CD80 antigen expression as a predictor of ex vivo chemosensitivity in chronic lymphocytic leukemia.

We investigated the correlation between expression of 31 surface membrane antigens and chemosensitivity of peripheral blood mononuclear cells from 36 patients with CLL. The sensitivity of CLL cells to nine drugs (2'-chlorodeoxyadenosine, cisplatin, chlorambucil, cyclosporin A, doxorubicin, fludarabine, prednisolone, verapamil and vincristine) and two types of irradiation (gamma and UV-irradiation) was determined from dose-response curves of 4-day cultures ex vivo. The results indicated that the CLL cases responding to purine analogs (2'-chlorodeoxyadenosine and fludarabine) can be identified according to CD80 expression: all resistant cases had low or negative CD80 expression. No other correlations were revealed. CD80 may be a surrogate chemosensitivity marker for purine analogs.