Refractory nontuberculous mycobacterial infection and potential hidden immunodeficiency related to RAG mutation and production of anti-interferon-α autoantibodies: a case report.

backgroundNontuberculous mycobacterial infectious diseases are associated with host immunological status. Neutralizing anti-interferon (IFN)-γ autoantibodies have been considered as a significant cause of nontuberculous mycobacterial infections. However, another autoantibody specifically targeting interferon-α, occurring in patients with nontuberculous mycobacterial infection, has been rarely reported. CASE PRESENTATION: We report the case of a 23-year-old female who developed refractory nontuberculous mycobacterial infection and subsequently manifested skin lesions and motor disorder of muscles. The laboratory examination results showed elevated levels of globulin and immunoglobulin, as well as local deposits of amyloid material in pleural sections. Additionally, various tissue biopsies showed no evidence of malignancy. After 6 months of anti-nontuberculous mycobacterial therapy, the patient recovered normal temperature but developed progressive pulmonary lesions. The patient received steroids and methotrexate treatment and her skin lesions as well limitation of muscle movement improved. Further evaluation revealed a hidden immunodeficiency with positive anti-interferon-α autoantibodies and recombinase activating gene (RAG) mutation.

conclusionsThis case highlights alternation of infection and immune dysregulation, likely resulting from RAG mutation and production of anti-interferon-α autoantibodies.