PCR assessment of minimal residual disease in 8 lymphoma-affected dogs

In recent years, the evaluation of lymphoproliferative malignancies by molecular assays has become increasingly popular in human medicine. Since microscopic techniques are often unable to recognise a residual neoplastic population whenever they account for less than 1% of the total cells, molecular tools are mainly used for the assessment of the MRD ( Campana et al., 1995; Rezuke et al., 1997). Many different molecular markers have been evaluated in order to increase the sensitivity of the diagnostic tools; among these, the clonal rearrangements of immunoglobulin (VDJ segments) and TCR receptor (TRCγ V and J segments) genes, have been investigated. A PCR assay for the identification of BCR and TCR clonal rearrangements has also recently validated in veterinary medicine; this assay was used in association with cytology and/or histology for diagnosing lymphoproliferative diseases in dogs (Burnett et al., 2003; Dreitz et al., 1999; Vernau et al., 1999). The aim of this work was to evaluate the usefulness of this PCR assay in identification of MRD in lymphoma-affected dogs, in order to modulate therapeutic protocols to obtain longer remission times.