Alpha-1-antitrypsin deficiency (carrier) as possible risk factor for development of colonic diverticula. A multicentre prospective case-control study: the ALADDIN study.

AIM: Connective tissue changes due to ageing or diseases leading to changes in the colonic wall are one theory for the development of diverticula. Alpha-1-antitrypsin (A1AT), a protease inhibitor that protects connective tissue, possibly plays a role in the aetiology of diverticulosis. The aim of this study was to explore associations between the development of diverticula and A1AT deficiency. METHODS: This was a multicentre prospective case-control study. A total of 221 patients aged ≥ 60 years with acute abdominal pain undergoing abdominal CT were included and analysed. Patients with diverticula were defined as the research group, patients without diverticula as controls. Genotype analysis for A1AT deficiency was performed. RESULTS: Twenty-six of 221 (11.8%) patients were diagnosed with (being a carrier of) A1AT deficiency. A non-significant difference in prevalence between patients with and without diverticula was found, 20 (13.9%) of 144 vs 6 (7.8%) of 77, respectively, with a crude OR of 1.9 (95% CI 0.7-5.0; P = 0.186) and after adjustment for confounders an adjusted OR of 1.5 (95% CI 0.5-4.0; P = 0.466). A non-significant difference in 30-day mortality rate from acute diverticulitis between A1AT deficient patients (or carriers) and those without was observed: two (22.2%) of nine patients with A1AT deficiency vs 1 (1.8%) of 55 without. CONCLUSION: We found no convincing evidence that A1AT deficiency plays a role in the aetiology of diverticulitis, although deficient patients and carriers had a higher mortality when experiencing diverticulitis. Diverticulitis is a multifactorial disease and larger numbers may be needed to explore the role of A1AT deficiency among other contributing factors.

Prevalence of alpha-1-antitrypsin deficiency carriers in a population with and without colonic diverticula. A multicentre prospective case-control study: the ALADDIN study.

PURPOSE: The underling pathophysiological mechanisms that cause the formation of colonic diverticula (diverticulosis) remain unclear. Connective tissue changes due to ageing that cause changes in collagen structure of the colonic wall is one theory. Alpha-1-antitrypsin (A1AT) is a protease inhibitor known to protect connective tissue in other organs. Associations between (carriers of) A1AT deficiency and the development of colonic diverticula will be the main focus of this study. METHODS: A multicentre prospective case-controlled study. In total, 230 patients ≥ 60 years with acute abdominal pain undergoing an abdominal computed tomography (CT) will be included. The research group consists of patients with diverticulosis and/or diverticulitis; controls are patients without diverticula (0 to ≤ 5 diverticula). Genotype analysis for A1AT deficiency will be performed. RATIONALE: Hypothetically, connective tissue changes, in particular related to (carriers of) A1AT deficiency, can contribute to the development of diverticula and diverticulitis. We expect to find a higher prevalence of A1AT carriers in patients with diverticulosis compared to patients without diverticulosis. Having diverticulosis does not affect the general health of these individuals per se, when asymptomatic. Once an association is found, present findings can be the basis for a second study to assess the risk of developing acute diverticulitis and its disease course in carriers of A1AT deficiency. Because a large cohort is needed in the latter, we shall first perform a pilot study to investigate the likelihood of the primary hypothesis. TRIAL REGISTRATION: Netherlands Trial register, NTR6251, NL55016.094.15.