A clonality analysis based on T-cell receptor beta and delta loci for high-grade gastrointestinal lymphoma in dogs

Abstract

Clonality assays based on antigen receptors are used as adjunct examinations in the diagnosis of lymphoproliferative diseases. We investigated the usefulness of the T-cell receptor beta ( TRB) and T-cell receptor delta ( TRD) loci in clonality assays for high-grade gastrointestinal (GI) lymphoma in dogs. For TRB, we used primers reported previously; for TRD, we designed primers for each of the V and J genes based on genomic sequences. Genomic DNA was extracted from 39 formalin-fixed, paraffin-embedded sections of high-grade GI lymphoma diagnosed histologically. The sensitivity of TRB and TRD primers for GI lymphoma was 41.0% and 38.5%, respectively, which was lower than the 82.1% sensitivity of T-cell receptor gamma ( TRG) primers However, some cases that could not be detected using TRG primers had clonality with either TRB or TRD primers. We found the TRG locus to be more suitable as a first choice for the assay of canine lymphoma clonality than the TRB and TRD loci. However, the detection rate of T-cell clonality may be enhanced using TRB and TRD primers for lymphoma cases not detected using TRG primers.