Molecular measurement of BCR-ABL transcript variations in chronic myeloid leukemia patients in cytogenetic remission

Enigmatic Inv(9): A Case Report on Rare Findings in Hematological Malignancies

Introduction

Inversion of chromosome 9 had been widely discussed among geneticists and evolutionary biologists because of its significant impact on various hereditary disorders and in the evolution of man. The role of such inversions in human disease evolution is an area hitherto unclear.

Case Presentation

We present the case of a chronic myeloid leukemia (CML) patient who showed intermittent relapse on treatment, with a rare appearance of clones with dual inversion (9) breakpoints [inv(9)(p22q34); inv(9)(p11q21)]. We also present the first report of inv(9)(p11,q13) as the sole abnormality in a patient with chronic myeloproliferative disorder(CMPD). Both the patients registered in 2012 and were from Kerala, India.

Conclusions

Both the cases discussed in our study have inv(9) as the sole abnormality and are found to confer a relatively poor prognosis.

Successful nilotinib treatment in a child with chronic myeloid leukemia

A 16-year-old female was diagnosed incedentally with chronic myeloid leukemia (CML) in the chronic phase. She showed complete remission after 3 months of nilotinib treatment. CML is a rare malignant neoplasm in pediatric age. It is characterized by a Philadelphia chromosome, which comes from a genetic translocation between chromosomes 9 and 22. This translocation results in an abnormal fusion called BCR-ABL oncogene which encodes a chimeric BCR-ABL protein. This protein is the underlying cause of CML. Nilotinib is a newly licensed drug for CML in adults. Structurally, it is similar to imatinib (the older tyrosine kinase inhibitor), but it is much more potent in inhibiting BCR-ABL due to its much increased affinity for its binding site. Specific guidelines for CML treatment in children have yet to be determined. In our patient, nilotinib was used as an off-label drug because it is not licensed for children. According to the pharmacokinetic response to drugs, children cannot be considered small adults irrespective of their weight. Off-label drug use based on evidence that it is the best treatment available is an important tool in the hands of expert treating physicians.

Pretherapeutic expression of the hOCT1 gene predicts a complete molecular response to imatinib mesylate in chronic-phase chronic myeloid leukemia

In this retrospective study we evaluated the pretherapeutic mRNA expression of the hOCT1 (human organic cation transporter 1) gene in patients with chronic-phase (CP) chronic myeloid leukemia (CML) who varied in terms of their response to imatinib (IM). hOCT1 mRNA was quantified by real-time PCR. Patients were classified as expressing either high (n = 44) or low hOCT1 mRNA (n = 44). The complete cytogenetic response rates observed at 6, 12 and 18 months were 47.7, 84.1 and 91%, respectively, in patients with high hOCT1 mRNA and 47.5, 81.8 and 86.3%, respectively, in patients with low hOCT1 transcripts. The major molecular response rates were not significantly different between patients with high and low hOCT1 mRNA after 6 months of therapy (22.7 vs. 9.1%; p = 0.07), but they were significantly different after 12 months (54.5 vs. 31.8%; p = 0.026) and 18 months (77.2 vs. 56.8%; p = 0.034). Complete molecular responses were observed in 5 patients with low and 17 patients with high hOCT1 mRNA (p = 0.003). The 5-year event-free and overall survival analyses revealed no significant differences between the groups. These data imply that knowledge of the pretherapeutic level of hOCT1 could be a useful marker to predict IM therapy outcome in treatment-naïve CP CML patients.