Renal insufficiency in patients with Crohn's disease

Abstract

Background and Aim: Patients with Crohn's Disease (CD) may develop renal insufficiency. The aim of this study was to analyze the reasons for the risk of renal insufficiency in CD patients. Patients and Methods: Among the 1500 patients of our tertiary center for CD we found eight patients (four female, four male; median age at diagnosis of CD: 33.5 years, range: 19 to 57; median duration at of CD at the time of onset of renal insufficiency: 21.5 years, range: 15 to 26; median age at diagnosis of renal insufficiency: 60.5 years, range: 39 to 73) suffering from renal impairment with permanently elevated creatinine serum levels above 1.5mg/100ml (median current creatinine level: 4.1mg/100ml). Four of those needed regular hemodialysis. Two of the patients had died. We matched those patients respectively with two CD patients of same sex, age at diagnosis and duration of disease, but normal kidney function. The medical histories of all patients were carefully reviewed and data were analyzed by Mann-Whitney-U or Fisher's exact test where appropriate. Results: Out of 8 patients with renal insufficiency 2 patients (29%) had L3 location of CD and 5 (71%) L4, in the control group 6 patients (43%) had L3 and 8 (57%) L4 (Vienna Classification). One patient developed renal insufficiency due to amyloidosis and one as a consequence of a nephrectomy due to fistulizing disease. No patient showed hypertension before onset of renal impairment. The median number of resected colonic segments in the group of patients with renal insufficiency was 2 (range 0 to 4), in the control group 0 (range 0 to 5), the median length of resected small bowel was 80cm (range: 20 to 340cm), controls: 65.5cm (range: 0 to 290cm), the median duration of 5-aminosalicylates at onset of renal impairment was 66 months (range: 0 to 264 months), controls: 19.5 months (range: 0 to 252 months) and the number of previous kidney stone lithotrypsies was 1 (range: 0 to 20), control: 0 (range: 0 to 6). There was no significant difference between both groups regarding these parameters. Conclusion: Patients with longstanding CD show a considerable risk for terminal renal insufficiency. Although we were not able to detect one single cause of renal insufficiency in patients with CD, it is evident, that the risk increases with the duration of disease, because all patients had a minimum duration of 15 years. This makes it more probable, that renal insufficiency may be a consequence of CD itself.