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Practice Paper 6: Answers
Published in Anthony B. Starr, Hiruni Jayasena, David Capewell, Saran Shantikumar, Get ahead! Medicine, 2016
Anthony B. Starr, Hiruni Jayasena, David Capewell
Essential thrombocythaemia (ET) is a myeloproliferative disorder characterized by excessive production of defective platelets derived from abnormal megakaryocytes in the bone marrow. The main complications of ET are due to the formation of thrombi within the microcirculation. Symptoms include headache, digital ischaemia and abdominal pain secondary to splenic infarction. Many patients also suffer from erythromelalgia, i.e. aching and burning of the hands and feet secondary to ischaemia. Occasionally, there is paradoxical bleeding from the mucous membranes, such as the gastrointestinal tract and uterus. Investigation usually shows a platelet count in excess of 1000 × 109/L. The haemoglobin concentration and haematocrit are normal (unless there is significant blood loss, in which case there may be a microcytic anaemia). Definitive diagnosis requires bone marrow aspiration, which typically shows a hypercellular marrow with large numbers of megakaryocytes. Asymptomatic disease often requires no intervention. Severe and symptomatic disease can be treated with chemotherapy, usually with hydroxyurea or interferon-β, and low-dose aspirin.
MPL gene mutation is a possible risk factor for thrombosis in patients with essential thrombocythemia in Japan
Published in Hematology, 2023
Chiho Furuya, Yoshinori Hashimoto, Soji Morishita, Tadaaki Inano, Tomonori Ochiai, Shuichi Shirane, Yoko Edahiro, Marito Araki, Miki Ando, Norio Komatsu
The risk classification of prognosis was estimated according to the International Prognostic Score for Essential Thrombocythemia (IPSET)-survival[11]. The conventional[12], IPSET-thrombosis[13], and revised IPSET-thrombosis[14, 15] risk scoring models were used for estimating the risk of thrombosis. Thrombotic events in the present study included cerebral infarction, transient ischemic attack, myocardial infarction, angina pectoris, peripheral arterial occlusion, pulmonary embolism, deep vein thrombosis, and other events requiring treatment. Overall survival (OS) and thrombosis-free survival (TFS) were calculated as the term from the day at diagnosis to the end of observation and from the day at diagnosis to the onset of arterial and venous thrombosis, respectively. Discontinuation of patient visit and death were considered censored events.
An update on VEXAS syndrome
Published in Expert Review of Clinical Immunology, 2023
In one particularly interesting case study, the patient was noted to have an initial CALR-mutated essential thrombocythemia (ET), which was later out-competed by a separate UBA1 gene mutation (pMet41Leu), with eventual UBA1 clonal dominance and resolution of the ET [17]. CALR mutations are themselves effective driver mutations in myeloproliferative neoplasms and the positive selective pressure of the UBA1 mutation in this patient highlights the strength of the mutant UBA1 survival advantage and raises questions around how this is achieved. One possibility is that the mutant UBA1 alleles create an autoinflammatory microenvironment which predispose these myeloid lineages to survival [17]. Ongoing studies in this area suggest that clonal haematopoiesis (CH) alleles are more commonly seen in VEXAS then previously thought, but the precise effects of co-occurring CH and mutated UBA1 on the clone survival and disease outcomes are yet to be fully characterised [18].
Anticoagulation and bone marrow biopsy: is it safe to proceed?
Published in Hematology, 2021
Cameron Moore, Rouslan Kotchetkov
To assess bleeding after BM biopsy at our institution, we reviewed electronic medical records and surveyed all current and former physicians who have performed BM biopsies from January 2010 to December 2020. Major bleeding was defined as: (1) fatal bleeding; and/or (2) symptomatic bleeding in a critical area or organ, such as intracranial, intraspinal, intraocular, retroperitoneal, intra-articular or pericardial, or intramuscular with compartment syndrome; and/or (3) bleeding causing a fall in hemoglobin level of 20 g/L or more, or leading to transfusion of two or more units of whole blood or red cells [11]. In total, 3,552 BM biopsies were performed. Forty-two percent of patients were males, and forty-eight percent females. Thirteen percent of patients were taking anticoagulants (warfarin, low molecular weight heparins, and DOACs), 32% of patients were taking antiplatelet drugs (ASA, clopidogrel), and 5.5% of patients were on both anticoagulants and antiplatelet agents. Only one incident of major bleeding (0.03%) was reported. This was a 65-year-old female patient with new Essential Thrombocythemia and extreme thrombocytosis (platelet count > 1,200,000 × 109/L) and AVWS. She had post-procedure hemorrhage for three days. There was a drop of hemoglobin of > 20 g/L, requiring hospitalization, desmopressin, tranexamic acid, and urgent initiation of cytoreductive therapy with hydroxyurea. No blood transfusions were necessary. Hemorrhage resolved with a decrease in platelet count to below 800,000 × 109/L.