Possible interferon response in a child with measles encephalitis during immunosuppression.

A 4-yr-old boy with acute lymphoblastic leukaemia in remission developed an encephalopathy following an attenuated measles infection. He was treated with interferon and further deterioration was halted. Three weeks after interferon treatment was stopped, leukaemic blast cells reappeared in his peripheral blood and he died shortly thereafter. Aspects of diagnosis and treatment of this syndrome are discussed now that the presumptive clinical diagnosis is made more frequently.