Evaluation of macroprolactin in hyperprolactinemic sera

Prolactin (PRL) is a hypophiseal hormone which exists in different forms in human serum. The predominant form is little PRL (MW 23KDa, 85-95%), with smaller amounts of big PRL (MW 50-60 KDa) and big big PRL or macroprolactin (MW 150-170 KDa). Some patients with hyperprolactinemia are symptom-free, so that identification of macroprolactinemia is clinically important to prevent unnecessary examinations and treatments in the patients with idiopathic hyperprolactinemia. The aim of our study was to evaluate macroprolactin and to estimate the prevalence of macroprolactinemia in hyperprolactinemic sera using polyethylenglycol (PEG) precipitation method and a compatible immunochemiluminiscent assay (ACCESS - Bayer Co).