Introduction:Chronic Myeloid Leukemia (CML) is myeloproliferative neoplasm characterized by translocation of chromosome 9 and 22, result in Philadelphia chromosome and creating the fusion oncogene BCR-ABL1 with constitutively active tyrosine kinase in haemopoietic progenitor. In the era of tyrosine kinase inhibitor (TKI) treatment, outcome of CML patients has significantly increased, including in Indonesia, where the treatment is already covered by National Health Insurance System. However, challenges with sub optimal and failure of TKI treatment have been reported.
Case and discussion:Chronic phase of CML was found in a 46 year old male in November 2017, with 1.5% blast in bone marrow (BM). His haemoglobin (Hb) was 13.3 g/dL, platelet (PLT) 230x103/uL, and leukocyte (WBC) 61x103/uL, with 1% blast, 3% basophil, and left shifted neutrophil. BCR-ABL1 was positive. The patient was treated with Imatinib for 11 months and then converted to Nilotinib. In February 2019, patient Hb was 12.7 g/dL, PLT 87x103/uL, and WBC 4.4x103/uL, with 62% blast. BM aspiration found 70% myeloblast, confirmed the progression to blast phase. Immunophenotyping was positive with CD 34, HLA DR, CD 13, CD 33, CD 117, and negative with CD 3, CD 5, CD 7, CD 10, CD 19, CD 20, consistent with myeloid lineage. The patient passed away within 3 months after blast phase detected. Cytogenetic testing and quantitative BCR-ABL1 assay which is important for therapy monitoring are available in limited facilities and not covered by the Insurance, that may lead to delay in monitoring molecular response. Most CML patients are monitored with hematological parameters.
Conclusion:blast phase of CML was found in a 47 year old male who was treated with Imatinib continued with Nilotinib, showing resistance to TKI. This case shows the need to enhance the role of the clinical laboratory in Indonesia for CML treatment monitoring.