INTERLEUKIN-10 IN NON-HODGKINS-LYMPHOMA

Interleukin-10 (IL-10) is a pleiotropic cytokine produced by type 2 he lper cells (Th2), as well as by monocytes and macrophages, and normal and neoplastic B lymphocytes. It is highly homologous to an open readi ng frame of Epstein-Barr virus (EBV) called BCRF1, and EBV infection o f B-cells up-regulates IL-10. IL-10 production has strong immunosuppre ssive effects via inhibition of Th1 type cytokines, including interfer on gamma and interleukin-2. On B-cells, IL-10 has a potent stimulating effect, inducing proliferation and differentiation. Interestingly, in cell lines derived from B-cell lymphomas, IL-10 production has been f ound to be up-regulated, and it serves as an autocrine growth factor. In patients with non-Hodgkin's lymphoma (NHL), serum IL-10 levels are significantly increased when compared to normal individuals and NHL pa tients in remission. The prognostic significance of these increased le vels vary according to the assay used. Both human IL-10 and viral IL-1 0 are increased, and when specific assays for human IL-10 are used, th ere seems to be no prognostic significance, whereas when the assay cro ss-reacts with viral IL-10, high levels correlate with poor prognosis. These results suggest that viral IL-10 might have some pathogenic rol e in NHL.