From the Research
Patients with Crohn's disease can develop chronic kidney disease (CKD) through several mechanisms, primarily involving chronic inflammation, nephrolithiasis, hydronephrosis, medication-related nephrotoxicity, and dehydration/electrolyte imbalances. The primary pathway involves chronic inflammation causing amyloidosis, where inflammatory proteins deposit in kidney tissues, impairing function 1. Nephrolithiasis (kidney stones) is common in Crohn's patients due to increased oxalate absorption from the intestine, particularly after small bowel resection. Hydronephrosis can occur when intestinal inflammation causes ureteral obstruction. Medication-related nephrotoxicity is another significant factor, with 5-aminosalicylates (like mesalamine), cyclosporine, and TNF-alpha inhibitors potentially causing interstitial nephritis or other kidney damage. Some studies suggest that non-steroidal anti-inflammatory drugs (NSAIDs) may also contribute to CKD progression, particularly when used in high doses 2, and both systemic and topical NSAIDs have been associated with acute adverse kidney outcomes in CKD patients 3. Patients may also develop glomerulonephritis from immune complex deposition related to chronic inflammation. Dehydration and electrolyte imbalances from chronic diarrhea can further stress kidney function. Additionally, recurrent urinary tract infections due to fistula formation between the intestine and urinary tract can lead to pyelonephritis and kidney scarring. Regular kidney function monitoring is essential for Crohn's patients, especially those on potentially nephrotoxic medications, with baseline assessment of renal function recommended at diagnosis and periodic follow-up evaluations. The most recent study on the topic highlights the importance of considering CKD as a systemic inflammatory syndrome, with inflammation playing a key role in the pathogenesis of CKD 1. Overall, the development of CKD in Crohn's patients is a complex process involving multiple mechanisms, and a comprehensive approach to management is necessary to mitigate the risk of CKD and its associated morbidities.