Related Experiment Video
Updated: Jun 18, 2026
MALDI Imaging Mass Spectrometry of Neuropeptides in Parkinson's Disease
Published on: February 14, 2012
Comparison of multiple methods for identification of hyperprolactinemia in the presence of macroprolactin
Christopher R McCudden1, Julie L Sharpless, David G Grenache
1Department of Pathology and Laboratory Medicine, University of North Carolina, School of Medicine, CB #7525, Chapel Hill, NC 27599-7525, United States. cmccudde@unch.unc.edu
Background:
Macroprolactin is a large, heterogeneous form of prolactin with limited bioavailability. Detection of macroprolactin by different immunoassays varies widely. The objectives of this study were to determine the immunoreactivity of macroprolactin by the Ortho Clinical Diagnostics Vitros((R)) ECi prolactin immunoassay, establish the most effective method for interpreting the prolactin concentration after PEG-precipitation, and correlate the clinical features of hyperprolactinemia with the presence of macroprolactin.
Methods:
PEG-precipitation was performed on 120 hyperprolactinemic specimens. Of these, 31 specimens with a recovery<80% were fractionated by GFC. Four different approaches for identifying true hyperprolactinemia were investigated. Clinical symptoms of hyperprolactinemia were determined by chart review.
Results:
Macroprolactin was detected by the Vitros ECi prolactin immunoassay. Use of a PEG modified prolactin reference interval was effective for identifying hyperprolactinemia in the presence of macroprolactin. There was no difference in the prevalence of abnormal menses, galactorrhea, or abnormal MRI between those with and without macroprolactin (p>0.05). Accounting for macroprolactin in patients with hyperprolactinemia reduced the number of idiopathic cases.
Conclusions:
The Vitros ECi prolactin immunoassay detects macroprolactin. PEG-precipitation is an acceptable surrogate to detect hyperprolactinemia in the presence of macroprolactin when using a prolactin reference interval derived from PEG precipitated reference sera. Although testing for macroprolactin should not substitute for standard evaluation of hyperprolactinemia, identification of macroprolactin may clarify a diagnosis and direct appropriate therapy.
Insights
Macroprolactin, a large prolactin variant, can be detected by the Vitros ECi immunoassay. Using PEG-precipitation helps accurately diagnose hyperprolactinemia in patients with macroprolactin.
Area of Science:
- Endocrinology
- Clinical Chemistry
Background:
- Macroprolactin is a heterogeneous, less bioavailable prolactin form.
- Immunoassay detection of macroprolactin varies significantly.
- Understanding macroprolactin is crucial for accurate hyperprolactinemia diagnosis.
Purpose of the Study:
- Evaluate macroprolactin detection by the Vitros ECi prolactin immunoassay.
- Determine optimal interpretation of prolactin levels after PEG-precipitation.
- Correlate clinical hyperprolactinemia features with macroprolactin presence.
Main Methods:
- PEG-precipitation performed on 120 hyperprolactinemic samples.
- 31 samples with <80% recovery were fractionated by GFC.
- Clinical data analyzed via chart review for hyperprolactinemia symptoms.
Main Results:
- Vitros ECi immunoassay successfully detected macroprolactin.
- PEG-modified prolactin reference intervals effectively identified hyperprolactinemia with macroprolactin.
- No significant difference in clinical symptoms (menses, galactorrhea, MRI) between macroprolactin-positive and negative groups.
- Accounting for macroprolactin reduced idiopathic hyperprolactinemia diagnoses.
Conclusions:
- The Vitros ECi prolactin immunoassay detects macroprolactin.
- PEG-precipitation serves as a viable method for diagnosing hyperprolactinemia in the presence of macroprolactin.
- Identifying macroprolactin aids in clarifying diagnoses and guiding therapy for hyperprolactinemia.
