JAK2 or CALR Mutations Status and Bone Marrow Histology in Patients with Essential Thrombocythemia in Chinese

Abstract

<jats:title>Abstract</jats:title> <jats:p><jats:bold>Objectives:</jats:bold> To characterize the clinical, and bone marrow histopathological features of essential thrombocythemia (ET) with different gene mutations status of CALR and JAK2.<jats:bold>Methods:</jats:bold> 159 patients of ET were centrally analyzed from January 2016 to December 2019, including 59 cases with CALR mutation, 96 JAK2 mutation, 2 MPL mutation, and 2 cases were triple-negative (TN). Bone marrow pathology observation and determination were performed by 2 immobilized experienced morphological specialists.<jats:bold>Results:</jats:bold> Compared to ET with JAK2 mutation, patients with CALR mutation were younger (p=0.000), showed lower count of white blood cell (WBC) and level of hemoglobin (p=0.001, p=0.001), and higher count of platelet (p=0.001). In the bone marrow (BM) biopsy, the median number of megakaryocyte and clusters of megakaryocytes in each high power field (HPF) of vision in patients with CALR mutations were lower than JAK2 mutations patients (p=0.001, p=0.001), thrombotic events in two group was different (5% vs 11.5%) (p=0.03).<jats:bold>Conclusion: </jats:bold>In Chinese ET patients, patients with CALR mutations were younger, and had lower levels of Hb, and count of WBC, the lower thrombotic evens although with higher platelet counts than those with JAK2 mutation. Patients with JAK2 mutations had a higher median number of megakaryocytes and median number of clusters of megakaryocytes, the clinical significance is worth exploring.</jats:p>