Haematotoxicity in Maintenance Therapy of Children With Acute Lymphoblastic Leukemia: Focus on Genotyping and Phenotyping of Mercaptopurine

On the day of the control patient, (usually the patient is asked for routine control at week 3 on mercaptopurin) routine blood tests are performed. Patients and parents were given an explanation of this study. If patients and parents are willing to take part in the study, they are asked to sign informed consent. Patients who meet the inclusion criteria and do not meet the exclusion criteria, are recorded for demographic data and 5 ml of blood taking. The blood is directly divided into three, 2 mL for hematologic examination and albumin level, 1 mL for genotyping, and 2 mL for examination of drug levels. Routine hematologic examination and albumin levels were performed in the Cipto Mangunkusumo hospital laboratory. For genotypic examination, blood samples were stored at -80C, until they were used for analysis. For examination of the drug levels the blood sample is centrifuged and the erythrocyte preparation is then stored at -80C, until it is used for analysis.