Successful treatment of refractory pure red cell aplasia secondary to chronic lymphocytic leukaemia with cyclosporine A: correlation between clinical and in vitro effects.

This report presents the case of a patient with PRCA in CLL where in vitro culture studies correlated well with successful CS-A treatment. Before initiating CS-A therapy, coculture studies showed that T-cells from peripheral blood of the patient suppressed the formation of CFU-E and BFU-E colonies by normal bone marrow cells. Normal erythropoiesis reappeared in the bone marrow of the patient 3 weeks after the start of CS-A therapy. At this time, cocultures demonstrated that peripheral blood T-cells no longer inhibited the growth of normal BFU-E, although there was persistent suppression of CFU-E. Six months later the patient was in stable remission from PRCA on maintenance therapy with CS-A. Moreover, cocultures showed no T-cell inhibition of normal BFU-E or CFU-E colony formation. The strong correlation between in vitro culture studies and a beneficial clinical outcome observed in this case suggests that in vitro cultures could be used to monitor CS-A treatment in patients with PRCA in CLL.