Defective immune interferon production and natural killer activity associated with poor neutrophil mobility and delayed umbilical cord separation.

Two infants with recurrent infections and a history of delay in separation of the umbilical cord (1 month and 17 days) had severely impaired neutrophil mobility. In addition very poor natural killer cell (NK) activity of blood lymphocytes against a leukaemia cell line (Molt 4F) was found. Incubation of lymphocytes with lymphoblastoid interferon increased NK activity in the one case tested. No immune (gamma) interferon production was detected in Raji cell and phytohaemagglutinin (PHA) stimulated cultures from the other case. Apart from an abnormal dose-response curve in thymidine uptake after PHA stimulation of blood lymphocytes, no other abnormalities were found in a range of immunological tests. Ascorbic acid improved neutrophil mobility but had no effect, on NK activity. Both children have subsequently died from septicaemic illnesses.