Autoantibodies to interferon-γ in a patient with selective susceptibility to mycobacterial infection and organ-specific autoimmunity

We evaluated a patient with disseminated Mycobacterium tuberculosis and Mycobacterium chelonae infection, of which he died. He also developed autoimmune ( type I) diabetes and primary hypothyroidism. His serum contained a high titer of immunoglobulin G autoantibody to interferon-gamma ( IFN-gamma) capable of blocking in vitro responses to this cytokine by peripheral blood mononuclear cells from normal donors. These results suggest that autoantibodies to IFN-gamma can induce susceptibility to disseminated mycobacterial infection, which may be refractory to chemotherapy.