JAK2(V617F) positive early stage myeloproliferative disease (essential thrombocythemia) as the cause of portal vein thrombosis in two middle-aged women: therapeutic implications in view of the literature

Bilateral Adrenal Infarction That Developed in Latent Essential Thrombocythemia

Bilateral adrenal infarction is an extremely rare disease, and it has been reported that some coagulation abnormalities, including essential thrombocythemia (ET), exist in the background. We herein report a 76-year-old patient in whom the platelet count had been in the normal range at the onset of adrenal infarction but subsequently increased to 102×104/μL at 7 months later, leading to the diagnosis of JAK2V617F-positive ET. As the presence of the JAK2V617F mutation increases the risk of thrombosis, Janus kinase 2 (JAK2) genetic testing should be considered in some cases of nonspecific unknown thrombosis, even if there are no obvious hematological findings, such as clonal hematopoiesis of indeterminate potential (CHIP).

Transcatheter thrombolysis combined with damage control surgery for treatment of acute mesenteric venous thrombosis associated with bowel necrosis: a retrospective study

OBJECTIVE

This study aims to evaluate the clinical outcomes of transcatheter thrombolysis in acute superior mesenteric venous thrombosis (ASMVT) associated with bowel necrosis.

METHODS

A retrospective study of six patients with ASMVT treated with catheter-directed thrombectomy/thrombolysis and damage control surgery at Jinling Hospital (Nanjing, China) between 2010 and 2013 was conducted. Demographics, past medical history, risk factors, therapeutic methods and effects, mortality, and follow-up of the study population were assessed.

RESULTS

Five of six patients underwent arteriovenous combined thrombolysis, while one patient underwent arterial thrombolysis. All patients required damage control surgery, and four of these patients underwent temporary abdominal closure. All patients survived and were free of recurrence.

CONCLUSIONS

Transcatheter thrombectomy/thrombolysis and damage control surgery could help avoid extensive bowel resection, prevent short bowel syndrome and reduce mortality for critically ill patients with acute mesenteric venous thrombosis associated with bowel necrosis.

A Case of Recurrent Ischemic Stroke Involving Subacute, Progressive Intracranial Cerebral Arterial Sclerosis Prior to Diagnosis with JAK2-mutated Polycythemia Vera

CASE REPORT

A 58-year-old man presenting with no vascular risk factors visited our hospital with right hemiparesis and total aphasia. Diffusion-weighted magnetic resonance imaging of the brain showed multiple hyperintensities in watershed distributions in the left hemisphere. Magnetic resonance angiography (MRA) revealed stenosis of the middle cerebral artery, despite normal MRA findings 2 months prior. One year after the first stroke, the patient experienced a recurrent ischemic stroke involving the left anterior choroidal artery, pulmonary embolism, and deep venous thrombosis. After the recurrent stroke event, hemoglobin levels increased gradually. Two years after the first stroke, a JAK2V-617F mutation was detected.

CONCLUSION

Our report suggests that progressive intracranial arterial sclerosis and venous thrombosis of undetermined etiologies could be several initial symptoms of polycythemia vera.

Aspirin-responsive, migraine-like transient cerebral and ocular ischemic attacks and erythromelalgia in JAK2-positive essential thrombocythemia and polycythemia vera

Migraine-like cerebral transient ischemic attacks (MIAs) and ocular ischemic manifestations were the main presenting features in 10 JAK2(V617F)-positive patients studied, with essential thrombocythemia (ET) in 6 and polycythemia vera (PV) in 4. Symptoms varied and included cerebral ischemic attacks, mental concentration disturbances followed by throbbing headaches, nausea, vomiting, syncope or even seizures. MIAs were frequently preceded or followed by ocular ischemic events of blurred vision, scotomas, transient flashing of the eyes, and sudden transient partial blindness preceded or followed erythromelalgia in the toes or fingers. The time lapse between the first symptoms of aspirin-responsive MIAs and the diagnosis of ET in 5 patients ranged from 4 to 12 years. At the time of erythromelalgia and MIAs, shortened platelet survival, an increase in the levels of the platelet activation markers β-thromboglobulin and platelet factor 4 and also in urinary thromboxane B2 were clearly indicative of the spontaneous in vivo platelet activation of constitutively JAK2(V617F)-activated thrombocythemic platelets. Aspirin relieves the peripheral, cerebral and ocular ischemic disturbances by irreversible inhibition of platelet cyclo-oxygenase (COX-1) activity and aggregation ex vivo. Vitamin K antagonist, dipyridamole, ticlopidine, sulfinpyrazone and sodium salicylate have no effect on platelet COX-1 activity and are ineffective in the treatment of thrombocythemia-specific manifestations of erythromelalgia and atypical MIAs. If not treated with aspirin, ET and PV patients are at a high risk of major arterial thrombosis including stroke, myocardial infarction and digital gangrene.

Deep vein thrombosis and pulmonary embolism in cirrhotic patients: Systematic review

Patients with liver cirrhosis were traditionally believed to be protected against development of blood clots. Lately, studies have shown that these patients may probably be at an increased risk of venous thrombotic complications. Although the hemostatic changes in the chronic liver disease patients and the factors that may predict bleeding vs thrombotic complications remains an area of active research, it is believed that the coagulation cascade is delicately balanced in these patients because of parallel reduced hepatic synthesis of pro and anticoagulant factors. Thrombotic state in cirrhotic patients is responsible for not only portal or non-portal thrombosis [deep vein thrombosis (DVT) and pulmonary embolism (PE)]; it has also been associated with progression of liver fibrosis. The use of anticoagulants in cirrhosis patients is a challenging, and often a scary situation. This review summarizes the current literature on the prevalence of venous thrombosis (DVT and PE), risk factors and safety of prophylactic and therapeutic anticoagulation in patients with chronic liver disease.

Cooperation between pathologists and clinicians allows a better diagnosis of Philadelphia chromosome-negative myeloproliferative neoplasms

As no specific genetic lesions have yet been identified, the diagnosis of Philadelphia chromosome-negative myeloproliferative neoplasms is based on a simultaneous evaluation of the clinical, morphological and molecular features defined by the updated WHO classification, which allow most cases of full-blown disease to be classified. Nevertheless, about 10-15% of the patients have unclassifiable myeloproliferative neoplasms, most of whom are in the prodromal (early) phase of disease and identified by the presence of the JAK2 mutation, but lack the complete phenotype required by the WHO classification. The detection of these prodromal phases is extremely important in order to prevent dramatic thrombo-hemorrhagic complications and improve prognosis.

Transient ischemic attacks as the first presentation of JAK2-V617F positive chronic myeloproliferative neoplasm

Several studies have shown that thrombotic events may underlie a latent or subclinical myeloproliferative neoplasm (MPN) and precede its definite diagnosis by 1–2 years. An early diagnosis of patients with MPN, especially those with thrombotic events in the latent MPN phase, would be beneficial for their management, preventing further morbidity and improving their quality of life. For the majority of these cases, the location of thrombosis is mainly in the splanchnic major veins, while ischemic stroke and cerebral venous thrombosis are rarely observed. In this report, we present a female patient with transient ischemic attacks who suffered from a latent MPN, on the basis of a positive testing for the JAK2-V617F mutation.

Budd-Chiari syndrome and portal vein thrombosis due to essential thrombocytosis

Budd-Chiari syndrome secondary to essential thrombocytosis has been described in a few reports in the English literature. Associated portal vein thrombosis occurs very rarely. Herein, we report a case presented with ascites and finally diagnosed with hepatic and portal vein thrombosis, and essential thrombocytosis. We discussed the therapeutic approaches in the light of pertinent literature.

Prodromal myeloproliferative neoplasms: the 2008 WHO classification

The concept of prodromal chronic myeloproliferative neoplasms has been endorsed by the WHO classification implicating a stepwise evolution of disease. Histology of the bone marrow (BM) and borderline to mildly expressed clinical features play a pivotal role for diagnosing prefibrotic-early primary myelofibrosis. By lowering the platelet count for essential thrombocythemia and regarding BM morphology, early manifestations are tackled. Pre-polycythemic stages of polycythemia vera with a low hemoglobin level at onset are diagnosed by positive JAK2V617F mutation status, a low erythropoietin value, and characteristic BM features. The revised WHO classification incorporates hematological, morphological, and molecular-genetic parameters to generate a consensus-based working diagnosis.

Use of thromboelastography PlateletMapping to monitor antithrombotic therapy in a patient with Budd-Chiari syndrome

Budd-Chiari syndrome (BCS) is the end result of a number of disease states resulting in hepatic venous outflow obstruction. We report a Janus kinase 2-homozygous patient with BCS who thrombosed a transjugular intrahepatic portosystemic shunt (TIPS) despite treatment with warfarin (international normalized ratio = 3.0), aspirin, and clopidogrel. PlateletMapping (Haemonetics Corp.) is a novel point-of-care assay of platelet function based on thromboelastography (TEG) that has the ability to detect platelet inhibition (%) by antiplatelet therapy. Initial PlateletMapping traces showed no platelet inhibition by aspirin or clopidogrel but demonstrated adequate suppression of plasmatic coagulation. On this basis, the aspirin dose was doubled, and this resulted in a significant increase in platelet inhibition (45%). To further suppress platelet activity, the patient was started on tirofiban, a glycoprotein IIb/IIIa inhibitor. Repeat PlateletMapping revealed 100% inhibition of platelets by both pathways, and this coincided with angiographic evidence of TIPS blood flow. Subsequently, the patient developed bleeding from the venous access sites. TEG demonstrated poor underlying plasmatic coagulation with a prolonged R time of 9.2 minutes (normal = 2-8 minutes), and the international normalized ratio was found to be supratherapeutic (>4). Treatment with fresh frozen plasma stopped the bleeding without compromising the platelet inhibition. This case demonstrates that increased platelet activation may contribute to the development of thromboses in BCS. Despite the standard dose of dual antiplatelet therapy, there was minimal inhibition in platelet function, and anticoagulation with warfarin alone was not adequate to prevent thrombotic events. PlateletMapping was used to assess and then optimize the antiplatelet treatment while facilitating the management of complications without an increased risk of thrombosis.

The saga of JAK2 mutations and translocations in hematologic disorders: pathogenesis, diagnostic and therapeutic prospects, and revised World Health Organization diagnostic criteria for myeloproliferative neoplasms

JAK2 is a tyrosine kinase involved in cytokine signaling. The JAK2V617F point mutation, first described in 2005, results in constitutive activation of JAK2 and is now widely used as a diagnostic marker for Philadelphia chromosome negative myeloproliferative neoplasms. In recent years, more novel JAK2 mutations and fusion genes have been discovered in myeloproliferative neoplasms and other hematologic malignancies. This review aims to summarize the discovery and use of the JAK2V617F point mutation, other novel JAK2 mutations, and JAK2 translocations in diagnosing myeloproliferative neoplasms, acute myeloid leukemia, and acute lymphoid leukemia. JAK2 mutation testing is addressed, including the sensitivity and specificity of the different JAK2 mutation testing methods, clinical indications for use, and the use of quantitative JAK2 mutation testing for routine pathologic diagnosis, prognosis, and monitoring response to therapy. The relationship of JAK2 mutation to endogenous erythroid colony formation, thrombopoietin receptor mutation, polycythemia rubra vera-1 overexpression, and thrombopoietin receptor underexpression in myeloproliferative neoplasms are explored. Also discussed are the JAK2 inhibitors for clinical trials. Finally, the advantages of the newly proposed World Health Organization classification for myeloproliferative neoplasms are reviewed.