Analysis of CALR-mutated essential thrombocythemia as a distinct disease entity compared with JAK2 V617F-mutated and triple-negative patients

Background/aim: Calreticulin (CALR) mutations in essential thrombocythemia (ET) are associated with younger age, higher platelet counts, and lower thrombosis rates. The present study analyzes the demographic, laboratory, and clinical features of the CALR mutation and its prognostic impact. Materials and methods: The clinical impact of CALR mutations was assessed in 391 ET patients. Results: /L were associated with a lower incidence of arterial thrombosis. Age <60 years was associated with lower risks of arterial and venous thrombosis. Overall, thrombosis-free, and leukemia-free survival were similar across all groups, while myelofibrosis-free survival was longer in the type 2 CALR-mutation group. Conclusion: The CALR mutation was lower among females, and was associated with lower leukocyte counts, and Hb and Hct levels, and with higher platelet counts. In multivariable analysis, the apparent protective association of CALR with thrombosis was not independent.