Exploring the Molecular Aspects of Myeloproliferative Neoplasms Associated with Unusual Site Vein Thrombosis: Review of the Literature and Latest Insights.

Myeloproliferative neoplasms (MPNs) are the leading causes of unusual site thrombosis, affecting nearly 40% of individuals with conditions like Budd-Chiari syndrome or portal vein thrombosis. Diagnosing MPNs in these cases is challenging because common indicators, such as spleen enlargement and elevated blood cell counts, can be obscured by portal hypertension or bleeding issues. Recent advancements in diagnostic tools have enhanced the accuracy of MPN diagnosis and classification. While bone marrow biopsies remain significant diagnostic criteria, molecular markers now play a pivotal role in both diagnosis and prognosis assessment. Hence, it is essential to initiate the diagnostic process for splanchnic vein thrombosis with a JAK2 V617F mutation screening, but a comprehensive approach is necessary. A multidisciplinary strategy is vital to accurately determine the specific subtype of MPNs, recommend additional tests, and propose the most effective treatment plan. Establishing specialized care pathways for patients with splanchnic vein thrombosis and underlying MPNs is crucial to tailor management approaches that reduce the risk of hematological outcomes and hepatic complications.

[Budd-Chiari syndrome and JAK2 gene mutation].

Budd-Chiari syndrome (BCS) is a rare vascular disorder characterized by obstruction of hepatic venous outflow, culminating in elevated hepatic and portal venous pressure. BCS is associated with myeloproliferative neoplasms (MPN) in 40% of cases, which is significantly higher than the rate observed in other venous thrombotic conditions, and suggests that MPN may contribute to the etiology of BCS. In particular, the JAK2 V617F mutation has recently attracted substantial attention, given its profound association with thrombogenesis, mechanically implicated through endothelial damage, increased blood cell adhesion, and facilitation of neutrophil extracellular trap formation. A common treatment approach consists of anticoagulation for prevention and treatment of thrombosis, and cytoreductive therapy targeting MPN. However, as no definitive evidence exists for this approach, a bespoke therapeutic strategy tailored to individual patient profiles is required.

[Comparison of clinical features of JAK2V617F gene mutation and non-mutation in patients with Budd-Chiari syndrome].

Objective: To investigate the clinical features of JAK2V617F gene mutation and non-mutation in patients with Budd-Chiari syndrome (BCS). Methods: 17 and 127 BCS cases with JAK2V617F gene mutation (mutation group) and non-gene mutation (non-mutation group) who were continuously treated with interventional therapy between January 2016 to December 2020 in the Affiliated Hospital of Xuzhou Medical University were selected as the research object for a comparative study. The hospitalization and follow-up data of the two groups were analyzed retrospectively, and the deadline for follow-up was June 2021. Quantitative data group differences were analyzed using the independent sample t-test and Wilcoxon rank sum test. Qualitative data group differences were analyzed with χ2 test or Fisher's exact test. Mann-Whitney U test was used to analyze the differences between groups in rank data. Kaplan-Meier method was used to calculate the patient survival and recurrence rate. Results: Age [(35.41±17.10) years vs. (50.09±14.16) years, t=3.915, P<0.001], time of onset (median duration: 3 months vs. 12 months), and the cumulative survival rate (65.5% vs 95.1%; χ2=5.21, P=0.022) were lower in mutation than non-mutation group. Aaspartate aminotransferase, alanine aminotransferase, prothrombin time, Child-Pugh score, Rotterdam score, Model for End-stage Liver Disease score, hepatic vein thrombosis incidence, and the cumulative recurrence rate after intervention were higher in mutation than non-mutation group. The above all indexes had statistically significant differences (P<0.05) between the groups. Conclusion: Younger age, acute onset, severe liver injury, high incidence of hepatic vein thrombosis, and poor prognosis are the features of patients with BCS with JAK2V617F gene mutation than non-mutation.

Next-generation sequencing in the diagnosis of non-cirrhotic splanchnic vein thrombosis.

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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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. LAY SUMMARY: 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.

From Budd-Chiari syndrome to acquired von Willebrand syndrome: thrombosis and bleeding complications in the myeloproliferative neoplasms.

Thrombotic and hemorrhagic complications are prevalent in patients with essential thrombocythemia, polycythemia vera, and myelofibrosis. Given the impact on morbidity and mortality, reducing the risk of thrombosis and/or hemorrhage is a major therapeutic goal. Historically, patients have been risk stratified on the basis of traditional factors, such as advanced age and thrombosis history. However, multiple factors contribute to the thrombotic tendency, including gender, mutational profile, inflammatory stress, and abnormal cell adhesion. Management includes cardiovascular risk reduction and use of antiplatelet therapy, depending on myeloproliferative neoplasm subtype and mutational status. Anticoagulation is a mainstay of therapy for those with venous thrombosis, but practice patterns remain heterogeneous. Cytoreduction is indicated for higher-risk patients, but efficacy may depend on the involved vascular bed. Management of special situations, such as unusual site thrombosis, bleeding, the perioperative period, and pregnancy, are especially challenging. In this article, risk factors and treatment strategies for myeloproliferative neoplasm thrombosis and bleeding, including special situations, are reviewed. Insights gained from recent studies may lead to the development of a more precise risk classification and tailored therapy.

Prevalence of prothrombotic factors in patients with Budd-Chiari syndrome or non-cirrhotic nonmalignant portal vein thrombosis: A hospital-based observational study.

BACKGROUND AND AIM: Comprehensive investigations on the prothrombotic factors of splanchnic vein thrombosis (SVT), including Budd-Chiari syndrome (BCS) and non-cirrhotic nonmalignant portal vein thrombosis (PVT), in Eastern patients are scarce. METHODS: Between March 2012 and July 2017, 812 consecutive patients, including 418 BCS and 394 non-cirrhotic nonmalignant PVT patients, were admitted to Xijing Hospital (a Chinese tertiary academic hospital) and screened for prothrombotic factors. Odds ratios (ORs), 95% confidence intervals (CIs), and P-trends were calculated by using conditional logistic regression. RESULTS: The prevalence of myeloproliferative neoplasms (MPNs) was only 6.3% among BCS patients but 28.3% among PVT patients. Notably, the presence of MPNs was associated with a higher risk of hepatic vein-type BCS (OR 9.9, 95% CI 3.6-26.7, P-trend < 0.001) and extensive thrombosis in PVT (OR 4.1, 95% CI 1.9-8.9, P-trend < 0.001). Calreticulin mutations existed in 2.7% of SVT patients. Furthermore, the prevalence of antiphospholipid antibody syndrome and protein C, protein S, or antithrombin deficiency in BCS patients was 7.3% and 22.5%, respectively, similar to that in patients with PVT (7.4% and 25.7%). In addition, factor V Leiden mutation, prothrombin G20210A mutation, and paroxysmal nocturnal hemoglobinuria were identified in < 1% of both BCS and PVT patients. CONCLUSION: There is a significant positive association between MPNs and hepatic vein-type BCS or non-cirrhotic nonmalignant PVT with extensive thrombosis. Additionally, calreticulin mutations should be tested in JAK2V617F -negative SVT patients in China. However, screening for factor V Leiden mutation, prothrombin G20210A mutation, and paroxysmal nocturnal hemoglobinuria may be unnecessary.

Association of factor V Leiden, Janus kinase 2, prothrombin, and MTHFR mutations with primary Budd-Chiari syndrome in Egyptian patients.

BACKGROUND AND AIM: Budd-Chiari syndrome (BCS) is defined as obstruction of hepatic venous outflow anywhere from the small hepatic veins to the suprahepatic inferior vena cava. The pathogenesis of BCS is still not fully understood. This study aimed to evaluate the association of factor V Leiden (FVL), Janus kinase 2 (JAK2), prothrombin, and methylene tetrahydrofolate reductase (MTHFR) mutations with primary BCS. METHODS: The study was carried out on 35 patients with primary BCS and 15 age and gender matched healthy individuals as a control group. Genotyping of FVL, prothrombin, and MTHFR mutations was determined by GENEQUALITY AB-THROMBO TYPE kit based on the reverse hybridization principle. JAK2 mutation was determined by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: There was a statistically significant difference between patients and controls regarding FVL, MTHFR C677T, and MTHFR A1298C mutations with odds ratio of 1.83, 2.0, and 1.79, respectively. Hetero MTHFR C677T, hetero FVL, and hetero MTHFR A1298C were the most common etiological factors being responsible for 57.1, 42.9, and 42.9% of primary BCS cases, respectively. CONCLUSION: It could be concluded that BCS is a multifactorial disease; in the current study, MTHFR C677T mutation was the most common cause of disease. Identification of one cause of BCS should not eliminate investigations for detection of other etiological factors.

Associations of coagulation factor V Leiden and prothrombin G20210A mutations with Budd-Chiari syndrome and portal vein thrombosis: a systematic review and meta-analysis.

BACKGROUND & AIMS: We conducted a systematic review and meta-analysis to evaluate the associations of the coagulation factor V (encoded by F5) Leiden (FVL) or prothrombin (encoded by F2) G20210A mutation with Budd-Chiari syndrome or portal vein thrombosis (PVT). METHODS: Relevant articles were identified in searches of the PubMed, EMBASE, Cochrane Library, and ScienceDirect databases. The prevalence of the FVL and prothrombin G20210A mutations were compared between patients with Budd-Chiari syndrome or PVT without cirrhosis and healthy individuals (controls) and between patients with cirrhosis, with and without PVT. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. RESULTS: We initially identified 869 articles, and included 27 in our final analysis. Compared with controls, patients with Budd-Chiari syndrome had a significantly higher prevalence of the FVL mutation (OR, 6.21; 95% CI, 3.93-9.79) and a similar prevalence of the prothrombin G20210A mutation (OR, 1.90; 95% CI, 0.69-5.23); patients with PVT without cirrhosis had a significantly higher prevalence of the FVL mutation (OR, 1.85; 95% CI, 1.09-3.13) or the prothrombin G20210A mutation (OR, 5.01; 95% CI, 3.03-8.30). Compared with patients with cirrhosis without PVT, patients with cirrhosis and PVT had a significantly higher prevalence of the FVL mutation (OR, 2.55; 95% CI, 1.29-5.07). We observed a trend toward a higher prevalence of the prothrombin G20210A mutation in patients with cirrhosis and PVT, but the difference was not statistically significant (OR, 2.93; 95% CI, 0.94-9.07). CONCLUSIONS: Based on a meta-analysis, the FVL mutation is associated with an increased risk of Budd-Chiari syndrome, PVT without cirrhosis, and PVT in cirrhosis. The prothrombin G20210A mutation is associated with PVT, but not Budd-Chiari syndrome. Studies are needed to confirm these findings in different racial and ethnic groups.

Myeloproliferative neoplasms in Budd-Chiari syndrome and portal vein thrombosis: a meta-analysis.

Myeloproliferative neoplasms (MPNs) are the most common cause of Budd-Chiari syndrome (BCS) and nonmalignant, noncirrhotic portal vein thrombosis (PVT). In this meta-analysis, we determined the prevalence of MPNs and their subtypes as well as JAK2V617F and its diagnostic role in these uncommon disorders. MEDLINE and EMBASE databases were searched. Prevalence of MPNs, JAK2V617F, and MPN subtypes were calculated using a random-effects model. A total of 1062 BCS and 855 PVT patients were included. In BCS, mean prevalence of MPNs and JAK2V617F was 40.9% (95% CI, 32.9%-49.5%) and 41.1% (95% CI, 32.3%-50.6%), respectively. In PVT, mean prevalence of MPNs and JAK2V617F was 31.5% (95% CI, 25.1%-38.8%) and 27.7% (95% CI, 20.8%-35.8%), respectively. JAK2V617F and MPNs were more frequent in BCS compared with PVT (P = .03 and P = .09, respectively). Polycythemia vera was more prevalent in BCS than in PVT (P = .001). JAK2V617F screening in splanchnic vein thrombosis (SVT) patients without typical hematologic MPN features identified MPN in 17.1% and 15.4% of screened BCS and PVT patients, respectively. These results demonstrate a high prevalence of MPNs and JAK2V617F in SVT patients and show differences in underlying etiology between these disorders. Furthermore, these results validate routine inclusion of JAK2V617F in the diagnostic workup of SVT patients.

JAK2 V617F mutation and 46/1 haplotype in Chinese Budd-Chiari syndrome patients.

BACKGROUND AND AIM: The presence of JAK2V617F was reported to be associated with JAK2 46/1 haplotype, which was considered as an independent risk factor for Budd-Chiari syndrome (BCS) in Western countries. However, little is known in China. Therefore, the aim of this study was to determine whether the 46/1 haplotype is associated with such patients. METHODS: Patients with primary BCS and controls were consecutively admitted in our study from October 2009 to December 2012. The subjects were detected for the JAK2V617F mutation by allele-specific polymerase chain reaction (AS-PCR) and the JAK2 46/1 haplotype by real-time PCR. RESULTS: The prevalence of JAK2V617F mutation was 2.37% (7/295) in BCS patients, and 46/1 haplotype was overrepresented in JAK2V617F-positive BCS patients compared with controls (P < 0.01). The risk for the JAK2V617F-positive BCS with CC genotype was elevated compared with subjects presented TT genotype (OR = 13.4, 95%CI = 2.01-89.5) and non-CC genotype (OR = 15.0, 95%CI = 2.45-91.7). CONCLUSIONS: Our study showed that the presence of 46/1 haplotype increased the risk of JAK2V617F-positive BCS in China. In addition, low prevalence of JAK2V617F mutation in BCS patients suggested that myeloproliferative neoplasms (MPNs) should not be an etiological factor of BCS in China.

Primary Budd-Chiari syndrome in a 3-year-old boy with homozygous factor V Leiden G1691A mutation.

UNLABELLED: Budd-Chiari syndrome (BCS) is an uncommon disorder characterized by obstruction of hepatic venous outflow. The primary BCS is a rare disease with an incidence about 0.2 per million inhabitants per year. We present a 3-year-old boy with intrahepatic inferior vena cava clot. Because of decreased levels of protein C (38.7 %), F II (69.1 %), and activated protein C resistance (1.43), a mutational gene analysis was performed. The patient was found to be homozygous for the FV G1691A mutation. CONCLUSION: The primary BCS is a rare disease especially in childhood. Activated protein C resistance caused by the factor V Leiden mutation may be responsible for primary BCS. Prompt recognition of underlying prothrombotic disease and early initiation of their specific therapy might translate into rapid improvement of liver disease.

Molecular characterization of a ß-thalassemia intermedia patient presenting inferior vena cava thrombosis: interaction of the ß-globin erythroid Krüppel-like factor binding site mutation with Hb E and α(+)-thalassemia.

The molecular basis and hematological phenotype of adult Thai ß-thalassemia intermedia (ß-TI) patients encountered with inferior vena cava (IVC) thrombosis were investigated. Hematological and molecular analysis revealed a trait previously not described. The disease was caused by interaction of the ß(+)-thalassemia (ß(+)-thal) gene with the -90 (C > T) (HBB: c.-140C > T) transition within the erythroid Krüppel-like factor (EKLF) binding site of the ß-globin gene promoter with Hb E (HBB: c.79G > A) and α(+)-thalassemia (α(+)-thal). Hematological data of the patient were compared with those of heterozygous forms of these defects found in his family members and different genotype-phenotype interactions are illustrated. Globin gene haplotype analysis indicates an independent origin of this Thai ß(+)-thal gene. Accurate diagnoses as well as knowledge of genotype-phenotype relationships were required for providing appropriate management of such cases.

The JAK2 46/1 haplotype in Budd-Chiari syndrome and portal vein thrombosis.

The germline JAK2 46/1 haplotype has been associated with the development of JAK2(V617F)-positive as well as JAK2(V617F)-negative myeloproliferative neoplasms (MPNs). In this study we examined the role of the 46/1 haplotype in the etiology and clinical presentation of patients with splanchnic vein thrombosis (SVT), in which MPNs are the most prominent underlying etiological factor. The single-nucleotide polymorphism rs12343867, which tags 46/1, was genotyped in 199 SVT patients. The 46/1 haplotype was overrepresented in JAK2(V617F)-positive SVT patients compared with controls (P < .01). Prevalence of the 46/1 haplotype in JAK2(V617F)-negative SVT patients did not differ from prevalence in the controls. However, JAK2(V617F)-negative SVT patients with a proven MPN also exhibited an increased frequency of the 46/1 haplotype (P = .06). Interestingly, 46/1 was associated with increased erythropoiesis in JAK2(V617F)-negative SVT patients. We conclude that the 46/1 haplotype is associated with the development of JAK2(V617F)-positive SVT. In addition, our findings in JAK2(V617F)-negative SVT patients indicate an important role for the 46/1 haplotype in the etiology and diagnosis of SVT-related MPNs, independent of JAK2(V617F), that requires further exploration.

Long-term follow-up study in Budd-Chiari syndrome: single-center experience in 22 years.

GOALS: We aimed to present our long-term surveillance experience in patients with Budd-Chiari syndrome (BCS), and we retrospectively evaluated the natural history, results of thrombophilia studies, and the factors related to mortality. BACKGROUND: Primary BCS is a rare form of vascular disease, secondary to underlying thrombophilia. Because of its rarity and heterogeneous nature, there is a scarcity of knowledge about the natural history of the disease. STUDY AND RESULTS: In 22 years, a total of 62 patients with primary BCS were followed in our tertiary hospital. We identified an acquired cause of BCS in 40 out of 62 patients (64.5%), whereas in 6 patients (9.7%), we found no identifiable cause. One or more thrombophilia causes were identified in 56 patients (90.3%). In 19 patients with myeloproliferative disease, 15 had Janus tyrosine kinase 2 mutation analysis and Janus tyrosine kinase 2 positivity was found in 10 patients. In regression analysis, portal vein thrombosis was found to be the only indicator of mortality, with an estimated instantaneous risk of 8.4. CONCLUSIONS: In this study, we present one of the largest series of BCS in the English literature. We have shown that the multifactorial nature of underlying thrombophilia should be thoroughly investigated. In a patient with BCS, a clinician should be alert for the development or coexistence of portal vein thrombosis due to its deleterious effect on mortality.

Successful liver transplantation in a patient with splanchnic vein thrombosis and pulmonary embolism due to polycythemia vera with Jak2v617f mutation and heparin-induced thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is a rare complication of heparin treatment resulting in a severe acquired thrombophilic condition with an associated mortality of about 10 %. We report the first case of successful urgent liver transplantation (LT) in a patient with end-stage liver disease due to a Budd-Chiari syndrome, portal vein thrombosis and pulmonary embolism due to acquired thrombophilia associated to polycythemia vera carrying JAK2V617F gene mutation and HIT in the acute phase. Lepirudin was used to provide anticoagulation in the LT perioperative period that was performed without haemorrhagic and thrombotic complications despite the donor received heparin during liver explantation.

Prothrombotic states in portal vein thrombosis and Budd-Chiari syndrome in India: A systematic review and meta-analysis.

BACKGROUND: Both Budd-Chiari syndrome (BCS) and portal vein thrombosis (PVT) have been linked to various prothrombotic (PT) conditions. The PT profile in Asians is different from the west and there are no nationwide epidemiological surveys from India. Hence, the present meta-analysis was aimed at analyzing the prevalence of acquired and hereditary thrombophilia among Indian patients with non-cirrhotic PVT and BCS. METHODS: A comprehensive literature search of Embase, Medline and Scopus was conducted from January 2000 to February 2022 for studies evaluating the prevalence of various PT conditions in Indian patients with PVT and BCS. Pooled prevalence rates across studies were expressed with summative statistics. RESULTS: Thirty-five studies with 1005 PVT patients and 1391 BCS patients were included in the meta-analysis. At least one PT condition was seen in 46.2% (28.7-63.7) of the PVT patients and 44.9% (37.3-60.7) of the BCS patients. Multiple PT conditions were seen in 13.0% (4.2-21.8) of the PVT patients and 7.9% (3.5-12.4) of the BCS patients. Among PVT patients, hyperhomocysteinemia was the commonest prothrombotic condition (21.6%) followed by protein C (PC) deficiency (10.7%), Janus kinase 2 (JAK-2) mutation (8.5%) and antiphospholipid antibodies (APLA) (7.5%). Among patients with BCS, PC deficiency was the commonest prothrombotic condition (10.6%) followed by methylenetetrahydrofolate reductase (MTHFR) mutation (9.8%), APLA (9.7%) and JAK-2 mutation (9.1%). CONCLUSION: The PT profile in Indian patients with abdominal vein thrombosis is different from that of the western data with a lower prevalence of PT conditions in patients with BCS.

Prevalence and clinical outcomes of the 46/1 haplotype, Janus kinase 2 mutations, and ten-eleven translocation 2 mutations in Budd-Chiari syndrome and their impact on thrombotic complications post liver transplantation.

Latent myeloproliferative disorders (MPDs) can be identified by Janus kinase 2 (JAK2) mutations in patients with idiopathic Budd-Chiari syndrome (BCS). The incidence and clinical outcomes of JAK2 mutations, novel ten-eleven translocation 2 (TET2) mutations, and the 46/1 haplotype in BCS are unknown for liver transplantation (LT). We undertook molecular studies of 66 patients presenting with BCS and correlated the results with the clinical outcomes. An overt MPD was present in 20% of the cases, and a latent MPD confirmed by the presence of a JAK2 mutation was detected in 45%. Testing for a TET2 mutation identified MPDs at the molecular level in another 7% of the subset of patients with BCS who were evaluated. The 46/1 haplotype frequency was significantly greater in BCS patients versus the general population (P < 0.001). The presence of JAK2 and TET2 mutations had no impact on 1-year survival. Thirty-six patients underwent LT, and 12 developed liver-related thrombotic complications (33%). Ten of these 12 patients required retransplantation. Retransplantation was more likely in those patients who developed liver-related thrombotic complications (P < 0.001). A JAK2 mutation was highly associated with the development of thrombotic complications after LT (P = 0.005). In conclusion, the presence of JAK2V617F predicts hepatic and extrahepatic thrombotic complications after LT. Testing for TET2 mutations can identify another 7% of idiopathic BCS patients with molecular MPDs.