Budd-Chiari syndrome as the first manifestation of polycythemia vera in young women with inherited thrombophilic state: an aggressive form of myeloproliferative disorder requiring multidisciplinary management

Characterization of myeloproliferative neoplasms in the paediatric and young adult population

The aim of this study was to compare the genomic features and clinical outcomes between paediatric and young adult patients (PAYA, <40 years) and older adults (OA, ≥40 years) with myeloproliferative neoplasms (MPN) to gain insight into pathogenesis, disease prognosis and management. Of 630 MPN patients, 171 (27%) were PAYA with an average age at diagnosis of 31 years. Females were more prevalent in PAYA than OA (71% vs 58%; p = 0.002), and PAYA more frequently presented with essential thrombocytosis (ET) at diagnosis (67% vs 39%; p < 0.001). The presence of a JAK2 somatic mutation was higher in OA (80.4% vs 64.3%; p < 0.001), while a CALR mutation or lack of any traditional driver mutation was more common in PAYA (20.5% vs 10.5%; p = 0.001, 8.8% vs 3.7%; p = 0.01 respectively). Venous thrombosis was more common in PAYA compared to OA (19.8% vs 10.7%; p = 0.002). PAYA had a higher prevalence of familial MPN and familial cancer predisposition, and two PAYA patients harboured pathogenic germline JAK2 lesions. PAYA demonstrated longer survival from diagnosis than OA (median not reached vs 13 years), while disease transformation was less frequent (19.3% vs 37.9%).

Low burden of a JAK2-V617F mutated clone in monoclonal haematopoiesis in a Japanese woman with Budd-Chiari syndrome

Approximately one-half of the cases of Budd-Chiari syndrome (BCS) are caused by bcr/abl negative chronic myeloproliferative disorders (CMPDs). Furthermore, a mutation in the Janus kinase protein (JAK2-V617F) is detected in half of the patients with BCS. However, whether the JAK2 mutation is the primary event leading to CMPDs and BCS is controversial. We present a report concerning a young woman who suffered from BCS prior to the onset of CMPDs. Analysis of X-chromosome inactivation patterns in this patient, using the human androgen receptor gene demonstrated monoclonal haematopoiesis in her granulocytes. In contrast, she had a low burden of a JAK2-V617F mutation positive clone among granulocyte populations. These results suggest that the JAK2-V617F mutation occurs after the onset of monoclonal haematopoiesis; thus the V617F mutation of JAK2 may not be the primary event in the induction of BCS.

Diagnostic usefulness of the Janus kinase 2 mutation in non BCR/ABL myeloproliferative disorders

BACKGROUND

We investigated the Janus kinase 2 (JAK2) mutation and its diagnostic value in patients suffering with non BCR/ABL myeloproliferative diseases (nMPD) or other reactive conditions.

METHODS

We reviewed the clinical records of 83 patients who underwent bone marrow (BM) examinations with suspect of nMPD. The diagnoses of nMPD were made based on the WHO criteria since 2001 and the PVSG criteria before 2001. The JAK2 mutation was examined by PCR in 54 patients whose BM samples were available.

RESULTS

The JAK2 mutation was detected in 25 patients (46%); 12 of 26 patients with essential thrombocythemia (ET), 9 of 12 patients with polycyhtemia vera (PV), one of 7 patients with chronic idiopathic myelofibrosis (CIM) and one patient with unclassifiable MPD. Additionally, JAK2 mutation was detected in each one patient with secondary polycythemia and reactive thrombocytosis. These two patients and two other patients among the JAK2 mutated ET did not meet the WHO PV criteria due to their initial low hemoglobin levels. These patients had liver cirrhosis and hypersplenism due to Budd-Chiari syndrome (1), gastrointestinal bleeding (1) or the initial hemoglobin level was slightly below the level as provided by the criteria, but the level showed a rising pattern despite cytoreductive therapy (2). With the results of the JAK2 mutation available, 4 patients' disease could be re-diagnosed as PV. Finally, the positive rate of the JAK2 mutation was 81% in PV, 48% in ET and 14% in CIM. The presence of JAK2 mutation closely correlated with PV (p = 0.001), leukocytosis (0 = 0.001) and an increased cellularity of BM (p=0.024).

CONCLUSIONS

The JAK2 mutation may help differentiate nMPD from secondary cytosis. Therefore, it should be incorporated into the guidelines for the nMPD work-up for making a more accurate diagnosis and administering proper treatment.

Abdominal vein thrombosis in essential thrombocythemia: prevalence, clinical correlates, and prognostic implications

Among 460 consecutive patients with essential thrombocythemia (ET) seen at our institution, 19 cases (4%) of abdominal vein thrombosis (AVT) were documented either at (n = 9) or after (n = 10) diagnosis. Women (P = 0.03) and the young (P = 0.002) were preferentially affected. Accordingly, clinical comparisons were performed among three groups of female patients: those with AVT (group A; n = 17), a control group without AVT but closely matched to group A in terms of age and year of diagnosis (group B; n = 34), and all female patients without AVT (group C; n = 288). As expected from the consequences of AVT-associated portal hypertension and anticoagulant therapy, patients in group A experienced significantly higher rates of hemorrhage, palpable splenomegaly, and anemia. Unexpectedly, however, compared with group B, group A displayed both a higher conversion rate into myelofibrosis/acute leukemia (P = 0.0008) and a shorter median survival (116 vs. 156 months; P = 0.0012). Multivariable analysis including all female patients with ET identified AVT, along with advanced age, leukocytosis, and tobacco use, as an independent risk factor for inferior survival. Groups A, B, and C did not differ in either JAK2(V617F) mutational frequency or incidence of non-abdominal thrombosis. We conclude that AVT in ET is a marker of aggressive disease biology.

The pathogenesis of venous thromboembolism in cancer: emerging links with tumour biology

Venous thromboembolism (VTE) is a frequent complication in individuals with cancer and is considered to be a cause of substantial mortality. Epidemiological studies identify malignancy as an independent VTE risk factor and show that cancer patients are at increased risk of both initial and recurrent VTE events. The risk due to cancer is compounded by the effects of chemotherapy and other treatments. The pathogenesis of cancer-associated VTE is complex involving multiple interactions between tumours and various components of haemostasis. The development of a systemic hypercoagulable state is considered a key pathogenetic feature and is attributed to tumour expression of tissue factor and other procoagulants, activation of vascular cells by tumour-derived cytokines and adhesive interactions between tumour cells and host cells. An increasing body of evidence indicates that the activation of haemostasis in malignant disease contributes to tumour growth and progression by stimulation of intracellular signalling pathways. The interaction of tissue factor, thrombin and other coagulation factors with protease activated receptor (PAR) proteins expressed by tumour cells and host vascular cells leads to the induction of genes related to the processes of angiogenesis, cell survival and cell adhesion and migration.