Alpha-interferon and lymphokine-activated killer cells in hairy cell leukemia.

Lymphokine-activated killer (LAK) cell activity generated from peripheral blood was tested in 6 patients with typical hairy cell leukemia, 3 not on treatment with alpha-interferon (alpha-IFN) and 3 receiving therapy. In all cases, substantial killing of the LAK-sensitive target Daudi was observed, but hairy cells, whether or not they had been pretreated with alpha-IFN, were uniformly resistant to LAK lysis. The hairy cells were also resistant to LAK cell killing generated from normal peripheral blood mononuclear cells. alpha-IFN added at various times during LAK generation had little or no effect on LAK activity. It is concluded that LAK cells are not important in mediating the beneficial effects of alpha-IFN in hairy cell leukemia.