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) receptor deficiency, unlike patients with other genetic defects predisposing them to mycobacterial diseases, have very high levels of IFN gamma in their plasma. This unexpected observation provides a simple and accurate diagnostic method for complete IFN gamma receptor deficiency in children with clinical disease caused by bacille Calmette-Guerin vaccines or environmental nontuberculous mycobacteria.