Background: Previous studies have not identified a convenient laboratory marker of colonoscopic activity in Crohn's colitis or ulcerative colitis.
Methods: Twenty-eight patients with either ulcerative colitis or Crohn's colitis undergoing colonoscopy by the same observed had laboratory measurements of serum albumin, orosomucoid, C-reactive protein, plasma viscosity, haemoglobin, leucocyte and platelet counts, and faecal alpha-1-antitrypsin from single non-lyophilized samples. Multiple linear regression was performed using each laboratory variable as the dependent variable and the lengths of each grade of endoscopic activity as the explanatory variables.
Results: Multiple regression analysis using all the endoscopic grades of acute activity showed significant correlations with faecal alpha-1-antitrypsin (p < 0.001), serum albumin (p < 0.001), C-reactive protein (p = 0.02), and plasma viscosity (p = 0.03).
Conclusions: The highest multiple correlation coefficients were obtained with faecal alpha-1-antitrypsin (r = 0.82) and serum albumin (r = 0.80), and these measurements can be recommended as convenient markers of endoscopic activity in these diseases.