Analysis of ABL kinase domain mutations as a probable cause of imatinib resistance in Chronic Myeloid Leukemia patients of Kashmir

Detection of mutations in CML patients resistant to tyrosine kinase inhibitor: imatinib mesylate therapy

Imatinib mesylate, a tyrosine kinase inhibitor, is the first choice in chronic myeloid leukemia treatment. However, resistance to imatinib may develop with time and in some cases, patients may not respond at all to imatinib. Progressive resistance to imatinib therapy is often due to mutations in the BCR/ABL region. Within the scope of our study 124 patients were evaluated via pyrosequencing between 2015 and 2020. In this regard, 32 patients who have a partial response and have no response to imatinib therapy were included in the study. In addition, next-generation sequencing (NGS) analysis was performed on 15 patients who were resistant to imatinib treatment according to the molecular follow-up reports. With pyrosequencing, 5 cases out of a total of 124 were found to be positive. This means that approximately 4.03% of the proportion is positive. But when we examined only 32 patients who have a partial response and have no response to imatinib therapy this rate is rising 15.6%. NGS analysis was performed with 15 patients who have no mutation with pyrosequencing of 32 patients and VUS (Variant of Uncertain Significance) mutation was detected in one. In this study, our aim was to determine the mutations of the BCR/ABL and to evaluate the mutations by NGS and pyrosequencing. Our study is important in terms of comparing the pyrosequencing with NGS mutation rates, drawing attention to the clinical importance of log reduction.

Effects of dasatinib on CD8+T, Th1, and Treg cells in patients with chronic myeloid leukemia

OBJECTIVE

To investigate the immunomodulatory effects of the tyrosine kinase inhibitor (TKI) dasatinib on T-cell subtypes in patients with chronic myeloid leukemia (CML).

METHODS

T helper (Th) 1, Th2, regulatory T (Treg), and CD8+T cell levels were detected in patients with CML (n = 9) before and after dasatinib treatment. The corresponding response level at the time of a blood test was evaluated.

RESULTS

After dasatinib treatment, six patients achieved a better response level, while three did not show improved response levels. Among the total nine patients, there were no significant differences in Th1, Th2, and Treg cell levels, whereas CD8+T cell levels were significantly increased after dasatinib treatment compared with before treatment. When we analyzed the six patients who obtained a better response level, Th1 and CD8+T cell levels were significantly increased after dasatinib treatment, but Th2 and Treg cell levels did not change. The other three patients who did not have improved response levels showed decreased Th1 cell levels and increased Treg cell levels after treatment.

CONCLUSIONS

Dasatinib may increase Th1 and CD8+T cell levels, and decrease Treg cell levels in patients with CML. This finding might be associated with a good therapeutic response to this drug.