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Tracking Macroprolactin: Use of an Optimized Polyethylene Glycol Precipitation Method More Compatible with the

Julien Favresse1, Pierre Bastin1, Catherine Fillée1

  • 1Department of Laboratory Medicine, St-Luc University Hospital and Catholic University of Louvain, Brussels, Belgium.

The Journal of Applied Laboratory Medicine
|December 31, 2020
PubMed
Abstract

Insights

Macroprolactin (MPRL) is a large prolactin form that can cause false hyperprolactinemia diagnoses. An optimized polyethylene glycol (PEG) precipitation method improves MPRL screening in core laboratories.

Area of Science:

  • Clinical Chemistry
  • Endocrinology
  • Laboratory Medicine

Background:

  • Macroprolactin (MPRL) is a large, potentially inactive prolactin variant.
  • MPRL interferes with standard immunoassays, leading to misdiagnosis of hyperprolactinemia.
  • Misdiagnosis results in unnecessary patient investigations and treatments.

Purpose of the Study:

  • To develop an optimized polyethylene glycol (PEG) precipitation method for macroprolactin detection.
  • To adapt the method for automated core laboratory settings.
  • To improve the accuracy of hyperprolactinemia diagnosis.

Main Methods:

  • Compared a rapid, high-g force PEG precipitation (2 min, 19744g) with a standard method (30 min, 1500g).
  • Assessed the long-term stability of PEG solutions.
  • Evaluated post-PEG prolactin concentrations and compared them to classic recovery calculations.

Main Results:

  • The optimized PEG method showed excellent agreement with the standard procedure (slope=1.00, y-intercept=-0.8 ng/mL).
  • PEG solutions remained stable for at least 261 days.
  • Post-PEG reference values correlated better with clinical symptoms than recovery calculations.

Conclusions:

  • An optimized PEG precipitation method is suitable for core laboratories.
  • The method offers a stable PEG solution, reduced sample volume, and no incubation time.
  • This optimized screening method can aid in the widespread detection of macroprolactinemia.

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