Establishment And Clinical Application Of Polyethylene Glycol Precipitation Method In Screening And Detection Of Macroprolactinemia In Patients

Objective To establish the polyethylene glycol (PEG6000) precipitation method for screening macroprolactinemia in serum prolactin (PRL)-elevated patients, and to verify this method with clinical specimens.Methods PEG6000precipitation method was used to remove macroprolactin (MPRL) molecule in sera of PRL-elevated patients. The effect of PEG6000precipitating serum MPRL was determined by both Sephacryl S-100HR chromatography plus chemiluminescent immunoassay and SDS-PAGE plus Western Blot assay. The PEG6000precipitation plus chemiluminescent immunoassay was applied to detect MPRL in sera of PRL-elevated patients as well as screen macroprolactinemia in the serum samples. The clinical manifestation of patients with true-hyperprolactinemia, hyperprolactinemia plus macroprolactinemia or true-macroprolactinemia was analyzed and compared.Results After precipitation with PEG6000, MPRL peak or hybridization signal in the serum samples was notably decreased, but no influence could be found to both the big or small prolactin (BPRL or SPRL). In the1538cases of serum PRL-elevated patients,16.1%(247/1538) were detectable for macroprolactinemia, while the83.9% (1291/1538) were identified as the true-hyperprolactinemia. In the247cases of macroprolactinemia samples,93.5%(231/247) were determined as true-macroprolactinemia, while6.5%(16/247) were identified as hyperprolactinemia plus macroprolactinemia. In the508true-hyperprolactinemia patients,438(86.2%,438/508) were confirmed to suffer from menoxenia, menolipsis/menostasia, dysgenesia or hypophysoma. The disease incidence in the7cases of hyperprolactinemia plus macroprolactinemia pateints was85.7%(6/7). However, only11cases in the71true-macroprolactinemia patients (15.5%,11/71) were found to suffer from these deseases.Conclusion There are a certain ratio of true-macroprolactinemia (pseudo-hyperprolactinemia) in serum PRL-elevated patients. The PEG6000precipitation method established in this study can conveniently and efficiently distinguish true-or pseudo-hyperprolactinemia in patients, which will contricute to the decrease of misdiagnosis and avoidance of incorrect medication in clinic.