Interferon responses of peripheral blood mononuclear cells from normal and leukaemic children

Human peripheral blood mononuclear cell cultures (PBMC) stimulated with Sendai virus or K562 cells produce a mixture of interferons. Temperature and pH stability characteristics and reactions with monospecific antibodies indicate that PBMC cultures from adults produce interferons alpha and gamma in approximately equal proportions. PBMC cultures from children produce lower levels of interferons with a higher proportion of type alpha. The ability of PBMC cultures from children with acute lymphoblastic leukaemia (ALL) to produce interferon was determined. Little or no gamma interferon was induced by either Sendai virus or K562 cells. Cultures from some children with ALL produced alpha interferon but mean levels were significantly lower than from normal children. A group of older children with ALL who had completed their course of therapy and were off treatment produced levels of interferon indistinguishable from those of normal children. This in vitro deficit, possibly induced by chemotherapy, may reflect an in vivo deficit and may contribute to the impaired handling of viruses seen in children being treated for ALL.