IFNG and Immunodeficiency: Therefore, to confirm the hypothesis that the presence of autoantibody to IFN-γ is associated with cell-mediated immune deficiency in northern Thailand, we conducted a case-control study to compare the prevalence of antibody to IFN-γ among non-HIV infected individuals presenting with repeated episodes of disseminated infection caused by unusual intracellular pathogens, HIV-infected controls, and healthy controls.