Chlamydia pneumoniae and cardiovascular disease

A Recombinase-Aided Amplification Assay for the Detection of Chlamydia felis

Chlamydia felis is an important zoonotic agent for humans and various animals. A recombinase-aided amplification (RAA) assay was developed for detecting C. felis. RAA can be performed in a closed tube at 39°C within 30 min. The detection limit was 10.6 copies of the C. felis plasmid DNA per reaction. No positive signals for other pathogens were detected. The coincidence rate of RAA and conventional PCR was 95.24% (20/21) and 100% (96/96) for positive and negative samples, respectively. The established RAA assay is a simple, rapid, highly sensitive, and specific method for detecting C. felis.

The double burden of disease among mining workers in Papua, Indonesia: at the crossroads between Old and New health paradigms

Background

As the global shift toward non-communicable diseases overlaps with the unfinished agenda of confronting infectious diseases in low- and middle-income countries, epidemiological links across both burdens must be recognized. This study examined the non-communicable disease-infectious disease overlap in the specific comorbidity rates for key diseases in an occupational cohort in Papua, Indonesia.

Methods

Diagnosed cases of ischaemic heart disease, stroke, hypertension, diabetes (types 1 and 2), chronic obstructive pulmonary disease, asthma, cancer, HIV and AIDS, tuberculosis, and malaria were extracted from 22,550 patient records (21,513 men, 1037 women) stored in identical electronic health information systems from two clinic sites in Papua, Indonesia. Data were collected as International Classification of Diseases, 10th Revision, entries from records spanning January-December 2013. A novel application of Circos software was used to visualize the interconnectedness between the disease burdens as overlapping prevalence estimates representing comorbidities.

Results

Overall, NCDs represented 38 % of all disease cases, primarily in the form of type 2 diabetes (n = 1440) and hypertension (n = 1398). Malaria cases represented the largest single portion of the disease burden with 5310 recorded cases, followed by type 2 diabetes with 1400 cases. Tuberculosis occurred most frequently alongside malaria (29 %), followed by chronic obstructive pulmonary disease (19 %), asthma (17 %), and stroke (12 %). Hypertension-tuberculosis (4 %), tuberculosis-cancer (4 %), and asthma-tuberculosis (2 %) comorbidities were also observed.

Conclusions

The high prevalence of multimorbidity, preponderance of non-communicable diseases, and extensive interweaving of non-communicable and infectious disease comorbidities highlighted in this cohort of mining workers in Papua, Indonesia reflect the markedly double disease burden increasingly plaguing Indonesia and other similar low- and middle-income countries – a challenge with which their over-stretched, under-resourced health systems are ill-equipped to cope. Integrated, person-centered treatment and control strategies rooted in the primary healthcare sector will be critical to reverse this trend.

Outcome of Chlamydia pneumoniae associated acute ischemic stroke in elderly patients: a case-control study

BACKGROUND

Limited data exists about the role of Chlamydia pneumoniae elderly patients with acute ischemic stroke.

OBJECTIVE

To study the role of C. pneumoniae in elderly patients (age more than 65 years) with acute ischemic stroke and its impact on stroke out come.

METHODS

We recruited 100 elderly patients with acute ischemic stroke and 100 age and sex matched controls over a period of 2 years. IgG and IgA anti C. pneumoniae antibodies were measured by microimmunofluorescence technique in patients and controls. Good outcome was defined as a Modified Rankin score (mRS) of ≤2.

RESULTS

We found C. pneumoniae antibodies in 35% stroke patients and in 18% control subjects (p=0.01). Good out come at 90 days follow up was found in 20/35(57.1%) seropositive stroke patients compared to 37/65(56.9%) seronegative stroke patients (p=0.9).

CONCLUSIONS

C. pneumoniae antibody positivity was independently associated with ischemic stroke in elderly patients and its presence does not alter the stroke outcome.

Seroprevalence of Chlamydia pneumoniae antibodies in stroke in young

BACKGROUND

Younger patients, aged below 45 years, usually lack the conventional risk factors of stroke whereas infections, especially in developing countries, may play a role. There have been many reports in the last decade about the association of Chlamydia pneumoniae (C. pneumoniae) and atherosclerosis involving cerebral vessels.

OBJECTIVE

To investigate the seroprevalence of C. pneumoniae IgG and IgA antibodies in patients aged below 45 years with acute ischemic stroke.

METHODS

This study was done at a tertiary care hospital in South India between January 2004 and December 2006 where we recruited consecutive patients aged less than 45 years with acute ischemic stroke. Age and sex matched controls were recruited from the outpatient department with non stroke diagnosis. All stroke patients underwent CT (Computerized Tomography), MRI (Magnetic Resonance Image), MRA (Magnetic Resonance Angiography), Transthoracic Echocardiography and Carotid Doppler for stroke sub group diagnosis. We measured C. pneumoniae antibodies IgG and IgA by microimmunofluorescence technique in all patients and controls.

RESULTS

A total of 120 patients and 120 controls were studied over a period of two years. We found C. pneumoniae antibodies in 29.1% (35/120) stroke patients and in 12.5% (15/120) control subjects (p=0.002). C. pneumoniae IgG antibodies were found in 27.5 % (33/120) of stroke patients and 12.5% (15/120) of controls (p=0.006). IgA antibodies were observed in 5% (6/120) of strokes and none in control group (p=0.03). After adjustment of all risk factors C. pneumoniae IgG seropositivity showed odds ratio of 2.6; 95% Confidence Interval 1.2-5.6.

CONCLUSIONS

C. pneumoniae IgG antibodies were found to be associated with ischemic stroke in young.

Chlamydial lipopolysaccharide (cLPS) is present in atherosclerotic and aneurysmal arterial wall--cLPS levels depend on disease manifestation

BACKGROUND

The role of Chlamydia pneumoniae in peripheral atherosclerosis disease and abdominal aortic aneurysm (AAA) remains unclear. Chlamydial lipopolysaccharide (cLPS) detection is a method used conventionally in routine chlamydial diagnosis of gynecological or ophthalmic samples.

METHODS

We compared cLPS concentrations, as well as other markers of bacterial load, in plaques and sera of patients operated on for carotid artery stenosis (n=110), aorto-occlusive disease (n=22), or AAAs (n=50) at the Helsinki University Central Hospital.

RESULTS

The median levels of cLPS in plaques were 2.28, 0.80, and 0.29 ng/ml in AAA, aorto-occlusive disease, and carotid artery stenosis patients, respectively (P<.001, Kruskal-Wallis). cLPS in serum correlated with LPS binding protein levels (Spearman's rho=0.52, P<.001), suggesting that the presence of chlamydiae is sufficient to produce an innate immune response reaction in these patients. Serum inflammatory markers interleukin 6 and highly sensitive C-reactive protein also correlate with cLPS (Spearman's rho=0.42 and 0.51, respectively, P<.001).

CONCLUSIONS

cLPS is present in arterial disease, and the potential role of C. pneumoniae in the pathogenesis of both peripheral atherosclerosis disease and AAA should not be forgotten. cLPS has a positive correlation with serum inflammatory markers, but this is no proof of a causal association.

Is there a link between atrial fibrillation and certain bacterial infections?

The pathogenesis of atrial fibrillation (AF), the most common cardiac dysrhythmia, remains unknown. However, many recent studies point to an association between AF and inflammation because of a demonstrable significant correlation between the dysrhythmia and various biomarkers of inflammation. For example, C-reactive protein (CRP), a sensitive biomarker of systemic inflammation, has been reported to be significantly higher in patients with AF compared with a control group with no history of atrial dysrhythmias. Histological anomalies in the atria of patients with AF have also been observed. These anomalies may have an inflammatory basis, although it is not known if the structural changes within the atria of patients with AF are a cause or consequence of the dysrhythmia. Given the suggested involvement of inflammation with this dysrhythmia, an initiating factor for inflammation has been sought. Chronic bacterial infection is the most likely event to initiate and maintain an inflammatory process. Recently, bacteria infections have been hypothesized to be involved in the pathogenesis of AF, and Helicobacter pylori and Chlamydia pneumoniae are two bacteria that have aroused interest. Here, we give a brief overview of AF and then specifically explore the recent evidence that suggests that AF may be caused by bacterial infection(s) in certain patients.

Is Helicobacter pylori a cause of atrial fibrillation?

Inflammation has been implicated in the pathogenesis of cardiovascular diseases. C-reactive protein, a sensitive marker of systemic inflammation, has recently been reported to be significantly higher in patients with atrial fibrillation (AF) compared with a control group with no history of atrial arrhythmia. Elevated C-reactive protein levels in patients with AF reflects an underlying inflammatory process. Histological anomalies in the atria of patients with AF have also been observed. These anomalies may have an inflammatory basis, although it is not known if any structural changes within the atria are a cause or a consequence of the arrhythmia. Ongoing chronic infection(s) has been suggested as a possible cause of the inflammatory process demonstrated in patients with AF. Helicobacter pylori, a Gram-negative bacterium more commonly known for infecting the gastric mucosa and causing peptic ulcers, is a noncardiac factor that has been controversially reported to be associated with cardiovascular diseases. This article gives a brief overview of AF and specifically explores the recent evidence that suggests that Helicobacter pylori infection causes AF.

Chlamydia pneumoniae in HIV-infected patients and controls assessed by a novel whole blood interferon-gamma assay, serology and PCR

Chlamydia pneumoniae seropositivity is associated with cardiovascular disease and HIV infection. Cell-mediated immune responses are important for control of C. pneumoniae, and such responses may be impaired in HIV-infected patients. An assay for detection of interferon (IFN)-gamma in whole blood stimulated with C. pneumoniae antigen was developed and studied in HIV-infected patients and uninfected controls. Among 34 HIV-infected patients, none had an IFN-gamma response to C. pneumoniae antigen, compared with five of 32 healthy controls (p < 0.001). Fewer HIV-infected individuals elicited a serum IgG response when tested with a commercial enzyme immunoassay (p 0.009), but this was not so for serum IgA (p 0.12). Additionally, the IFN-gamma and antibody assays showed a trend towards a bivariate response in normal controls. This indicates that cellular and antibody responses against C. pneumoniae may be mutually exclusive, with potential implications for the role of this organism in the genesis of cardiovascular disease in both immunocompetent and HIV-infected populations.

Update on general health risk of periodontal disease

OBJECTIVES

To review the potential of periodontal infections to cause nonoral diseases. Therapeutic recommendations are provided to help patients and dental practitioners prevent systemic complications from periodontal infections.

FINDINGS

Systemic diseases from oral bacteria are mostly caused by transient bacteraemias, which can occur spontaneously from dental foci of infection, from mastication, brushing, flossing or other daily manipulations, or from dental treatments. Examples of systemic infections that may involve oral microorganisms include infective endocarditis, aspiration pneumonia, HIV-related disseminated candidiasis and cancrum oris, septicaemia associated with cancer chemotherapy and radiotherapy, necrotising faciitis and various other life-threatening infections. Inflamed gingiva constitutes a significant reservoir for herpes viruses, which have the potential to cause serious systemic diseases in immunocompromised patients. Periodontal disease may also aggravate chronic insulin insensitivity and thus interfere with glycaemic control in diabetic patients. Controversy surrounds the involvement of periodontal infections in coronary heart disease.

CONCLUSIONS

Cumulative evidence suggests that periodontal disease can be an important cause of morbidity and mortality of various systemic diseases, especially in individuals exhibiting compromised host defence. Maintaining a healthy dentition and periodontium by means of daily oral hygiene practice and regular professional care is the most effective way of preventing systemic diseases from oral infections.