Abstract Background Crohn’s disease (CD) is a chronic, transmural inflammatory disorder that may lead to stenosis, fistulas, and abscesses. Ileocolonoscopy is the gold standard for mucosal assessment, but its repeated use is limited by its invasive nature. Magnetic Resonance Index of Activity (MaRIA) provides a non-invasive evaluation of inflammatory activity. Correlating MaRIA with clinical indices and biomarkers may optimize disease monitoring, particularly in resource-limited settings. The objective is to determine the correlation between MaRIA index and clinical/biochemical parameters—Harvey–Bradshaw Index (HBI), Crohn’s Disease Activity Index (CDAI), C-reactive protein (CRP), and fecal calprotectin (FC)—in patients with CD at a tertiary care center in Mexico. Methods A retrospective, observational, analytical study was conducted in 46 patients with CD treated at the Inflammatory Bowel Disease Clinic of the Hospital General de México. Data collected included enterography findings (MaRIA index), clinical indices, and biomarkers. Distribution was assessed using the Shapiro–Wilk test; correlations were evaluated using Spearman’s rank test. ROC curves were constructed to assess the discriminative ability of MaRIA for clinical remission. Analyses were performed with SPSS v29. Results Clinical and demographic characteristics are summarized in Table 1. The mean age was 47.5 years, and 58.7% were women. According to the Montreal classification, L3 location predominated (41.3%), and A2–A3 age groups were most frequent (47.8%). Extraintestinal manifestations were observed in 47.8%, and perianal disease in 28.3%. Biologic therapy was used by 78.3%, predominantly ustekinumab (52.2%). During follow-up, 45.7% were hospitalized and 41.3% required surgery. MaRIA showed a significant positive correlation with HBI (rho = 0.525, p = 0.0021) and CDAI (rho = 0.522, p = 0.0022), but no association with CRP (rho = 0.293, p = 0.1037) or FC (rho = 0.053, p = 0.7721). ROC analysis showed an AUC of 0.750 for HBI and 0.821 for CDAI, indicating good discriminative ability for identifying clinical activity. Conclusion The MaRIA index demonstrated significant correlation with clinical indices (HBI and CDAI) but not with biochemical biomarkers. These findings suggest that MaRIA may represent a reliable, non-invasive tool for assessing inflammatory activity in CD, particularly valuable in settings with limited resources. Conflict of interest: Sebastian Ocampo, Valeria Natalie: No conflict of interest Contreras Aviles, Estefania: No conflict of interest Philippe Ponce, Mildred: No conflict of interest Rosales Tellez, Paola: No conflict of interest Rodríguez Cruz, Hector: No conflict of interest Hernandez Antolin, Victor: No conflict of interest Chida Romero, Jesus Antonio: No conflict of interest Gonzalez Lopez, Roberto Emmanuel: No conflict of interest Lopez Perez, Raquel Yazmin: No conflict of interest Jimenez Bobadilla, Billy: No conflict of interest Dr. De Leon Rendon, Jorge Luis: Dr. Jorge Luis De León Rendón is a member of Advisory Boards, key opinion leader, and speaker for Abbvie Mexico, Takeda Mexico, and Janssen Mexico. He has served as a key opinion leader and lecturer for Schwabe Pharma Mexico, Servier, Pfizer, Alfasigma, and Siegfried Rhein Mexico. He has received support for research manuscript publication and editing from Takeda and Schwabe Pharma Mexico. Additionally, he has coordinated research studies and medical education programs with Shire, Bristol Myers Squibb, Takeda, Schwabe Pharma, Abbvie, Janssen, MSD, and Roche.
Ocampo et al. (Thu,) studied this question.