Construction of a multicolor GeneScan analytical system to detect clonal rearrangements of immunoglobulin and T cell receptor genes in canine lymphoid tumors.

Polymerase chain reaction (PCR) amplification to detect immunoglobulin heavy chain (IgH) and T cell receptor γ-chain (TCRγ) gene rearrangements has recently become widely used as part of the diagnostic strategy for lymphoid tumors in dogs. In this study, we constructed a multicolor GeneScan analytical system to improve the sensitivity and resolution of the clonality analysis of antigen receptor gene rearrangements in dogs. We used 7 reactions per sample, with 2 PCR conditions, to amplify IgH/TCRγ and control genes. By using multicolor-labeled primers, these 7 PCR products could be combined into 3 tubes before capillary electrophoresis. Clonal rearrangement of the IgH/TCRγ genes was detected in 93.3% of dogs with multicentric lymphoma and 84.6% of dogs with gastrointestinal lymphoma. Detection sensitivity of the clonally expanded cells in the background of normal peripheral blood mononuclear cells was 1-10%. The multicolor GeneScan analytical system developed here may prove to be helpful for the diagnosis of lymphoid tumors in dogs.