Serum Maresin-1 and Resolvin-D1 Levels as Non-Invasive Biomarkers for Monitoring Disease Activity in Ulcerative Colitis

<b>Background:</b> Specialized pro-resolving lipid mediators (SPMs), such as maresins and resolvins, play a key role in resolving inflammation and repairing tissues. This study aimed to evaluate whether maresin-1 (MaR1) and resolvin-D1 (RvD1) could serve as serum non-invasive biomarkers for monitoring disease activity in ulcerative colitis (UC). <b>Methods:</b> This cross-sectional study included 60 UC patients (30 active, 30 remission) and 30 healthy controls. Disease activity was assessed using the Mayo Endoscopic Subscore (MES). Inflammatory indices, including the neutrophil-lymphocyte ratio (NLR), monocyte-HDL cholesterol ratio (MHR), platelet-lymphocyte ratio (PLR), CRP-lymphocyte ratio (CLR), CRP-albumin ratio (CAR), systemic inflammation response index (SIRI), and systemic immune-inflammation index (SII), were calculated. Plasma MaR1 and RvD1 levels were measured via enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) analysis was performed to evaluate biomarker accuracy. <b>Results:</b> CRP, NLR, PLR, CLR, CAR, SIRI, and SII were significantly elevated in active UC, whereas MaR1 and RvD1 were lower compared to remission and controls (<i>p</i> < 0.05). MaR1 levels were lower in the remission group than in controls. ROC analysis demonstrated high area under the curve (AUC) values for RvD1 (0.906), CAR (0.872), CLR (0.861), and CRP (0.858) in distinguishing active UC from remission, and for CRP (0.944), CAR (0.939), CLR (0.939), RvD1 (0.928), and MaR1 (0.889) in distinguishing active UC from controls. The specificity for detecting active UC was 60% for MaR1 and 80% for RvD1. Both RvD1 and MaR1 showed a negative correlation with the MES, with RvD1 demonstrating a stronger correlation (r = -0.754, <i>p</i> < 0.001). <b>Conclusions:</b> RvD1 shows a strong negative correlation with disease severity in ulcerative colitis, while low MaR1 levels in remission may indicate subclinical inflammation. Although MaR1 and RvD1 are not disease-specific, their role in inflammation resolution suggests they may complement conventional inflammatory markers for more comprehensive UC monitoring.