Collagen-V and K-α-1 Tubulin Antibodies as Potential Markers of Unsuspected GERD-Related Lung Damage: Insights from a Cross-Sectional Analysis

Purpose: Our group has proposed that aspiration of gastric contents leads to exposure of normally sequestered lung self-antigens (SAgs), specifically collagen-V (Col-V) and K-α-1-tubulin (Kα1T), which elicits an immune response characterized by increasing concentrations of self-antibodies (SAbs) anti-Col-V and anti-Kα1T. We sought to establish the point prevalence of abnormally elevated concentrations of SAbs among patients with pathological gastroesophageal reflux disease (GERD) and/or hiatal hernia undergoing antireflux surgery (ARS). Methods: For this cross-sectional study, we retrieved a plasma aliquot from the Norton Thoracic Institute BioBank from blood samples that were taken preoperatively from patients who underwent ARS between November 2019 and August 2022. Enzyme-linked immunosorbent assays were employed to detect and quantify anti-Col-V and anti-Kα1T. Results: Samples from 43 patients (females, n = 34 [79.1%]; mean age, 62 ± 12 years; and mean BMI, 30.5 ± 7 kg/m²) were analyzed. Before ARS, 28 (65.1%, CI95: 50.3–80.0%) patients had abnormally elevated concentrations of anti-Col-V and 19 (44.2%, CI95: 28.7–59.7%) had elevated concentrations of circulating anti-Kα1T. Overall, 13 patients (30.2%) had low (i.e., normal) concentrations of both SAbs, 13 (30.2%) were positive only for one, and 17 (39.5%) were positive for both SAbs. Conclusion: A relative high point prevalence of abnormally elevated circulating SAbs (i.e., anti-Col-V and/or anti-Kα1T) before ARS was found. This result suggests clinically unsuspected pulmonary parenchymal injury secondary to GERD-related aspiration. Further studies are required to confirm this hypothesis and to identify alternative non-invasive early biomarkers of GERD-related lung damage.