Background: Several studies suggest an imbalance of protease activation and inhibition in inflammatory bowel disease. Alpha1-Antitrypsin (AAT), one protease inhibitor of paramount importance, exists in numerous subtypes, some of them representing deficient phenotypes. The present study evaluated the prevalence of AAT-alleles and phenotypes in patients with inflammatory bowel disease.
Methods: The study population comprised 74 patients with Crohn's disease and 61 patients with ulcerative colitis. Isoelectric focusing was used for AAT subtyping. The prevalence of AAT alleles and phenotypes was compared with the frequency in 752 healthy unrelated controls.
Results: The rare phenotype M2F was detected in one patient with ulcerative colitis. No further significant differences in the distribution of AAT alleles or phenotypes between patients with inflammatory bowel disease and the healthy controls were observed.
Conclusion: The low prevalence of deficient AAT subtypes does not point towards a contribution of AAT deficiency in the pathophysiology of IBD.