T-CELL DYSFUNCTION IN HAIRY-CELL LEUKEMIA - AN UPDATED REVIEW

Hairy cell leukemia (HCL) is clinically associated with severe T-cell dysfunction. Several new observations have given more insight into the abnormal T-cell responses seen in this disease, T-lymphocytes in the spleen of patients with HCL seem to be abnormally activated. On the ot her hand, they are non-responsive, possibly as a result of monocytopen ia which may lead to inadequate antigen presentation. This, together w ith the lack of CD28 on T-cells, may cause T-cell dysfunction. Further more, there is a very restricted repertoire of the T-cell receptor-bet a family, which may also result in non-responsiveness. Otherwise, T-ce ll clonal excess may be indicative for activated, possibly autoreactiv e T-cells.