Immunoglobulin super-gene family and its related genes in detecting MRD in ALL

OBJECTIVE: To study the rearrangements of the immunoglobulin super-gene family and its related genes, as well as their application in the detection of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL). METHODS: 15 ALL cases including 11 B-ALLs and 3 T-ALLs were studied separately by using immunophenotype detection and molecular clonging methods. RESULTS: Using DNA Southern blot analysis, we found that the rearrangement of IgH gene existed in 11 B-lineage ALL cases. The specific PCR band was visualized through amplification of the CDR3 region and J region of IgH gene. Furthermore, we sequenced the V-D-J junctional region of IgH gene in 3 B-lineage patients and synthesized two probes against the V-D-J junctional region in order to detect MRD. The hybridization results showing the sensitive of the two probes were 10(-4). In addition, we performed comparative study of MRD detection by using both T cell receptor (TCR) gamma gene as gene specific marker and SIL-TAL-1 fusion gene as tumor-specific marker in one T-ALL patient. CONCLUSION: The rearrangements of IgH gene, as well as TCR gene and tumor fusion gene can be used as specific markers in the detection of MRD in ALL.