Proposed algorithm for the best detection of different bcr-abl gene fusion transcripts in molecular diagnostics laboratories: experience of a major referral center.

AIMS: Detection of bcr-abl transcripts is important both in diagnosis as well as in prognostication and treatment modalities of different types of leukemia, both chronic and acute. However, the techniques employed are variable and different among laboratories. Our aim was to share with other labs a strategy/algorithm that we find highly useful for implementation to best detect all bcr-abl fusion transcripts for proper patient management.

METHODS: We have used two techniques for the detection of bcr-abl transcripts, an in-house developed polymerase chain reaction and a real-time quantitative commercial polymerase chain reaction (PCR) kit and tested 849 patients referred for initial screening for bcr-abl.

RESULTS: Out of 849 cases, 146 (17.2%) were positive for bcr-abl. Around 92.11% of the total bcr-abl positive cases (N=76) detected by the real-time quantitative technique were also positive by the gel-based PCR assay; however, six cases (around 7.89%) were missed by the real-time assay and detected by the other technique in chronic myelogenous leukemia-proven cases.

CONCLUSION: We highly encourage other laboratories to perform testing using a simple and inexpensive gel-based PCR screening assay followed by a real-time quantitative assay for a baseline bcr-abl expression level. This combination will enable laboratories to detect all the reported fusion transcripts in accordance with the clinical presentation of the patient as well as other laboratory tests for the best use of this genetic test in patient management and care.