Elevated serum levels of anti-collagen type I antibodies in patients with spontaneous cervical artery dissection and ischemic stroke: a prospective multicenter study.

Introduction: Spontaneous cervical artery dissection (sCAD) is a rare vasculopathy whose trigger is still unknown. We hypothesized that autoimmunity against components of the vascular wall might play a critical role in sCAD and examined anti-collagen type I antibodies in patients with sCAD, acute ischemic stroke, patients with thromboendarterectomy, and controls. Methods: Fifty-seven patients with sCAD (age 45.7 ± 10.2 years, female 18 (31.6%)) were prospectively enrolled in four German stroke centers. Blood samples were collected at baseline, at day 10 ± 3, and after 6 ± 1 months. Patients with ischemic stroke not related to CAD (n=54, age 56.7 ± 13.7 years, female 15 (27.8%)), healthy probands (n=80, age 57.4 ± 12.9 years, female 56 (70%)), and patients undergoing thromboendarterectomy of the carotid artery (n=9, age 70.7 ± 9.3 years, female 2 (22.2%)) served as controls. Anti-collagen type I antibodies were determined by enzyme-linked immunosorbent assays (ELISAs). Results: Patients with acute sCAD had higher serum levels of anti-collagen type I antibodies (33.9 ± 24.6 µg/ml) than probands (18.5 ± 11.0 µg/ml; p <0.001) but lower levels than patients with ischemic stroke not related to sCAD (47.8 ± 28.4 µg/ml; p=0.003). In patients with sCAD, serum levels of anti-collagen type I antibodies were similar in the acute, subacute, and chronic phase. Levels of anti-collagen type I antibodies significantly correlated with circulating collagen type I (rho=0.207, p=0.003). Conclusion: Anti-collagen type I antibodies seem not to represent a trigger for acute sCAD or ischemic stroke but may rather be linked to the metabolism and turnover of collagen type I.

Involvement of Matrix Metalloproteinase 9 in Vertebral Arterial Dissection With Posterior Circulation Ischemic Stroke.

Background Spontaneous vertebral arterial dissection (VAD) is an important cause of posterior circulation ischemic stroke (PCS), but its pathogenesis remains elusive. Matrix metalloproteinase 9 (MMP-9) is a gelatinase involved in inflammation process and several vascular diseases, such as aorta dissection, but its role in VBD is unclear yet. The present study aimed to determine the association between serum MMP-9 level and VAD-related PCS. Methods and Results We recruited 149 patients with PCS, of which 30 were VAD and 119 had other determined etiologies (non-VAD), and 219 non-stroke individuals. Serum MMP-9 was measured within 14 days from stroke onset. The age of VAD group was 59.6±15.0 years, which is similar to non-stroke group (P=0.510) but significantly younger than non-VAD group (69.9±14.0 years, P<0.001). Males and vascular risk factors were significantly more prevalent in VAD and non-VAD groups than non-stroke group (P<0.001). Multivariate logistic regression analysis adjusting potential confounders revealed that every 100 ng/mL of serum MMP-9 level increment significantly predicted VAD (versus non-stroke group: odds ratio (OR), 4.572; 95% CI, 2.240-9.333, P<0.001; versus non-VAD group: OR, 1.819; 95% CI, 1.034-3.200, P=0.038). Conclusions Patients with VAD-related PCS had higher levels of serum MMP-9 at the acute stage of stroke compared with non-stroke individuals and PCS of other causes, supporting the potential involvement of extracellular matrix-degrading protease in the mechanism of VAD, which leads to ischemic events.

The value of plasma fibrillin-1 level in patients with spontaneous cerebral artery dissection.

OBJECTIVE: To explore the value of plasma fibrillin-1 levels in patients with spontaneous cerebral artery dissection (sCeAD). METHODS: A single-center prospective cohort of 99 consecutive patients with sCeAD between February 2013 and December 2015 were age and sex matched with 115 patients with non-sCeAD ischemic stroke and 20 healthy participants undergoing routine physical examination. The plasma fibrillin-1 level was measured with ELISA and compared among the 3 groups. The associations of fibrillin-1 with site, acuity, and severity of dissection, as well as clinical and radiographic prognosis of patients, were analyzed. RESULTS: One hundred nine plasma samples from 99 patients with sCeAD, 115 from disease control patients, and 20 from healthy participants were collected. The plasma fibrillin-1 level of the dissection group (mean 85.56 ng/mL [95% confidence interval 81.53-89.59]) was higher than that of non-sCeAD ischemic stroke group (77.13 ng/mL [73.64-80.63], p = 0.015) or healthy controls (73.04 ng/mL [65.94-80.13], p = 0.029). Such differences were most prominent in the acute stage (97.64 ng/mL [91.64-103.64], 74.39 ng/mL [68.95-79.84], and 73.04 ng/mL [65.95-80.13], respectively). A cutoff value of 88.455 ng/mL was determined to differentiate acute dissection from nondissection stroke with a sensitivity of 0.778 and a specificity of 0.800. Higher fibrillin-1 level was detected in patients with more severe dissection radiographically (p < 0.001), while patients with lower fibrillin-1 concentration at baseline achieved better morphologic recovery on follow-up imaging tests (p = 0.003). CONCLUSION: Plasma fibrillin-1 is a promising biomarker for aiding the diagnosis of acute sCeAD and may have potential value in lesion severity grading and radiographic prognosis prediction. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that patients with sCeAD have significantly higher levels of plasma fibrillin-1 than patients with ischemic stroke attributable to a cause other than sCeAD.

Serum Neurofilament Light Chain Levels Are Associated with Clinical Characteristics and Outcome in Patients with Cervical Artery Dissection.

BACKGROUND: Serum neurofilament light chain (sNfL) levels represent a promising marker of neuroaxonal injury. They are elevated in several neurological conditions, but their importance in cerebrovascular diseases remains unclear. In a proof of concept study, we compared sNfL levels with clinical characteristics and outcome in patients with cervical artery dissection (CeAD). METHODS: A total of 49 non-traumatic CeAD patients were included. sNfL levels were measured by high-sensitivity electrochemiluminescence immunoassay. Levels were compared with regard to (i) type of presenting symptoms (local symptoms only (n = 8), transient ischemic attack (TIA; n = 10) or ischemic stroke (n = 31)), (ii) stroke severity quantified by National Institute of Health Stroke Scale (NIHSS), (iii) time interval between onset of symptoms and blood sampling and (iv) 3-month outcome as measured by the modified Rankin Scale score. Analyses were performed using univariate and multivariate linear and ordinal regression models. RESULTS: CeAD patients presenting with stroke had significantly higher sNfL levels (median 108.9 pg/ml, interquartile range (37.8-427.7)) than patients with TIA (16.4 pg/ml (8.7-36.3), p = 0.002) or local symptoms (23.4 pg/ml (17.8-30.8), p = 0.0007). Among stroke patients, sNfL levels were positively associated with both NIHSS (p = 0.0002) and time between stroke onset and serum sampling (p = 1.9 × 10-6). Higher sNfL levels were associated with unfavorable outcome at 3 months (OR 4.67, 95% CI 1.69-12.95, p = 0.003). However, this association lost significance after adjustment for NIHSS. The highest sNfL level was observed in a TIA patient who had ischemic stroke 1 day after serum sampling for sNfL measurement. CONCLUSION: sNfL levels were increased in CeAD patients presenting with stroke, correlated with clinical severity and were influenced by the time point of blood sampling. The prognostic meaning of sNfL in CeAD deserves further testing.

Efficacy and safety of novel oral anticoagulants in patients with cervical artery dissections.

BACKGROUND: American and European guidelines support antiplatelet agents and anticoagulants as reasonable treatments of cervical artery dissection (CAD), though randomized clinical trials are lacking. The utility of novel oral anticoagulants (NOAC), effective in reducing embolic stroke risk in non-valvular atrial fibrillation (NVAF), has not been reported in patients with CAD. We report on the use, safety, and efficacy of NOACs in the treatment of CAD. METHODS: We retrospectively identified patients diagnosed with CAD at a single academic center between January 2010 and August 2013. Patients were categorized by their antithrombotic treatment at hospital discharge with a NOAC (dabigatran, rivaroxaban, or apixaban), traditional anticoagulant (AC: warfarin or treatment dose low-molecular weight heparin), or antiplatelet agent (AP: aspirin, clopidogrel, or aspirin/extended-release dypyridamole). Using appropriate tests, we compared the baseline medical history, presenting clinical symptoms and initial radiographic characteristics among patients in the 3 treatment groups. We then evaluated for the following outcomes: recurrent stroke, vessel recanalization, and bleeding complications. p values <0.05 were considered significant. RESULTS: Of the 149 included patients (mean age 43.4 years; 63.1% female; 70.5% vertebral artery CAD), 39 (26.2%), 70 (47.0%), and 40 (26.8%) were treated with a NOAC, AC, and AP, respectively. More patients with severe stenosis or occlusion were treated with NOAC than with AC or AP (61.8 vs. 60.0 vs. 22.5%, p = 0.002). Other baseline clinical and radiographic findings, including the presence of acute infarction and hematoma, did not differ between the 3 treatment groups. One hundred and thirty-five (90.6%) patients had clinical follow-up (median time 7.5 months) and 125 (83.9%) had radiographic follow-up (median time 5 months) information. There were 2 recurrent strokes in the NOAC group and 1 in each of the AC and AP groups (p = 0.822). There were more major hemorrhagic events in the AC group (11.4%) compared to the NOAC (0.0%) and AP (2.5%) groups (p = 0.034). Three patients treated with NOAC and none treated with AC or AP had a worsened degree of stenosis on follow-up imaging (8.6 vs. 0.0 vs. 0.0%, p = 0.019). CONCLUSION: Compared to traditional anticoagulants for CAD, treatment with NOACs is associated with similar rates of recurrent stroke, fewer hemorrhagic complications, but greater rates of radiographic worsening. These data suggest that NOACs may be a reasonable alternative in the management of CAD. Prospective validation of these findings is needed.

Mild hyperhomocysteinemia and low folate concentrations as risk factors for cervical arterial dissection.

BACKGROUND AND PURPOSE: Elevated homocysteine (Hcy) plasma levels are associated with an increased risk of spontaneous cervical artery dissection (sCAD). We examined the potential association between Hcy, folate, vitamin B(12) levels and 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms in patients with cerebral infarct caused by sCAD. PATIENTS AND METHODS: 39 patients who survived a cerebral infarct caused by sCAD [20 (51%) women; 24 (61.5%) vertebral and 15 (38.5%) internal carotid arteries], and 76 healthy control subjects were included. Hcy plasma levels (fasting and after methionine load), folate and vitamin B(12) levels were measured. We also performed polymorphisms of MTHFR. Hcy, vitamin B(12), folates and polymorphisms of MTHFR were assessed and any associations were analyzed using multivariate statistics. RESULTS: Mean plasma fasting Hcy level was 9.81 mumol/l for cases and 6.38 for controls (p = 0.001). The occurrence of sCAD was associated with elevated fasting Hcy levels (>95th percentile over the control group) with an adjusted odds ratio of 7.9 (95% CI 1.66-35). The association between low plasma folate values (<5th percentile) and the presence of CAD was 7.9 (95% CI 1.6-31) after adjusting for confounding variables. The distribution of the MTHFR genotype showed a higher TT mutant frequency among CAD patients (p = 0.034). CONCLUSIONS: High plasma concentrations of Hcy and low plasma levels of folate were associated with an increased risk of sCAD in the sample studied. We conclude that deficiencies in nutritional status may contribute to the relatively high incidence of CAD in Mexico.

Protease inhibitors in spontaneous cervical artery dissections.

BACKGROUND AND PURPOSE: Observations in patients with arterial aneurysms, fibromuscular dysplasia, and spontaneous cervical artery dissection (sCAD) indicate that protease inhibitor deficiency might boost the enzymatic destruction of arterial tissue and increase the risk of these arterial wall diseases. Here we present the first large investigation of the protease inhibitor hypothesis in patients with sCAD. METHODS: Eighty patients with sCAD were compared with 80 age- and sex-matched healthy individuals. Alpha1-antitrypsin (alpha1-AT) and alpha2-macroglobulin (alpha2-MG) levels, and alpha1-AT genotypes were assessed and compared between groups. RESULTS: alpha1-AT and alpha2-MG levels as well as alpha1-AT genotypes did not differ significantly between patients and controls. The frequency of Z alleles in the patient group was higher than in the control group and than in other cohorts from Europe; however, the difference remained nonsignificant. All patients with Z alleles had internal carotid artery dissections. CONCLUSIONS: Overall, this data does not support the hypothesis that protease inhibitor levels or alpha1-AT genotypes play an important role in the etiology of sCAD. The present data does not exclude that the Pi-Z allele might have an influence on subgroups of sCAD, such as internal carotid artery dissections.

Plasma homocysteine, MTHFR C677T, CBS 844ins68bp, and MTHFD1 G1958A polymorphisms in spontaneous cervical artery dissections.

Mild hyperhomocysteinemia is a probable risk factor for atherosclerotic diseases and stroke. Recently, associations of elevated plasma homocysteine concentrations in the acute phase and of MTHFR 677 TT genotype with spontaneous cervical artery dissections (sCAD) have been reported. The purpose of this study was to test this hypothesis in the currently largest sample of patients with sCAD, taking into account known factors influencing plasma homocysteine levels. Ninety-five patients with past sCAD were compared with 95 age- and sex-matched healthy individuals. Homocysteine, vitamin B6, B12, folate, and polymorphisms of methylenetetrahydrofolate reductase (MTHFR C677T), cystathionine beta-synthase (CBS 844ins68bp) and methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase/formyltetrahydrofolate synthetase (MTHFD1 G1958A) were assessed and any associations were analysed using multivariate statistics. The occurrence of sCAD was associated with elevated homocysteine levels with an odds ratio of 1.327 per 20 % percentile. Homocysteine levels were influenced by gender, smoking status, occurrence of hypertension, vitamin B12 and folate levels, and by the MTHFR TT genotype. MTHFR, CBS 844ins68bp, and MTHFD1 G1958A genotype were not independently associated with the occurrence of sCAD. These data suggest that elevated homocysteine is associated with the occurrence of sCAD. The MTHFR C677T polymorphism is associated with the homocysteine level.

Levels of alpha1-antitrypsin in plasma and risk of spontaneous cervical artery dissections: a case-control study.

BACKGROUND AND PURPOSE: Abnormalities of dermal connective tissue have been detected in patients with spontaneous cervical artery dissections (sCAD), suggesting an underlying structural defect of the arterial wall. Alpha1-antitrypsin (A1-AT) is a circulating serine proteinase inhibitor of proteolytic enzymes that helps to maintain the integrity of elastic and collagen fibers. METHODS: To test the hypothesis that moderate deficiency of A1-AT may be a risk factor for sCAD, 22 cases with sCAD and 113 controls were included in the study. RESULTS: Patients with sCAD had significantly mean lower levels of A1-AT compared with controls (116.0+/-24.9 versus 141.1+/-31.7 mg/dL; P<0.01). Low levels of A1-AT (<90 mg/dL) were more frequently observed in patients with sCAD compared with controls (27.3% versus 2.7%; P<0.001). A positive correlation between age and plasma levels of A1-AT was found (r=0.22; P<0.01). A1-AT levels were not affected by sex or vascular risk factors, including smoking habit. On multivariate analysis, A1-AT <90 mg/dL was associated with sCAD independently of age, sex, or vascular risk factors (odds ratio, 17.7; 95% confidence interval, 2.9 to 105.6). CONCLUSIONS: Low plasma levels of A1-AT may be a risk factor for sCAD.

Hyperhomocyst(e)inemia and risk of ischemic stroke among young Asian adults.

BACKGROUND AND PURPOSE: Hyperhomocyst(e)inemia is emerging as a possible risk factor for stroke, possibly because of accelerated atherosclerosis. There are no previous publications evaluating homocyst(e)ine in young Asian ischemic stroke patients. We conducted a case-control study examining homocyst(e)ine, vitamin B12, and folate levels in young, first-ever Asian ischemic stroke patients. METHODS: We prospectively recruited 109 consecutive young (<50 years) first-ever hospitalized ischemic stroke patients and 88 age/gender-matched hospital-based controls during a period of 18 months. Prevalence of vascular risk factors was assessed; fasting homocyst(e)ine, vitamin B12, and folate were assayed. Stroke mechanisms were subtyped using TOAST study criteria. RESULTS: Mean age was 43.8 (cases) and 43.1 (controls) years; 71.6% were male (cases and controls). Diabetes mellitus, hypertension, and hyperlipidemia were significantly more prevalent in cases. Mean fasting homocyst(e)ine levels were significantly higher in cases (13.7 micro mol/L, 95% CI: 12.7 to 14.9) than controls (10.8 micro mol/L, 95% CI: 9.9 to 11.8, P<0.001). Mean vitamin B12 levels were significantly lower in cases (299.5 pmol/L, 95% CI: 266.7 to 332.3) than controls (394.5 pmol/L, 95% CI: 357.9 to 431.0, P<0.001). Folate levels were not significantly different. Mean homocyst(e)ine levels were significantly elevated in large-artery strokes (16.9 micro mol/L, 95% CI: 14.5 to 19.7, P<0.001) but not other stroke subtypes compared with controls. Compared with the lowest homocyst(e)ine quartile, the highest quartile was significantly associated with an adjusted odds ratio of 4.3 for ischemic stroke and 25.3 for large-artery stroke. Using a logistic regression model, the adjusted odds ratio was 5.17 (95% CI: 1.96 to 13.63, P=0.001) for every 1 micro mol/L increase in log homocyst(e)ine. CONCLUSIONS: Hyperhomocyst(e)inemia is an independent risk factor for ischemic strokes in young Asian adults. The relationship between increasing homocyst(e)ine and stroke risk is strong, graded, and significant. The association with large-artery strokes suggests that hyperhomocyst(e)inemia may increase stroke risk via a proatherogenic effect.

Mild hyperhomocyst(e)inemia: a possible risk factor for cervical artery dissection.

BACKGROUND AND PURPOSE: The pathogenesis of cervical artery dissection (CAD) remains unknown in most cases. Hyperhomocyst(e)inemia [hyperH(e)], an independent risk factor for cerebrovascular disease, induces damage in endothelial cells in animal cell culture. Consecutive patients with CAD and age-matched control subjects have been studied by serum levels of homocyst(e)ine and the genotype of 5,10-methylenetetrahydrofolate reductase (MTHFR). METHODS: Twenty-six patients with CAD, admitted to our Stroke Unit (15 men and 11 women; 16 vertebral arteries, 10 internal carotid arteries), were compared with age-matched control subjects. All patients underwent duplex ultrasound, MR angiography, and/or conventional angiography. RESULTS: Mean plasma homocyst(e)ine level was 17.88 micromol/L (range 5.95 to 40.0 micromol/L) for patients with CAD and 6.0+/-0.99 micromol/L for controls (P:<0.001). The genetic analysis for the thermolabile form of MTHFR in CAD patients showed heterozygosity in 54% and homozygosity in 27%; comparable figures for controls were 40% (P:=0.4) and 10% (P:=0.1), respectively. CONCLUSIONS: Mild hyperH(e) might represent a risk factor for cervical artery dissection. The MTHFR mutation is not significantly associated with CAD. An interaction between different genetic and environmental factors probably takes place in the cascade of pathogenetic events leading to arterial wall damage.