Department of Pediatric Gastroenterology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
J Pediatr Gastroenterol Nutr. 2012 Nov;55(5):599-604. doi: 10.1097/MPG.0b013e318261814d.
The aim of this study was to describe the prevalence of main hereditary thrombophilias, Janus kinase 2 (JAK2) V617F mutation, antiphospholipid antibody syndrome (APS), and hyperhomocysteinemia in Brazilian children and adolescents diagnosed with portal vein thrombosis (PVT) without associated hepatic disease.
A cross-sectional study was carried out with 32 children with PVT in accompaniment at Hospital das Clínicas of the Universidade Federal de Minas Gerais from January 1990 to July 2011. Laboratory evaluation of thrombophilias was performed from September 2010 to July 2011.
Thirty-two patients were evaluated; 59% were boys. Median age at diagnosis was 2.4 years. Mean time of patients' accompaniment was between 4.7 and 5.2 years. The presence of hereditary and acquired thrombophilias occurred in 34.4% of patients, and 9 of them also showed other risk factors in the previous history evaluation. Risk factors were absent in the previous history of 18 patients (56.3%). Two patients showed persistent high titres of anticardiolipin antibodies. Hyperhomocysteinemia was not observed. One patient was heterozygous for factor V Leiden and prothrombin G20210A mutation (3.1%). Eleven patients (34.4%) showed heterozygous methylenetetrahydrofolate reductase (MTHFR) C677T, and no patient had the JAK2V617F mutation.
Even after investigation of main hereditary and acquired thrombophilia, PVT remains without apparent cause in most patients. Nevertheless, association of local and systemic risk factors seems to be important also in the pediatric age group. Therefore, despite the low prevalence, a complete investigation, which includes both hereditary and acquired thrombophilias, may be necessary.
本研究旨在描述无相关肝脏疾病的巴西儿童和青少年门静脉血栓形成（PVT）患者中主要遗传性血栓形成倾向、Janus 激酶 2（JAK2）V617F 突变、抗磷脂抗体综合征（APS）和高同型半胱氨酸血症的流行情况。
本研究采用病例对照研究，纳入了 1990 年 1 月至 2011 年 7 月期间在巴西联邦米纳斯吉拉斯州联邦大学临床医院就诊的 32 例 PVT 患儿。2010 年 9 月至 2011 年 7 月进行了血栓形成倾向的实验室评估。
共评估了 32 例患者，其中 59%为男性。诊断时的中位年龄为 2.4 岁。患者就诊的平均时间为 4.7 至 5.2 年。34.4%的患者存在遗传性和获得性血栓形成倾向，其中 9 例在既往病史评估中还存在其他危险因素。18 例（56.3%）患者既往病史中无危险因素。2 例患者持续存在高滴度抗心磷脂抗体。未观察到高同型半胱氨酸血症。1 例患者为因子 V Leiden 和凝血酶原 G20210A 突变杂合子（3.1%）。11 例（34.4%）患者存在亚甲基四氢叶酸还原酶（MTHFR）C677T 杂合子，无患者存在 JAK2 V617F 突变。
即使对主要遗传性和获得性血栓形成倾向进行了调查，大多数患者的 PVT 仍无明显病因。然而，局部和全身危险因素的联合作用在儿科年龄组中似乎也很重要。因此，尽管发病率较低，但可能仍需要进行包括遗传性和获得性血栓形成倾向在内的全面调查。
