[Analysis of T-cell receptor delta chain gene in hematological malignancies]

We analyzed the rearrangement of T-cell receptor (TcR) delta chain gene in 196 cases of hematological malignancies. This rearranged band (s) was observed in 15% of the total cases investigated. All T-ALL patients and cell lines, except for P30/Okubo, had a new band (s) or deletion of J delta 1 gene locus, indicating the gamma delta T-cell type or the alpha beta T-cell type. In the other T-cell malignancies, the delta rearranged band (s) was recognized in 5% of T-cell lymphomas, 20% of AILD but not in ATL, Hodgkin's disease, T-CLL. Inappropriate delta rearrangement was frequently recognized in 63% of B-ALL and 50% of CML-BC but none or few (5% less) in B-CLL, B-lymphoma and AML. Southern blotting, using J delta 1 and V delta gene probes or Pst I enzyme digestion, indicated that the inappropriate delta rearranged band in B-ALL and CML-BC is V delta 2D or DD without a J delta locus. The rearranged band (s) involved J delta locus, was mostly recognized in 5/6 cases of CD7 (+) stem cell leukemia. Therefore, the TcR delta gene is useful in evaluating clonality for the most immature T-cell neoplasms, not showing rearrangement of the other TcR genes. Moreover, this delta gene may be a useful tool for distinguishing T-lineage from the other lineages, using the characteristic rearrangement pattern (V delta 2D as a inappropriate pattern, or (D) DJ and V (D) DJ as the T-lineage pattern (s)).