Chlamydia pneumoniae and chronic bronchitis: association with severity and bacterial clearance following treatment

Abstract

Background: A study was undertaken to evaluate Chlamydia pneumoniae chronic infection, other respiratory infections, and functional impairment in patients with chronic bronchitis (stage 1) and to examine chronic C pneumoniae infection, rate of acute exacerbations of chronic bronchitis, and rate of C pneumoniae eradication following antibiotic treatment (stage 2). Methods: In the stage 1 study respiratory specimens from 42 patients with steady state chronic bronchitis were analysed for Gram staining, sputum culture, and C pneumoniae DNA detection by nested touchdown polymerase chain reaction (PCR). On the basis of the results of stage 1, a second population of 141 consecutive patients with steady state mild to moderate chronic bronchitis (FEV 1 >50% predicted) was studied. On admission, at regular intervals, and at exacerbation all patients underwent serological testing for C pneumoniae (microimmunofluorescence) and a nested touchdown PCR to detect C pneumoniae DNA was performed on peripheral blood mononuclear cells (PBMCs). Patients were assessed over a 12 month period. Information regarding the previous 12 months was taken from medical records. Results: Chronic colonisation of the sputum with C pneumoniae was significantly associated with lower FEV 1 and greater airway bacterial colonisation. On admission to the stage 2 study, 80 patients were PCR negative and 61 were PCR positive. Over the 2 years a mean (SD) of 1.43 (1.32) acute exacerbations occurred in PCR negative patients and 2.03 (1.21) in PCR positive patients (p<0.01). During the 12 month follow up period 34 PCR positive patients had acute exacerbations and were treated with azithromycin for 6 weeks. Serological evidence of acute C pneumoniae reinfection/reactivation was found in two of the 34 patients. The rate of C pneumoniae DNA clearance from blood following treatment was 29% at follow up. Conclusion: Chronic colonisation with C pneumoniae is associated with a higher rate of exacerbations of chronic bronchitis. Long term treatment is required to obtain clearance of the organism from the blood.

The role of atypical respiratory pathogens in exacerbations of chronic obstructive pulmonary disease

“…The present PCR results are in disagreement with those reported by BLASI et al [38], which showed that C. pneumoniae DNA detection is associated with higher rates of exacerbation and airway microbial colonisation in patients with COPD. Of the 42 patients enrolled, individuals whose respiratory samples were C. pneumoniae DNA PCR positive (38%) had a significantly greater number of pathogens on sputum culture than PCR negative patients.…”

“…Of the 42 patients enrolled, individuals whose respiratory samples were C. pneumoniae DNA PCR positive (38%) had a significantly greater number of pathogens on sputum culture than PCR negative patients. BLASI et al [38] also found that C. pneumoniae-positive patients (in stable COPD) had a greater tendency towards frequent exacerbation, although this difference in exacerbation frequency between the two groups was small (0.6 exacerbations?yr -1 ). In a smaller, but similar, study SEEMUNGAL et al [39] found no relationship between C. pneumoniae DNA detection in the airway at exacerbation and exacerbation frequency.…”

Imbalanced secretion of IL‐1β and IL‐1RA inChlamydia pneumoniae-infected mononuclear cells from COPD patients

“…The present findings indicate a possible pathophysiological mechanism for perpetuating the inflammatory process in the lungs, since a well balanced anti-inflammatory cytokine response is indispensable for limiting inflammation in the pulmonary compartment. Further studies are needed to evaluate the balance of pro-and anti-inflammatory cytokines in BALF from COPD patients with acute exacerbations with respect to their status regarding acute or persistent C. pneumoniae infection, and to clarify whether the higher exacerbation rate in patients with persistent C. pneumoniae infection [30] is associated with the in vitro observed cytokine mismatch. In patients with C. pneumoniae DNA-positive pneumonia without underlying pulmonary disease, balanced secretion of IL-1b and IL-1RA was observed in BALF (unpublished data).…”

Function and Regulation of SPLUNC1 Protein in Mycoplasma Infection and Allergic Inflammation

“…A typical bacterial infections in the airways, such as those caused by Mycoplasma pneumoniae (Mp), 3 can be involved in the pathogenesis of chronic lung diseases including asthma (1)(2)(3)(4). Our clinical studies have demonstrated that nearly 40% of chronic stable asthmatics are positive for Mp (1).…”