BCP first rearrange their immunoglobulin (Ig) heavy chain (IGH) genes to form the pre-B-cell receptor (pre-BCR) complex together with surrogate light chains.
At our institute, we incorporated the use of FGFR3/IGH dual-color dual-fusion DNA probes for confirmation of aneuploidy 4 and 14 in diagnostic B-ALL specimens.
The T-cell epitopes encoded by the IgHV gene in the B-ALL patients were predicted by SYFPEITHI and BIMAS programs and compared with those from 56 representative germline IgHV sequences in the genebank.
In a patient with precursor B-cell acute lymphoblastic leukemia (ALL) associated with eosinophilia that completely responded to induction chemotherapy, we assayed serial remission cerebrospinal fluid and bone marrow specimens for minimal residual disease using a quantitative polymerase chain reaction assay to assess for clone-specific immunoglobulin heavy-chain gene cluster (IGH) gene rearrangement.
We show that the B cell blockage at the pro-B to pre-B cell transition is due to a large homologous deletion in the IGH locus encompassing the IGHM gene leading to the inability to form a functional pre-BCR.
Kaplan-Meier plot analysis revealed no significant difference between adult precursor B-ALL patients with monoclonal or oligoclonal IgH gene rearrangements and their disease-free survival rates.
DNA from 2 patients with pre-pre-B-ALL (CD10-) and 1 patient with common ALL contained rearranged Ig light chain (kappa in two, lambda in one case) in addition to rearranged IgH genes.
As the detection limit of the Southern blot technique is 2-5%, it might well be that small subclones remained undetected, implying that the frequency of subclone formation at the IgH gene level in precursor B-ALL is probably higher than 40%.
We have used a more sensitive, polymerase chain reaction based immunoglobulin gene 'fingerprinting' approach in the analysis of B-cell clonality in eight patients with common ALL which were apparently monoclonal on the basis of Southern blot analysis of their IgH genes.