Cell-mediated immune response associated with Chlamydia pneumoniae infection in atherosclerotic patients.

BACKGROUND: Chlamydia pneumoniae is an obligate intracellular bacterium that activates cell mediated immune responses; several investigations have demonstrated its strong implication in atherosclerosis. OBJECTIVES: The main objective of our study was to explore the cell-mediated immune response to C. pneumoniae infection in patients with atherosclerosis by evaluating CD14, CD8 and CD4 expression. METHODS: This investigation involved a total of 27 patients with atherosclerosis and 32 controls, among patients recruited to evaluate the association of C. pneumoniae with atherosclerosis. C. pneumoniae DNA was detected in PBMCs by nested PCR as described in our previous studies. CD4, CD8 and CD14 expression was measured by flow cytometry and data analysis was performed using FlowJo software. RESULTS: The results revealed an increase in MFI expression of CD4, CD8 and CD14 in Cpn DNA+ subjects among both patients and healthy subject controls (CD4 Cpn DNA+ = 829.11 vs. CD4 Cpn DNA- = 571.14; CD8 Cpn DNA+ = 1562 vs. CD8 Cpn DNA- = 699; CD14 Cpn DNA+ = 1513.83 vs. CD14 Cpn DNA- = 1170.70), with a statistically significant difference (p < 0.05). Furthermore, the comparison of CD4, CD8 and CD14 expression between Cpn DNA+ patients and Cpn DNA+ healthy subject controls showed a statistically significant increase in expression in the former group (p < 0.05). CONCLUSION: These data provide incentive to further explore the role of C. pneumoniae in stimulating and changing mechanisms of the cell-mediated immune response induced by C. pneumoniae antigens. This may alter immune cell-mediated responses via increased expression of CD4, CD8 and CD14 during inflammation and the development of thrombosis, leading to fatal atherosclerosis.

Chlamydia pneumoniae sero-prevalence in Moroccan patients with cardiovascular diseases.

BACKGROUND: Chlamydia pneumoniae is a pathogen associated with human respiratory tract infection, its viable presence in atherosclerotic plaques is also assumed to play significant function in cardiac diseases. Our study's main objective is to evaluate Chlamydia pneumoniae sero-prevalence in Moroccan patients with cardiovascular diseases using and comparing two serological methods. METHODS: Two hundred eighteen patients were enrolled; serums were tested by microimmunofluorescence to explore the sero-prevalence. Simultaneously 74 serums were analyzed by both immunoblot and micro-immunofluorescence to evaluate recombinant proteins diagnosis value. RESULTS: MIF results revealed 81% male and 84.5% female positive cases. The comparative study among 74 patients showed 78% men and 89% women positive cases by immunoblot, whereas MIF showed respectively 80% and 72%, a significant concordance between these methods was revealed. However, this comparison showed also two types of discrepancies, which may be related to difficulties in antigens detection by micro-immunofluorescence resulting from their structure complexity, or the antibodies reactivity with species' common antigens. CONCLUSIONS: The study revealed a high sero-prevalence of Chlamydia pneumoniae in the studied population, a big interest of recombinant protein was also revealed in the diagnosis accuracy. We suggest therefore using immunoblot for diagnosis confirmation because it provides additional useful information.

Investigation of Chlamydia pneumoniae infection in Moroccan patients suffering from cardiovascular diseases.

Chlamydia pneumoniae is an intracellular bacterium responsible for respiratory diseases and is highly involved in cardiovascular disease development, mainly atherosclerosis. The main objective of our study was to evaluate C. pneumoniae prevalence in Moroccan patients suffering from cardiovascular diseases. A total of 115 patients with cardiovascular diseases were enrolled, and their clinical and behavioral information was recorded. Blood was sampled from all patients as well as the atheroma plaques from 36 patients undergoing surgery. Nested PCR was performed for C. pneumoniae DNA detection in both peripheral blood mononuclear cells (PBMCs) and atheroma plaques. Statistical analysis was performed using EpiInfo software. Data analysis showed cardiovascular disease dominance in men, with a sex ratio M/F of 3.4, a majority of tobacco users (52.2%), and many diabetics (44.3%). A significant difference between genders was shown for tobacco use (p<0.05). Positive cases for PBMCs and atheroma plaques were 61% and 86%, respectively, and a significant difference between PBMCs and atheroma plaque infection was identified (p=0.02). Data analysis also showed that 12% of patients presented only C. pneumoniae infection as a risk factor. Therefore, the high prevalence of C. pneumoniae suggests its involvement in atherosclerosis, and further investigation is recommended for confirmation.

Molecular characterisation of Chlamydia pneumoniae associated to atherosclerosis.

Chlamydia pneumoniae is a respiratory pathogen associated with chronic inflammatory diseases such as asthma and atherosclerosis, and its detection in human carotid and coronary atheroma suggests some support for its involvement in atherogenesis. The main objective of our study was to evaluate the association between Chlamydia pneumoniae and atherosclerosis in Moroccan patients through a case-control approach and detected strain genotyping. A total of 137 cases and 124 controls were enrolled, nested PCR was performed for Chlamydia pneumoniae screening of the peripheral blood mononuclear cells (PBMCs) of both cases and controls as well as atheroma plaques from 37 cases, and positive samples were subjected to sequencing for genotyping and phylogenetic analysis. The results showed 54% and 18%, respectively, for positivity in cases and control PBMCs and 86.5% in atheroma plaques, the difference being significant between the two groups (P < 0.001, ORa = 8.580, CI, 95% [3.273-22.491]). Strain sequence analyses showed more than 98% similarity with human reference strains, and revealed various genotypes. This study supports the involvement of Chlamydia pneumoniae in atherosclerosis in the studied population and genotyping revealed that detected strains were identical to human strains circulating worldwide.