The causal relationship between inflammatory bowel diseases and erythema nodosum: a bidirectional two-sample mendelian randomization study

BackgroundIndividuals with inflammatory bowel disease (IBD) exhibit a heightened likelihood of developing erythema nodosum (EN), but the presence of causal link is unknown. The purpose of the present research was to investigate this connection using a bidirectional two-sample Mendelian randomization (MR) analysis.MethodsSummarized statistics for EN were sourced from the FinnGen consortium of European ancestry. The International Inflammatory Bowel Disease Genetic Consortium (IBDGC) was used to extract summary data for IBD. The inverse variance weighted (IVW) technique was the major method used to determine the causative link between them.ResultsThe study evaluated the reciprocal causal link between IBD and EN. The IVW technique confirmed a positive causal link between IBD and EN (OR = 1.237, 95% CI: 1.109-1.37, p = 1.43 x 10- 8), as well as a strong causality connection between Crohn's disease (CD) and EN (OR = 1.248, 95% CI: 1.156-1.348, p = 1.00 x 10- 4). Nevertheless, a causal connection between ulcerative colitis (UC) and EN could not be established by the data. The reverse MR research findings indicated that analysis indicated that an increase in EN risks decreased the likelihood of UC (OR = 0.927, 95% CI: 0.861-0.997, p = 0.041), but the causal association of EN to IBD and CD could not be established.ConclusionThis investigation confirmed that IBD and CD had a causal connection with EN, whereas UC did not. In addition, EN may decrease the likelihood of UC. Further study must be performed to uncover the underlying pathophysiological mechanisms producing that connection.