Isolated respiratory tract microorganisms and clinical characteristics in asthma exacerbation of obese patients: a multicenter study.

BACKGROUND: Viral infection is a risk factor for asthma exacerbation (AE). However, bacterial infections related to AE in adults are poorly known. On the other hand, obese patients with asthma have their own clinical and biological characteristics compared with non-obese patients. METHODS: We investigated the differences in isolated pathogens for AE between obese and non-obese patients with asthma. We included 407 patients with AE from 24 medical centers in Korea. Microorganisms isolated from culture, RT-PCR or serologic tests using lower respiratory tract specimens were retrospectively investigated. RESULTS: A total of 171 obese and 236 non-obese patients with asthma were included for analysis. Compared to non-obese patients, obese patients were associated with women (77.2% vs. 63.6%), never smoker (82.5% vs. 73.9%), shorter duration of asthma (7.9 ± 8.4 vs. 10.5 ± 10.1 years), less history of pulmonary tuberculosis (8.8% vs. 17.4%), and more comorbidity of allergic rhinitis (48.5% vs. 0.8%). Viral and/or bacterial infections were detected in 205 patients (50.4%) with AE. The numbers of patients with viral only, bacterial only, or both infections were 119, 49, and 37, respectively. The most commonly isolated bacterium was Streptococcus pneumoniae, followed by Pseudomonas aeruginosa and Chlamydia pneumoniae. Obese patients showed a lower incidence of Chlamydia pneumoniae infection. In the non-obese group, bacterial infection, especially Chlamydia pneumoniae infection, was significantly associated with the duration of systemic corticosteroid use (13.6 ± 19.8 vs. 9.7 ± 6.7 days, p = 0.049). CONCLUSION: Bacterial infection was associated with a longer period of corticosteroid use in the non-obese group. Acute Chlamydia pneumoniae infection was less associated with obese patients with AE. Further well-designed studies are needed to evaluate microorganisms and the efficacy of antibiotics in patients with AE.

Longitudinal analysis of quality of life in primary lung cancer patients with chlamydia pneumoniae infection: a time-to-deterioration model.

BACKGROUND: Chlamydia pneumoniae (Cpn) IgG and IgA has been strongly linked to lung cancer, but its impact on patients' quality of life remains unclear. Our objective was to investigate the relationship between pre-treatment Cpn IgG and IgA and time to deterioration (TTD) of the HRQoL in patients with primary lung cancer. METHODS: A prospective hospital-based study was conducted from June 2017 to December 2018, enrolling 82 patients with primary lung cancer admitted to the First Affiliated Hospital of Fujian Medical University for questionnaire surveys. Cpn IgG and IgA was detected by microimmunofluorescence method. HRQoL was assessed at baseline and during follow-up using the EORTC Quality of Life Questionnaire version 3.0 (EORTC QLQ-C30) and EORTC Quality of Life Questionnaire-Lung Cancer (EORTC QLQ-LC13). HRQoL scores were calculated using the QoLR package, and TTD events were determined (minimum clinically significant difference = 5 points). Cox regression analysis was used to evaluate the effect of Cpn IgG and IgA on HRQoL. RESULTS: We investigated the relationship between Cpn IgG and IgA and quality of life in patients with primary lung cancer. The study was found that 75.61% of cases were Cpn IgG + and 45.12% were Cpn IgA + . Cpn IgA + IgG + was 41.46%. For EORTC QLQ-C30, Physical function (PF) and Pain (PA) TTD events on the functional scale and Symptom scale were the most common during follow-up. After adjusting for gender and smoking status, Pre-treatment Cpn IgA + was found to signifcantly delay TTD of Physical functioning(HR = 0.539, 95% CI: 0.291-0.996, P = 0.048). In addition, Cpn IgG + before treatment significantly delayed TTD in Emotional functioning (HR = 0.310, 95% CI: 0.115-0.836, P = 0.021). For EORTC QLQ-LC13, deterioration of dyspnea (LC-DY) was the most common event. However, Cpn IgG and IgA before treatment had no effect on the TTD of EORTC QLQ-LC13 items. CONCLUSIONS: According to EORTC QLQ-C30 and EORTC QLQ-LC13, Cpn IgA delayed TTD in Physical functioning and Cpn IgG delayed TTD in Emotional functioning.

Systematic Infection of Chlamydia Pneumoniae.

BACKGROUND: Chlamydia pneumoniae (Cpn) is one of the most common respiratory pathogens in children and adults. It is characterized as an obligate intracellular parasite. Peripheral blood monocytes (PBMC), lymphocytes, and macrophages are involved in spreading chlamydia infection to extrapulmonary organs indicating that Cpn infection can cause systematic symptoms in vivo via blood transmission. METHODS: This review summarizes the mechanisms of Cpn infection in host cells, the immune response of the body, and the relationship between Cpn infection and some chronic diseases. RESULTS: Cpn participation in extrapulmonary chronic diseases has been proven owing to the presence of Cpn DNA in AS plaque, nerve tissues, and synovium tissues of the joints. CONCLUSIONS: Cpn infection is related to the development of chronic diseases such as atherosclerosis, Alzheimer's Disease (AD), and reactive arthritis through in vivo and in vitro experiments.

Chlamydia pneumoniae can infect the central nervous system via the olfactory and trigeminal nerves and contributes to Alzheimer's disease risk.

Chlamydia pneumoniae is a respiratory tract pathogen but can also infect the central nervous system (CNS). Recently, the link between C. pneumoniae CNS infection and late-onset dementia has become increasingly evident. In mice, CNS infection has been shown to occur weeks to months after intranasal inoculation. By isolating live C. pneumoniae from tissues and using immunohistochemistry, we show that C. pneumoniae can infect the olfactory and trigeminal nerves, olfactory bulb and brain within 72 h in mice. C. pneumoniae infection also resulted in dysregulation of key pathways involved in Alzheimer's disease pathogenesis at 7 and 28 days after inoculation. Interestingly, amyloid beta accumulations were also detected adjacent to the C. pneumoniae inclusions in the olfactory system. Furthermore, injury to the nasal epithelium resulted in increased peripheral nerve and olfactory bulb infection, but did not alter general CNS infection. In vitro, C. pneumoniae was able to infect peripheral nerve and CNS glia. In summary, the nerves extending between the nasal cavity and the brain constitute invasion paths by which C. pneumoniae can rapidly invade the CNS likely by surviving in glia and leading to Aß deposition.

Chlamydia pneumoniae-associated pleuropericarditis: a case report and systematic review of the literature.

BACKGROUND: Chlamydia pneumoniae is a common cause of atypical community acquired pneumonia (CAP). The diagnostic approach of chlamydial infections remains a challenge. Diagnosis of delayed chlamydial-associated complications, involving complex autoimmune pathophysiological mechanisms, is still more challenging. C. pneumoniae-related cardiac complications have been rarely reported, including cases of endocarditis, myocarditis and pericarditis. CASE PRESENTATION: A 40-year old female was hospitalized for pleuropericarditis following lower respiratory tract infection. The patient had been hospitalized for CAP (fever, dyspnea, chest X-ray positive for consolidation on the left upper lobe) 5 weeks ago and had received ceftriaxone and moxifloxacin. Four weeks after her discharge, the patient presented with fever, shortness of breath and pleuritic chest pain and was readmitted because of pericardial and bilateral pleural effusions (mainly left). The patient did not improve on antibiotics and sequential introduction of colchicine and methylprednisolone was performed. The patient presented impressive clinical and laboratory response. Several laboratory and clinical assessments failed to demonstrate any etiological factor for serositis. Chlamydial IgM and IgG antibodies were positive and serial measurements showed increasing kinetics for IgG. Gold standard polymerase chain reaction of respiratory tract samples was not feasible but possibly would not have provided any additional information since CAP occurred 5 weeks ago. The patient was discharged under colchicine and tapered methylprednisolone course. During regular clinic visits, she remained in good clinical condition without pericardial and pleural effusions relapse. CONCLUSIONS: C. pneumoniae should be considered as possible pathogen in case of pleuritis and/or pericarditis during or after a lower respiratory tract infection. In a systematic review of the literature only five cases of C. pneumoniae associated pericarditis were identified. Exact mechanisms of cardiovascular damage have not yet been defined, yet autoimmune pathways might be implicated.

Chlamydia pneumoniae and chronic asthma: Updated systematic review and meta-analysis of population attributable risk.

BACKGROUND: Chlamydia pneumoniae (Cp) is an obligate intracellular human respiratory pathogen producing persisting lung infection with a plausible link to asthma pathogenesis. The population attributable risk of potentially treatable Cp infection in asthma has not been reported. METHODS: The author searched from 2000 to 2020 inclusive for previously un-reviewed and new cross sectional and prospective controlled studies of Cp biomarkers and chronic asthma in both children and adults. Qualitative descriptive results and quantitative estimates of population attributable risk for selected biomarkers (specific IgG, IgA and IgE) are presented. FINDINGS: No large, long-term prospective population-based studies of Cp infection and asthma were identified. About half of case-control studies reported one or more significant associations of Cp biomarkers and chronic asthma. Heterogeneity of results by age group (pediatric v adult asthma), severity category (severe/uncontrolled, moderate/partly controlled, mild/controlled) and antibody isotype (specific IgG, IgA, IgE) were suggested by the qualitative results and confirmed by meta-analyses. The population attributable risks for Cp-specific IgG and IgA were nul in children and were 6% (95% confidence interval 2%-10%, p = 0.002) and 13% (9%-18%, p<0.00001) respectively in adults. In contrast to the nul or small population attributable risks for Cp-specific IgG and IgA, the population attributable risk for C. pneumoniae-specific IgE (children and adults combined) was 47% (39%-55%, p<0.00001). In the subset of studies that reported on asthma severity categories, Cp biomarkers were positively and significantly (P<0.00001) associated with asthma severity. INTERPRETATION: C. pneumoniae-specific IgE is strongly associated with asthma and asthma severity, suggesting a possible mechanism linking chronic Cp infection with asthma in a subset of individuals with asthma. Infection biomarkers should be included in future macrolide treatment trials for severe and uncontrolled asthma.

The association of Chlamydia pneumoniae infection with atherosclerosis: Review and update of in vitro and animal studies.

Previous studies have tended to relate Chlamydia pneumoniae (Cpn) infection to atherosclerosis. However, while serological studies have mostly reinforced this hypothesis, inconsistent and even contradictory findings have been reported in various researches. Recent papers have pointed to the significance of Cpn in atherosclerotic lesions, which are regarded as the initiator and cause of chronic inflammation. This bacterium develops atherosclerosis by phenotypic changes in vascular smooth muscle cells, dysregulation of endothelin-1 in the vascular wall, and releasing pro-inflammatory cytokines from Toll-like receptor-2 (TLR2). Furthermore, Cpn infection, particularly under hyperlipidemic conditions, enhances monocyte adhesion to endothelium; changes the physiology of the host, e.g., cholesterol homeostasis; and activates the Low-density lipoprotein (LDL) receptor, which is the initial step in atherogenesis. On the other hand, it has been reported that Cpn, even without the immune system of the host, has the ability to stimulate arterial thickening. Moreover, there is evidence that Cpn can increase the impact of the classical risk factors such as hyperlipidemia, pro-inflammatory cytokines, and smoking for atherosclerosis. Furthermore, animal studies have shown that Cpn infection can induce atherosclerotic, which alongside hyperlipidemia is a co-risk factor for cardiovascular disease. Although the exact link between Cpn and atherosclerosis has not been determined yet, previous studies have reported possible mechanisms of pathogenesis for this bacterium. Accordingly, investigating the exact role of this infection in causing atherosclerosis may be helpful in controlling the disease.

Case Report: Refractory Acute Respiratory Distress Syndrome Supported by Extracorporeal Membrane Oxygenation due to Coinfection with Chlamydia pneumoniae and Leptospirosis in Reunion Island.

Infection with Leptospira spp. is common in Réunion, a tropical island in the Indian Ocean. However, respiratory coinfections between strains of Leptospira spp. and other microorganisms are rarely described. Here, we describe the first reported case of coinfection between Leptospira spp. and Chlamydia pneumoniae, responsible for refractory acute respiratory distress syndrome requiring extracorporeal membrane oxygenation with a favorable outcome. In a case of leptospirosis with severe respiratory illness, testing for respiratory coinfection, especially with atypical pathogens, could explain the seriousness of the clinical condition and lead to specific treatment.

Skin and Mucous Membrane Eruptions Associated with Chlamydophila Pneumoniae Respiratory Infections: Literature Review.

BACKGROUND: Mycoplasma pneumoniae pneumonia is sometimes associated with skin or mucous membrane eruptions. Available reviews do not address the association of Chlamydophila pneumoniae pneumonia with skin eruptions. We therefore conducted a systematic review of the literature addressing this issue. The National Library of Medicine, Excerpta Medica, and Web of Science databases were employed. SUMMARY: In two reports, skin lesions and especially urticaria were more common (p < 0.05) in atypical pneumonia caused by C. pneumoniae as compared with M. pneumoniae. We found 47 patients (<18 years, n = 16; ≥18 years, n = 31) affected by a C. pneumoniae atypical pneumonia, which was associated with erythema nodosum, erythema multiforme minus, erythema multiforme majus, isolated mucositis, or cutaneous vasculitis. We also found the case of a boy with C. pneumoniae pneumonia and acute generalized exanthematous pustulosis. We did not find any case of C. pneumoniae respiratory infection associated with either Gianotti-Crosti syndrome, pityriasis lichenoides et varioliformis acuta Mucha-Habermann, or varicella-like skin eruptions.

Azithromycin decreases Chlamydia pneumoniae-mediated Interleukin-4 responses but not Immunoglobulin E responses.

BACKGROUND: Chlamydia pneumoniae is an obligate intracellular bacterium that causes respiratory infection. There may exist an association between C. pneumoniae, asthma, and production of immunoglobulin (Ig) E responses in vitro. Interleukin (IL-4) is required for IgE production. OBJECTIVE: We previously demonstrated that doxycycline suppresses C. pneumoniae-induced production of IgE and IL-4 responses in peripheral blood mononuclear cells (PBMC) from asthmatic subjects. Whereas macrolides have anti-chlamydial activity, their effect on in vitro anti-inflammatory (IgE) and IL-4 responses to C. pneumoniae have not been studied. METHODS: PBMC from IgE- adult atopic subjects (N = 5) were infected +/- C. pneumoniae BAL69, +/- azithromycin (0.1, 1.0 ug/mL) for 10 days. IL-4 and IgE levels were determined in supernatants by ELISA. IL-4 and IgE were detected in supernatants of PBMC (day 10). RESULTS: When azithromycin (0.1, 1.0 ug/ml) was added, IL-4 levels decreased. At low dose, IgE levels increased and at high dose, IgE levels decreased. When PBMC were infected with C. pneumoniae, both IL-4 and IgE levels decreased. Addition of azithromycin (0.1, 1.0 ug/mL) decreased IL-4 levels and had no effect on IgE levels. CONCLUSIONS: These findings indicate that azithromycin decreases IL-4 responses but has a bimodal effect on IgE responses in PBMC from atopic patients in vitro.

TLR2/CXCR4 coassociation facilitates Chlamydia pneumoniae infection-induced atherosclerosis.

Chlamydia pneumoniae infection could play a role in atherosclerosis. Toll-like receptor 2 (TLR2) and C-X-C motif chemokine receptor 4 (CXCR4) have been both shown to be involved in atherosclerosis. However, whether and how TLR2/CXCR4 cross talk is involved in C. pneumoniae infection-induced atherosclerosis remains to be determined. Our study aims to demonstrate that C. pneumoniae infection induced the cross talk between TLR2 and CXCR4 to mediate C. pneumoniae infection-induced vascular smooth muscle cell (VSMC) migration and even accelerate atherosclerosis. We first found that C. pneumoniae infection increased the aortic lesion size (en face), cross-sectional lesion area, and lipid content in aortic root lesion, which were both significantly reduced in apolipoprotein E-null (ApoE-/-)TLR2-/- or CXCR4-blocked ApoE-/- mice and were almost reversed in CXCR4-blocked ApoE-/-TLR2-/- mice. Subsequently, our data showed that C. pneumoniae infection-induced increases in VSMC contents in the atherosclerotic lesion were remarkably suppressed in ApoE-/-TLR2-/- mice or CXCR4-blocked ApoE-/- mice, and were further decreased in CXCR4-blocked ApoE-/-TLR2-/- mice. We then demonstrated that the increase in VSMC migratory capacity caused by C. pneumoniae infection was inhibited by either TLR2 or CXCR4 depletion, and downregulating both TLR2 and CXCR4 further decreased C. pneumoniae infection-induced VSMC migration by suppressing the infection-stimulated F-actin reorganization through the inhibition of the phosphorylation of focal adhesion kinase. Taken together, our data indicate that TLR2/CXCR4 coassociation facilitates C. pneumoniae infection-induced acceleration of atherosclerosis by inducing VSMC migration via focal adhesion kinase-mediated F-actin reorganization.NEW & NOTEWORTHY Toll-like receptor 2 (TLR2) and C-X-C motif chemokine receptor 4 (CXCR4) have both been shown to be involved in atherosclerosis. We demonstrate for the first time the presence of TLR2/CXCR4 coassociation during Chlamydia pneumoniae infection-induced atherosclerosis. Amazingly, blocking of both TLR2 and CXCR4 significantly retards and even almost reverses this infection-induced atherosclerosis. Our work reveals new mechanisms about C. pneumoniae infection-induced atherosclerosis and identifies potential new therapeutic targets for the prevention and treatment of atherosclerosis.

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.

Assessment of evidence for or against contributions of Chlamydia pneumoniae infections to Alzheimer's disease etiology.

Alzheimer's disease, the most common form of dementia, was first formally described in 1907 yet its etiology has remained elusive. Recent proposals that Aß peptide may be part of the brain immune response have revived longstanding contention about the possibility of causal relationships between brain pathogens and Alzheimer's disease. Research has focused on infectious pathogens that may colonize the brain such as herpes simplex type I. Some researchers have proposed the respiratory bacteria Chlamydia pneumoniae may also be implicated in Alzheimer's disease, however this remains controversial. This review aims to provide a balanced overview of the current evidence and its limitations and future approaches that may resolve controversies. We discuss the evidence from in vitro, animal and human studies proposed to implicate Chlamydia pneumoniae in Alzheimer's disease and other neurological conditions, the potential mechanisms by which the bacterium may contribute to pathogenesis and limitations of previous studies that may explain the inconsistencies in the literature.

Outbreak of Chlamydia pneumoniae Infections and X-ray-Confirmed Pneumonia in Army Trainees at Fort Leonard Wood, Missouri, 2014.

INTRODUCTION: Chlamydia pneumoniae (Cp) is a bacterium that causes pneumonia and other respiratory diseases. Fever may be present early but absent by time of presentation to clinic. Increases in X-ray-confirmed pneumonia (XCP) and laboratory-confirmed Cp infections were observed in new soldiers in training at Fort Leonard Wood (FLW), Missouri, early in 2014. These findings prompted a site assistance visit from the U.S. Army Public Health Command, Aberdeen Proving Ground, Maryland, with a review of available data and information to describe the outbreak, and inspections of barracks and training facilities and review of training practices to identify opportunities for interventions to reduce the risk of respiratory disease agent transmission. MATERIALS AND METHODS: The study population was trainee soldiers at FLW in 2013-2014. Data from two acute respiratory disease surveillance systems were studied. A local surveillance system operated by the FLW General Leonard Wood Army Community Hospital Preventive Medicine Department tracked weekly chest X-rays taken and the numbers positive for pneumonia. A Naval Health Research Center, San Diego, California, laboratory-based Febrile Respiratory Illness Surveillance Program collected clinical data and nasal, or nasal and pharyngeal swabs, for nucleic acid amplification testing from up to 15 trainees/week with fever and either cough or sore throat. Up to 4 of the 15 specimens could be from afebrile patients with XCP. Specimens were tested for a variety of agents. RESULTS: Monthly rates of XCP rose quickly in 2014 and peaked at 0.9/100 trainees in May. The percentage of the San Diego surveillance system specimens that were positive for Cp also increased quickly in 2014, peaking at 54% in May. During the first half of 2014, the San Diego program studied specimens from 141 ill trainees; 37% (52/141) were positive for Cp, making it the most common organism identified, followed by rhinoviruses (8%), influenza viruses (4%), Mycoplasma pneumoniae (2%), and adenoviruses (1%). The remaining specimens (48%) were negative for all respiratory pathogens. Only 12% (6/52) of Cp positive patients were febrile. Facilities inspections and review of training practices failed to identify variables that might be contributing to an increased risk of respiratory agent transmission. CONCLUSION: The XCP rate and the percentage of specimens positive for Cp increased in early 2014, peaking in May. Only 12% of trainees with laboratory-confirmed Cp were febrile. Historically, acute respiratory disease surveillance at military training centers focused on febrile diseases, particularly those caused by adenoviruses. With introduction of an adenovirus vaccine in late 2011, respiratory disease rates dropped with only sporadic occurrences of adenovirus-associated disease. In 2012, the San Diego surveillance program began providing data on multiple respiratory disease agents, in addition to adenoviruses and influenza viruses. Since then, Cp, rhinoviruses and Mycoplasma pneumoniae have frequently been detected in trainees with acute respiratory disease. Respiratory surveillance programs supporting Army training centers should be re-evaluated in this post-adenovirus vaccine era, to include assessment of the fever criterion for selecting patients for study, the value of chest X-ray surveillance and the value of rapidly providing laboratory results to inform provider decisions regarding antibiotic use.

Intranasal immunization with recombinant chlamydial protease-like activity factor attenuates atherosclerotic pathology following Chlamydia pneumoniae infection in mice.

We have shown previously that intranasal vaccination with recombinant chlamydial protease-like activity factor (rCPAF: antigen) and interleukin-12 (IL-12) as an adjuvant induces robust protection against pathological consequences of female genital tract infection with Chlamydia muridarum, a closely related species and a rodent model for the human pathogen Chlamydia trachomatis. Another related species Chlamydia pneumoniae, a human respiratory pathogen, has been associated with exacerbation of atherosclerotic pathology. CPAF is highly conserved among Chlamydia spp. leading us to hypothesize that immunization with rCPAF with IL-12 will protect against high-fat diet (HFD) and C. pneumoniae-induced acceleration of atherosclerosis. rCPAF ± IL-12 immunization induced robust splenic antigen (Ag)-specific IFN-γ and TNF-α production and significantly elevated serum total anti-CPAF Ab, IgG2c, and IgG1 antibody levels compared to mock or IL-12 alone groups. The addition of IL-12 to rCPAF significantly elevated splenic Ag-specific IFN-γ production and IgG2c/IgG1 anti-CPAF antibody ratio. Following intranasal C. pneumoniae challenge and HFD feeding, rCPAF ± IL-12-immunized mice displayed significantly enhanced splenic IFN-γ, not TNF-α, response on days 6 and 9 after challenge, and significantly reduced lung chlamydial burden on day 9 post-challenge compared to mock- or IL-12-immunized mice. Importantly, rCPAF ± IL-12-immunized mice displayed significantly reduced atherosclerotic pathology in the aortas after C. pneumoniae challenge. Serum cholesterol levels were comparable between the groups suggesting that the observed differences in pathology were due to protective immunity against the infection. Together, these results confirm and extend our previous observations that CPAF is a promising candidate antigen for a multisubunit vaccine regimen to protect against Chlamydia-induced pathologies, including atherosclerosis.

No evidence of Chlamydia pneumoniae in the synovia of patients with osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is a common cause of disability affecting millions of people of all ages worldwide. The pathogenesis involves an inflammatory component, but the cause of the inflammation remains incompletely understood. The intracellular bacteria Chlamydia trachomatis and C. pneumoniae have been demonstrated in patients with reactive arthritis. Both of these microorganisms can cause chronic and persistent infections, with C. trachomatis being the most common cause of reactive arthritis. This study was performed to investigate the presence of C. pneumoniae in a large number of patients with primary OA. METHODS: The study included 75 patients who underwent total knee arthroplasty. During surgery, a synovial biopsy was performed and synovial fluid drawn. Real-time polymerase chain reaction (PCR) of C. pneumoniae was run on all patients, and real-time PCR of bacterial 16S rDNA was conducted on 30 of the 75 patients to screen for the presence of other bacteria. RESULTS: Real-time PCR showed no evidence of the presence of C. pneumoniae in the patients' specimens, nor were other bacteria detected. CONCLUSIONS: Although an inflammatory component is part of the pathogenesis of OA, we found no evidence indicating that C. pneumoniae is a stimulator of that inflammation.

Chlamydophila pneumoniae infection is not associated with primary biliary cholangitis / La infección por Chlamydophila pneumoniae no está asociada con colangitis biliar primaria

ANTECEDENTES: La colangitis biliar primaria (CBP) es una enfermedad hepática inflamatoria crónica colestásica de causa desconocida. Varios patógenos virales y bacterianos han sido propuestos como factores que podrían gatillar una respuesta inmune por mimetismo molecular, o directamente estar relacionados en la persistencia del daño biliar. Existen reportes controversiales respecto al rol de en la patogenia de CBP. OBJETIVOS: Investigar marcadores de infección de séricos y en hígado de pacientes con CBP. PACIENTES Y MÉTODOS: Veinte pacientes diagnosticados con CBP y 20 pacientes control con otras enfermedades hepáticas crónicas no colestásicas fueron estudiados. Se determinaron anticuerpos séricos anti- (IgG). Se realizó detección inmunohistoquímica de antígenos de en hígado. Se extrajo DNA de hígado para amplificación de la secuencia específica de rRNA 16S de por PCR. Fueron usados controles de amplificación de DNA bacteriano y humano. Los pacientes firmaron consentimiento informado. Se realizó un metaanálisis de la diferencia de riesgo de CBP en pacientes infectados por y en un grupo control. RESULTADOS: Los anticuerpos séricos fueron positivos en 30% de los pacientes con CBP y 50% de los controles (p = NS). Antígenos de no fueron detectados en tejido hepático de pacientes con CBP ni de controles. No se amplificó ADN bacteriano en ninguna de las muestras. El metaanálisis de la diferencia de riesgo mostró gran heterogeneidad de los estudios, por lo que no se realizó una estimación de diferencia de riesgo agrupada. DISCUSIÓN: No encontramos asociación entre infección por y CBP. En la evidencia actual, un estudio presenta resultados a favor de la asociación entre y CBP y tres estudios resultados en contra.,

Primary biliary cholangitis (PBC) is a chronic cholestatic inflammatory liver disease of unknown cause. Several viral and bacterial pathogens have been proposed as factors that could either trigger an immune response by molecular mimicry or directly be involved in the persistence of biliary damage. There are conflicting reports respecting the role of in the pathogenesis of PBC. To investigate markers of infection in serum and liver tissue from patients with PBC. Twenty patients with diagnosis of PBC and 20 control patients with other non-cholestatic chronic liver diseases were studied. Serum anti- antibodies (IgG) were determined. Liver tissue was available for immunohistochemistry detection of antigens. DNA was extracted from liver tissue and a specific sequence of 16S rRNA gene was amplified by CPR. Adequate controls of bacterial and human DNA amplification were used. Informed consent was obtained from patients. A meta-analysis of risk difference of PBC in Chlamydophila pneumoniae infected patients and in the control groupwas performed. Serum antibodies were positive in 30% of patients with PBC and 50% of controls (p = NS). antigens were not detected in liver tissue neither of patients with PBC nor controls. Bacterial DNA did not amplify in any of the samples, despite good amplification of internal and external controls. Risk difference meta-analysis showed high heterogeneity between studies. Therefore, we did not estimate a pooled risk difference. Our results do not support the association between infection and PBC. In the current literature only one study shows an association between and PBC, but other three studies do not support it.

A retrospective seroepidemiologic survey of Chlamydia pneumoniae infection in patients in Beijing between 2008 and 2017.

BACKGROUND: Chlamydia pneumoniae (C. pneumoniae) is an obligate intracellular bacterium and a human pathogen that causes respiratory infectious diseases. More than 50% of the adult population worldwide was once infected with C. pneumoniae, but investigations into this topic are insufficient in mainland China. METHODS: Anti-C. pneumoniae IgG and IgM antibodies were detected using micro-immunofluorescence test in serum samples of patients visiting Peking Union Medical College Hospital between 2008 and 2017 for routine medical purposes, and the aim of this retrospective study was to analyze the test results. RESULTS: Among 12,050 serum specimens tested for anti-C. pneumoniae IgG and IgM antibodies, the overall prevalence of anti-C. pneumoniae IgG antibodies was 86.6%, 87.2% for men and 86.0% for women. Adult men (>20 years) were found to have a significantly higher prevalence of anti-C. pneumoniae IgG than women (χ2 = 30.32, P = 0.000). 3 to 5 years old patients were observed to have the lowest prevalence of anti-C. pneumoniae IgG, 42.8%, then increased with age, reaching the highest level of 98.6% in patients over 70 years of age. In the 10,434 specimens with C. pneumoniae IgG antibodies, the total geometric mean titer (GMT) for C. pneumoniae IgG was 45.71. Although GMTs were found to be significantly higher among all men than among all women (t = 5.916, P = 0.000), sex difference actually began in patients over 40 years of age and increased in the elderly. In the total 12,050 specimens, 1.2% had anti-C. pneumoniae IgM, 3.3% had anti-C. pneumoniae IgG with titers equal to or greater than 1:512; 0.39% had ≥4-fold increasing titers of antibodies in acute and convalescent phase paired samples, and 4.4% were finally confirmed to have acute antibodies against C. pneumoniae. 6 to 10 years old patients were found to have the highest rate of both IgM antibodies (3.9%) and acute antibodies (6.2%) against C. pneumoniae. Acute antibodies against C. pneumoniae were found to be more frequent in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD, 14.0%, χ2 = 20.43, P = 0.000), patients with pneumonia (7.8%, χ2 = 51.87, P = 0.000) and patients with acute respiratory tract infection (12.3%, χ2 = 60.91, P = 0.000) than among all patients (4.4%). Both anti-C. pneumoniae IgG and IgM antibodies should be tested for acute antibodies against C. pneumoniae as testing for either alone will underestimate by a maximum of two-thirds the incidence of acute antibodies against C. pneumoniae. CONCLUSIONS: More than 86% of Chinese patients on an average were once infected with C. pneumoniae. Adult men had both a higher prevalence and higher levels of antibodies than women. 6 to10 year old patients were found to have the most frequent acute infection of C. pneumoniae. C. pneumoniae is associated with AECOPD, pneumonia and acute respiratory tract infection. Anti-C. pneumoniae IgG and IgM should be tested simultaneously to avoid underestimation of acute antibodies against C. pneumoniae.