Expression of lineage markers using real-time quantitative polymerase chain reaction (RT-qPCR) in normal and in leukemia bone marrow

Abstract

The study of lineage markers by real-time quantitative polymerase chain reaction (RT-qPCR) at diagnosis enables differentiation between acute myeloblastic leukemia, B- or T-lineage acute lymphoblastic leukemia, without cell sorting. Our objective was to assess the relationship between protein expression and the amount of lineage marker mRNA in acute leukemia samples and to determine whether four lineage markers could be used to differentiate between normal and acute leukemia bone marrow (BM) without cell sorting. Quantification of the mRNA of CD19, CD79a, CD3e, and myeloperoxidase was performed by RT-qPCR on 130 acute leukemia BM samples at diagnosis and on 20 BM samples from healthy donors, without cell sorting. Immunophenotyping of leukemia samples was performed after manual gating around the blastic population. Reference values for the four lineage markers were established by RT-qPCR for normal BM. The mRNA expression levels of these four lineage markers allowed the distinction between normal samples and 100% of acute leukemia samples. With 92% congruence for protein expression and amount of mRNA in acute leukemias, these four lineage markers, essential for diagnosis and subclassification of acute leukemias by flow cytometry, also represent excellent candidate genes when using RT-qPCR technology as a diagnostic tool for molecular cancer class prediction.