Effects of cyclosporin A on refractory B-cell chronic lymphocytic leukemia.

This report details the effects of cyclosporin A (Cs-A) on the clinical course of B-cell chronic lymphocytic leukemia (B-CLL) with an increase in circulating T cells that express CD3, CD8, CD25, CD45RO, and T-cell receptor alpha beta chain. Cs-A was used for treatment of a female patient with refractory B-CLL and was shown to increase dramatically the number of leukemic B cells in association with a simultaneous increase in T cells in vivo. To study this effect more precisely, CD19+ (B cells) and CD3+ (T cells) cells were isolated from the patient and cultured in the presence or absence of Cs-A. When Cs-A was added to the culture, no cell stimulation was seen. However, CD3+ cells from the patient underwent cell death, relative to those from healthy donors. On the other hand, CD19+ cells from the patient were more resistant to Cs-A than those from healthy donors. Because in vitro experiments cannot explain this phenomenon of Cs-A increasing leukemic cells (not only B-CLL cells but also T cells), care should be exercised in the clinical use of Cs-A in B-CLL patients.