Division of Allergic Diseases, Department of Medicine, Mayo Clinic, Rochester, MN, United States of America.
Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, United States of America.
J Immunol Methods. 2021 Jun;493:113015. doi: 10.1016/j.jim.2021.113015. Epub 2021 Mar 6.
During eosinophil differentiation, the granule eosinophil major basic protein 1 (eMBP1) is synthesized as a 32-kDa precursor form, referred to as proMBP1, which is processed into the 14-kDa mature form of eMBP1. The prevalence of these two forms of MBP1 in most pathological conditions remains unknown.
To develop the immunoassays that differentiate mature eMBP1 and proMBP1 and apply them to analyze their levels in biological fluids from patients with eosinophilia and hematologic disorders.
We produced a series of monoclonal antibodies and selected pairs capable of discriminating between the two molecular forms of eMBP1. Radioimmunoassay (RIA) was performed to simultaneously quantitate the levels of mature eMBP1 and proMBP1 in secretions from patients with chronic rhinosinusitis (CRS) and sera from patients with hypereosinophilic syndrome (HES) and other myeloproliferative disorders.
The novel immunoassays possessed less than 1% crossreactivity between mature eMBP1 and proMBP1. Mature eMBP1, but not proMBP1, was found in nasal secretions of CRS patients. In contrast, elevated serum levels of mature eMBP1 and proMBP1 were observed in approximately 60% and 90% of HES patients, respectively, with proMBP1 present in greater quantities than mature eMBP1. Patients with several myeloproliferative disorders also showed high serum levels of proMBP1 while mature eMBP1 remained at basal levels.
The novel immunoassays successfully differentiated mature eMBP1 and proMBP1 in human biological fluids. Further studies addressing the clinical correlates of these assays will help to develop biomarkers to diagnose and monitor patients with eosinophilia and myeloproliferative disorders.
在嗜酸性粒细胞分化过程中，颗粒蛋白嗜酸性粒细胞主要碱性蛋白 1（eMBP1）作为 32kDa 的前体形式合成，称为前 MBP1，其被加工成 14kDa 的成熟 eMBP1 形式。在大多数病理情况下，这两种形式的 MBP1 的流行程度尚不清楚。
开发能够区分成熟 eMBP1 和前 MBP1 的免疫分析方法，并将其应用于分析嗜酸性粒细胞增多症和血液系统疾病患者的生物体液中的水平。
我们制备了一系列单克隆抗体，并选择了能够区分 eMBP1 两种分子形式的配对。放射免疫分析（RIA）用于同时定量分析慢性鼻-鼻窦炎（CRS）患者分泌物和嗜酸性粒细胞增多综合征（HES）及其他骨髓增生性疾病患者血清中成熟 eMBP1 和前 MBP1 的水平。
新型免疫分析方法在前 MBP1 和成熟 eMBP1 之间的交叉反应性小于 1%。在 CRS 患者的鼻分泌物中发现了成熟 eMBP1，但未发现前 MBP1。相比之下，大约 60%的 HES 患者血清中成熟 eMBP1 和前 MBP1 水平升高，而前 MBP1 的含量高于成熟 eMBP1。几种骨髓增生性疾病患者的血清前 MBP1 水平也很高，而成熟 eMBP1 仍处于基础水平。
新型免疫分析方法成功地区分了人类生物体液中的成熟 eMBP1 和前 MBP1。进一步研究这些分析方法的临床相关性将有助于开发诊断和监测嗜酸性粒细胞增多症和骨髓增生性疾病患者的生物标志物。
