Laboratory Assessment of Patients with Chronic Myeloproliferative Diseases

目前公认的三种主要的慢性骨髓增生性疾病是真性红细胞增多症、原发性血小板增多症和特发性骨髓纤维化。在过去，缺乏可靠和容易获得的慢性骨髓增殖性疾病的生物标志物导致了诊断的困难。PV和ET的诊断在很大程度上是通过排除。然而，最近的报道表明，76%到97%的PV患者，29%到57%的ET患者和50%的IMF患者都有JAK2的体细胞点突变。该突变JAK V617F在健康受试者中未发现，与JAK2及其下游效应物的结构性磷酸化有关。对疑似慢性骨髓增殖性疾病患者的实验室评估包括JAK2突变的分子检测和用流式细胞术进行造血细胞的免疫表型分析。如果材料可用，将进行形态审查。在过去的一年里，我们建立了一种新的RT-PCR/RFLP方法来检测JAK V617F突变。我们还开发了一种用于慢性髓系疾病的流式细胞仪小组，其中包括评估具有和不具有JAK2 V617F突变的患者髓系细胞上CD177的表达。我们的目标之一是研究中性粒细胞表达CD177糖蛋白作为慢性骨髓增殖性疾病的生物标志物的可能作用。中性粒细胞CD177 gp表达的改变或与其他中性粒细胞膜蛋白的联合表达变化可能是ET或PV诊断或分期的有用生物标志物。

The three main classic chronic myeloproliferative disorders recognized today are polycythemia vera, essential thrombocythemia and idiopathic myelofibrosis. A lack of reliable and readily available biomarkers for the chronic myeloproliferative disorders has led to diagnostic difficulties in the past. The diagnosis of both PV and ET has largely been by exclusion. However, recent reports described that 76% to 97% of patients with PV, 29% to 57% of patients with ET and 50% of patients with IMF have a somatic point mutation in JAK2. The mutation, JAK V617F, is not found in healthy subjects and is associated with constitutive phosphorylation of JAK2 and its downstream effectors. Laboratory evaluation of patients with suspected chronic myeloproliferative disorders includes molecular testing for the presence of the JAK2 mutation and immunophenotypic analysis of hematopoietic cells by flow cytometry. Morphologic review will be performed if material is available. We have developed in the past year novel RT-PCR/RFLP assay for detection of the JAK V617F mutation. We have also developed a flow cytometric panel for chronic myeloid disorders, which includes evaluation of CD177 expression on myeloid elements in patients with and without JAK2 V617F mutation. One of our goals is to investigate the possible role of neutrophil expression of CD177 gp as a biomarker of chronic myeloproliferative disorders. Changes in neutrophil expression of CD177 gp alone or in combination with other neutrophil membrane proteins might be useful biomarkers for the diagnosis or staging of ET or PV.