Study of the Patterns of Renal Affection among Inflammatory Bowel Disease Patients

Background: Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), is a long-term immune-mediated condition that mainly affects the gastrointestinal tract but is often linked to extraintestinal manifestations (EIMs). Renal involvement is one of these that is still underappreciated despite its clinical significance and its influence on patient outcomes. This study aimed to identify and characterize the different patterns of renal involvement among Egyptian patients with IBD and to explore the relationship between renal affection, disease type, and clinical characteristics. Methods: This cross-sectional study was conducted at the Department of Internal Medicine, Zagazig University Hospitals, and the Theodor Bilharz Research Institute, Forty-two adult patients with confirmed IBD, including 17 with Crohn’s disease and 25 with ulcerative colitis, who showed evidence of renal involvement were enrolled. All participants underwent comprehensive clinical evaluation, laboratory investigations, and imaging studies, with renal biopsy performed when indicated. Results: The mean age of patients was 34.45±6.53 years, and the mean disease duration was 4.88±0.91 years. The pattern of renal involvement in our patients, revealed amyloidosis in (26.5%) being the most prevalent histopathological finding, followed by IgA nephropathy (20.6%). A significant association was observed between the type of IBD and type of renal affection (p=0.033), as amyloidosis was more frequent in CD(42%) than UC(18.2%). Nephrolithiasis was also significantly higher among CD patients (p=0.045*). Inflammatory markers specially ESR were more elevated in CD patients compared to UC (p