JAK2V617F , CALR and MPL515L/K mutations and plateletcrit in essential thrombocythemia: A single centre's experience

Abstract

Aims JAK2V617F (JAK2), calreticulin (CALR) and MPL515L/K (MPL) mutations are important in essential thrombocythemia (ET) and may be associated with various clinical consequences of the disease. This study aimed to compare the clinical and haematological parameters of ET patients regarding the mentioned mutations and the role of plateletcrit (PCT). Methods Seventy patients who were diagnosed with ET between 2005 and 2017 in a single centre were included in this descriptive study. The initial symptoms and clinical findings were retrieved from the electronic database. JAK2 gene V617F mutations, MPL gene exon 10 mutations and CALR gene exon 9 DNA sequence analyses were performed. Forty‐one healthy volunteers were included to perform ROC curve analysis for interpreting PCT value. Results The distributions of patients according to the mutations were as follows: Thirty‐seven (52.9%) patients were JAK2‐positive, 15 (21.4%) were CALR‐positive, 2 (2.8%) patients were positive for both CALR and JAK2, and 1 (1.4%) was only MPL‐positive. Fifteen (21.4%) patients were triple‐negative. The ET patients with JAK2 mutation showed a higher level of haemoglobin at the time of diagnosis. The ET patients with CALR mutation presented with higher platelet and LDH levels (P = .002 and P = .001, respectively). The PCT level was higher in the CALR‐positive group when compared to the others (P = .026). A sensitivity value of 97.6% and specificity value of 98.6% were determined regarding PCT% at a cut‐off value of 0.37 in ET patients. In CALR‐positive patients, the sensitivity and specificity values were 100% for the PCT at a cut‐off value of 0.42%. Conclusion We determined that the platelet count and blood LDH level was high in the ET patient group with CALR mutation. Besides, we found that the blood haemoglobin level was higher in the ET patient group with JAK2 mutation. Additionally, the PCT level was higher in the CALR group when compared to the other patient groups.

Impact of CALR and JAK2V617F Mutations on Clinical Course and Disease Outcomes in Essential Thrombocythemia: A Multicenter Retrospective Study in Turkish Patients

“…The majority of our patients (77.8%) were treated with cytoreductive agents. In our study, the overall cytoreduction rate was comparable to that of a Romanian cohort (77.8% vs. 76.8%, respectively), although approximately half of the Romanian patients received cytoreductive therapy without ASA/antiplatelets or anticoagulants [ 23 ]. HU was the most preferred cytoreductive treatment in both patient cohorts.…”

“…In addition, patients with CALR mutations in Tunisian and Belgian cohorts had higher platelet counts and lower hemoglobin levels and leukocyte counts than patients with JAK2 V617F mutations [ 18 , 22 ]. Ceylan et al [ 23 ] showed that patients with CALR mutations presented with higher platelet counts and lactate dehydrogenase levels compared to JAK2 - and MPL -mutated patients. Similarly, in our patient cohort, CALR -mutated patients had significantly higher platelet counts and lower hemoglobin levels (p<0.001).…”

Co‑existence of triple‑negative essential thrombocythemia and double transcript chronic myeloid leukemia: A case report

“…Mutations leading to platelet proliferation in ET have been identified in prospective studies. JAK2V617F mutations are found in 50 to 65% of the patients, CALR exon 9 mutations in 20 to 25%, and MPL exon 10 mutations in 5% (13). Another prospective study done on 40 patients with ET found the most frequent sequence variants were in the TET2 gene, followed by the KIT gene (14).…”