Investigation of Cytokine Profiles, the Expression of Genes Involved in Somatic Hypermutation and Peripheral Tolerance, and Their Correlation with Autoantibody Levels in Northern-Thai Immunodeficient Patients Carrying Anti-Interferon-γ Autoantibodies

Anti-interferon-γ (IFN-γ) autoantibody (AAb)-associated adult-onset immunodeficiency (AOID) is an emerging disorder in East Asian adults characterized by severe opportunistic infections despite negative HIV status. The mechanisms driving anti-IFN-γ AAb production remain unclear. This study investigated B-cell gene expression, serum cytokine profiles, associations with AAb levels, and IFN-γ genetic variations in AOID patients. A cross-sectional study was conducted in 63 AOID patients and 30 healthy controls at Chiang Mai University Hospital, Thailand. Patients were classified as active or inactive according to infection status. B-cell gene expression, serum cytokines, anti-IFN-γ Aabs levels, and IFN-γ polymorphisms were analyzed by quantitative PCR, multiplex assays, ELISA, and nucleotide sequencing, respectively. AOID patients exhibited increased PAX5 and BLIMP1 expression and reduced XBP1, BCL6, KRAS, and BAFF expression. Active patients had higher levels of TNF-α, IL-6, IL-17A, IL-10, IL-21, and more chemokines than inactive patients. AAb levels positively correlated with TNF-α, IL-6, and IL-10. Correlation analysis showed positive associations among PAX5, XBP1, and KRAS, and a negative association between BLIMP1 and BCL6. No significant IFN-γ sequence differences were identified within the analyzed transcript region. These findings suggest altered B-cell gene expression and inflammatory cytokine profiles in AOID, which may be associated with the immunological alterations observed in these patients and may provide insights into potential mechanisms underlying anti-IFN-γ AAb production.