Department of Clinical Laboratory, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, 310014, China.
Department of Clinical Laboratory, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2021 Jun 15;1175:122723. doi: 10.1016/j.jchromb.2021.122723. Epub 2021 Apr 25.
To optimize a screening method for macroprolactinemia and improve the accuracy of free prolactin (freePRL) detection.
Overall efficiency, calculated as the product of the immunoglobulin G (IgG) precipitation rate and the freePRL recovery rate were employed to determine the concentration of the precipitant polyethylene glycol (PEG). Then, an optimized screening method for macroprolactinemia was established. The concentrations of freePRL, obtained by gel filtration chromatography (GFC), from 66 cases were used as the gold standard, and the sensitivity, specificity, accuracy and precision of the optimized and traditional methods for detecting macroprolactinemia were compared.
(1) The IgG precipitation rate increased with increasing PEG6000 concentration, and the freePRL recovery rate decreased with increasing PEG6000 concentration; the overall efficiency first increased and then decreased. When the IgG concentrations in the mixture were 10 g/L, 25 g/L and 40 g/L, the concentrations of PEG6000 with the highest overall efficiency were 24%, 20% and 18%, respectively. (2) The effect of high and low IgG on the overall efficiency was 4.7% when using 20% PEG6000, which was lower than the effects when using 18% or 24% PEG6000 (9.2% and 13.2%). (3) In the optimized method established using 20% PEG6000, the macroprolactin (macroPRL) chromatographic peak disappeared, but the freePRL chromatographic peak was retained. The sensitivity of this macroprolactinemia screening method was 96.7%, and the specificity was 100%. (4) The freePRL concentrations obtained by the optimized method for samples from 30 macroprolactinemia cases and 36 true hyperprolactinemia cases were 15.8 (10.2-21.4) ng/mL and 60.2 (51.8-79.9) ng/mL; the concentrations were similar to those obtained using the GFC method (16.3 (11.9-27.2) ng/mL and 68.1 (49.5-92.9) ng/mL, respectively (p > 0.05)) and higher than those obtained using the traditional method (9.1 (6.1-17.6) ng/mL and 51.4 (43.7-71.9) ng/mL), respectively, p < 0.05)). (5) The relative deviation between the optimized and GFC methods was -7.0%, which was significantly lower than the relative deviation between the traditional and GFC methods (-21.4%, p < 0.01). (6) The in-batch coefficients of variation (CVs) for the dual-level quality control materials measured by the optimized method were 1.88% and 1.87%, and the within-laboratory CVs were 2.55% and 2.29%, which were slightly lower than the in-batch CVs (1.93% and 2.81%) and within-laboratory CVs (2.75% and 2.81%) measured by the traditional method.
The established optimized method for screening macroprolactinemia using 20% PEG6000 as a precipitant can completely precipitate macroPRL components and effectively retain freePRL components. Compared with traditional methods, the optimized method is simpler, more accurate and more stable for the quantitative detection of freePRL.
优化巨泌乳素血症的筛查方法，提高游离泌乳素（freePRL）检测的准确性。
采用免疫球蛋白 G（IgG）沉淀率和游离 PRL 回收率的乘积来计算总体效率，以确定聚乙二醇（PEG）沉淀剂的浓度。然后，建立了一种优化的巨泌乳素血症筛查方法。使用凝胶过滤色谱（GFC）获得的 66 例游离 PRL 浓度作为金标准，比较了优化和传统方法检测巨泌乳素血症的灵敏度、特异性、准确性和精密度。
（1）随着 PEG6000 浓度的增加，IgG 沉淀率增加，游离 PRL 回收率降低；总体效率先增加后降低。当混合物中的 IgG 浓度分别为 10 g/L、25 g/L 和 40 g/L 时，总体效率最高的 PEG6000 浓度分别为 24%、20%和 18%。（2）使用 20%PEG6000 时，高和低 IgG 对总体效率的影响分别为 4.7%和 9.2%、13.2%。（3）在使用 20%PEG6000 建立的优化方法中，巨泌乳素（macroPRL）色谱峰消失，但保留了游离 PRL 色谱峰。这种巨泌乳素血症筛查方法的灵敏度为 96.7%，特异性为 100%。（4）优化方法用于 30 例巨泌乳素血症和 36 例真性高泌乳素血症样本的游离 PRL 浓度分别为 15.8（10.2-21.4）ng/mL 和 60.2（51.8-79.9）ng/mL；与 GFC 法获得的浓度相似（16.3（11.9-27.2）ng/mL 和 68.1（49.5-92.9）ng/mL，分别为 p>0.05），高于传统方法获得的浓度（9.1（6.1-17.6）ng/mL 和 51.4（43.7-71.9）ng/mL，分别为 p<0.05）。（5）优化法与 GFC 法的相对偏差为-7.0%，明显低于传统法与 GFC 法的相对偏差（-21.4%，p<0.01）。（6）用优化法测定双水平质控材料的批内变异系数（CV）为 1.88%和 1.87%，实验室内 CV 为 2.55%和 2.29%，略低于传统法测定的批内 CV（1.93%和 2.81%）和实验室内 CV（2.75%和 2.81%）。
用 20%PEG6000 作为沉淀剂建立的优化巨泌乳素血症筛查方法可以完全沉淀巨泌乳素成分，有效保留游离泌乳素成分。与传统方法相比，优化方法在游离 PRL 的定量检测方面更简单、更准确、更稳定。
