A multicenter comparison study on the detection of BCR-ABL tyrosine kinase domain point mutation / 中华血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the accuracy and consistency of the detection of BCR-ABL tyrosine kinase domain point mutation among different laboratories.</p><p><b>METHODS</b>Every one of 6 laboratories prepared 10 cDNA samples from tyrosine kinase inhibitors resistant BCR-ABL (P210 or P190) positive patients'bone marrow or peripheral blood. Each cDNA sample was divided into 6 aliquots and delivered to the laboratories. All 6 laboratories tested BCR-ABL point mutations of 60 samples according to their own protocols. Peking University People's Hospital analyzed the comparison results based on both the reports and sequencing chromatogram from all laboratories.</p><p><b>RESULTS</b>All laboratories reported the same nucleotide and corresponding amino acid mutations in 37 samples (61.7%）. Of 60 samples, 53 had confirmed mutation types, and a total of 23 types were included; 1 had no mutation; mutation types of 6 samples could not be determined because of the big differences among chromatograms from different laboratories. Low percentages of mutants were significantly related to results inconsistency (P=0.008). Inconsistent result of one sample was caused by the unique chromatogram of the mutant L248V, and one by the non-coverage amplification of PCR product from different laboratories. Amplification was failed in 3 samples. Testing or sequencing mistakes occurred in 7 samples. The differences in the mutant percentages among laboratories were less than 20% in the 80.6% of samples with confirmed results. Low internal control gene copies (ABL<10 000) were significantly related to both failed amplification and big differences among chromatograms from different laboratories (P=0.005 and <0.001, respectively).</p><p><b>CONCLUSION</b>Problems in the clinical routine detection of BCR-ABL point mutation could be exposed and improvement could be achieved by sample exchange and comparison. Low percentage of mutant is the main reason which causes the discrepancy of BCR-ABL point mutation results among different laboratories.</p>