Proteome-Wide Serological Profiling Reveals Broad Elevation of EBV Immunity in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease with uncertain etiology. Chronic viral infection, including Epstein-Barr virus (EBV), has been implicated as a potential driver of repetitive epithelial injury and dysregulated repair. We sought to evaluate and define the breadth versus specificity of EBV-directed humoral immunity in IPF. We performed proteome-scale serological profiling using an EBV protein microarray (202 proteins) representing all proteins expressed by the EBV proteome (type I and II) on plasma samples from 32 patients with confirmed IPF (87.5% male; mean age 60.9 years) and 15 healthy disease-free controls (40% male; mean age 57.9 years). Per-sample global EBV IgG means were higher in IPF than controls (Welch p = 0.005), and the difference persisted after sex adjustment (p = 0.012). Although no single antigen met a stringent FDR significance threshold, 10 EBV antigen-specific antibody responses showed nominal elevation in IPF, with 2 remaining nominally significant after sex adjustment and 5 additional antibody responses reaching significance only in linear regression models. Overall, these results support the concept that IPF is associated with a diffuse elevation of EBV-directed humoral responses rather than antigen-specific dominance, consistent with ongoing, low-level viral reactivation. The presence of an EBV-negative subgroup within the IPF cohort underscores etiological heterogeneity within IPF.