[Selective defect on interferon secretion associated with impaired natural killing activity (author's transl)]

A 4-year-old boy suffering from repeated, severe bacterial (staphylococcus, pneumococcus, klebsiella, moraxella) and viral (adenovirus) infections did not show any deficiency of either humoral, cellular or non-specific immunity when investigated by classical immunological tests. In contrast, a profound defect of interferon secretion was found in leucocyte cultures induced by mitomycin-treated Raji lymphoblastoid cells or soluble antigens. This was associated with a profound impairment of non-specific "natural" killer (NK) cytotoxic activity of peripheral leucocytes tested in a 4 hour-chromium release assay against K 562 target cells. Addition of leucocyte interferon in culture increased the cytotoxic potential of the patient's leucocytes. Intramuscular administration of interferon completely (but transiently) reversed the NK defect in vivo. The expression of HLA-A and B on the membrane of platelets was diminished, whereas the expression of HLA-A, B and la antigens on the membrane of lymphocytes was normal. This observation indicates that an apparently primitive defect of interferon secretion may result in a special type of immune deficiency with complex biological consequences, some of which can be reversed by interferon therapy.