Chlamydia pneumoniae replicates in Kupffer cells in mouse model of liver infection

AIM: To develop an animal model of liver infection with Chlamydia pneumoniae (C. pneumoniae) in intraperito-neally infected mice for studying the presence of chlamy-diae in Kupffer cells and hepatocytes.METHODS: A total of 80 BALB/c mice were inoculated intraperitoneally with C. pneumoniae and sacrificed at various time points after infection. Chlamydiae were looked for in liver homogenates as well as in Kupffer cells and hepatocytes separated by liver perfusion with collagenase. C. pneumoniae was detected by both isola-tion in LLC-MK2 cells and fluorescence in situ hybridiza-tion (FISH). The releasing of TNFA-α by C. pneumoniae in vitro stimulated Kupffer cells was studied by enzyme-linked immunosorbent assay.RESULTS: C. pneumoniae isolation from liver homoge-nates reached a plateau on d 7 after infection when 6 of 10 animals were positive, then decreased, and became negative by d 20. C. pneumoniae isolation from sepa-rated Kupffer cells reached a plateau on d 7 when 5 of 10 animals were positive, and became negative by d 20. The detection of C. pneumoniae in separated Kupffer cells by FISH, confirmed the results obtained by culture. Isolated hepatocytes were always negative. Stimula-tion of Kupffer cells by alive C. pneumoniae elicited high TNF-α levels. CONCLUSION: A productive infection by C. pneumo-niae may take place in Kupffer cells and C. pneumoniae induces a local pro-inflammatory activity. C. pneumoniae is therefore, able to act as antigenic stimulus when local-ized in the liver. One could speculate that C. pneumoniaeinfection, involving cells of the innate immunity such as Kupffer cells, could also trigger pathological immune re-actions involving the liver, as observed in human patients with primary biliary cirrhosis.

Relationship between Chlamydia pneumoniae infection and occurrence of bronchial asthma

Objective: To study the relationship between Chlamydia pneumoniae (C. pneumoniae) infection and asthma exacerbation. Methods: A prospective study of C. pneumoniae infection was conducted in 75 patients with asthma and 63 patients with respiratory tract infection, and 100 blood donors served as controls. The presence of infection was convinced by the polymerase chain reaction and direct immunofluorescence assay for C. pneumoniae DNA from throat swab specimens and micro-immunofluorescence testing for C. pneu-moniae-specific IgG, IgM and IgA antibodies. Results: Prevalence of specific IgG in asthma patients (81. 3%) was higher than that of the blood donors (68. 0%, P<0. 05) and was not significantly different from respiratory tract infection patients (68. 0%, P>0. 05). The acute C. pneumoniae infection rate of symptomatic asthma patients (59. 4%) was markedly higher than that of respiratory tract infection patients (34. 9% , P<0. 05). The average titer of C. pneumoniae IgG instead of IgA in asthma patients (48. 38±6. 94) was significantly higher than respiratory tract infection patients (24. 70±8. 77, P<0. 05). Other pathogens were identified in 12 of 21 (57. 1%) asthma patients with C. pneumoniae. The symptoms of 7 asthma patients with C. pneumoniae infection were improved through antibiotic treatment. Conclusion: The findings suggest a possible role of C. pneumoniae infection in asthma.

The Study of Chlamydia Pneumoniae DNA in the Peripheral Blood Mononuclear Cell of Coronary Heart Disease

Objectives To detection of chlamydia pneumoniae (Cpn) DNA in the circulating mononuclear cell fractions of coronary heart disease and to investigate the association between infection with chlamydia pneumoniae and coronary heart disease (CHD) and prospectively whether blood - based nes- ted polymerase chain reaction(nPCR ) is useful in i- dentifying Cpn infection. Methods The peripheral blood mononuclear cell (PBMC) Cpn DNA was exam- ined using nPCR technique and confirmed by electro- phoresis in 150 patients with CHD. Select 55 patients with clinical suspected CHD but angiography result are normal as control group (CG). Then we conducted a prospective , randomized, double - blind, placebo - controlled study of 6 months of azithromycin and place- bo treatment in CHD group. Patients with Cpn DNA positive were then randomized to receive azithromycin or placebo. After treatment blood sample were collect- ed for repeated measurement . Results Chlamydia pneumoniae DNA was detected in 49(32. 7% ) of 150 persons with CHD and in 1 (1. 8% ) of 55 persons with control group,odds ratio 26. 2, 95% confidence interva 13. 52 - 194. 98. The positivity rates of nPCR in CHD groups were higher than those in control group. 16 ca- ses (29. 1%) in latent coronary heart diseases (LCHD)group , 19 cases (39.6%) in unstable angi- na(UAP) group ,and 14 cases (29.9% ) in acute my- ocardial infarction (AMI) group were Cpn positive by nPCR. There were no significant difference among in AMI^UAP and LCHD group. There were significiantdifference in Cpn DNA negative rates after the azithro- mycin and the placebo treatment. Conclusions Chlamydia pneumoniae is present in PBMC of a signifi- cant proportion of persons with CHD. The potential role of chlamydia pneumoniae in coronary atherosclerosis may therefore be more related to acceleration of disease or systemic effects by persistent infection than to sud- den initiation of progressive coronary artery disease by acute infection. The detection of Cpn DNA in PBMC with nPCR may be of great value for identifying Cpn carriers and for monitoring antichlamydial therapy.

The Role of Chlamydia pneumoniae in the Atherosclerotic Process of Patients under 50 Years of Age Who Underwent Coronary Artery Bypass Graft Surgery

Background: To evaluate the presence of C. pneumoniae DNA in the tissues and C. pneumoniae DNA antibodies in the blood samples of patients who underwent CABG surgery. Material and Methods: Fifty-one patients aorta. C. pneumoniae DNA was evaluated in the tissues collected from the atrium, left internal thoracic artery and ascending aorta of patients. Results: Although, C. pneumoniae DNA was negative in the atrial and left internal thoracic artery tissues of all patients, it was positive in the tissues obtained from the ascending aortas of twelve patients. C. pneumoniae DNA positivity was significantly higher in patients with increased aortic intimal thickness compared to those without increased aortic thickness. Conclusion: The question whether C. pneumoniae is triggering atherosclerosis or is involved as a super-infection could not be clarified.

The pathogenesis of Chlamydia pneumoniae-type pneumonitis in mice

Objective To evaluate mice as experimental animals for Chlamydia pneumoniae (C.pneumoniae) infection and investigate the pathogenesis of C.pneumoniae derived pneumonitis.Methods Icr mice were inoculated with the C.pneumoniae strain, CWL-029, either intranasally or intravenously. After a single dose inoculation, mice were killed on the 1st, 3rd, 7th, 14th, 21st, 28th and 60th days. The pathological changes in lung tissue were analyzed.Results The Icr mice were shown to be susceptible to C.pneumoniae. Inoculation into mice with C.pneumoniae induced a prolonged course of lung infection, as demonstrated by persistence of lung pathology (up to 60 days). Via intranasal inoculation of mice, lung pathology was characterized by patchy interstitial pneumonitis with predominately neutrophil leukocyte infiltration early (within the first 7 days) and lymphocyte infiltration in the later stages (14 days later) of infection. After intravenous inoculation, a similarly developed interstitial pneumonitis was observed, but it was milder and patchier, especially in early stages. C.pneumoniae DNA was detected by polymerase chain reaction (PCR) intermittently in the lung tissue. Inoculated mice developed serum IgG antibody responses.Conclusion The Icr mice were susceptible to C.pneumoniae, resulting in a pulmonary infection characterized by interstitial pneumonitis, occurring most strongly via intranasal inoculation.

Correlation of Chlamydia pneumonias infection with primary biliary cirrhosis

AIM:To evaluate the association between Chlamydia pneumoniae (Cpn) infection and primary biliary cirrhosis (PBC). METHODS: CpnIq/G and IgM were determined by enzyme-linked immunosorbent assay (ELBA) in 41 well-established PBC patients and two race-matched control groups (post-hepatitis cirrhosis, n = 70; healthy controls, n = 57). RESULTS: The mean level and seroprevalence of Cpn IgG in PBC group and post-hepatitis cirrhosis (PHC) group were significantly higher than those in healthy controls (46.8±43.4 RU/mL, 49.5±45.2 RU/mL vs28.3±32.7 RU/mL; 68.3%, 71.4%, 42.1%, respectively; P<0.05). There was a remarkably elevated seroprevalence of Cpn IgM in patients with PBC (22.0%) compared to the PHC and healthy control (HC) groups. For the PBC patients versus the HCs, the odds ratios (ORs) of the presence of Cpn IgG and IgM were 2.7 (95% CI 0.9-6.1) and 5.1 (95% CI 1.4-18.5), respectively. Though there was no correlation in the level of Cpn IgG with total IgG in sera of patients with PBC (r = -0.857, P = 0.344>0.05), Cpn IgM was related with the abnormally high concentrations of total IgM in PBC group. CONCLUSION: The results of this study do not support the hypothesis that infection with Chlamydia pneumoniae may be a triggering agent or even a causative agent in PBC, but suggest that Chlamydia pneumoniae infection probably contributes to the high level of IgM present in most patients with PBC.

Detection of Chlamydia pneumonia DNA in nasopharyngolaryngeal swab samples from patients with rhinitis and pharyngolaryngitis with polymerase chain reaction

Objective To assess the prevalence of Chlamydia pneumomia DNA in patients with otolaryngic disease Methods PCR assay was used to detect Chlamydia pneumonia specific Pst Ⅰ 474 fragment DNA in swabs from patients with acute or subacute pharyngolaryngitis or rhinitis and sinusitis C pneumonia specific antibodies in sera were also assayed with microimmuno fluoresence (MIF) Results About 28% (49/175) of the patients were PCR positive and 25 7%(45/175) were MIF antibodies positive The accordance rate of the two methods was 91 8% Conclusion It is suggested that the C pneumonia infection was common in this group of patients and the C pneumonia Pst Ⅰ474 specific PCR was sensitive and specific for detecting C pneumonia in pharyngolaryngitis or rhinitis and sinusitis