Calreticulin mutation frequency and clinical correlations in patients with chronic myeloproliferative neoplasia in the Çukurova Region

Calreticulin mutation frequency and clinical correlations in patients with chronic myeloproliferative neoplasia in the Çukurova region Background and aims: The presence of the CALR mutation has led to a significant diagnostic and clinical and prognostic progress in a substantial proportion of patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF) without JAK2 mutations. In myeloproliferative diseases, JAK2 mutation was found in 60-65% of all cases, MPL exon 10 mutation in 5% and CALR exon 9 mutation in 20-25% patients. The presence of mutation supports the diagnosis of these diseases. Mutations in the MPL gene occur in 5-10% of patients with ET and PMF. There is evidence that CALR mutation is a predictive value in terms of age, sex, hemoglobin, leukocyte and platelet count, LDH level and clinical bleeding, thrombosis, splenomegaly, hepatomegaly, myelofibrosis transformation and leukemic transformation. We aimed to investigate the relationship between CALR mutation frequency and clinical and prognostic factors in patients with myeloproliferative neoplasia. Material and methods: A total of 110 patients were included in the study, 50 patients with policytemia vera (PV), 56 essential thrombocythemia (ET), and 4 patients with primary myelofibrosis (PMF). JAK2 and MPL mutations were performed by PCR method in all patients. Calreticulin mutation was analyzed by primers in the first step, gene region was identified by sequence analysis in mutation detection samples. Results: Mutations were detected in 76 of all patients (69.1%). CALR mutation was detected in 25.6% of patients without JAK2 and MPL mutations. In patients with CALR mutation, platelet value was significantly higher and hemoglobin value was significantly lower (p <0.05). Platelet level was higher in patients with CALR mutations, but no significant difference was found in terms of thrombosis. In 7 out of 15 patients in whom CALR mutation was detected, insertion (type 2) in 5 base pairs, deletion and insertion in 7, and deletion in one patient were detected. All those with Type 2 CALR mutations were found in patients with essential thrombocytosis. Conclusion: Clinical and laboratory differences were similarly like other studies in CALR mutation. Calreticulin mutation may be a guiding factor in the laboratory and clinical follow-up and prognosis of the patients. Our study of CALR mutation was the first in our region and results similar to other study findings were obtained. Keywords:aCALR,aMPD,aclinical,aprognosis