Supplementary Material for: International Reporting Scale of <i>BCR-ABL1</i> Fusion Transcript in Chronic Myeloid Leukemia: First Report from India

Achieving a major molecular response (MMR) is an important predictor of progression-free survival in chronic myeloid leukemia patients treated with imatinib. This requires accurate measurement of <i>BCR-ABL1</i> transcripts normalized to a control gene, as well as defining a level (<i>BCR-ABL1</i>/control gene ratio) that will correlate with sustained clinical response. To make these measurements comparable between laboratories, an international scale (IS) is necessary. A <i>BCR-ABL1</i>/control gene ratio of 0.10% represents MMR in the IS. In collaboration with an international reference laboratory in Adelaide, S.A., Australia, we have established and validated a lab-specific conversion factor for expressing <i>BCR-ABL1</i> transcript levels in the IS. In this report, we explain the process and steps involved in obtaining a valid lab-specific conversion factor for expressing <i>BCR-ABL1</i> transcript levels in the IS.