Using inverse polymerase chain reaction, we identified CD44, located on chromosome 11p13, as a novel translocation partner of IGH in 9 of 114 cases of gastric, nongastric extranodal, follicular, and nodal diffuse large B-cell lymphoma (DLBCL).
High levels of clonal IGHV SHM (SHM<sup>high</sup>) were associated with prolonged overall survival in DLBCL patients, particularly those without BCL2 or MYC translocation.
However, the complemented analysis using Multi-FISH and/or chromosomal whole paint enabled the characterization of complex IGH translocations in follicular lymphomas and mantle cell lymphomas and the identification of all the chromosomal partners involved in the IGH rearrangement in diffuse large B-cell lymphomas.
FISH screening of a population-based cohort of B-cell lymphomas from a prospective trial for the treatment of lymphoma in childhood (BFM-NHL) identified additionally a follicular lymphoma Grade 3/diffuse large B-cell lymphoma with IGH-CBFA2T3/ACSF3 juxtaposition.
Immunoglobulin gene rearrangement studies showed a clonal rearrangement of the IGH gene in both HS and DLBCL with identical amplicons, suggesting a shared origin of the neoplastic clones.
The biological significance of BAFF signalling in t(11;18)(q21;q21)-negative lymphoma cells was further studied in two types of lymphoma B cell: OCI-Ly3 [non-germinal centre B-cell origin DLBCL without t(11;18)(q21;q21) cell line] and MA-1 [t(14;18)(q32;q21)/IGH-MALT1-positive DLBCL cell line].
However, the complemented analysis using 24-color FISH, chromosomal whole paints, telomeric probes and locus specific identifiers enabled us to characterize complex and/or masked IGH translocations in follicular lymphomas and mantle cell lymphomas and to identify all the chromosomal partners involved in IGH rearrangements in diffuse large B-cell lymphomas.
Immunoglobulin heavy chain locus variable gene segment V4-34 (V(H)4.21) use in productive heavy chain (IgH) gene rearrangements has been described in a number of human reactive and autoimmune B cell responses, and has been shown to be frequently used in some series of cases of diffuse large cell lymphoma (DLCL).