#1852 When ‘pebbles’ affect the kidney: nephrolithiasis and chronic renal failure in Crohn's disease. The experience of a 3rd level centre

Abstract

Abstract Background and Aims Nephrolithiasis is the most common expression of kidney involvement in chronic inflammatory bowel disease (IBD), especially in Crohn's disease (CD). Stone formation favoring factors are hyperoxaluria, dehydration, acidosis, common conditions in CD patient, who present a little higher incidence of renal stones, made of calcium oxalate, than the normal population. Only few studies focused on the relationship between CD activity (defined by CDAI score) and the development of nephrolithiasis and possible subsequent development of chronic renal failure (CRF). Materials and Method We conducted a retrospective study on a cohort of 1236 patients affected by CD referring to our Centre of IBD- Sant'Orsola between 2014 and 2021. We identified two cohorts from this population: 118 patients with nephrolithiasis and 118 patients without nephrolithiasis. Among these two groups, we identified variable clinical manifestations of CD and their relation with CRF and lithiasis. Results The prevalence of nephrolithiasis in all CD patients was 10.3%, a little higher than in the general population. The results of the analysis of patient and disease variables in the two groups are shown in Table 1. The mean age at diagnosis of CD was higher in the group without nephrolithiasis, so the treatment was started later. The presence of perianal disease, extraintestinal manifestations (MEI), like ankylosing spondylitis (APS), biliary tract involvement, or previous surgery, and presence of ileostomy correlate with the formation of stones in univariate regression analysis (Table 2). Perianal disease and MEI also maintained significance in multivariate analysis. Conclusion Our data suggest that a higher degree of disease activity, defined by the presence of perianal disease (a variable on CDAI score) and the presence of MEI, correlates with higher risk of lithiasis. It is advisable to start early the study of nephrolithiasis in these patients to adopt preventive strategies against formation and progression of renal stones. Future studies are required for a better definition of this deep relationship.