Association between growth factors and Sjögren syndrome: A two-sample Mendelian randomization study

Previous observational studies have suggested a link between growth factors and Sjögren syndrome, but a definitive causal relationship has yet to be established. We conducted a two-sample Mendelian randomization (MR) study using summary statistics from the FinnGen study on Sjögren syndrome and various growth factors. Analytical techniques included inverse variance weighted, MR-Egger, weighted median, and weighted mode to explore potential causal links. Our analysis indicated that genetically determined growth factors did not have a causal effect on Sjögren syndrome. The inverse variance weighted method showed nonsignificant associations for various exposures, including epidermal growth factor (odds ratios [OR] = 0.94, P = .720), proheparin-binding EGF-like growth factor (OR = 0.95, P = .621), VEGF sR2 (OR = 1.0, P = .988), FGF7 (OR = 1.08, P = .519), PDGF-AA (OR = 0.87, P = .218), VEGF121 (OR = 0.93, P = .466), TGF-β R II (OR = 1.01, P = .934), and NGFI-A-binding protein 2 (OR = 1.13, P = .264). The MR-Egger, weighted median, and weighted mode methods supported these findings. Our study did not find significant causal associations between genetic levels of the studied growth factors and the onset of Sjögren syndrome. Future research should investigate more detailed genetic interactions and modifiable environmental factors to better understand pathways relevant to the prevention and management of Sjögren syndrome.