Related Experiment Video
Updated: Nov 27, 2025
Engineering Oncogenic Heterozygous Gain-of-Function Mutations in Human Hematopoietic Stem and Progenitor Cells
Published on: March 10, 2023
The risk of thrombosis in essential thrombocythemia is associated with the type of CALR mutation: A multicentre
Manuel M Pérez Encinas1, Marta Sobas2, María Teresa Gómez-Casares3
1Hematology Department, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Galicia, Spain.
Objectives:
In patients with essential thrombocythemia (ET), after the JAK2V617F driver mutation, mutations in CALR are common (classified as type 1, 52-bp deletion or type 2, 5-bp insertion). CALR mutations have generally been associated with a lower risk of thrombosis. This study aimed to confirm the impact of CALR mutation type on thrombotic risk.
Methods:
We retrospectively investigated 983 ET patients diagnosed in Spanish and Polish hospitals.
Results:
With 7.5 years of median follow-up from diagnosis, 155 patients (15.8%) had one or more thrombotic event. The 5-year thrombosis-free survival (TFS) rate was 83.8%, 91.6% and 93.9% for the JAK2V617F, CALR-type 1 and CALR-type 2 groups, respectively (P = .002). Comparing CALR-type 1 and CALR-type 2 groups, TFS for venous thrombosis was lower in CALR-type 1 (P = .046), with no difference in TFS for arterial thrombosis observed. The cumulative incidence of thrombosis was significantly different comparing JAK2V617F vs CALR-type 2 groups but not JAK2V617F vs CALR-type 1 groups. Moreover, CALR-type 2 mutation was a statistically significant protective factor for thrombosis with respect to JAK2V617F in multivariate logistic regression (OR: 0.45, P = .04) adjusted by age.
Conclusions:
Our results suggest that CALR mutation type has prognostic value for the stratification of thrombotic risk in ET patients.
More Related Videos
Related Concept Videos
01:25Imaging Studies for Cardiovascular System VI: Calcium -Scoring CT
01:30Anticoagulant Drugs: Low-Molecular-Weight Heparins
01:23Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...