Detection of clonality by polymerase chain reaction in childhood B-lineage acute lymphoblastic leukemia

Summary DNA-based PCR with various sets of primers for TCR /, and Ig heavy chain (IgH) genes were used to study clonality in childhood B-lineage acute lymphoblastic leukemia. Amplification of the IgH CDR-III was observed in 75 of 120 analyzed cases (62.5%). From all analyzed groups, the IgH gene rearrangement was most often observed in pre-B ALL (85.7%) and was rather rare in null-ALL (34.5%). TCR delta gene rearrangement was the most common, and was observed in 77 patients (64.2%). The typical pattern of rearrangements was defined as anincomplete V2 to D3, V2 to D2, or D3 to D3 to D2 recombination product. Rearrangements of TCR gamma gene we observed in 61 cases (50.8%). TCR gamma gene rearrangements were detected predominantly in null-ALL and early B-ALL (55.2% and 60%, respectively) and were rather rare in other groups. Of all eight V segments of VI group, the most frequent gene usage concerns regions V2, V4, and V7. We have confirmed that IgH gene amplification, together with TCR gamma and delta gene amplification, provides a rapid, sensitive approach to assessing clonality in ALL almost in 100% of cases.This work was financed by KBN grants 4.0551.91.01 and 6.6346.92.03