Association between infectious burden, socioeconomic status, and ischemic stroke

Detecting prokaryote-specific gene and other bacterial signatures in thrombi from patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Microbial infection has been associated with thrombogenesis. This study aimed to detect bacterium-specific genes and other signatures in thrombi from patients with acute ischemic stroke and to relate these signatures to clinical characteristics.

METHODS

Blood samples were collected before thrombectomy procedures, and thrombus samples were obtained during the procedure. Identification and classification of bacteria in the samples were accomplished using 16 S rRNA gene sequencing. Bacterium-specific structures were observed with transmission electron microscopy. Bacterium-specific biomarkers were detected through immunohistochemical staining.

RESULTS

16 S rRNA gene was detected in 32.1% of the thrombus samples from 81 patients. Bacillus (0.04% vs. 0.00046%, p = 0.003), Parabacteroides (0.20% vs. 0.09%, p = 0.029), Prevotella (1.57% vs. 0.38%, p = 0.010), Streptococcus (1.53% vs. 0.29%, p = 0.001), Romboutsia (0.18% vs. 0.0070%, p = 0.029), Corynebacterium (1.61% vs. 1.26%, p = 0.026) and Roseburia (0.53% vs. 0.05%, p = 0.005) exhibited significantly higher abundance in thrombi compared to arterial blood. Bacteria-like structures were observed in 22 (27.1%), while whole bacteria-like structures were observed in 7 (8.6%) thrombi under transmission electron microscopy. Immunohistochemical staining detected bacterium-specific monocyte/macrophage markers in 51 (63.0%) out of 81 thrombi. Logistic regression analysis indicated that alcohol consumption was associated with a higher bacteria burden in thrombi (odds ratio = 3.19; 95% CI, 1.10-9.27; p = 0.033).

CONCLUSION

Bacterial signatures usually found in the oral cavity and digestive tract were detected in thrombi from patients with ischemic stroke. This suggests a potential involvement of bacterial infection in the development of thrombosis. Long-term alcohol consumption may potentially enhance this possibility.

Effects of herpes zoster vaccination and antiviral treatment on the risk of stroke: a systematic review and meta-analysis

Background

Evidence suggests that there is an increased risk of stroke after herpes zoster (HZ). However, reports on the effects of HZ vaccination (HZV) and antiviral treatment on stroke risk are inconsistent. Thus, we examined these associations in a meta-analysis.

Methods

To identify relevant studies, we searched three databases for articles published up to January 2023. Random-effect models were examined to determine overall pooled estimates and 95% confidence intervals (CIs).

Results

This review included 12 observational studies (six on HZV and seven on antiviral treatment). When comparing vaccinated and unvaccinated patients, vaccination was found to be associated with a lower risk of stroke (OR, 0.78; 95% CI 0.68-0.9; P = 0.001). A meta-analysis of self-controlled case series (SCCS) revealed evidence of a reduced OR in individuals who received the vaccine (OR, 1.14; 95% CI 0.94-1.37; P = 0.181) compared with unvaccinated individuals (OR, 1.36; 95% CI 1.15-1.61; P < 0.001). Compared with untreated patients, antiviral therapy was not associated with a reduced risk of stroke (OR, 1.13; 95% CI 0.94-1.36; P = 0.201). The meta-analysis of the SCCS showed no evidence of a reduced OR in individuals who received antiviral therapy (OR, 1.33; 95% CI 1.17-1.51; P < 0.001) compared to untreated individuals (OR, 1.45; 95% CI 1.25-1.69; P < 0.001).

Conclusions

This meta-analysis suggests that the HZV, but not antiviral treatment, decreases the odds of developing stroke.

Recent Advances in the Impact of Infection and Inflammation on Stroke Risk and Outcomes

PURPOSE OF THE REVIEW

Inflammation is a key component in the pathogenesis of cerebrovascular diseases. In the past few years, the role of systemic infection and gut dysbiosis in modulating inflammation and stroke risk has been increasingly acknowledged. In this review, we synthesize contemporary literature on the effects of infection and inflammation on stroke risk and outcomes, with a focus on periodontal disease, COVID-19 infection, and gut dysbiosis.

RECENT FINDINGS

Chronic and acute infections such as periodontitis and COVID-19 induce systemic inflammation that cause atherogenesis and increase cardiac injury and arrhythmias. These infections also directly injure the endothelium leading to worsened secondary inflammation after stroke. Gut dysbiosis engenders a pro-inflammatory state by modulating intestinal lymphocyte populations that can traffic directly to the brain. Additionally, post-stroke immune dysregulation creates a compounding feedback loop of further infections and gut dysbiosis that worsen outcomes. Recent advances in understanding the pathophysiology of how infection and dysbiosis affect the progression of stroke, as well as long-term recovery, have revealed tantalizing glimpses at potential therapeutic targets. We discuss the multidirectional relationship between stroke, infection, and gut dysbiosis, and identify areas for future research to further explore therapeutic opportunities.

Guhong Injection Protects Against Apoptosis in Cerebral Ischemia by Maintaining Cerebral Microvasculature and Mitochondrial Integrity Through the PI3K/AKT Pathway

Guhong injection (GHI) can be used for the treatment of ischemic stroke. We investigated the antiapoptotic activity of GHI, its ability to repair the cerebral microvessels and mitochondria, and the PI3K/AKT signaling pathway of GHI against cerebral ischemia. Western blot and immunohistochemical analyses were used to determine the expression of cleaved caspase-3, B-cell lymphoma-2 (Bcl-2), cytochrome c (Cyt-c), basic fibroblast growth factor (BFGF), vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1), and proteins in the PI3K/AKT signaling pathway. Transmission electron microscopy and scanning electron microscopy were used to evaluate the structures of the cerebral microvasculature and cells. Hoechst 33342 staining was used to evaluate the nuclear morphology. FITC-AV/PI double staining was used to measure the antiapoptotic effects. The fluorescent dye JC-1 was used to measure mitochondrial membrane potential. The enzyme-linked immunosorbent assay (ELISA) was used to detect the activities of matrix metalloproteinase-9 (MMP-9). Biochemical assay kits were used to detect the activities of lactate dehydrogenase (LDH), superoxide dismutase (SOD), and malondialdehyde (MDA). Compared with the middle cerebral artery occlusion (MCAO) group, there was decreased infarct volume and significantly improved neurological deficits in the GHI group. In addition, the expression of Bcl-2 was significantly upregulated, while the expression of Cyt-c, Bax, and cleaved caspase-3 was notably downregulated. GHI administration attenuated the pathological change and morphology of the cerebral microvasculature, and immunohistochemical staining indicated that the expressions of BFGF, VEGF, and TGF-β1 were significantly increased. The cell morphology, cell viability, cell nuclei characteristics, and mitochondrial morphology normalized following GHI treatment, which decreased the release of Cyt-c and the mitochondrial membrane potential. The levels of LDH, MMP-9, and MDA decreased, while SOD increased. Moreover, GHI administration inhibited the activation of the PI3K/AKT signaling pathway in rat brain microvascular endothelial cells (rBMECs) following oxygen/glucose deprivation (OGD) injury. Therefore, our results show that GHI administration resulted in antiapoptosis of cerebral cells and repair of cerebral microvessels and mitochondria via the PI3K/AKT signaling pathway.

Filling the gaps on stroke research: Focus on inflammation and immunity

For the last two decades, researchers have placed hopes in a new era in which a combination of reperfusion and neuroprotection would revolutionize the treatment of stroke. Nevertheless, despite the thousands of papers available in the literature showing positive results in preclinical stroke models, randomized clinical trials have failed to show efficacy. It seems clear now that the existing data obtained in preclinical research have depicted an incomplete picture of stroke pathophysiology. In order to ameliorate bench-to-bed translation, in this review we first describe the main actors on stroke inflammatory and immune responses based on the available preclinical data, highlighting the fact that the link between leukocyte infiltration, lesion volume and neurological outcome remains unclear. We then describe what is known on neuroinflammation and immune responses in stroke patients, and summarize the results of the clinical trials on immunomodulatory drugs. In order to understand the gap between clinical trials and preclinical results on stroke, we discuss in detail the experimental results that served as the basis for the summarized clinical trials on immunomodulatory drugs, focusing on (i) experimental stroke models, (ii) the timing and selection of outcome measuring, (iii) alternative entry routes for leukocytes into the ischemic region, and (iv) factors affecting stroke outcome such as gender differences, ageing, comorbidities like hypertension and diabetes, obesity, tobacco, alcohol consumption and previous infections like Covid-19. We can do better for stroke treatment, especially when targeting inflammation following stroke. We need to re-think the design of stroke experimental setups, notably by (i) using clinically relevant models of stroke, (ii) including both radiological and neurological outcomes, (iii) performing long-term follow-up studies, (iv) conducting large-scale preclinical stroke trials, and (v) including stroke comorbidities in preclinical research.

A meta-analysis of the association between Helicobacter pylori infection and risk of atherosclerotic cardiovascular disease

BACKGROUND

Helicobacter pylori (H pylori) infection may be a risk factor for cardiovascular disease (CVD), but the reported researches have given conflicting results.

AIMS

To investigate the association between H pylori infection and risk of atherosclerotic CVD.

MATERIALS AND METHODS

The studies were retrieved in Embase, PubMed, Web of Science (published from Jan 1, 1990, to Jan 31, 2020, language restrictions: English). All studies included used data from case-control studies and cohort studies of cardiovascular adverse events. Random effect models were used to measure pooled estimates. All data were analyzed with Stata 11.2 SE (StataCorp, College Station, TX).

RESULTS

Helicobacter pylori infection increased the risk of adverse cardiovascular events by 51% (40 studies, n = 19 691, odd ratio [OR] = 1.51, 95% confidence interval [CI]: 1.34-1.70). The effect was greater for studies that the type of CVDs was myocardial infarction (MI) and cerebrovascular disease (MI OR = 1.80, 95% CI: 1.42-2.26, cerebrovascular disease OR = 1.54, 95% CI: 1.27-1.89). Meanwhile, CagA seropositive H pylori strains were associated with a significantly increased risk of cardiovascular adverse events based on published research data (OR = 1.73, 95% CI: 1.40-2.14).

CONCLUSION

In conclusion, H pylori infection enhanced the risk of atherosclerotic cardiovascular adverse events, especially in some patients with MI and cerebrovascular disease. This study will provide guidance for the targeted prevention and treatment of CVDs. But this association need to be confirmed by more prospective studies.

Infection as a Stroke Risk Factor and Determinant of Outcome After Stroke

Understanding the relationship between infection and stroke has taken on new urgency in the era of the coronavirus disease 2019 (COVID-19) pandemic. This association is not a new concept, as several infections have long been recognized to contribute to stroke risk. The association of infection and stroke is also bidirectional. Although infection can lead to stroke, stroke also induces immune suppression which increases risk of infection. Apart from their short-term effects, emerging evidence suggests that poststroke immune changes may also adversely affect long-term cognitive outcomes in patients with stroke, increasing the risk of poststroke neurodegeneration and dementia. Infections at the time of stroke may also increase immune dysregulation after the stroke, further exacerbating the risk of cognitive decline. This review will cover the role of acute infections, including respiratory infections such as COVID-19, as a trigger for stroke; the role of infectious burden, or the cumulative number of infections throughout life, as a contributor to long-term risk of atherosclerotic disease and stroke; immune dysregulation after stroke and its effect on the risk of stroke-associated infection; and the impact of infection at the time of a stroke on the immune reaction to brain injury and subsequent long-term cognitive and functional outcomes. Finally, we will present a model to conceptualize the many relationships among chronic and acute infections and their short- and long-term neurological consequences. This model will suggest several directions for future research.

Association between Helicobacter Pylori infection and stroke: a meta-analysis of 273,135 patients

BACKGROUND

Stroke stands among the most leading causes of mortality worldwide. Although modifiable risk factors for stroke have been identified, current risk factors do not sufficiently explain the risk in young patients. Previous studies have postulated an association between infection by Helicobacter pylori (HP) and stroke.

OBJECTIVE

To investigate the association between HP infection and stroke by using a systematic review and meta-analysis approach.

METHODS

Four electronic search engines/libraries were systematically searched for relevant observational studies. Studies were screened for eligibility and data were extracted. The odds ratio (OR) and 95% confidence interval (95% CI) were combined under the random-effect model. The protocol was registered in PROSPERO (CRD42019123689).

RESULTS

Among the included studies, 25 studies were analyzed for anti-HP IgG, 9 studies were for anti-Cag A, and 6 studies were for the C-urea breath test. The results showed that positive anti-HP IgG was significantly associated with an increased risk of stroke [OR (95% CI) = 1.43 (1.25-1.46)]. Similarly, both antiCag A and C-urea breath test were significantly associated with an increased risk of stroke with [OR (95% CI) = 1.77 (1.25-2.49)], and [OR (95% CI) = 2.21 (1.33-3.66)], respectively. Furthermore, our results indicated that positive anti-HP IgG was associated with stroke caused by atherothrombosis and small artery disease.

CONCLUSIONS

This study suggests that HP infection is significantly associated with increased risk of stroke. However, more well-designed studies are required to investigate if early HP eradication might decrease the incidence of stroke.

Serum lipopolysaccharide neutralizing capacity in ischemic stroke

Introduction

Periodontitis is associated with increased serum lipopolysaccharide (LPS) activity, which may be one mechanism linking periodontitis with the risk of cardiovascular diseases. As LPS-carrying proteins including lipoproteins modify LPS-activity, we investigated the determinants of serum LPS-neutralizing capacity (LPS-NC) in ischemic stroke. The association of LPS-NC and Aggregatibacter actinomycetemcomitans, a major microbial biomarker in periodontitis, was also investigated.

Materials and methods

The assay to measure LPS-NC was set up by spiking serum samples with E. coli LPS. The LPS-NC, LPS-binding protein (LBP), soluble CD14 (sCD14), lipoprotein profiles, apo(lipoprotein) A-I, apoB, and phospholipid transfer protein (PLTP) activity, were determined in 98 ischemic stroke patients and 100 age- and sex-matched controls. Serum and saliva immune response to A. actinomycetemcomitans, its concentration in saliva, and serotype-distribution were examined.

Results

LPS-NC values ranged between 51–83% in the whole population. Although several of the LPS-NC determinants differed significantly between cases and controls (PLTP, sCD14, apoA-I, HDL-cholesterol), the levels did not (p = 0.056). The main determinants of LPS-NC were i) triglycerides (β = -0.68, p<0.001), and ii) HDL cholesterol (0.260, <0.001), LDL cholesterol (-0.265, <0.001), PLTP (-0.196, 0.011), and IgG against A. actinomycetemcomitans (0.174, 0.011). Saliva A. actinomycetemcomitans concentration was higher [log mean (95% CI), 4.39 (2.35–8.19) vs. 10.7 (5.45–21) genomes/ml, p = 0.023) and serotype D more frequent (4 vs. 0%, p = 0.043) in cases than controls. Serotypeablity or serotypes did not, however, relate to the LPS-NC.

Conclusion

Serum LPS-NC comprised low PLTP-activity, triglyceride and LDL cholesterol concentrations, as well as high HDL cholesterol and IgG against A. actinomycetemcomitans. The present findings let us to conclude that LPS-NC did not associate with stroke.

Regional Variation in the Association of Poverty and Heart Failure Mortality in the 3135 Counties of the United States

Background There is significant geographical variation in heart failure (HF) mortality across the United States. County socioeconomic factors that influence these outcomes are unknown. We studied the association between county socioeconomic factors and HF mortality and compared it with coronary heart disease (CHD) mortality. Methods and Results This is a cross-sectional analysis of socioeconomic factors and mortality in HF and CHD across 3135 US counties from 2010 to 2015. County-level poverty, education, income, unemployment, health insurance status, and cause-specific mortality rates were collected from the Centers for Disease Control and Prevention and US Census Bureau databases. Poverty had the strongest correlation with both HF and CHD mortality, disproportionately higher for HF (r=0.48) than CHD (r=0.24). HF mortality increased by 5.2 deaths/100 000 for each percentage increase in county poverty prevalence in a frequency-weighted, demographic-adjusted, multivariate regression model. The greatest attenuation in the poverty regression coefficient (66.4%) was seen after adjustment for prevalence of diabetes mellitus and obesity. Subgroup analysis by census region showed that this relationship was the strongest in the South and weakest in the Northeast (6.1 versus 1.4 deaths/100 000 per 1% increase in county poverty in a demographics-adjusted model). Conclusions County poverty is the strongest socioeconomic factor associated with HF and CHD mortality, an association that is stronger with HF than with CHD and varied by census region. Over half of the association was explained by differences in the prevalence of diabetes mellitus and obesity across the counties. Health policies targeting improvement in these risk factors may address and possibly minimize health disparities caused by socioeconomic factors.

Ischemic stroke and infectious diseases in low-income and middle-income countries

PURPOSE OF REVIEW

To address the important relationships between stroke and infection, focusing on the most frequent infections found in low-income and middle-income countries.

RECENT FINDINGS

Stroke is one of the leading causes of mortality and disability worldwide, with a great proportion of the stroke burden occurring in low-income and middle-income countries. Infectious diseases are still a great health problem in developing countries and it is possible that the proportion of infection-related strokes is greater in these nations. Infectious diseases and stroke have a bidirectional relationship. Common infections may act as risk factors and can trigger stroke through different mechanisms in their acute phase. Several intracranial and systemic infections can cause stroke as a direct complication, such as Chagas disease, neurosyphilis, tuberculous meningitis, and neurocysticercosis. These conditions are of particular interest to low-income and middle-income countries, but also relevant to high-income nations because of increasing migration. Finally, infection is a frequent poststroke complication, with great impact in the patient outcome.

SUMMARY

Infectious diseases and stroke are common problems in low-income and middle-income countries. More studies are necessary to fully elucidate the real impact of infectious diseases on stroke burden, especially in countries where epidemiological data are still scarce.

Mediators between oral dysbiosis and cardiovascular diseases

Clinical periodontitis is associated with an increased risk for cardiovascular diseases (CVDs) through systemic inflammation as the etiopathogenic link. Whether the oral microbiota, especially its quality, quantity, serology, and virulence factors, plays a role in atherogenesis is not clarified. Patients with periodontitis are exposed to bacteria and their products, which have access to the circulation directly through inflamed oral tissues and indirectly (via saliva) through the gastrointestinal tract, resulting in systemic inflammatory and immunologic responses. Periodontitis is associated with persistent endotoxemia, which has been identified as a notable cardiometabolic risk factor. The serology of bacterial biomarkers for oral dysbiosis is associated with an increased risk for subclinical atherosclerosis, prevalent and future coronary artery disease, and incident and recurrent stroke. In addition to species-specific antibodies, the immunologic response includes persistent, cross-reactive, proatherogenic antibodies against host-derived antigens. Periodontitis may affect lipoprotein metabolism at all levels, and all lipoprotein classes are affected. Periodontitis or its bacterial signatures may be involved not only in increased storage of proatherogenic lipids but also in attenuation of the anti-atherogenic processes, thereby putatively increasing the net risk of atherosclerosis. In this review we summarize possible molecular mediators between the dysbiotic oral microbiota and atherosclerotic processes.

Association of Childhood Oral Infections With Cardiovascular Risk Factors and Subclinical Atherosclerosis in Adulthood

IMPORTANCE

Severe forms of common chronic oral infections or inflammations are associated with increased cardiovascular risk in adults. To date, the role of childhood oral infections in cardiovascular risk is not known because no long-term studies have been conducted.

OBJECTIVE

To investigate whether signs of oral infections in childhood are associated with cardiovascular risk factors and subclinical atherosclerosis in adulthood.

DESIGN, SETTING, AND PARTICIPANTS

The cohort study (n = 755) was derived from the Cardiovascular Risk in Young Finns Study, an ongoing prospective cohort study in Finland initiated in 1980. Participants underwent clinical oral examinations during childhood, when they were aged 6, 9, or 12 years and a clinical cardiovascular follow-up in adulthood in 2001 at age 27, 30, or 33 years and/or in 2007 at age 33, 36, or 39 years. Cardiovascular risk factors were measured at baseline and during the follow-up until the end of 2007. Final statistical analyses were completed on February 19, 2019.

MAIN OUTCOMES AND MEASURES

Four signs of oral infections (bleeding on probing, periodontal probing pocket depth, caries, and dental fillings) were documented. Cumulative lifetime exposure to 6 cardiovascular risk factors was calculated from dichotomized variables obtained by using the area-under-the-curve method. Subclinical atherosclerosis (ie, carotid artery intima-media thickness [IMT]) was quantified in 2001 (n = 468) and 2007 (n = 489).

RESULTS

This study included 755 participants, of whom 371 (49.1%) were male; the mean (SD) age at baseline examination was 8.07 (2.00) years. In this cohort, 33 children (4.5%) had no sign of oral infections, whereas 41 (5.6%) had 1 sign, 127 (17.4%) had 2 signs, 278 (38.3%) had 3 signs, and 248 (34.1%) had 4 signs. The cumulative exposure to risk factors increased with the increasing number of oral infections both in childhood and adulthood. In multiple linear regression models, childhood oral infections, including signs of either periodontal disease (R2 = 0.018; P = .01), caries (R2 = 0.022; P = .008), or both (R2 = 0.024; P = .004), were associated with adulthood IMT. The presence of any sign of oral infection in childhood was associated with increased IMT (third tertile vs tertiles 1 and 2) with a relative risk of 1.87 (95% CI, 1.25-2.79), whereas the presence of all 4 signs produced a relative risk of 1.95 (95% CI, 1.28-3.00). The associations were more obvious in boys: if periodontal disease were present, the corresponding estimate was 1.69 (95% CI, 1.21-2.36); if caries, 1.46 (95% CI, 1.04-2.05); and if all 4 signs of oral infections, 2.25 (95% CI, 1.30-3.89). The associations were independent of cardiovascular risk factors.

CONCLUSIONS AND RELEVANCE

Oral infections in childhood appear to be associated with the subclinical carotid atherosclerosis seen in adulthood.

The Impacts of Peptic Ulcer on Functional Outcomes of Ischemic Stroke

BACKGROUND AND PURPOSE

Studies have shown that peptic ulcer increased the risk of ischemic stroke and stroke recurrence. This study aimed to evaluate the impacts of peptic ulcer on functional outcomes of ischemic stroke.

METHODS

Patients with first-ever ischemic stroke were grouped as with and without history of peptic ulcer. Functional outcomes were evaluated with modified Rankin scale at 90 days after the index stroke. Favorable functional outcomes were defined as with a modified Rankin scale score of 0-2. Logistic regression was used to identify predictors for favorable functional outcomes at 90 days.

RESULTS

Among the 2577 enrolled patients with ischemic stroke, 129 (5.0%) had a history of peptic ulcer. The proportion of favorable outcome was higher in patients without peptic ulcer than those with (59.3% versus 42.6%, P < .001). Multivariate logistic analysis detected that history of peptic ulcer (odds ratio [OR] = 2.89, 95% confidence interval [CI], 1.03-8.10, P = .043), National Institute of Health Stroke Scale score (OR = 2.11, 95% CI, 1.79-2.48, P < .001), and large-artery atherosclerosis stroke subtype (OR = 4.08, 95% CI, 1.11-15.03, P = .035) decreased the likelihood of favorable outcomes.

CONCLUSIONS

Ischemic stroke patients with peptic ulcer may have an increased risk of less favorable neurological outcome at 90 days after the index stroke.

The Impacts of Peptic Ulcer on Stroke Recurrence

BACKGROUND

Peptic ulcer has been associated with an increased risk of stroke. This study aimed to evaluate the impacts of peptic ulcer on stroke recurrence and mortality.

SUBJECTS AND METHODS

Patients with first-ever ischemic stroke were retrospectively confirmed with or without a history of peptic ulcer. The primary end point was defined as fatal and nonfatal stroke recurrence. Risks of 1-year fatal and nonfatal stroke recurrence were analyzed with the Kaplan-Meier method. Predictors of fatal and nonfatal stroke recurrence were evaluated with the Cox proportional hazards model.

RESULTS

Among the 2577 enrolled patients with ischemic stroke, 129 (5.0%) had a history of peptic ulcer. The fatal and nonfatal stroke recurrence within 1 year of the index stroke was higher in patients with peptic ulcer than in patients without peptic ulcer (12.4% versus 7.2%, P = .030). Cox proportional hazards model detected that age (hazard ratio [HR] = 1.018, 95% confidence interval [CI] 1.005-1.031, P = .008), hypertension (HR = 1.397, 95% CI 1.017-1.918, P = .039), and history of peptic ulcer (HR = 1.853, 95% CI 1.111-3.091, P = .018) were associated with stroke recurrence.

CONCLUSIONS

Ischemic stroke patients with peptic ulcer may have an increased risk of stroke recurrence. The results emphasize the importance of appropriate prevention and management of peptic ulcer for secondary stroke prevention.

Whole blood gene expression and white matter Hyperintensities

Background

White matter hyperintensities (WMH) are an important biomarker of cumulative vascular brain injury and have been associated with cognitive decline and an increased risk of dementia, stroke, depression, and gait impairments. The pathogenesis of white matter lesions however, remains uncertain. The characterization of gene expression profiles associated with WMH might help uncover molecular mechanisms underlying WMH.

Methods

We performed a transcriptome-wide association study of gene expression profiles with WMH in 3248 participants from the Framingham Heart Study using the Affymetrix Human Exon 1.0 ST Array.

Results

We identified 13 genes that were significantly associated with WMH (FDR < 0.05) after adjusting for age, sex and blood cell components. Many of these genes are involved in inflammation-related pathways.

Conclusion

Thirteen genes were significantly associated with WMH. Our study confirms the hypothesis that inflammation might be an important factor contributing to white matter lesions. Future work is needed to explore if these gene products might serve as potential therapeutic targets.

Electronic supplementary material

The online version of this article (10.1186/s13024-017-0209-5) contains supplementary material, which is available to authorized users.