Immunoregulatory T cells in the peripheral blood of patients with Hodgkin's lymphoma.

We aimed at investigating the distribution of various types of immunoregulatory T cells in the peripheral blood of patients with Hodgkin's lymphoma (HL) (n = 94) being in the state of long-lasting complete remission using flow cytometry. Healthy patients (n = 41) as 'negative' and patients in complete remission with breast cancer (n = 47) as 'positive' controls were investigated in the study. We found significant elevations in the number of CD4+ CD25high naturally occurring regulatory T cells, CD4+/intracellular IL-10+ (Tr1) and CD8+/intracellular IL-10+ T cells in HL compared to the healthy controls. In carcinoma patients, however, the number of Tr1 and CD8+/IL-10+ T cells was higher than that in the other two groups. The increase in the number of CD4+ CD25high T cells seems to be characteristic of HL compared to the two other types of regulatory T cells. This change exists for a long time and it seems to be a characteristic of HL and independent of the types of therapy and the duration of time since therapy. Copyright 2006 S. Karger AG, Basel.