Elevated telomerase activity in essential thrombocythemia with extreme thrombocytosis

We performed a comparative analysis of telomerase activity (TA) in patients with myeloproliferative neoplasm (MPN) and myelodysplastic syndrome (MDS). The relationships between TA and known prognostic factors were also analyzed.

A telomeric repeat amplification protocol was performed with bone marrow hematopoietic cells from 96 normal controls, 44 MPNs, and 40 MDSs.

TA (measured as molecules/reaction) showed no correlation with age in the control group (R(2)=0.0057, p=0.464). MPN showed elevated TA compared with controls (15,537.57 vs. 7775.44, p=0.020). Patients with essential thrombocythemia showed markedly elevated TA (22,688.56, p=0.030), particularly in cases with extreme thrombocytosis versus those without extreme thrombocytosis (34,522.19 vs. 9375.71, p=0.041). MDS patients showed a TA value of 7578.50.

There was no association between age and TA in bone marrow hematopoietic cells. TA was elevated in MPN but borderline in MDS, probably because of differences in the nature of the diseases. Elevated TA in patients with essential thrombocythemia, especially those with extreme thrombocytosis, suggests that an anti-telomerase strategy could be beneficial in the prevention of thrombotic complications.