Abstract
CD4+ T lymphocytes appear to be the preferential target for replication of HHV-6 (human herpes virus) as well as HHV-7 viruses in vivo. In addition, CD8+ T cells, monocytes/macrophages, natural killer cells, epithelial, endothelial, neural cells and fibroblasts may be infected. By definition, however, even a tumour designated by pathologists to be early stage may be late stage when considered by the immune system. Certainly, even early stage tumours have evaded immune control, suggesting that they have acquired many immunosuppressive characteristics. The aim of the study was to clarify the influence of beta-herpes viruses on cellular immune response. In 95 gastrointestinal cancer patients we determined the immunocompetent cell level CD3, CD4, CD8, CD19, CD38, CD95, CD25 using laser flow cytofluorimeter and B- herpes viruses HHV-6, HHV-7 presence using a nested polymerase chain reaction method. Our data showed no statistically significant difference in immunocompetent cell level between negative, latent and active HHV-6, HHV-7 infection. Patients with immunocompromised immune status (lymphopenia) had a tendency to decreased CD4+, CD19+ absolute count. It may be suggested that virus-mediated immune response inhibition seems to be similar to cancer mediated, but differences in immune response among the same group of individuals had no influence on the average number of the immunocompetent cells in the group. Therefore, to characterise host-virus-tumour interactions, individual interpretation of each case is needed.