Prospective study of Chlamydia pneumoniae IgG and IgA seropositivity and risk of incident ischemic stroke

BACKGROUND AND PURPOSE: Chlamydia pneumoniae infection or exposure to C. pneumoniae was implicated as a risk factor for ischemic stroke. Our aim was to evaluate prospectively the association between the presence of antibodies to C. pneumoniae (IgG and IgA) and the risk of incident ischemic stroke among patients with pre-existing vascular disease. METHODS: Sera were collected from 3,090 coronary heart disease patients enrolled in a secondary prevention trial. We measured baseline antibodies (IgG and IgA) in the sera of patients who developed subsequent ischemic strokes (cases, n = 134) during follow-up (mean 8.2 years), and in 134 age- and gender-matched pairs without subsequent stroke or myocardial infarction. RESULTS: The crude relative odds (95%CI) of incident ischemic strokes in seropositive patients at baseline (>1.1 relative value units) were 1.29 (95%CI, 0.69-2.47) for IgG and 1.31 (95% CI, 0.69-2.55) for IgA by matched-pair analyses, and 1.42 (95%CI, 0.69-2.98) for IgG and 1.57 (95%CI, 0.76-3.35) for IgA after adjustments for conventional risk factors and the inflammatory marker, soluble intercellular adhesion molecule-1. We explored the possibility that the risk of ischemic stroke may increase in parallel to increasing antibody titers, but did not demonstrate any significant association. CONCLUSIONS: Serological evidence for prior infection with C. pneumoniae did not emerge as an independent risk factor for incident ischemic stroke among patients at high risk due to pre-existing vascular disease.     

Chlamydia pneumoniae and the risk of first ischemic stroke : The Northern Manhattan Stroke Study

BACKGROUND AND PURPOSE: Serological evidence of infection with Chlamydia pneumoniae has been associated with cardiovascular disease in multiple epidemiological studies. The data on its association with ischemic stroke are limited. We sought to determine whether chronic C pneumoniae infection is associated with ischemic stroke in a multi-ethnic population. METHODS: The Northern Manhattan Stroke Study contains a population-based, case-control study component. Cases had first ischemic stroke and matched control subjects were derived through random digit dialing. Titers of IgG, IgA, and IgM antibodies specific for C pneumoniae were measured with the use of microimmunofluorescence, and titers >/=1:16 were considered positive. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) after adjustment for medical, behavioral, and socioeconomic factors. RESULTS: Eighty-nine cases and 89 control subjects were selected. Mean age among cases was 68.5+/-12.8 years; 53% were women and 15% of the subjects were white, 28% were black, and 54% were Hispanic. Elevated C pneumoniae IgA titers were significantly associated with risk of ischemic stroke after adjusting for other stroke risk factors (adjusted OR 4. 51, 95% CI 1.44 to 14.06). IgG titers were less strongly associated with stroke risk (adjusted OR 2.59, 95% CI 0.87 to 7.75). The association of IgA with stroke risk was detected in both younger and older groups, in men and women, and in whites, blacks, and Hispanics. There was also a significant continuous increase in risk associated with the log-transformation of the titer for IgA (adjusted OR 1.32, 95% CI 1.05 to 1.66) but not IgG. CONCLUSIONS: Serological evidence of chronic infection with C pneumoniae is associated with risk of ischemic stroke in an urban, multi-ethnic population. IgA titers may be a better marker of this risk than are IgG titers. This association is independent of other vascular disease risk factors. Further prospective epidemiological studies of the effect of this infection on stroke risk are warranted.     

Elevated levels of anti-Chlamydia pneumoniae IgA and IgG antibodies in young adults with ischemic stroke

INTRODUCTION: Data on the role of Chlamydia pneumoniae in patients with ischemic stroke are inconsistent. We investigated the presence of anti-C. pneumoniae antibodies in young adults with ischemic stroke. METHODS: 94 patients (<55 years) with ischemic stroke and 103 controls were enrolled. Indices of anti-C. pneumoniae IgA and IgG were assessed with an ELISA. We determined OR and 95% CI for the IgA and IgG seropositivity in stroke cases. RESULTS: Mean IgA and IgG indices were higher in stroke patients vs controls (IgA: 1.40 vs 0.56; P < 0.001; IgG: 0.85 vs. 0.78; P < 0.003). The IgA seropositivity was associated with stroke risk (11.92; 5.94-23.92; P < 0.001) as well as IgG seropositivity was (2.31; 1.15-4.61; P < 0.016). Seropositivity assessed with combined IgA and IgG indices was associated with increased stroke risk (OR 9.35; 95% CI 4.78-18.29; P < 0.0001). After controlling for age and sex, the IgA seropositivity yielded a significantly adjusted OR for stroke (8.95; 4.44-18.07; P < 0.002), while IgG seropositivity did not (0.85; 0.53-1.63). CONCLUSIONS: We find an increased risk of stroke in young patients seropositive to C. pneumoniae in the IgA antibody class. Further studies to explore this finding are warranted.     

Mycoplasma pneumoniae in elderly patients with stroke. a case-control study on the seroprevalence of M. pneumoniae in elderly patients with acute cerebrovascular disease - the M-PEPS Study

BACKGROUND AND PURPOSE: Previous studies have suggested certain infections as potential risk factors for stroke. Chlamydia pneumoniae, an atypical respiratory pathogen, has been linked to atherosclerotic vascular diseases. Mycoplasma pneumoniae, another atypical respiratory micro-organism, can rarely cause stroke. We investigated whether serological markers of M. pneumoniae infection were associated with acute stroke or transient ischaemic attack (TIA) in elderly patients. METHODS: This case-control study was nested within the C-PEPS study - a case-control study on the seroprevalence of C. pneumoniae in elderly stroke and medical patients. Ninety-five incident cases of patients admitted consecutively with acute stroke or TIA, and 82 control subjects admitted concurrently with acute non-cardiopulmonary, non-infective disorders, were included in this study (both groups aged 65 years or older). Using commercial enzyme-linked immunosorbent assay (ELISA) kits, the presence of M. pneumoniae immunoglobulins IgA, IgG and IgM in patients' sera was determined. RESULTS: The seroprevalence of M. pneumoniae IgA, IgG and IgM in the stroke or TIA group (median age = 80) were 79, 61 and 6%, respectively. In the control group (median age = 80), the seroprevalence of respective M. pneumoniae IgA, IgG and IgM were 84, 50 and 11%. Using a logistic regression statistical model, adjusting for history of hypertension, smoking, diabetes mellitus, age and sex, history of ischaemic heart disease, and ischaemic electrocardiogram, the odds ratios of having a stroke or TIA in relation to M. pneumoniae IgA, IgG and IgM were 0.63 (95% confidence interval (CI) = 0.26-1.52, p = 0.31), 1.32 (95% CI = 0.66-2.64, p = 0.43) and 0.52 (95% CI = 0.14-1.92, p = 0.32), respectively. CONCLUSIONS: The study showed a high seroprevalence of M. pneumoniae in an elderly hospital population, using ELISA. Although the study ruled out M. pneumoniae seropositivity as a major risk factor for stroke in this elderly population, a smaller effect could not be excluded due to the small sample size. Future larger studies may be required to determine the precise role of M. pneumoniae infection in the pathogenesis of different subtypes of ischaemic stroke, in all age groups, and in different ethnic populations.     

Chlamydia pneumoniae in elderly patients with stroke (C-PEPS): a case-control study on the seroprevalence of Chlamydia pneumoniae in elderly patients with acute cerebrovascular disease

BACKGROUND AND PURPOSE: Multiple studies have suggested an association between Chlamydia pneumoniae infection and atherosclerotic vascular disease. We investigated whether serological markers of C. pneumoniae infection were associated with acute stroke or transient ischaemic attack (TIA), exclusively in elderly patients. METHODS: One-hundred white patients aged over 65 years admitted with acute stroke or TIA, and 87 control patients admitted with acute non-cardiopulmonary, non-infective disorders were recruited prospectively. Using an enzyme-linked immunosorbent assay kit, the presence of C. pneumoniae immunoglobulins IgA, IgG, IgM in patients' sera was determined. RESULTS: The seroprevalence of C. pneumoniae-specific IgA, IgG, IgM were 63, 71, and 14% in the stroke/TIA group (median age = 80), and 62, 65, and 17% in the control group (median age = 80), respectively. Using a logistic regression statistical model, adjusting for age and sex, history of hypertension, smoking, diabetes, ischaemic heart disease (IHD), ischaemic electrocardiogram (ECG), the odds ratios (ORs) of having a stroke/TIA in relation to C. pneumoniae-specific IgA, IgG, IgM were 1.04, 1.24, 0.79 (p = NS). Further analysis identified 43 acute stroke/TIA cases and 44 controls without history of IHD or ischaemic ECG or both. After adjusting for history of hypertension, smoking, diabetes, age and sex, the ORs in this subgroup were 1.40 for IgA [95% confidence interval (CI) 0.53-3.65; p = 0.49], 2.41 for IgG (95% CI 0.90-6.46; p = 0.08) and 1.55 for IgM (95% CI 0.45-5.40; p = 0.49). CONCLUSIONS: Although a high seroprevalence of C. pneumoniae in elderly patients was confirmed, no significant association between serological markers of C. pneumoniae infection and acute cerebrovascular events was found. There was, however, a weak trend towards increased ORs for acute cerebrovascular disease in a subgroup of C. pneumoniae seropositive elderly patients without any history of IHD or ischaemic ECG.     

Chlamydia pneumoniae seropositivity in adults with acute ischemic stroke: A case�Ccontrol 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.     

Demonstration of an association between Chlamydia pneumoniae infection and venous thromboembolic disease

Chlamydia pneumoniae infection has been linked to atherosclerosis, but a possible relationship with venous thromboembolism (VTE) has not been sought. We determined circulating anti-C. pneumoniae antibody levels in patients with VTE. We studied 176 case patients with objectively diagnosed VTE and 197 age- and sex-matched healthy controls, in a retrospective study. Acquired risk factors for VTE and frequent predisposing genetic factors (factor V Arg 506 Gln and factor II G 20210 A mutations) were assessed in all the subjects. Anti-C. pneumoniae IgG antibodies were determined by microimmunofluorescence. All positive plasma samples (titer > or =128) were precisely quantified and tested for the presence of specific IgM antibodies. Fifty-four percent of the cases and 15.9% of the controls had specific IgG titers of at least 256 (p <0.0001). The crude odds ratio for VTE was 6.2 (95% CI, 3.8-10.1), and rose to 7.7 (4.5-13.2) after excluding subjects carrying the factor V Arg 506 Gln or factor II G 20210 A mutations. The odds ratio for VTE increased with the IgG titer: the adjusted odds ratios were 2.1 (95% CI, 1.1-4.1), 5.3 (2.7-10.6) and 33.0 (4.4-248.4) for titers of 256, 512 and 1024, respectively. Only one subject (a case patient) with a high IgG titer (> or =256) also had specific IgM. High titers of anti-C. pneumoniae IgG antibodies are frequently found in patients with previous venous thromboembolism. This association deserves to be confirmed in other case-control studies and prospective studies.     

Association between carotid atherosclerosis, inflammatory markers and Chlamydia pneumoniae infection

BACKGROUND AND PURPOSE: The aim of this study was to assess the correlation between morphological markers of carotid atherosclerosis, such as intima-media thickness (IMT) and the cross-sectional plaque area with markers of inflammation and C. pneumoniae infection. MATERIAL AND METHODS: The study involved a group of 128 persons (63 females, 49.2%), including 54 atherothrombotic stroke patients. The IMT and cross-sectional plaque area of common and internal carotid arteries were measured by ultrasonography. We assessed the C-reactive protein (CRP) and fibrinogen blood level, white blood cell (WBC) count, levels of IgA and IgG antibodies against C. pneumoniae , additionally the presence of C. pneumoniae DNA in WBCs was detected by PCR. We also considered the following risk factors: hypertension, diabetes, obesity and smoking. RESULTS: The multiple regression analysis showed the strongest and independent correlations of WBC with the IMT (r=0.32; p=0.0003) and plaque area (r=0.24; p=0.008) increase. Also other factors, such as smoking (r=0.19; p=0.026), hypertension (r=0.18; p=0.023) and CRP concentration (r=0.17; p=0.036) showed a significant correlation with carotid IMT. C. pneumoniae -specific IgG antibodies level showed a significant correlation with IMT only in the linear regression analysis, but not in the multiple regression analysis. C. pneumoniae DNA presence results did not reveal a significant correlation with either IMT or the carotid plaque area. CONCLUSION: Inflammatory markers, especially the WBC count and CRP level, showed an independent and stronger correlation with carotid atherosclerosis than markers of C. pneumoniae infection.     

Corticosteroid use and risk of aneurysmal subarachnoid haemorrhage

OBJECTIVES: Corticosteroids can induce hypertension and inhibit collagen synthesis in the blood vessel wall. Deficiencies in collagen have been found in intracranial aneurysms. Therefore use of corticosteroids could be a risk factor for intracranial aneurysms and aneurysmal subarachnoid haemorrhage (SAH). We investigated the relationship between the systemic use of corticosteroids in the past and the occurrence of aneurysmal SAH. METHODS: We compared the systemic use of corticosteroids (oral or intravenous) in the past between a consecutive series of 1158 patients with aneurysmal SAH and a control group consisting of 1019 patients diagnosed with a primary central nervous system (CNS) tumour. We discriminated between definite use of corticosteroids defined as use mentioned in the medical record and possible use defined as note in the medical record of a disease that may be treated with corticosteroids. We calculated odds ratios (OR) with corresponding 95% confidence intervals (CI) and adjusted for age and sex by means of logistic regression analyses. RESULTS: Twenty (1.7%, 95% CI 1.1-2.7) of the SAH patients and eight (0.8%, 95% CI 0.3-1.5) of the controls had used systemic corticosteroids (OR: 2.22; 95% CI 0.97-5.05; p-value 0.058; adjusted OR 2.23; 95 % CI 0.97-5.15; p-value 0.059). For definite plus possible use the OR was 1.67 (95% CI 1.09-2.54; p-value 0.016) and the adjusted OR 1.52 (95% CI 0.99-2.33; p-value 0.055). CONCLUSIONS: Patients with aneurysmal SAH more often have used systemic corticosteroids in the past than controls. This may suggest that the use of corticosteroids is a risk factor for aneurysmal SAH.     

Helicobacter pylori infection as an independent risk factor for cerebral ischemia of atherothrombotic origin.

Chronic infection may increase the risk for ischemic stroke. Presently, it is insufficiently established whether Helicobacter pylori infection represents a risk factor for ischemic stroke. We analyzed IgG antibodies against H. pylori in 109 patients with acute cerebral ischemia and 82 age- and sex-matched control patients with non-vascular and non-inflammatory neurological diseases. Antibody titers were significantly higher in patients than in control subjects (p=0.007). H. pylori seropositivity tended to be more common in patients (odds ratio (OR) 1.55, 95% confidence interval (ci) 0.87-2.76), but this trend was further attenuated in multivariate analysis (OR 1.42; 95% 0.75-2.67) with hypertension, diabetes mellitus, current or previous smoking, previous cerebral ischemia and low socioeconomic status. H. pylori seropositivity increased the odds for cerebral ischemia of atherothrombotic origin in univariate (OR 3.63; 95% ci 1.37-9.65) and multivariate analysis (OR 3.53; 95% ci 1.09-11.4). H. pylori seropositivity may be an independent risk factor for stroke of atherothrombotic origin.     

A study of circulating gliadin antibodies in schizophrenia among a Chinese population

The present work measured circulating antibodies against native gliadins, deamidated gliadin-derived epitopes, and transglutaminase 2 (TGM2) in 473 patients with schizophrenia and 478 control subjects among a Chinese population. The results showed that 27.1% of patients with schizophrenia were positive for the IgA antibody against native gliadins compared with 17.8% of control subjects (χ(2) = 11.52, P = .0007, OR = 1.72, 95% CI 1.25-2.35), although this significant difference appeared to be due mainly to low IgA gliadin antibody levels in female controls. A total of 27.6% of female patients were positive for IgA gliadin antibodies compared with 13.9% of female controls (χ(2) = 10.46, P = .0012, OR = 2.36, 95% CI 1.39-4.01), and 26.4% of male patients were positive for IgA antibodies compared with 19.8% of male controls (χ(2) = 3.26, P = .071, OR = 1.46, 95% CI 0.97-2.19). Of 128 patients who were positive for the IgA antibody against native gliadins, 8 were positive for the IgA antibody against deamidated gliadin epitopes and 1 was positive for IgA anti-TGM2 antibody. However, quantitative analysis demonstrated that the mean levels of IgA antibodies against deamidated gliadin epitopes and TGM2 were significantly lower in patients with schizophrenia than the control subjects (P < .001 and P = .008, respectively). The prevalence of IgG antibodies against native gliadins was not significantly different between the patient group and the control group (χ(2) = 2.25, P = .134, OR = 1.32, 95% CI 0.92-1.88). This study suggests that specific gliadin-derived epitopes may be involved in schizophrenia.     

Risk factors for aneurysmal subarachnoid haemorrhage: the Tromsø study

Methods: The Tromsø health study is a population based survey of risk factors for cardiovascular disease in 27 161 subjects. 26 cases of aneurysmal SAH were identified in which risk factors were registered before the bleeding. Four age and sex matched controls were selected for each case. A backward logistic regression analysis was conducted and odds ratios (ORs) for significant risk factors were calculated. Systolic and diastolic blood pressure, cigarette smoking habits, serum concentrations of lipoproteins, body mass index, and coffee consumption were analysed. Results: The crude annual incidence rate of aneurysmal SAH was 8.84/100 000 population. The proportion of current smokers was significantly (p = 0.003) higher in patients with SAH (73.1%) than in controls (41.3%). Drinking more than five cups of coffee per day was more common among patients (85%) than controls (59%) (p = 0.004). Mean (SD) systolic blood pressure was higher (p = 0.017) in patients (154.0 (32.5)) than in controls (136.3 (23.3)). Regression analysis showed that cigarette smoking (p = 0.04), systolic blood pressure (p < 0.0001), and coffee consumption (p = 0.004) were independent risk factors for SAH. The OR of current smokers versus never smokers was 4.55 (95% confidence interval (CI) 1.08 to 19.30) and the OR of drinking more than five cups of coffee a day was 3.86 (95% CI 1.01 to 14.73). The OR of an increase in systolic blood pressure of 20 mm Hg was 2.46 (95% CI 1.52 to 3.97). Conclusions: Cigarette smoking and hypertension are significant independent risk factors for aneurysmal SAH. A high coffee consumption may also predispose patients to aneurysmal SAH.     

Chlamydia pneumoniae infection in young stroke patients: a case–control study

Retrospective and cross-sectional studies have suggested that both bacterial and viral infections may be risk factors for atherosclerosis, ischemic stroke and acute coronary events. The correlation between Chlamydia pneumoniae and atherosclerosis remains a source of controversy. Our case-control study is aimed at evaluating the frequency of C. pneumoniae infection in a cohort of young adults with recent cerebrovascular disease and in particular etiologic stroke subtypes. Chlamydia pneumoniae IgG, IgM and IgA antibodies were evaluated by microimmunofluorescence method and antibody titers to both recombinant antigens chlamydial outer protein 2 and 60-kDa chlamydial heat shock protein (HSP60) by ELISA. The two groups differed with regard to the prevalence of C. pneumoniae IgA (P < 0.001) and IgG (P < 0.0001), as well as the titer of anti-R-HSP60 IgG (P < 0.001). We found an increase in IgA titers, suggestive of persistent, chronic active infection, in 16 patients in whom the etiology of the cerebral ischemic event was large-vessel atherothrombosis. Persistent, active C. pneumoniae infection may be an additional risk factor for ischemic stroke mainly of atherotrombotic origin in young subjects. However, a large-scale prospective confirmation of our findings is required.     

High titer of anticardiolipin antibody is associated with first-ever ischemic stroke in Taiwan

BACKGROUND AND PURPOSE: The association between anticardiolipin antibody (aCL) and ischemic stroke is controversial, and there are few case-control studies of Asian populations. The aim of this study, therefore, was to determine whether aCL is an independent risk factor for ischemic stroke in Taiwanese patients over the age of 40 years. METHODS: Both the IgG and IgM isotypes of aCL were measured in 273 patients (> 40 years of age) hospitalized for first-ever ischemic stroke and in 181 non-stroke controls. Results were defined as: negative (< 10 IgG phospholipid units [GPL] or < 7.5 IgM phospholipid units [MPL]); low positive (10-20 GPL or 7.5-15 MPL); or, high positive (> 20 GPL or > 15 MPL). Odds ratios (OR) were estimated by logistic regression with adjustment for potential confounders. RESULTS: A high positive IgG aCL was present in 4.4% of the stroke patients and 1.2% of the controls. Age- and sex-adjusted analysis showed a borderline association between a high positive level for aCL IgG titer and stroke, with an OR of 4.01 (95% CI 0.87-18.37; p = 0.0739). Final analysis, with adjustments for age, sex, hypertension, diabetes, tobacco smoking, atrial fibrillation, left ventricular hypertrophy and hyperlipidemia, revealed an OR of 5.25 (95% CI 1.06-25.89; p = 0.0419). CONCLUSIONS: The results of this study suggest that elevated titer of aCL IgG (> 20 GPL) is associated with first-ever ischemic stroke in Taiwanese patients aged over 40 years. High positive aCL titer is related to ischemic stroke after adjustment for conventional cerebrovascular risk factors, indicating that it is probably an independent risk factor for ischemic stroke.     

Chlamydia pneumoniae antibody titers in patients with acute ischemic stroke]

To evaluate an association of ischemic stroke and Chlamydia pneumoniae (C. pneumoniae) infection, we investigated specific antibodies to C. pneumoniae by ELISA in sera of 91 patients (male 53, female 38, mean age 73 years) with acute ischemic stroke. We divided the patients under clinical diagnosis into three groups, those with cardiac embolism (E group, n = 35), atherothrombotic infarction (A group, n = 29) and lacunar infarction (L group, n = 27). Carotid ultrasound examination was performed in 79 patients. The active infection, including acute primary infection, reinfection and chronic active infection, was defined by IgG or IgA index being > or = 3.00, while inactive infection, including previous and chronic inactive infection, was defined by IgG index being > or = 1.10 and < 3.00, and IgA index being < 3.00. We found that 20.7% of A group, 2.9% of E group, and 7.4% of L group had indexes suggesting an active infection (A vs. E. p = 0.040, A vs. L, p = 0.254, L vs. E, p = 0.575: Fisher's exact test). The IgG indexes of A group (mean, 1.50) were higher than those of E group (mean, 1.35) and those of L group (mean, 0.93, A vs. L, p = 0.049: unpaired t-test). The patients with carotid plaque (n = 7) had higher IgG indexes (mean, 2.28) than those without carotid plaque (n = 72, mean, 1.11, p = 0.002: unpaired t-test). These data support the association of acute atherothrombotic infarction with chronic active C. pneumoniae infection.     

Different independent susceptibility markers for first-ever cerebral infarction and myocardial infarction in young patients

Cerebral infarction (CI) and myocardial infarction (MI) share some common features, but there are other differences in risk factors. The aim of our study is to determine whether there are some significantly independent susceptibility markers for them. All consecutive patients between the ages of 18 and 45 years with first-ever CI and MI during 2001-2010 were recruited to participate in the study. Using multivariate logistic regression modeling, we explore many different data, such as age at onset, sex ratio, numbers of patients with history of hypertension, smoking, drinking, and serum lipid, uric acid, prealbumin (PA), and white blood cell (WBC) count levels. Logistic regression analysis adjusted for confounders confirmed the following independent susceptibility markers for young CI patients: hypertension, admission serum PA levels, daily alcohol [odds ratio (OR), 0.251; 95% confidence interval (CI), 0.097-0.648, p = 0.004; OR, 0.994; 95% CI, 0.988-0.999, p = 0.031; OR, 0.150; 95% CI, 0.047-0.473, p = 0.001], and for MI patients: age at onset, current smoking, serum WBC, and glucose levels (OR, 1.293; 95% CI, 1.146-1.457, p = 0.000; OR, 8.914; 95% CI, 3.575-22.231, p = 0.000; OR, 1.344; 95% CI, 1.169-1.544, p = 0.000; OR, 1.149; 95% CI, 1.022-1.291, p = 0.020). We conclude that there are some significantly different independent susceptibility markers for young CI and MI patients.     

Infectious agents associated with schizophrenia: a meta-analysis

Schizophrenia is a highly disabling and limiting disorder for patients and the possibility that infections by some microorganisms may be associated to its development may allow prevention and recovery. In the current study we have done a meta-analysis of studies that have assessed the possible association between detection of different infectious agents and schizophrenia. We report results that support the idea that there is a statistically significant association between schizophrenia and infection by Human Herpesvirus 2 (OR=1.34; CI 95%: 1.09-1.70; p=0.05), Borna Disease Virus (OR=2.03; CI 95%: 1.35-3.06; p<0.01), Human Endogenous Retrovirus W (OR=19.31; CI 95%: 6.74-55.29; p<0.001), Chlamydophila pneumoniae (OR=6.34; CI 95%: 2.83-14.19; p<0.001), Chlamydophila psittaci (OR=29.05; CI 95%: 8.91-94.70; p<0.001) and Toxoplasma gondii (OR=2.70; CI 95%: 1.34-4.42; p=0.005). The implications of these findings are discussed and further research options are also explicated.     

Prevalence and risk factors of middle cerebral artery stenosis in asymptomatic residents in Rongqi County, Guangdong

BACKGROUNDS: Intracranial atherosclerosis is the commonest vascular lesion for ischemic stroke in Asians. Most research on risk factors for middle cerebral artery (MCA) stenosis has been conducted in symptomatic patients with ischemic stroke or transient ischemic attack. The present study aimed to investigate risk factors for MCA stenosis in an asymptomatic population in Rongqi County in Southern China. METHODS: We assessed 1,068 asymptomatic subjects over 50 years of age by transcranial Doppler. Medical history documentation and investigation of biochemical markers were performed for each subject. Multivariant, unconditioned, logistic regression analyses were employed to assess the risk factors associated with MCA stenosis. RESULTS: MCA stenosis was found in 63 subjects (5.9%). Male gender, advancing age, hypertension, diabetes and systolic blood pressure were significant risk factors for MCA stenosis (p < 0.001). Based on logistic regression analyses, 4 factors emerged as independent risk factors (p < 0.001) of MCA stenosis: male gender [95% confidence interval (CI) = 1.49-4.66, OR = 2.63], age (95% CI = 1.01-1.06, OR = 1.04), hypertension (95% CI = 4.57-18.35, OR = 9.16) and diabetes mellitus (95% CI = 3.09-11.29, OR = 5.9). CONCLUSION: MCA stenosis is relatively common among asymptomatic Chinese subjects. Male gender, advanced age, hypertension and diabetes mellitus are risk factors for MCA stenosis.     

Hemostatic risk factors in ischemic stroke

The role played by hemostasis in the pathogenesis of ischemic stroke is still controversial. In the present study, we looked for a possible association of ischemic stroke and high clotting activity of factor II (FII:C), factor V (FV:C), factor VII (FVII:C), factor X (FX:C) and fibrinogen. We investigated 157 non-anti-coagulated patients (86 males, 71 females; median age 41 y, range 16-73 ), who had survived ischemic stroke for at least 2 months, and 193 healthy controls with similar age and sex distribution (104 males, 89 females; median age 39 y, range 19-74). Patients showed significantly higher body mass index, as well as significantly higher prevalence of arterial hypertension, smoking and hyperlipidemia. FV:C (p = 0.05), FX:C (p = 0.04) and fibrinogen (p = 0.05) were higher in patients as compared to controls. In a univariate risk analysis FX:C and FV:C were associated with the relative risk for ischemic stroke showing an odds ratio (OR) of up to 2.8 (95% CI: 1.05-7.6) and 3.4 (95%CI: 1.4-7.9), respectively, for levels above 130%. In a multivariate analysis using a logistic regression model including age, sex, arterial hypertension, smoking habit, diabetes, hyperlipidemia, BMI and the coagulation factors, FV:C was still found to significantly (p=0.03) add to the risk of ischemic stroke. An increase of factor FV:C by 10% was associated with an increase in the relative risk of 19% (95% CI.: 2%-38%). In conclusion, we found a high plasma level of FV:C to be a prevalent (FV:C > 130% in 20/157 patients) and independent risk factor for ischemic stroke.     

Thrombophilic risk factors in patients with central retinal vein occlusion

Few and contrasting data are available on the prevalence of hemostatic risk factors in patients with central retinal vein occlusion (CRVO). Aim of this study was to investigate the metabolic and inherited risk factors for venous thrombosis in 100 CRVO patients (age: 59 yrs; range 18-77) and in 100 controls (age: 56 yrs; range 18-84). In patients homocysteine (Hcy) levels were significantly higher than in controls and were affected by the C677T methylenetetrahydrofolate reductase (MTHFR) polymorphism (p < 0.001). The prevalences of activated protein C resistance (APCR), factor V Leiden positivity, elevated PAI-1 and Lp(a) levels were significantly higher in patients with respect to controls. At multivariate analysis, only hyperhomocysteinemia (OR 11, 95% CI 3.6-36.2; p < 0.0001) and elevated PAI-1 levels (OR 8.9, 95% CI 3.5-41.3; p < 0.01), in addition to hypertension (OR 40.5, 95% CI 8.6-188.8; p < 0.00001) and hypercholesterolemia (OR 3.1, 95% CI 1.6-20.5; p < 0.05), were independent risk factors for CRVO. These data demonstrate a potential role of hemostatic risk factors in the pathophysiology of CRVO.