Seroprevalence of Chlamydia pneumoniae antibodies in stroke in young

Potential association between bacterial infections and ischemic stroke based on fifty case-control studies: A systematic review and meta-analysis

Background

Stroke is considered as one of the most important concerns in health care centers around the world. By definition there are two types of stroke including ischemic stroke and hemorrhagic stroke. Approximately three-quarters of stroke cases are ischemic strokes, which occur due to several risk factors such as hypertension, obesity, atherosclerosis, diabetes mellitus, osteoarthritis, and inflammatory responses. In recent years, infectious diseases have noticed as a new risk factor for ischemic stroke. Given the importance of the issue, some bacteria that cause chronic infections, especially Chlamydia pneumonia, Helicobacter pylori, Mycoplasma pneumonia, Mycobacterium tuberculosis, and Coxiella burnetii have been considered.

Methods

In the present meta-analysis, we reviewed 50 case-control studies and assessed the possible association of bacterial infections with the occurrence of ischemic stroke.

Results

We analyzed the information of 33,978 participants in several nested case-control studies, and ultimately showed that bacterial infections could increase the risk of ischemic stroke. Our results suggest that bacterial infections significantly increase in the risk of ischemic stroke (OR: 1.704; 1.57-1.84 with 95% CIs; p value = 0.01).

Conclusions

In this meta-analysis, a significant relationship was observed between infection by three bacteria such as C. pneumoniae, H. pylori, and M. tuberculosis with the occurrence of ischemic stroke. Furthermore, due to the similarity between TLRVYK domain in β2-glycoprotein-I and TLRVYK peptide in various of microorganisms, produced antibodies against pathogens interact with β2-glycoprotein-I, hence the cross-reaction phenomenon increases the positive relationship between infectious diseases and ischemic stroke.

COVID-19 and Stroke: Incidental, Triggered or Causative

Stroke is a serious neurological comorbidity observed during the ongoing COVID-19 (coronavirus associated disease 2019) pandemic caused by SARS-CoV-2 (severe acute respiratory syndrome, corona virus 2) and includes ischemic stroke, intracerebral haemorrhage and cerebral venous thrombosis. We reviewed factors that could potentially contribute to the occurrence of stroke among patients with COVID-19. There could be an interaction between the conventional risk factors of stroke, infection, systemic inflammatory response and plaque destabilisation. Inflammatory markers, D-dimer elevation and increased cytokine activity have been observed in patients with COVID-19. Other probable contributing factors include cardiac injury leading to embolism, a prothrombotic state and a possibility of direct neuroinvasive potential causing vasculopathy. Data from stroke patients gathered in large multicentric cohorts could help shed more light on the occurrence, behaviour, aetiology, pathophysiology, biomarkers and outcomes of stroke occurring during the ongoing pandemic.

Childhood infections and trauma as risk factors for stroke

Stroke is as common as brain tumor in children. The etiology of childhood arterial ischemic stroke (AIS) appears to be multifactorial, resulting from the interaction between genetic predisposition and environmental triggers. The risk factors for AIS in children are markedly different from the atherosclerotic risk factors in adults. Trauma and infections have been identified as associations in previous studies and are exposures of particular interest because of their increased prevalence in the children. The aim of this review article is to provide an overview of the research studies that have addressed the role of infections and trauma in pediatric AIS.

Chlamydia pneumoniae infection and cerebral infarction risk: a meta-analysis

BACKGROUND

Chlamydia pneumoniae infection and the risk of cerebral infarction have been previously studied in several publications; however, conflicting results have been reported. This meta-analysis assessed whether C. pneumoniae infection was associated with risk of cerebral infarction.

METHODS

Systematic computerized searches of the PubMed and Web of Knowledge were performed. Adjusted odds ratio and 95% confidence interval from original studies were extracted for combined meta-analysis.

RESULTS

Twenty-three studies with 2924 cerebral infarction patients and 4692 control patients were included in the meta-analysis. When the positive C. pneumoniae infection was defined by microimmunofluorescence-detected immunoglobulin A, the pooled odds ratio between two groups was 2.04 (95% confidence interval 1.42-2.9). In the most frequently used immunoglobulin A ≥1:16 sub-group, the pooled odds ratio was 2.07 (95% confidence interval 1.31-3.26). When the infection was defined by enzyme-linked immunosorbent assay-detected immunoglobulin A, the pooled odds ratio was 2.89 (95% confidence interval 1.23-6.81). When the infection was defined by microimmunofluorescence-detected immunoglobulin G, the pooled odds ratio was 1.46 (95% confidence interval 1.18-1.81). In the most frequently used immunoglobulin G ≥1:32 sub-group, the pooled odds ratio was 1.43 (95% confidence interval 1.06-1.92). When the infection was defined by enzyme-linked immunosorbent assay-detected immunoglobulin G, the pooled odds ratio was 1.54 (95% confidence interval 0.86-2.74). No significant publication bias was found. Sensitivity analyses showed the results were robust.

CONCLUSION

(1) This meta-analysis indicated that C. pneumoniae infection was significantly associated with an increased risk of cerebral infarction. (2) Compared with anti-C. pneumoniae immunoglobulin G, anti-C. pneumoniae immunoglobulin A seemed more effective for predicting the risk of cerebral infarction. (3) No evidence existed that anti-C. pneumoniae-immunoglobulin G detected by enzyme-linked immunosorbent assay could predict the risk of cerebral infarction.

Chlamydia pneumoniae infection and cerebrovascular disease: a systematic review and meta-analysis

Background

A wealth of published studies have been published on association between Chlamydia pneumoniae (C.pneumoniae) infection and cerebrovascular (CV) disease, but the results were inconsistent. This meta-analysis provides a systematic review of the available evidence from all serological and pathological studies of CV disease and C.pneumoniae.

Methods

A comprehensive research was conducted of MEDLINE, EMBASE, CNKI, WanFang technological periodical database and reference lists of articles to identify eligible case-control and cohort studies. Odds radio (OR) was calculated for each study outcome. Random effect model was used as pooling method and publication bias was estimated for the results.

Results

Fifty-two published studies that met criteria were selected. In case control studies, an association between C.pneumoniae infection and CV disease was revealed by serum specific IgG (OR, 1.61; 95% CI: 1.34 to 1.94), serum IgA (OR, 2.33; 95% CI: 1.76 to 3.08) and PCR technique of C.pneumoniae in peripheral blood cells (OR, 1.90; 95% CI: 1.17 to 3.07). No significant association was found in serum anti-C.pneumonae IgM seropositivity or in-situ-detection of C.pneumoniae in arterial biopsies with CV disease. Subgroup analysis by available studies suggested that C.pneumoniae may paly a role in atherosclerotic stroke, but be less significant in stroke of cardioembolism or other etiologies.

Conclusion

Association between C.pneumoniae infection and CV disease depends on the analytical method adopted, which seems stronger with stroke due to large artery atherosclerosis. Establishing a causal relationship between C.peumoniae infection and CV disease will require more prospective studies with combination of techniques and stratified by etiological subtypes.

Elevated thyroid autoantibodies and intracranial stenosis in stroke at an early age

BACKGROUND

Previous studies have shown that hyperthyroidism was related to Moyamoya disease and intracranial artery stenosis. However, it is not clear whether thyroid hormone or thyroid autoantibodies was associated with them.

AIMS AND/OR HYPOTHESIS

Thyroid autoimmunity was previously shown to be associated with Moyamoya disease. Our study aimed to investigate the association between thyroid autoantibodies and intracranial large artery stenosis in young ischemic stroke patients with apparent euthyroid states.

METHODS

We retrospectively reviewed first-onset ischemic stroke patients (age ≤55 years old) consecutively admitted to a single academic center. Intracranial large artery stenosis was defined as ≥50% luminal diameter narrowing. We compared demographic profiles, risk factors (age, hypertension, diabetes, current smoker, atrial fibrillation, hyperlipidemia), thyroid function test, and thyroid autoantibodies including antithyroperoxidase antibody and antithyroglobulin antibody between patients with and without intracranial large artery stenosis. We also performed multivariate logistic regression analysis to evaluate the association between thyroid autoantibodies and intracranial large artery stenosis.

RESULTS

A total of 351 patients were analyzed. The mean age of the patients was 47·0 ± 7·7 (range, 10-55 years), and 252 (71·8%) patients were male. We identified intracranial large artery stenosis in 121 (34·5%) patients. Patients with intracranial large artery stenosis showed a higher frequency of elevated antithyroperpxidase antibody levels in comparison with nonintracranial large artery stenosis group (16·5% vs. 3·9%, P < 0·001). After adjusting for covariates, the presence of elevated antithyroperpxidase antibody levels (odds ratio: 5·318; 95% confidence interval: 2·157-13·110, P < 0·001), age (odds ratio: 1·037; 95% confidence interval: 1·002-1·073, P = 0·039), and atrial fibrillation (odds ratio: 0·091; 95% confidence interval: 0·011-0·756, P = 0·027) was independently associated with intracranial large artery stenosis.

CONCLUSIONS

Thyroid autoantibodies may be associated with the presence of intracranial large artery stenosis in young stroke patients, potentially providing insight on immune pathogenesis of intracranial large artery stenosis.

Current role of biomarkers in carotid disease: a systematic review

BACKGROUND AND PURPOSE

Accumulating evidence suggests that carotid plaque vulnerability can be used as a determinant of ischemic stroke risk stratification and carotid intervention. Novel markers of high-risk carotid plaque in patients are needed.

SUMMARY OF REVIEW

Advances in cellular and molecular pathophysiology, the demand for accurately predicting carotid risk, and choosing the optimal prevention strategy are stimulating great interest in the development of novel surrogate markers. Biomarkers in cardiovascular disease are expected to predict the natural history, clinical outcomes, and the efficacy of disease-modifying interventions. We aimed to review the literature regarding clinical data on novel serum biomarkers related to ischemic cerebrovascular events associated with carotid artery disease. We provide background information on the biomarkers related to all aspects of carotid disease: natural history, carotid intervention strategies for symptomatic and asymptomatic patients, perioperative risk prediction, and their therapeutic implications.

CONCLUSION

At present, heterogeneous data support evidence that biological markers can help existing practices to more accurately assess patients at risk for stroke. Randomized-controlled trials for carotid artery disease and carotid intervention, incorporating biomarkers, are needed.

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.

Chlamydia pneumoniae seropositivity in adults with acute ischemic stroke: A case-control study

BACKGROUND

Causative role of Chlamydia pneumoniae infection in patients with acute ischemic stroke (AIS) remains unresolved till date.

AIM

To investigate the role of C. pneumoniae antibodies in AIS.

MATERIALS AND METHODS

Patients with AIS and sex- and environment-matched controls were enrolled. Antibodies to C. pneumoniae (IgA, IgG and IgM) were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

A total of 51 patients and 48 controls were enrolled. The IgA seropositivity was significantly associated with AIS (unadjusted odds ratio 3.1; 95% CI 1.38, 6.96; P = 0.005), whereas IgG (unadjusted OR 0.44; 95% CI 0.18, 1.09; P = 0.07) and IgM (unadjusted OR 1.1; 95% CI 0.36, 3.3; P = 0.88) were not. There was no difference in IgA or IgG positivity in different stroke subtypes. On multivariate analysis after adjusting for sex, hypertension, diabetes mellitus, smoking and alcohol, the IgA seropositivity yielded an adjusted OR for stroke (4.72; 95% CI 1.61, 13.83; P = 0.005), while IgG seropositivity did not (OR 0.25; 95% CI 0.08, 0.83; P = 0.23).

CONCLUSIONS

An increased risk of AIS was demonstrated in patients seropositive for C. pneumoniae for IgA antibodies.

Common infections and the risk of stroke

The occurrence of stroke in populations is incompletely explained by traditional vascular risk factors. Data from several case-control studies and one large study using case series methodology indicate that recent infection is a temporarily acting, independent trigger factor for ischemic stroke. Both bacterial and viral infections, particularly respiratory tract infections, contribute to this association. A causal role for infection in stroke is supported by a graded temporal relationship between these conditions, and by multiple pathophysiological pathways linking infection and inflammation, thrombosis, and stroke. Furthermore, observational studies suggest that influenza vaccination confers a preventive effect against stroke. Case-control and prospective studies indicate that chronic infections, such as periodontitis, chronic bronchitis and infection with Helicobacter pylori, Chlamydia pneumoniae or Cytomegalovirus, might increase stroke risk, although considerable variation exists in the results of these studies, and methodological issues regarding serological results remain unresolved. Increasing evidence indicates that the aggregate burden of chronic and/or past infections rather than any one single infectious disease is associated with the risk of stroke. Furthermore, genetic predispositions relating to infection susceptibility and the strength of the inflammatory response seem to co-determine this risk. Here, we summarize and analyze the evidence for common acute and chronic infectious diseases as stroke risk factors.