Two faces of ET: CALR and JAK2

Area of Science:

• Hematology
• Oncology
• Molecular Biology

Background:

• Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by high platelet counts.
• JAK2 and CALR mutations are key drivers in ET pathogenesis.
• Understanding genotype-phenotype correlations is crucial for risk stratification.

Purpose of the Study:

• To compare clinical and laboratory features of ET patients with CALR mutations versus JAK2 mutations.
• To assess the impact of mutation status on thrombosis risk and disease course.

Main Methods:

• Retrospective analysis of ET patient data.
• Comparison of hematological parameters (hemoglobin, leukocytes, platelets) between mutation groups.
• Evaluation of thrombosis incidence based on mutation type.

Main Results:

• CALR-mutated ET patients exhibited significantly lower leukocyte and hemoglobin levels compared to JAK2-mutated ET.
• Platelet counts were higher in the CALR-mutated group.
• A reduced risk of thrombosis was observed in patients with CALR mutations.

Conclusions:

• ET with CALR mutations represents a distinct clinical and molecular entity.
• CALR-mutated ET follows a more indolent clinical course with a lower thrombosis risk.
• These findings support distinct therapeutic and monitoring strategies based on mutation status.