In vitro hyporeactivity to alpha-interferon in children with severe combined immunodeficiency disease.

Interferon (IFN) treatment of peripheral blood mononuclear cells from seven children with severe combined immunodeficiency (SCID) failed, with one exception, to induce the IFN-dependent enzyme, 2-5A synthetase or enhance natural killer cell activity. In one patient this hyporeactivity was demonstrated in both T cell enriched and T cell depleted lymphocyte preparations. These results may reflect the absence of an IFN reactive lymphocyte subpopulation or of the IFN receptor. This defect in SCID patients may be partly responsible for their increased susceptibility to viral infections and may contribute to the regulatory imbalances in T lymphocyte subpopulations.