Derangement of the T-cell repertoire in patients with B-cell non-Hodgkin's lymphoma.

Although a number of studies suggest that different immune pathways may play a role in the pathogenesis of non-Hodgkin's lymphomas (NHL), the shape of the T-cell compartment has been only superficially explored in these patients. In our study, we analyzed the peripheral T-cell receptor (TCR) repertoire and the distribution of different T-cell subsets - including regulatory T cells (Treg) - in 30 patients with NHL, by combining flow cytometry and spectratyping. We first demonstrated by flow cytometry an increased frequency of expanded T-cell subpopulations expressing the same TCR beta variable (BV) subfamilies in CD8+ cells from NHL patients when compared with healthy controls, beside a higher frequency of Treg. Moreover, NHL patients were characterized by a higher percentage of BVs showing a skewed CDR3 profile both in CD4+ and CD8+ cells when analyzed by spectratyping. Our data suggest that the T-cell branch of the immune system of patients with B-cell NHL is deeply deranged, as witnessed by the increased degree of activation and skewing of their TCR repertoire along with the higher frequency of Treg.