Beda-Maluga K, Pisarek H, Komorowski J, Swietoslawski J, Fuss-Chmielewska J, Winczyk K
Department of Neuroendocrinology, Chair of Laboratory Diagnostics, Medical University of Lodz, Poland.
J Physiol Pharmacol. 2014 Jun;65(3):359-64.
Macroprolactin (MaPRL) - a complex of monomeric prolactin (PRL) with immunoglobulin G, may be a cause of laboratory diagnosed hyperprolactinaemia. To quantify MaPRL, a precipitation with polyethylene glycol may be performed. This method involves calculating of recovery ratio but the cut-off value is not precisely determined. Moreover, it is proposed that the assessment of macroprolactinaemia should include also the evaluation of real PRL concentration which means the level of the hormone after macroforms separation. The study included 245 patients with hyperprolactinaemia, in whom precipitation was performed. A recovery ratio ≤40% indicated macroprolactinaemia. The real PRL concentrations of the studied subjects were compared with reference ranges suggested by the assay manufacturer and with new intervals for PRL after macroforms separation. On the base of the recovery ratio after the precipitation, macroprolactinaemia was detected in 21 persons. In these patients true hyperprolactinaemia (elevation of real PRL concentration above manufacturer's reference ranges) was noted in 9 cases. Among 224 patients with a recovery >40%, real PRL concentration turned out to be within the manufacturer's reference range (pseudohyperprolactinaemia) in 36 persons. The new intervals for PRL after macroforms separation were about 20% lower than the manufacturer's reference ranges. After applying new ranges in patients with macroprolactinaemia, true hyperprolactinaemia was observed in 14 persons, while in the group without MaPRL dominance, pseudohyperprolactinaemia was noted in 5 patients. The use of the recovery ratio only to recognize macroprolactinaemia may lead in some subjects to the misclassification of the results. For that reason the assessment of the PRL concentration after macroforms separation that can help to distinguish true hyperprolactinaemia and pseudohyperprolactinaemia, seems to be reasonable. To evaluate the real PRL concentration, the reference intervals suggested by the manufacturer of immunoassay might be used. However, possibly better means to diagnose patients with hyperprolactinaemia accurately is using an appropriate range for the concentration of PRL after macroforms separation.
巨泌乳素（MaPRL）——单体泌乳素（PRL）与免疫球蛋白G的复合物，可能是实验室诊断的高泌乳素血症的一个原因。为了定量测定MaPRL，可以用聚乙二醇进行沉淀。该方法涉及回收率的计算，但临界值尚未精确确定。此外，有人提出，巨泌乳素血症的评估还应包括对实际PRL浓度的评估，即巨泌乳素形式分离后激素的水平。该研究纳入了245例高泌乳素血症患者，对其进行了沉淀检测。回收率≤40%表明存在巨泌乳素血症。将研究对象的实际PRL浓度与检测试剂盒制造商建议的参考范围以及巨泌乳素形式分离后的PRL新区间进行比较。根据沉淀后的回收率，在21人检测到巨泌乳素血症。在这些患者中，有9例出现真正的高泌乳素血症（实际PRL浓度高于制造商的参考范围）。在224例回收率>40%的患者中，有36人的实际PRL浓度在制造商的参考范围内（假性高泌乳素血症）。巨泌乳素形式分离后的PRL新区间比制造商的参考范围低约20%。在巨泌乳素血症患者中应用新范围后，观察到14例真正的高泌乳素血症，而在无MaPRL占优势的组中，有5例患者出现假性高泌乳素血症。仅使用回收率来识别巨泌乳素血症可能会导致一些受试者的结果分类错误。因此，评估巨泌乳素形式分离后的PRL浓度有助于区分真正的高泌乳素血症和假性高泌乳素血症，这似乎是合理的。为了评估实际PRL浓度，可以使用免疫分析制造商建议的参考区间。然而，可能更准确诊断高泌乳素血症患者的方法是使用巨泌乳素形式分离后PRL浓度的适当范围。
