High levels of interferon gamma in the plasma of children with complete interferon gamma receptor deficiency

We have found that children with complete interferon gamma (IFN gamma) rece ptor deficiency, unlike patients with other genetic defects predisposing th em to mycobacterial diseases, have very high levels of IFN gamma in their p lasma. This unexpected observation provides a simple and accurate diagnosti c method for complete IFN gamma receptor deficiency in children with clinic al disease caused by bacille Calmette-Guerin vaccines or environmental nont uberculous mycobacteria.