Helicobacter pylori infection and asthma:Is there a direct or an inverse association?A meta-analysis

AIM:To analyze the consistency of a potential involvement of the bacterium infection in the asthma disease. METHODS:A systematic literature search of the terms "Helicobacter pylori "(H. pylori) associated to "asthma" using PubM ed,Scopus and the Cochrane Library Central was performed. Reference lists from published articles were also employed. Titles of these publications and their abstracts were scanned in order to eliminate duplicates and irrelevant articles. The criteria of inclusion of the studies were:Original studies; the H. pylori diagnostic method has been declared; all ranges of age have been included in our study; a definitive diagnosis of asthma has been reported.RESULTS:We selected 14 articles in which the association between the two conditions was addressed. In 7 studies the prevalence of H. pylori infection in the asthma population and in the control population was made explicit. There was heterogeneity between the studies(Cohran's Q = 0.02). The H. pylori infection in the asthma population resulted 33.6%(518 of 1542),while in the control population resulted 37.6%(2746 of 7310)(relative risk of H. pylori infection in the asthma population = 0.87,95%CI:0.72-1.05,P = 0.015,random effects model). Instead,considering the morevirulent strains,the majority of studies showed an inverse relationship between the prevalence of H. pylori infection and asthma.CONCLUSION:In our meta-analysis the prevalence of H. pylori infection in the asthma population resulted not statistically significant lower than in control population(P = 0.15). Instead,considering the more virulent strains,the majority of studies showed an inverse relationship between the prevalence of H. pylori infection and asthma.

Microscopic colitis in patients with mild duodenal damage:A new clinical and pathological entity(“lymphocytic enterocolitis”)?

AIM To evaluate the potential association between mild duodenal damage and microscopic colitis(MC).METHODS We retrospectively included 105 consecutive patients with type I Marsh-Oberhuber duodenal damage and negativity for immunoglobulin A anti-endomysium and anti-tissue transglutaminase.The following parameters were analyzed:Sex,age at execution of esophagogastroduodenoscopy,duodenal damage,and number of intraepithelial lymphocytes at biopsies,prevalenceof Helicobacter pylori infection,age at execution of colonoscopy,macroscopic and microscopic features of colonoscopy,family history of gastrointestinal and autoimmune diseases,smoking habits,biochemical parameters of inflammation and autoimmunity,use of proton pump inhibitors or nonsteroidal anti-inflammatory drugs,adverse reactions to drugs or foods,pathologies known to be associated with celiac disease or MC,living on a gluten-free diet or on a gluten-low diet for at least 1 mo.RESULTS Colonoscopy was performed in 59 patients,but only in 48 of them biopsies were taken in the entire colon.Considering the latter cohort,the diagnosis of MC was met in 25(52.1%) patients while in 18 patients other pathologic findings were reported:13(27%) cases of nonspecific inflammatory bowel disease,2(4.2%) cases of Crohn's disease,2(4.2%) cases of eosinophilic gastroenteritis,and 1(2.1%) case of autoimmune enteritis.Five(10.4%) patients had a normal colonoscopic result.Matching the groups by age,and considering only patients who underwent colonoscopy(42.7 ± 15.5 years) vs those who did not undergo colonoscopy(36.9 ± 10.6 years),a statistical difference was found(P = 0.039).Focusing on symptoms,diarrhea was statistically more prevalent in MC group than in patients who did not undergo colonoscopy(P = 0.03).CONCLUSION Mild duodenal damage is associated with MC in more than half of the cases.This association supports the hypothesis of a link between these two entities.