Secondary amyloidosis in inflammatory bowel disease patients: findings from three tertiary medical centers

Secondary amyloidosis (AA) is a disorder of protein conformation associated with inflammatory disorders. Detailed reports of patients diagnosed with AA and inflammatory bowel disease (IBD) are limited. This study reports the cases of eight patients, across three tertiary medical centers, diagnosed with both IBD and AA between 2000 and 2020. Seven patients had a diagnosis of Crohn disease (CD), while one had ulcerative colitis (UC). All patients were diagnosed with AA after being diagnosed with IBD (median: 15 years later). The small bowel (62.5%) and the colon (62.5%) were the most common IBD locations. 4 patients had undergone TNF-alpha inhibitor therapy and all CD patients required surgical treatment of their IBD. A history of fistula or abscess was identified in 5 patients. The most common initial site of AA was the kidney (75%). All 8 patients presented with some form of renal dysfunction and proteinuria (median: 1500 mg/24 h). Hypoalbuminemia was found in most patients. Six patients developed chronic kidney disease and 4 required dialysis. Anti TNF-alpha antibody therapy led to rapid improvement of renal function in one of four patients who received it. Three patients required a renal transplant. Four patients had died upon the latest follow-up (5-year survival: 75%). The presence of proteinuria, fistula, or abscess should serve as indicators for potentially increased AA risk in CD patients.