Chlamydophila pneumoniae infection and COPD: more evidence for lack of evidence?

Chlamydophila pneumoniae has been recognized as a common cause of respiratory tract infections affecting all age groups. The organism has been implicated as an infectious trigger for acute exacerbations of COPD. Moreover, the intracellular existence of this pathogen and the ability to cause chronic respiratory infections have led to a number of studies that investigated its possible association with disease development. The present paper examines and discusses the possible association of acute C. pneumoniae infection in episodes of acute exacerbation of COPD. It also reviews the existing evidence of chronic C. pneumoniae infection with disease pathogenesis and severity. The significant interstudy variation of the choice of diagnostic methods and criteria applied is most likely responsible for the great diversity of results observed. The use of well-standardized, commercially available diagnostic tools, as well as the adoption of a more unified diagnostic approach is probably the key element missing in order to clarify the exact role of C. pneumoniae in COPD.

Serological diagnosis of Chlamydophila pneumoniae infection in Greek COPD patients by microimmunofluorescence and ELISA.

BACKGROUND: The possible role of Chlamydophila pneumoniae infection in episodes of acute exacerbation of COPD (AECOPD) was described in 4-34% of COPD patients, but never in Greece. The possible association of chronic C. pneumoniae infection with disease severity is under study, with a diversity of results reported. MATERIAL/METHODS: Seventy-five Greek patients with AECOPD were tested for serum C. pneumoniae antibodies using the microimmunofluorescence (MIF) test and ELISA during the first day of their hospitalization and 30 days after enrollment. Serological diagnosis of acute and past C. pneumoniae infection was determined and the sensitivities, specificities, and predictive values of both methods were evaluated. Chronic C. pneumoniae infection was also estimated in both the patient group and a control group. RESULTS: Seven patients (9.3%) had serological evidence of acute C. pneumoniae infection. Although ELISA and MIF produced equal results for the diagnosis of acute C. pneumoniae infection, the sensitivity and negative predictive value of ELISA for the diagnosis of past C. pneumoniae infection was low when MIF was used as the gold-standard method. Chronic C. pneumoniae infection was more common in COPD patients than in the control group and was even more common in patients with FEV(1)<50%. CONCLUSIONS: Acute C. pneumoniae infection is associated with AECOPD in Greece. ELISA may currently be a valuable diagnostic tool for the diagnosis of acute C. pneumoniae infection, but not for the diagnosis of past infection. The possible role of chronic C. pneumoniae infection in COPD progression needs further investigation.

Helicobacter pylori seroprevalence in patients with chronic obstructive pulmonary disease.

An increased seroprevalence of Helicobacter pylori (H. pylori) and especially of the high virulent cytotoxin-associated gene-A (CagA) positive strains has been found in several extragastroduodenal pathologies, characterized by activation of inflammatory mediators. Moreover, it has been reported that the risk of chronic bronchitis may be increased in H. pylori infected patients. The aim of the present study was to assess the seroprevalence of H. pylori and in particular of CagA-positive virulent strains in patients with chronic obstructive pulmonary disease (COPD). We evaluated 126 COPD patients (88 males and 38 females, aged 61.3+/-8.1 years) and 126, age and sex-matched, control subjects. All subjects enrolled underwent an enzyme-linked immunosorbent assay (ELISA) IgG serologic test for H. pylori and CagA protein. The prevalence of H. pylori infection in patients and controls was 77.8% and 54.7%, respectively (P<0.001) and that of CagA-positive H. pylori infection was 53.9% and 29.3%, respectively (P<0.001). Moreover, COPD patients had a significantly increased mean serum concentration of both anti-H. pylori IgG (118.3+/-24.4 vs. 61.9+/-12.9U/ml, P<0.001) and anti-CagA IgG antibodies (33.8+/-3.4 vs. 19.0+/-1.5U/ml, P<0.001). Finally, no statistically significant difference, as regards the spirometric values, was detected between H. pylori infected COPD patients and uninfected ones. In conclusion, H. pylori infection may be associated with COPD. Further studies should be undertaken to clarify the potential underlying pathogenetic mechanisms.

Helicobacter pylori seroprevalence in patients with lung cancer.

AIM: To assess Helicobacter pylori (H pylori) seroprevalence in a cohort of Greek patients with lung cancer. METHODS: Seventy-two lung cancer patients (55 males and 17 females, aged 58.2+/-11.7 years) and 68, age and gender-matched, control subjects were enrolled. All subjects underwent an enzyme-linked immunosorbent assay IgG serologic test for H pylori diagnosis. RESULTS: A correlation between age and H pylori IgG level was detected for both lung cancer patients (r = 0.42, P = 0.004) and controls (r = 0.44, P = 0.004). Seropositivity for H pylori did not differ significantly between patients with lung cancer and controls (61.1% vs 55.9%, P>0.05). Concerning the mean serum concentration of IgG antibodies against H pylori, no significant difference between the two groups was detected (32.6+/-19.1 vs 27.4+/-18.3 U/mL, P>0.05). CONCLUSION: No significant association between H pylori infection and lung cancer was found.

Helicobacter pylori seroprevalence in patients with chronic bronchitis.

BACKGROUND: A high Helicobacter pylori seroprevalence has been found in many extragastrointestinal disorders. Moreover, it has been reported that the risk of chronic bronchitis may be increased in H. pylori-infected patients. The aim of this study was to assess the H. pylori seroprevalence in patients with chronic bronchitis. METHODS: We evaluated 144 patients with chronic bronchitis (81 men and 63 women, aged 53.2+/-12.7 years) and 120 age and sex-matched control subjects. All enrolled subjects (bronchitic patients and controls) underwent an enzyme-linked immunosorbent assay (ELISA) IgG serologic test for H. pylori diagnosis. RESULTS: A correlation between age and H. pylori IgG level was detected for both bronchitic patients (r = 0.42; P = 0.004) and controls (r = 0.44; P = 0.004). H. pylori seropositivity in the chronic bronchitis group was significantly higher than that in controls (83.3% vs 60%; P = 0.007). The mean serum concentration of IgG antibodies against H. pylori was also significantly higher in patients with chronic bronchitis than in the control subjects (38.7+/-24.1 U/ml vs 25.9+/-19.3 U/ml; P = 0.02). CONCLUSIONS: Helicobacter pylori infection may be associated with chronic bronchitis. Further studies should be undertaken to confirm our results and to clarify the potential underlying pathogenetic mechanisms.