Case report: Peri-procedural hydroxyurea helps minimize bleeding in patients with Essential Thrombocythemia associated with acquired von Willebrand syndrome

Background

Essential Thrombocythemia is a chronic myeloproliferative neoplasm characterized by an isolated excessive production of platelets. Extreme thrombocytosis is defined by having a platelet count greater than or equal to 1,000 x 109/L, which may lead to the development of acquired von Willebrand syndrome and complications of excessive hemorrhage.

Case description

A 74-year-old female patient was brought in for a bone marrow examination regarding elevated platelet count. She had no history of excessive bleeding. The physical exam was unremarkable with no petechiae or hematomas. Complete blood count showed platelet count 1,491x109/L. Bone marrow aspiration and biopsy were unremarkable, however, the patient developed bleeding from the biopsy site. Local pressure and an ice pack were ineffective, so she received 20 mcg of desmopressin subcutaneously, 1 unit of fresh frozen plasma and was started on tranexamic acid 1,000 mg orally every 8 hours. She was admitted for bleeding control and had another dose of desmopressin. Blood work showed elevated partial thromboplastin time and normal international normalized ratio. Acquired von Willebrand syndrome was suspected and a sample for von Willebrand disease was sent out. The next day her bleeding continued, and her Hb decreased from 145 to 89 g/L, she became symptomatic (tachycardic) and fatigued. The coagulation profile was consistent with acquired von Willebrand syndrome. Since she continued bleeding, she received 1 unit of packed red blood cells. A high dose of hydroxyurea (3g/day) was started urgently; within 24 hours platelet count was halved, and the bleeding resolved. Blood work was repeated 24 hours later and showed normalization of partial thromboplastin time and a normal Von Willebrand profile.

Conclusion

Patients with extreme thrombocytosis are at high risk of bleeding due to acquired Von Willebrand Syndrome. Initiation of hydroxyurea at the time of bone marrow exam helps to control platelet count and minimizes the risk of peri-procedural hemorrhage in high-risk Essential Thrombocythemia patients with suspected acquired Von Willebrand Syndrome.

Effectiveness of Ropeginterferon Alfa-2B in High-Risk Patients with Philadelphia Chromosome Negative Myeloproliferative Neoplasms- Evaluation of Clinicohaematologic Response, and Safety Profile: Single Centre Experience

Background: Treatment of Philadelphia chromosome negative myeloproliferative neoplasms (Ph - MPNs) requires individualized approach depending on multiple factors. Novel pegylated Interferon (IFN) formulations have become an attractive therapeutic option in young Ph- MPN patients associated with better patient compliance. Methods: In this retrospective observational study a total of 16 high-risk Ph- MPN patients treated off-label with ropeginterferon alfa-2b given twice monthly, were included. Median follow-up was 24 months. High-risk patients were defined using the IPSET score. Response to treatment was evaluated using ELN, IWG-MET EUMNET standardized criteria and occurrence of side effects was documented. Results: 11 patients were female (68.8%) and 5 male (31.2%); average age at diagnosis was 36 years (17-51); 12 patients (75%) had ET, one (6.2%) PV and three (18.8%) hypercellular phase of PMF. JAK2V617F mutation was detected in 10 patients (62.5%), CALR in three (18.8%), and three (18.7%) were triple-negative cases. In 7 patients (43.7%), ropeginterferon alfa-2b was used in first-line, and 9 (56.3%) were previously treated with HU and/or standard IFN. Among initially ropeginterferon alfa-2b treated patients, complete haematological response was observed in 4/7 (57.1%), partial in 2/7 (28.6%) and suboptimal in one (14.3%). Complete haematological response was observed in 8/9 (88.9%) among previously treated patients. Average time to blood count normalization was 8 weeks, at a dose ranging between 100mcg and 300mcg. Side effects were observed in one patient (6.2%). Conclusion: Our experience is in support of previous studies regarding ropeginterferon alfa-2b efficacy and safety profile in the treatment of young patients with Ph- MPNs.

A Rare Case of Essential Thrombocythemia with Coexisting JAK2 and MPL Driver Mutations

Philadelphia-negative (Ph-) classical myeloproliferative neoplasms (MPNs) include polycythemia vera, essential thrombocythemia (ET), and primary myelofibrosis. Somatic driver mutations in the JAK2, CALR, and MPL genes serve as major diagnostic criteria of the Ph- MPNs and these mutations occur in a mutually exclusive manner. In this report, we describe the first case of ET harboring double mutations in JAK2 V617F and MPL. For MPL, the patient had multiple clones of MPL mutations: c.1543_1546delinsAGGG (p.Trp515_Gln516delinsArgGlu) and c.1546C>G (p.Gln516Glu). The JAK2 V617F allele burden in our patient is very low (4%) compared to the relatively high (17%-78%) allele frequency of MPL mutations. The low JAK2 mutant burden might be explained by preexisting clonal hematopoiesis before overt signs of MPNs, followed by the acquisition of a second oncogenic mutation of CALR or MPL leading to the MPN phenotype. This highlights that screening for a second driver mutation should be considered in patients with a low JAK2 mutant burden by reporting a 57-year-old Korean man with ET.

Cardiovascular Risk in Essential Thrombocythemia and Polycythemia Vera: Thrombotic Risk and Survival

Thromboembolic and bleeding events pose a severe risk for patients with Polycythemia Vera (PV) and Essential Thrombocythemia (ET). Many factors can contribute to promoting the thrombotic event due to the interaction between platelets, leukocytes, and endothelium alterations. Moreover, a significant role can be played by cardiovascular risk factors (CV.R) such as cigarette smoking habits, hypertension, diabetes, obesity and dyslipidemia. In this study, we evaluated the impact that CV.R plays on thrombotic risk and survival in patients with PV and ET.

High platelet count at diagnosis is a protective factor for thrombosis in patients with essential thrombocythemia

To assess the role of platelet (PLT) count for thrombotic complications in Essential Thrombocythemia (ET), 1201 patients followed in 11 Hematological centers in the Latium region were retrospectively evaluated. At multivariate analysis, the following factors at diagnosis were predictive for a worse Thrombosis-free Survival (TFS): the occurrence of previous thrombotic events (p=0.0004), age>60years (p=0.0044), spleen enlargement (p=0.042) and a lower PLT count (p=0.03). Receiver Operating Characteristic (ROC) analyses based on thrombotic events during follow-up identified a baseline platelet count of 944×10⁹/l as the best predictive threshold: thrombotic events were 40/384 (10.4%) in patients with PLT count >944×10⁹/l and 109/817 (13.3%) in patients with PLT count <944×10⁹/l, respectively (p=0.04). Patients with PLT count <944×10⁹/l were older (median age 60.4years. vs 57.1years., p=0.016), had a lower median WBC count (8.8×10⁹/l vs 10.6×10⁹/l, p<0.0001), a higher median Hb level (14.1g/dl vs 13.6g/dl, p<0.0001) and a higher rate of JAK-2-V617F positivity (67.2% vs 41.6%, p<0.0001); no difference was observed as to thrombotic events before diagnosis, spleen enlargement and concomitant Cardiovascular Risk Factors. In conclusion, our results confirm the protective role for thrombosis of an high PLT count at diagnosis. The older age and the higher rate of JAK-2 V617F positivity in the group of patients with a baseline lower PLT count could in part be responsible of this counterintuitive finding.

(32)P in the treatment of myeloproliferative disorders

(32)P has been available for the treatment of myeloproliferative neoplasms (MPNs) for over seventy years. It was first used in 1938 by John H Lawrence in the treatment of polycythaemia and chronic leukaemias. With the introduction of agents such as hydroxycarbamide, interferon and anagrelide the role of (32)P has been diminished. Today, Polycythaemia Rubra Vera (PRV) and Essential Thrombocythaemia (ET) remain the only myeloproliferative conditions in which (32)P is indicated.

MATERIALS AND METHODS

We carried out a retrospective review of all patients who had received 32P in Northern Ireland over a 24 year period. The time to successful response, duration of response, and associated complications were reviewed.

RESULTS

(32)P was successful in inducing remission in 90% of patients. This remission was sustained following one dose without the need for further therapy in 37% of cases. 47% required repeated doses. 26% required recommencement of alternative therapies. No cases of thrombosis, myelofibrosis or acute leukaemia were observed.

DISCUSSION

We conclude that (32)P is a well-tolerated and efficacious treatment option in the elderly. We discuss our results compared with previous work in this area. (32)P will continue to be offered to elderly patients in our practice.

Pretreatment with hydroxyurea of the patient with essential thrombocythemia followed by coronary artery bypass surgery

The risk of thrombosis is high in patients with essential thrombocythemia. Special precaution needed for those patients who will undergo Coronary artery bypass grafting. We are reporting a 62 years old patient with ischemic heart disease who was found to have essential thrombocythemia. This report explains the preoperative management and the postoperative risks anticipated due to the treatment.

Dkk3 levels in patients with myeloproliferative neoplasms

INTRODUCTION

Dickkopf-3 (Dkk3) has been proposed as tumor suppressor gene and a marker for tumor blood vessels and has pro-angiogenic properties. Dkk3 is expressed in platelets and megakaryocytes from healthy controls and patients with BCR-ABL1-negative myeloproliferative neoplasms (MPN). The aim of this study is, to find out whether patients with MPN have higher Dkk3 serum levels than normal controls.

MATERIAL & METHODS

We analyzed Dkk3 serum levels with ELISA in patients with newly diagnosed and untreated MPN, including 10 essential thrombocythemia (ET), 10 polycythemia vera (PV), 10 primary meylofibrosis (PMF) and 10 healthy blood donors and correlated these findings with biological and clinical key data and the JAK2-V617F status. Dkk3 levels were corrected to platelet count, Dkk3c, as patients with MPN have higher platelet counts than controls.

RESULTS

As expected, patients with MPN have higher platelet counts than normal controls. Dkk3 serum levels of patients with MPN (5.4 ± 6.1 ng/ml) showed no significant difference compared to normal controls (4.4 ± 3.8 ng/ml). Regarding Dkk3c, a significant difference to controls was found in PV (8.5 ± 8.7 ng/ml; p=0.04), but not in ET and PMF (5.7 ± 3.8 ng/ml; p=0.07 and 2.7 ± 3.6 ng/ml; p=0.9; respectively. Dkk3c correlated with the JAK2-V617F mutational burden (p=0.014, Rho=0.445).

CONCLUSION

Dkk3 levels corrected to platelet count showed higher levels in PV than normal controls. Elevated Dkk3c level could possibly correlate to platelet activation in PV patients and increased Dkk3 release. Whether this remains a surrogate marker of platelet release or it contributes to the thrombophilic state through its pro-angiogenic properties remains to be shown.