Helicobacter pylori infection and respiratory diseases:a review

In the past few years,a variety of extradigestive disorders,including cardiovascular,skin,rheumatic and liver diseases,have been associated with Helicobacter pylori(H.pylori)infection.The activation of inflammatory mediators by H.pyloriseems to be the pathogenetic mechanism underlying theobserved associations.The present review summarizes thecurrent literature,including our own studies,concerning theassociation between H.pyloriinfection and respiratory diseases.A small number of epidemiological and serologic,case-control studies suggest that H.pylori infection may beassociated with the development of chronic bronchitis.Afrequent coexistence of pulmonary tuberculosis and H.pyloriinfection has also been found.Moreover,recent studies haveshown an increased H.pyloriseroprevalence in patients withbronchiectasis and in those with lung cancer.On the otherhand,bronchial asthma seems not to be related with H.pyloriinfection.All associations between H.pylori infection and respiratorydiseases are primarily based on case-control studies,concerning relatively small numbers of patients.Moreover,there is a lack of studies focused on the pathogenetic linkbetween respiratory diseases and H.pylori infection.Therefore,we believe that larger studies should beundertaken to confirm the observed results and to clarifythe underlying pathogenetic mechanisms.