Publication details
IgG-Switched CLL Has a Distinct Immunogenetic Signature from the Common MD Variant: Ontogenetic Implications
| Authors | |
|---|---|
| Year of publication | 2014 |
| Type | Article in Periodical |
| Magazine / Source | Clinical Cancer Research |
| MU Faculty or unit | |
| Citation | |
| web | http://clincancerres.aacrjournals.org/content/20/2/323.long |
| Doi | http://dx.doi.org/10.1158/1078-0432.CCR-13-1993 |
| Field | Oncology and hematology |
| Keywords | CHRONIC LYMPHOCYTIC-LEUKEMIA; B-CELL RECEPTOR; GENE MUTATIONAL STATUS; SOMATIC HYPERMUTATION; CLONAL EVOLUTION; UNMUTATED CLL; ANTIGEN; RECOMBINATION; ACTIVATION; EXPRESSION |
| Description | Purpose: Immunoglobulin G-switched chronic lymphocytic leukemia (G-CLL) is a rare variant of CLL, whose origin and ontogenetic relationship to the common IgM/IgD (MD-CLL) variant remains undefined. Here, we sought for clues about the ontogeny of G-CLL versus MD-CLL by profiling the relevant IG gene repertoires. Experimental Design: Using purpose-built bioinformatics methods, we performed detailed immunogenetic profiling of a multinational CLL cohort comprising 1,256 cases, of which 1,087 and 169 expressed IG mu/delta and gamma heavy chains, respectively. Results: G-CLL has a highly skewed IG gene repertoire that is distinct from MD-CLL, especially in terms of (i) overuse of the IGHV4-34 and IGHV4-39 genes and (ii) differential somatic hypermutation (SHM) load. Repertoire differences were also found when comparing subgroups with similar SHM status and were mainly attributed to the exclusive representation in G-CLL of two major subsets with quasi-identical (stereotyped) B-cell receptors. These subsets, namely #4 (IGHV4-34/IGKV2-30) and 8 (IGHV4-39/IGKV1(D)-39), were found to display sharply contrasting SHM and clinical behavior. Conclusions: G-CLL exhibits an overall distinct immunogenetic signature from MD-CLL, prompting speculations about distinct ontogenetic derivation and/or immune triggering. The reasons underlying the differential regulation of SHM among G-CLL cases remain to be elucidated. (C) 2013 AACR. |
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