infertility. Serum
PRL samples (n=240) above the manufacturer’s reference cutoff level (PRL ≥30 ng/mL) were obtained from patients with or
without symptoms of hyperprolactinemia. Retesting for PRL
levels were done following precipitation of macroprolactin
using Polyethylene Glycol (PEG, MW: 6000). Fourty cases with
physiological causes of PRL excess, hypothyroidism, Polycystic
ovary syndrome, antidopaminergic drug intake, hepatorenal
diseases and chest wall disorders were excluded. The results
were expressed in terms of Mean±Standard Deviation (SD) and
compared using student t-test.
Results: Prevalence of macroprolactin was 13.9% (16/120)
among true hyperprolactaemic cases (male=2; female, n=14)
based on percentage recovery of PRL in post-PEG cases
(Recovery Rate (RR) <40%). The mean pre-PEG and post-PEG
values were 52.5 ng/mL and 19.2 ng/mL (RR: 36.5%; p-value
<0.05), respectively. The mean pre PEG, PRL values were
significantly lower in macroprolactaemic cases than those with
true hyperprolactinaemia (52.5 ng/mL versus 74.57ng/mL; p-value
0.038). Some of the Macro-PRL cases reported with complaints
of galactorrhoea, menstrual irregularities and infertility.
Conclusion: The results revealed a prevalence rate similar to
those reported in other studies worldwide. Clinical features alone
are an unreliable tool to distinguish between cases with true
high PRL levels and macroprolactinaemia. Macro-PRL cases
once diagnosed requires no extended endocrine review and
long term management. Hence, in cases with high PRL levels
discordant with clinical symptoms/radiological data routine PEG
precipitation test is an inexpensive assay for initial screening
for presence of macroprolactin and also monitoring of patients
already started on dopamine agonists for hyperprolactinaemia
of unknown aetiology. |
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ISSN: | 2277-8551 2455-6882 |