The Southern Medical Journal (SMJ) is the official, peer-reviewed journal of the Southern Medical Association. It has a multidisciplinary and inter-professional focus that covers a broad range of topics relevant to physicians and other healthcare specialists.

SMJ // Article

Editorial

The Macroprolactinemia Problem and Its Solution

Authors: Michael Fahie-Wilson, MPhil, MRSc

Abstract

Symptoms of the hyperprolactinemic syndrome (menstrual disturbance, infertility and galactorrhea in women, impotence and loss of libido in men) are common and nonspecific and in the investigation of patients with these symptoms much depends on the measurement of serum prolactin (PRL) concentration. This is especially true of the diagnosis of prolactinoma because confirmatory imaging techniques are insensitive and nonspecific. Unfortunately immunoassays for serum prolactin are also nonspecific; in addition to detecting the free, monomeric form of circulating PRL, immunoassays also react with a high molecular mass complex of PRL, macroprolactin or big-big PRL, which has minimal bioactivity in vivo. In some individuals, as in the case reported in this issue by Khandwala et al, macroprolactin is the predominant form of circulating immunoreactive PRL (macroprolactinemia) and, if the cause is not recognized, the coincidence of apparent hyperprolactinemia and symptoms of the hyperprolactinemic syndrome can lead to misdiagnosis and mistreatment, unnecessary concern for patient and physician and waste of healthcare resources.1

This content is limited to qualifying members.

Existing members, please login first

If you have an existing account please login now to access this article or view purchase options.

Purchase only this article ($25)

Create a free account, then purchase this article to download or access it online for 24 hours.

Purchase an SMJ online subscription ($75)

Create a free account, then purchase a subscription to get complete access to all articles for a full year.

Purchase a membership plan (fees vary)

Premium members can access all articles plus recieve many more benefits. View all membership plans and benefit packages.

References

1. Suliman AM, Smith TP, Gibney J, et al. Frequent misdiagnosis and mismanagement of hyperprolactinemic patients before the introduction of macroprolactin screening: application of a new strict laboratory definition of macroprolactinemia. Clin Chem 2003;49:1504–1509.
 
2. Whittaker PG, Wilcox T, Lind T. Maintained fertility in a patient with hyperprolactinemia due to big, big prolactin. J Clin Endocrinol Metab 1981;53:863–866.
 
3. Soong YK, Ferguson KM, McGarrick G, Jeffcoate SL. Size heterogeneity of immunoreactive prolactin in hyperprolactinaemic serum. Clin Endocrinol (Oxf) 1982;16:259–265.
 
4. Fahie-Wilson M, John R, Ellis AR. Macroprolactin; high molecular mass forms of circulating prolactin.Ann Clin Biochem 2005;42:175–192.
 
5. Gibney J, Smith TP, McKenna TJ. Clinical relevance of macroprolactin. Clin Endocrinol (Oxf)2005;62:633–643.
 
6. Smith TP, Suliman AM, Fahie-Wilson MN, McKenna TJ. Gross variability in the detection of prolactin in sera containing big big prolactin (macroprolactin) by commercial immunoassays. J Clin Endocrinol Metab 2002;87:5410–5415.