Subcutaneous injection of interferon gamma therapy could be useful for anti-IFN-γ autoantibody associated disseminated nontuberculous mycobacterial infection.

One of the human natural defense systems protects against nontuberculous mycobacterial (NTM) infection by IFN-γ producing T lymphocyte cells. Most disseminated NTM infections usually occur in severe immune-compromised patients, such as HIV infection or after organ transplant patients. However, there have been several reports of non-compromised patients with disseminated NTM infection, including antibiotic resistance cases and the presence of a neutralizing antibody against IFN-γ. We elucidated the anti-IFN-γ neutralizing antibody in a 65 year-old Japanese man whose legs were paralyzed because of multiple abscesses in vertebral bodies. Although his vertebral bodies were released due to an operation and antibiotics were administered, this treatment efficacy was poor. Patient's plasma demanded not only IFN-γ expression in peripheral blood mononuclear cells (PBMC) obtained from healthy controls, but also recombinant human IFN-γ expression. Furthermore, IFN-γ receptor expression was increased, compared to the healthy control. Finally, anti-IFN-γ antibody was detected in his plasma. These results suggested that anti-IFN-γ antibody induced an incurable NTM infection. IFN-γ was subcutaneously administrated with antibiotics, and then the abscesses diminished and his general condition was successfully improved. This therapy might be useful against severe NTM infections.