Indian Journal of Pathology and Microbiology

ORIGINAL ARTICLE
Year
: 2019  |  Volume : 62  |  Issue : 2  |  Page : 256--260

Distribution of common BCR-ABL fusion transcripts and their impact on treatment response in Imatinib treated CML patients: A study from India


Sudha Sazawal, Sunita Chhikara, Kanwaljeet Singh, Rekha Chaubey, Manoranjan Mahapatra, Tulika Seth, Renu Saxena 
 Department of Hematology, All India Institute of Medical Sciences, New Delhi, India

Correspondence Address:
Renu Saxena
Department of Hematology, All India Institute of Medical Sciences, New Delhi - 110 029
India

Background: Philadelphia chromosome (Ph): Hallmark of CML is caused by reciprocal translocation between chromosomes 9 and 22 resulting in BCR-ABL fusion protein. Most commonly associated breakpoint with CML is M-bcr in exon 13 or exon 14, producing splice variant b2a2 or b3a2 respectively. The distribution of these transcripts and their influence on clinico-hematological parameters is variable. Impact of the fusion transcripts on treatment outcome in Imatinib treated CML patients is still a matter of debate. Aims/settings and design: We conducted this study on 400 CML-CP patients to look for the distribution of fusion transcripts i.e. b3a2 and b2a2, their clinico-hematological profile and impact on treatment response in patients treated with Imatinib. Material and Methods: CML-CP was diagnosed by reverse transcriptase PCR (RT-PCR) for the BCR-ABL fusion transcript. Real-time quantitative PCR (RQ-PCR) was performed on peripheral blood every 3-6 monthly to look for treatment response. Results: The overall frequency of b3a2 transcript was observed in 288 (72%) followed by b2a2 in 104 (26%) and hybrid fusion transcript (b3a2 + b2a2) was seen in 8 (2%) cases. MMR was attained in 198/288 (68.7%) patients with b3a2 transcript and 90/288 (31.3%) patients failed to achieve MMR after 12 months of Imatinib therapy. Among the patients with b2a2 transcript, 44/104 (42.3%) patients achieved MMR and 60/104 (57.7%) patients failed to achieve MMR after 12 months of Imatinib therapy. Conclusions: In conclusion, the frequency of b3a2 transcript was more as compared to b2a2 transcript. MMR was significantly higher in patients with b3a2 transcript as compared to patients with b2a2.


How to cite this article:
Sazawal S, Chhikara S, Singh K, Chaubey R, Mahapatra M, Seth T, Saxena R. Distribution of common BCR-ABL fusion transcripts and their impact on treatment response in Imatinib treated CML patients: A study from India.Indian J Pathol Microbiol 2019;62:256-260


How to cite this URL:
Sazawal S, Chhikara S, Singh K, Chaubey R, Mahapatra M, Seth T, Saxena R. Distribution of common BCR-ABL fusion transcripts and their impact on treatment response in Imatinib treated CML patients: A study from India. Indian J Pathol Microbiol [serial online] 2019 [cited 2020 Aug 6 ];62:256-260
Available from: http://www.ijpmonline.org/article.asp?issn=0377-4929;year=2019;volume=62;issue=2;spage=256;epage=260;aulast=Sazawal;type=0