The Association of Glutathione S-Transferase P1 Polymorphism to Imatinib Mesylate Resistance in Chronic Myelogenous Leukemia Patients According to Haematology Response at General Hospital Haji Adam Malik and Branch Hospital in Kota Medan

Abstract

Objective: Variations in the genes coding for drug metabolism enzymes may explain the variability response to treatment. Previous studies reported that GSTP1 polymorphism was associated with the incidence of Imatinib Mesylate resistance as first-line therapy in CML patients. This study aims to determine the association between GSTP1 polymorphism and Imatinib Mesylate resistance in CML patients according to haematology response. Methods: Total of 46 people (consisting of 23 CML patients with Imatinib Mesilat resistance and 23 CML patients without Imatinib Mesilat resistance) at General Hospital H. Adam Malik and branch hospital in Medan City, Indonesia was analyzed in this study. Blood samples were taken for examination of GSTP1 polymorphism through Polymerase Chain Reaction (PCR). Resistance status was taken from medical records based on ELN criteria. Data were analyzed using Fisher's Exact test; p value <0,05 was applied to each statistical test as significant. Result: The distribution of research subjects characteristic was divided into imatinib resistance and non-imatinib resistance groups. In both cases, the highest frequency was found in male (65,2% and 69,6%) in 35-44 years old group (34,8% and 39,1%). In the imatinib resistance group, the highest frequency was found in Javanese (39,1%) and GSTP1 polymorphism Ile/Ile (65,2%). In the non-imatinib-resistant group, the highest frequency was found in Batak tribe (43,5%) and GSTP1 polymorphism Ile/Val (52,2%). This study found 11 cases of leukocytosis and 7 cases of thrombocytosis in the imatinib resistance group. According to statistical measurement, p value was 0,142 (p>0,05). Conclusion: The association of GSTP1 polymorphism to imatinib mesylate resistance in chronic myelogenous leukemia patients according to haematology response was not significant. Keywords: Chronic Myeloid Leukemia, GSTP1 Polymorphism, Imatinib Mesylate Resistance.