MICROALBUMINURIA CORRELATES WITH INTESTINAL HISTOPATHOLOGICAL GRADINGIN PATIENTS WITH INFLAMMATORY BOWEL-DISEASE

It has previously been shown that microalbuminuria is a useful disease activity marker for inflammatory bowel disease (IBD). Microalbuminuri a correlates strongly with the markers of clinical and laboratory dise ase activity such as erythrocyte sedimentation rate (ESR), and C react ive protein (CRP). The aim of this study was to discover if microalbum inuria accurately reflects the intestinal inflammation by correlating it with intestinal inflammation using a standard histopathological gra ding system in patients with ulcerative colitis and Crohn's colitis. F orty two patients with IBD who had undergone endoscopic examination of the entire colon for the assessment of severity and extent of the dis ease (Crohn's colitis (n=21), ulcerative colitis (n=21)) were recruite d to the study. Patients with small bowel Crohn's disease were not stu died. Twenty four patients had left sided colonic disease and 18 patie nts had extensive colonic disease. Each patient's colonic biopsy speci mens were scored blindly by a histopathologist and a composite score w as compiled on the basis of the severity of changes in the enterocytes and crypts and the cellularity of the lamina propria. A clinical dise ase activity was obtained using the simple index of Harvey and Bradsha w. Microalbuminuria was measured in all patients by an immunoturbiditi metric method. ESR and CRP were also measured, as indicators of acute phase response in the same patients. It was found that patients with a ctive IBD had higher concentrations of microalbuminuria compared with those patients in remission (median 222 mu g/min (range 40-686 mu g/mi n) v median 96 mu g/min (range 30-376 mu g/min); p<0.001)). Significan tly higher concentrations of microalbuminuria were also detected in pa tients with extensive colonic IBD compared with those patients with le ft sided disease (median 297 mu g/min (range 132-686 mu g/min) v media n 101 mu g/min (range 30-433 mu g/min); p<0.001). A strong positive co rrelation was seen between microalbuminuria and intestinal histopathol ogical score in IBD patient groups with left sided colitis (r=0.77; p< 0.001) and extensive disease (r=0.71; p<0.01). The standard histopatho logical grading system correlated with the clinical disease activity ( r=0.64; p<0.005) and CRP (r=0.62; p<0.02), however, it did not correla te with ESR. In conclusion, the strong correlation of microalbuminuria with a standard intestinal histopathological grading system suggests that microalbuminuria accurately reflects the severity of colonic infl ammation in patients with Crohn's colitis and ulcerative colitis.