Chlamydia pneumoniae and Lung Cancer: Epidemiologic Evidence

Abstract

Chlamydia pneumoniae is a common cause of acute respiratory infection and has been hypothesized to cause several chronic diseases, including lung cancer. The purpose of this article is to identify, describe, and critically examine the published studies on the association between C. pneumoniae infection and risk of lung cancer. In the six studies identified, previous C. pneumoniae infection was defined on the basis of serologic criteria, which varied between studies. All studies reported elevated relative risk estimates for the association of serologic evidence of infection and risk of lung cancer. The three studies in which past infection was defined based on testing of prediagnostic blood specimens tended to have weaker results (odds ratio range, 1.2-2.1) than those based on postdiagnostic blood specimens (odds ratio range, 1.4-9.9).

An Experimental Model for Induction of Lung Cancer in Rats by Chlamydia Pneumoniae

“…Many clinical epidemiological studies analyzing the association between Cpn infection and the risk of lung cancer have been reported (Jackson et al, 2000;Koyi et al, 2001;Anttila et al, 2003;Kocazeybek, 2003;Littman et al, 2004;Littman et al, 2005;Chaturvedi et al, 2010), but no clear consensus has been reached (Koh et al, 2005;Sessa et al, 2008;Smith et al, 2008). This relationship was assessed more closely by performing a meta-analysis (Zhan et al, 2011) based on publications collected from electronic databases such as Pubmed, Embase, Web of Science, and CNKI.…”

A clinically silent respiratory infection withChlamydophilaspp. in calves is associated with airway obstruction and pulmonary inflammation

“…The phenomenon of chronicity and persistence, however, is thought to be involved in the pathogenesis of chronic inflammatory airway diseases, i.e. human asthma and COPD, and even in pulmonary emphysema or lung cancer [2,3,14,19,22,26,50,51,56].…”

Chlamydiae and Mycoplasma infections in pulmonary MALT lymphoma

“…Nonetheless, Chlamydia sp. and Mycoplasma pneumoniae can cause chronic pulmonary diseases such as chronic bronchitis and adult-onset asthma (Bjornsson et al, 1996;Daian et al, 2000), and chronic infection with C. pneumoniae or M. pneumoniae has been linked to an increased risk of lung cancer (Pehlivan et al, 2004;Littman et al, 2005). C. pneumoniae and C. trachomatis infections, particularly the former, are also associated with an increased risk of lymphoma although their specific association with pulmonary MALT lymphoma is unclear (Anttila et al, 1998).…”