The Open Clinical Biochemistry Journal

2008, 1 : 38-41
Published online 2008 July 23. DOI: 10.2174/1874241600801010038
Publisher ID: TOCCHEMJ-1-38

Prolactin Immunoreactivity in Rheumatoid Factor-Containing Specimens: Is it Prolactin, Macroprolactin or Assay Interference?

M.J. Ellis , J.H. Livesey and S.G. Soule
Endolab, Christchurch Hospital, Private Bag 4710, Christchurch, New Zealand.

ABSTRACT

Specimens containing Rheumatoid factor (RF) were examined for possible interference in Prolactin (PRL) measurement. PRL levels following polyethylene glycol (PEG) treatment were significantly lower than in untreated RFpositive samples (p<0.001; n=43) and spurious hyperprolactinemia was indicated in 7 percent. Gel filtration chromatography suggested that the PRL-like immunoreactivity was from assay interference rather than a macroPRL complex and that PEG treatment successfully removed the interference. It is important that laboratories consider explanations other than macroPRL when interpreting PRL results following PEG treatment.