Barcelona Hepatic Hemodynamic Laboratory, Liver Unit, Hospital Clinic, Institut de Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas, Health Care Provider of the European Reference Network on Rare Liver Disorders, Barcelona, Spain.
Hematology Department, Hospital Clinic, Institut de Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain.
J Hepatol. 2021 Jan;74(1):89-95. doi: 10.1016/j.jhep.2020.06.045. Epub 2020 Jul 15.
BACKGROUND & AIMS: Myeloproliferative neoplasms (MPNs) are the most frequent cause of non-tumoural non-cirrhotic splanchnic vein thrombosis (NC-SVT). Diagnosis of MPN is based on blood cell count alterations, bone marrow histology, and detection of specific gene mutations. Next-generation sequencing (NGS) allows the simultaneous evaluation of multiple genes implicated in myeloid clonal pathology. The aim of this study was to evaluate the potential role of NGS in elucidating the aetiology of NC-SVT.
DNA samples from 80 patients (75 with idiopathic or exclusively local factor [Idiop/loc-NC-SVT] and 5 with MPN and NC-SVT [SVT-MPN] negative for Janus kinase 2 gene [JAK2] [V617F and exon 12], calreticulin gene [CALR], and thrombopoietin gene [MPL] mutations by classic techniques) were analysed by NGS. Mutations involved in myeloid disorders different from JAK2, CALR, and MPL genes were categorised as high-molecular-risk (HMR) variants or variants of unknown significance.
In 2/5 triple-negative SVT-MPN cases (40%), a mutation in exon 12 of JAK2 was identified. JAK2-exon 12 mutation was also identified in 1/75 patients with Idiop/loc-NC-SVT. Moreover, 28/74 (37.8%) of the remaining Idiop/loc-NC-SVT had at least 1 HMR variant. Sixty-two patients with Idiop/loc-NC-SVT were not receiving long-term anticoagulation and 5 of them (8.1%) had recurrent NC-SVT. This cumulative incidence was significantly higher in patients with HMR variants than in those without.
NGS identified JAK2-exon12 mutations not previously detected by conventional techniques. In addition, NGS detected HMR variants in approximately one-third of patients with Idiop/loc-NC-SVT. These patients seem to have a higher risk of splanchnic rethrombosis. NGS might be a useful diagnostic tool in NC-SVT.
Next-generation sequencing (NGS) performs massive sequencing of DNA allowing the simultaneous evaluation of multiple genes even at very low mutational levels. Application of this technique in a cohort of patients with non-cirrhotic non-tumoral portal vein thrombosis (NC-SVT) and a negative study for thrombophilic disorders was able to identify patients with a mutation in exon 12 not previously detected by conventional techniques. Moreover, NGS detected High Molecular Risk (HMR)-variants (Mutations involved in myeloid disorders different from JAK2, CALR and MPL genes) in approximately one third of patients. These patients appear to be at increased risk of rethrombosis. All these findings supports NGS as a potential useful tool in the management of NC-SVT.
骨髓增殖性肿瘤（MPN）是导致非肿瘤性非肝硬化性门脉系统血栓形成（NC-SVT）最常见的原因。MPN 的诊断基于血细胞计数改变、骨髓组织学和特定基因突变的检测。下一代测序（NGS）允许同时评估多种与髓系克隆病理学相关的基因。本研究旨在评估 NGS 在阐明 NC-SVT 病因学中的潜在作用。
对 80 名患者（75 名患有特发性或仅局部因素引起的 NC-SVT[Idiop/loc-NC-SVT]，5 名患有 MPN 和 NC-SVT[SVT-MPN]，但 JAK2 基因[V617F 和外显子 12]、钙网蛋白基因[CALR]和血小板生成素基因[MPL]突变检测为阴性）的 DNA 样本进行 NGS 分析。通过经典技术鉴定与 JAK2、CALR 和 MPL 基因不同的髓系疾病相关的突变被归类为高分子风险（HMR）变体或意义不明的变体。
在 5 例三阴性 SVT-MPN 病例（40%）中，发现了 JAK2 外显子 12 突变。在 75 例 Idiop/loc-NC-SVT 患者中，也发现了 1 例 JAK2 外显子 12 突变。此外，74 例剩余的 Idiop/loc-NC-SVT 中有 28 例（37.8%）至少有 1 种 HMR 变体。62 名患有 Idiop/loc-NC-SVT 的患者未接受长期抗凝治疗，其中 5 名（8.1%）发生复发性 NC-SVT。与无 HMR 变体的患者相比，HMR 变体患者的累积发生率明显更高。
NGS 鉴定了以前通过常规技术未检测到的 JAK2-exon12 突变。此外，NGS 在大约三分之一的 Idiop/loc-NC-SVT 患者中检测到 HMR 变体。这些患者似乎有更高的再次发生肠系膜血栓的风险。NGS 可能是 NC-SVT 的一种有用的诊断工具。
下一代测序（NGS）对 DNA 进行大规模测序，允许同时评估多个基因，即使在突变水平非常低的情况下也是如此。该技术在一组非肝硬化性非肿瘤性门静脉血栓形成（NC-SVT）和阴性血栓形成倾向疾病的患者中的应用，能够识别出以前通过常规技术未检测到的外显子 12 突变。此外，NGS 在大约三分之一的患者中检测到高分子风险（HMR）变体（与 JAK2、CALR 和 MPL 基因不同的髓系疾病相关的突变）。这些患者似乎有更高的再血栓形成风险。所有这些发现都支持 NGS 作为 NC-SVT 管理的潜在有用工具。
