Antiphosphatidyl serine antibodies are independently associated with ischemic stroke

Pediatric Chiari I malformation: novel and traditional measurements associated with syrinx and surgery

PURPOSE

Multiple imaging parameters have been examined to estimate the presence of syrinx and the need for surgery in Chiari I patients (CM1); however, no consistent or definitive criteria have been proposed. The objective of this study was to review existing and identify novel radiological and clinical characteristics of CM1 patients that associate syrinx development and surgical intervention.

METHODS

Patients with Chiari I malformation diagnosed on imaging between 0 and 18 years were retrospectively reviewed from January 1, 2007 to February 12, 2020. Participants were included if they had a baseline MRI of the head and spine prior to surgical intervention if required. Forty age-matched controls with cranial imaging were identified for comparison. Imaging parameters and clinical symptoms were recorded.

RESULTS

A total of 122 CM1 patients were included in this study. Of the 122 patients, 28 (23%) had syrinx, and 27 (22%) had surgery. The following imaging parameters associated with syrinx and surgical intervention were identified: midbrain length (P < 0.001; P = 0.032), the obex position (P = 0.002; P < 0.001) and medullary kinking (P = 0.041; P < 0.001). Among the clinical features, the presence of overall pain (P = 0.017; P = 0.042), neck pain (P = 0.005; P = 0.027), and sensory dysfunction (P < 0.001) were found to be strongly associated with syrinx and surgery.

CONCLUSION

While further investigation is needed, these specific radiological and clinical parameters should be considered when evaluating CM1 patients and may be used to guide further management.

Sex Differences in Hemostatic Factors in Patients With Ischemic Stroke and the Relation With Migraine-A Systematic Review

Background: Women are more affected by stroke than men. This might, in part, be explained by sex differences in stroke pathophysiology. The hemostasis system is influenced by sex hormones and associated with female risk factors for stroke, such as migraine.

Aim: To systematically review possible sex differences in hemostatic related factors in patients with ischemic stroke in general, and the influence of migraine on these factors in women with ischemic stroke.

Results: We included 24 studies with data on sex differences of hemostatic factors in 7247 patients with ischemic stroke (mean age 57–72 years, 27–57% women) and 25 hemostatic related factors. Levels of several factors were higher in women compared with men; FVII:C (116% ± 30% vs. 104% ± 30%), FXI (0.14 UI/mL higher in women), PAI-1 (125.35 ± 49.37 vs. 96.67 ± 38.90 ng/mL), D-dimer (1.25 ± 0.31 vs. 0.95 ± 0.24 μg/mL), and aPS (18.7% vs. 12.0% positive). In contrast, protein-S (86.2% ± 23.0% vs. 104.7% ± 19.8% antigen) and P-selectin (48.9 ± 14.4 vs. 79.1 ± 66.7 pg/mL) were higher in men. Most factors were investigated in single studies, at different time points after stroke, and in different stroke subtypes. Only one small study reported data on migraine and hemostatic factors in women with ischemic stroke. No differences in fibrinogen, D-dimer, t-PA, and PAI-1 levels were found between women with and without migraine.

Conclusion: Our systematic review suggests that sex differences exist in the activation of the hemostatic system in ischemic stroke. Women seem to lean more toward increased levels of procoagulant factors whereas men exhibit increased levels of coagulation inhibitors. To obtain better insight in sex-related differences in hemostatic factors, additional studies are needed to confirm these findings with special attention for different stroke phases, stroke subtypes, and not in the least women specific risk factors, such as migraine.

Arterial thrombosis in antiphospholipid syndrome (APS): Clinical approach and treatment. A systematic review

Thrombotic Antiphospholipid Syndrome (APS) is a condition affecting young individuals in whom a thromboembolic event occurs in the presence of circulating antiphospholipid antibodies (aPL). An extensive body of literature has covered the most common clinical presentation of the syndrome, venous thromboembolism. Arterial thrombosis in APS, a lesser clinical expression, is less studied. This review will concentrate on the body of literature concerning pathogenesis, clinical presentation and management of arterial thrombosis in APS.

Antiphospholipid antibodies predict post-stroke depression after acute ischemic stroke

BACKGROUND

Antiphospholipid activity was reported to be increased in depressive patients, while the impact of antiphospholipid antibodies (aPLs) on post-stroke depression (PSD) is unclear. We aimed to investigate the associations of aPLs, including antiphosphatidylserine (aPS) and anticardiolipin (aCL) antibodies with depression after acute ischemic stroke.

METHODS

aPS and aCL were measured in 497 ischemic stroke patients recruited from 7 of 26 participating hospitals of China Antihypertensive Trial in Acute Ischemic Stroke. 24-item Hamilton Depression Rating Scale was used to evaluate PSD status at 3 months after stroke.

RESULTS

Compared with aPS-negative or aCL-negative, the adjusted odds ratios (ORs) [95% confidence intervals (CIs)] associated with aPS-positive or aCL-positive were 1.77 (1.07-2.92) or 2.06 (1.11-3.80) for risk of PSD. On continuous analyses, per 1-SD increment of aPS and aCL were associated with 29% (OR 1.29, 95% CI 1.06-1.58) and 30% (OR 1.30, 95% CI 1.06-1.60) increased risks for PSD, respectively. Adding aPLs to conventional risk factors models significantly improved risk reclassification for PSD (net reclassification improvement index = 21.87%, P = 0.016 for aPS; net reclassification improvement index = 32.24%, P = 0.0004 for aCL).

LIMITATIONS

aPLs levels were tested only at baseline without serial measurements, and we were unable to detect the association between aPLs changes and PSD.

CONCLUSIONS

Higher aPS and aCL levels in the acute phase of ischemic stroke were associated with increased risk of 3-month PSD, suggesting that aPLs may play an important role in post-stroke depression prediction.

Multiple biomarkers covering distinct pathways for predicting outcomes after ischemic stroke

OBJECTIVE

To study the prognostic significance of multiple novel biomarkers in combination after ischemic stroke.

METHODS

We derived data from the China Antihypertensive Trial in Acute Ischemic Stroke, and 12 informative biomarkers were measured. The primary outcome was the combination of death and major disability (modified Rankin Scale score ≥3) at 3 months after ischemic stroke, and secondary outcomes included major disability, death, and vascular events.

RESULTS

In 3,405 participants, 866 participants (25.4%) experienced major disability or died within 3 months. In multivariable analyses, elevated high-sensitive C-reactive protein, complement C3, matrix metalloproteinase-9, hepatocyte growth factor, and antiphosphatidylserine antibodies were individually associated with the primary outcome. Participants with a larger number of elevated biomarkers had increased risk of all study outcomes. The adjusted odds ratios (95% confidence intervals) of participants with 5 elevated biomarkers were 3.88 (2.05-7.36) for the primary outcome, 2.81 (1.49-5.33) for major disability, 5.67 (1.09-29.52) for death, and 4.00 (1.22-13.14) for vascular events, compared to those with no elevated biomarkers. Simultaneously adding these 5 biomarkers to the basic model with traditional risk factors led to substantial reclassification for the combined outcome (net reclassification improvement 28.5%, p < 0.001; integrated discrimination improvement 2.2%, p < 0.001) and vascular events (net reclassification improvement 37.0%, p = 0.001; integrated discrimination improvement 0.8%, p = 0.001).

CONCLUSION

We observed a clear gradient relationship between the numbers of elevated novel biomarkers and risk of major disability, mortality, and vascular events. Incorporation of a combination of multiple biomarkers observed substantially improved the risk stratification for adverse outcomes in ischemic stroke patients.

Classical and additional antiphospholipid antibodies in blood samples of ischemic stroke patients and healthy controls

Classical antiphospholipid antibodies (aPLa) are found in 6-25% of blood samples from stroke patients. The frequency of novel aPLa antibodies in blood samples of CVA patients is not known. Enzyme-linked immunosorbent assays (ELISA) were performed on blood samples from 209 CVA patients (170 samples were obtained during the acute phase and 39 samples were from patients with complete carotid stenosis) and compared to 54 healthy controls. Subjects were tested for the presence of the classical aPL antibodies anticardiolipin (aCL) and anti-beta2-glycoprotein (aβ2gI), in addition to antiphosphatidylethanolamine (aPE), anti-phosphatidylserine (aPS), and Annexin V. All antibodies were tested for both IgM and IgG subclasses. Numeric analysis of the antibody titer levels (μ/ml) revealed a significantly higher subclinical titer by two standard deviations of many aPL autoantibodies among CVA patients (Pv < 0.05). However, according to the kit manufacturer's cutoff value, no positive antibodies were found except a trend toward higher percentage of positive aPS IgG titer in the CVA group compared to controls (6.2 vs. %0; P = 0.077). According to the manufacturer's cutoff, significantly higher levels of positive antibodies were not found among stroke patients. However, the absolute ELISA values of stroke patients were significantly higher. These results suggest that lower cutoff values than those used for APS diagnosis should be used for risk stratification of CVA among healthy individuals.

Antiphosphatidylserine Antibodies and Clinical Outcomes in Patients With Acute Ischemic Stroke

Background and Purpose—

Antiphosphatidylserine antibodies (aPS) have been associated with the risk of ischemic stroke. However, it remains unclear whether aPS will influence clinical outcomes in patients with acute ischemic stroke.

Methods—

A total of 3013 patients with acute ischemic stroke recruited from 26 hospitals across China from August 2009 to May 2013 were included in the study The primary outcome was a combination of death and major disability (modified Rankin Scale score ≥3) at 3 months after stroke. Secondary outcomes included death, major disability, recurrent stroke, and vascular events.

Results—

Composite outcome of death and major disability rates were 29.1% versus 23.9% in aPS-positive and aPS-negative groups. Compared with aPS-negative, adjusted odds ratios or hazard ratios (95% confidence interval) associated with aPS-positive were 1.35 (1.07–1.71), 1.63 (0.99–2.69), and 1.25 (0.98–1.59) for composite outcome of death or major disability, death, and major disability, respectively. For 1 interquartile range increase of aPS, the adjusted odds ratios or hazard ratios were 1.10 (1.01–1.20), 1.19 (1.05–1.35), and 1.05 (0.96–1.14), respectively. Adding aPS status to a model containing conventional risk factors improved risk prediction for composite outcome of death or major disability (net reclassification improvement index=11.3%, P =0.006; integrated discrimination improvement=0.2%, P =0.04). There was no significant association between aPS and risks of recurrent stroke and vascular events.

Conclusions—

We found that positive aPS increased risks of death or major disability at 3 months after an acute ischemic stroke, suggesting that aPS might be a prognostic marker for ischemic stroke.

Antiphospholipid Antibodies and Recurrent Thrombotic Events: Persistence and Portfolio

BACKGROUND

There are very limited prospective data on the significance of persistent antiphospholipid antibodies (aPL) and recurrent thrombo-occlusive events (TOEs). We investigated the prognostic value of (1) 2 newer aPL assays, (2) an aPL portfolio and (3) persistent aPL positivity following stroke.

METHODS

A total of 1,770 subjects from the APASS-WARSS study underwent further aPL testing for antibodies to phosphatidylserine (aPS) and anti-β2-glycoprotein-I (anti-β2GPI) from stored sera. Follow-up aPL status was also tested in a subset of subjects. Primary analysis was based on time to any TOE (ischemic stroke, myocardial infarction, transient ischemic attack, deep vein thrombosis, pulmonary embolism or systemic arterial occlusion)/death at 2 years. Cox proportional hazard analyses assessed whether aPL independently related to outcome.

RESULTS

Persistent anti-β2GPI decreased the time to TOE/death after adjustment for potential confounders (hazards ratio (HR) 2.86, 95% CI 1.21-6.76, p = 0.017). When persistent anti-β2GPI was combined with another persistently positive aPL, time to TOE/death was also reduced (HR 3.79, 95% CI 1.18-12.14, p = 0.025). Neither persistent anticardiolipin antibodies nor persistent aPS alone nor a single positive anti-β2GPI nor aPS was associated with decreased time to TOE/death. No single positive aPL, portfolio of baseline aPL or any persistent aPL increased the rate of TOE/death.

CONCLUSIONS

Rates of TOE/death were not influenced by aPL results at baseline or follow-up. Persistent anti-β2GPI alone, and with persistent second aPL, was independently associated with decreased time to TOE/death. Persistent aPL, an aPL portfolio and newer aPL in ischemic stroke patients are not helpful in predicting an increased rate of recurrent TOEs.

Multiple presence of prothrombotic risk factors in Croatian children with arterial ischemic stroke and transient ischemic attack

Aim

To determine the frequency of inherited and acquired prothrombotic risk factors in children with arterial ischemic stroke (AIS) and transient ischemic attacks (TIA) in Croatia.

Methods

We investigated 14 prothrombotic risk factors using blood samples from 124 children with AIS or TIA and 42 healthy children. Prothrombotic risk factors were classified into five groups: natural coagulation inhibitors (antithrombin, protein C, protein S), blood coagulation factors (FV Leiden and FII 20210), homocysteine, lipid and lipoprotein profile (lipoprotein (a), triglycerides, total, high- and low-density lipoprotein), and antiphospholipid antibodies (lupus anticoagulant, anticardiolipin, and antiphosphatidylserine antibodies).

Results

The most common prothrombotic risk factor was elevated lipoprotein (a), which was identified in about 31% of patients and in 24% of controls. Natural coagulation inhibitors were decreased in about 19% of patients, but not in controls. Pathological values of homocysteine, blood coagulation factor polymorphisms, and antiphospholipid antibodies were found in similar frequencies in all groups. Fourteen children with AIS and TIA (11.3%) and no children from the control group had three or more investigated risk factors.

Conclusion

The presence of multiple prothrombotic risk factors in children with cerebrovascular disorder suggests that a combination of risk factors rather than individual risk factors could contribute to cerebrovascular disorders in children.

Investigation of antiphosphatidyl-serine antibody and antiphosphatidyl-inositol antibody in ischemic stroke patients

Antiphospholipid syndrome is characterized by arterial or venous thrombosis and the presence of antiphospholipid antibodies (aPL). We measured β2-GPI aCL, IgGaCL, LA, antiphosphatidyl-serine antibody (PS), and antiphosphatidyl-inositol antibody (PI) in each patient at one month after the onset of stroke. In addition, carotid artery echography was performed in patients positive for PI or PS. Among the 250 patients, 13.6% (34/250) were positive for either PI or PS, and 6.8% (17/250) were positive for both. Carotid artery echography performed on these 34 patients showed that the frequencies of increased intimal-medial thickness (IMT) of 1.1 mm or more, plaque, and carotid artery stenosis of 50% or more were all significantly higher in patients positive for antinuclear antibody than those negative for the antibody (P < .05). PI and PS are associated with antinuclear antibody and precipitation of atherosclerosis. Ischemic stroke patients with SLE frequently showed a variety of antiphospholipid-protein antibodies.

Lupus anticoagulants and anti-phospholipid antibodies as risk factors for a first episode of ischemic stroke

BACKGROUND

Antiphospholipid antibodies (aPLA) and lupus anticoagulant (LAC) were shown to precipitate thromboembolic events. Their association with ischemic stroke remains to be seen.

OBJECTIVES

We investigated the contribution of LAC, and antibodies directed against the phospholipids cardiolipin (aCL), phosphatidylserine (aPS), and the phospholipid-dependent cofactors beta2-glycoprotein I and annexin V, to the risk for ischemic stroke.

PATIENTS/METHODS

LAC and antibody levels were measured in 208 stroke patients and 203 age- and gender-matched control subjects.

RESULTS

Positive LAC resulted in an increased risk for stroke [OR (95% CI) = 8.1 (2.4-27.5)]. Significant elevation in aPS IgG, aCL IgM and aCL IgG titers, and increased prevalence of elevated aPS IgG, aCL IgM and aCL IgG (based on P95 cutoff values of healthy individuals) were seen in patients. aPS IgG was associated with cardioembolic, whereas aCL IgG and IgM were elevated in lacunar, atherosclerotic and cardioembolic, and LAC positivity was documented only in lacunar stroke subtypes. The co-presence of LAC with a positive aCL IgM/IgG or aPS IgG did not affect the overall risk for stroke. Multivariate analysis confirmed the association of positive LAC with stroke [aOR (95% CI) = 9.7 (1.8-52.5)], and demonstrated a clear gradation of increasing risk of stroke associated with the four categories of aCL IgG and aPS IgG, and identified aCL IgM P95 as independent predictors of stroke after adjusting for potentially confounding covariates.

CONCLUSIONS

Our study demonstrates that the presence of LAC, and elevated aCL IgG and aPS IgG antibodies are risk factors for stroke.

Antiphospholipid syndrome and vascular ischemic (occlusive) diseases: an overview

Antiphospholipid syndrome (APS) is primarily considered to be an autoimmune pathological condition that is also referred to as "Hughes syndrome". It is characterized by arterial and/or venous thrombosis and pregnancy pathologies in the presence of anticardiolipin antibodies and/or lupus anticoagulant. APS can occur either as a primary disease or secondary to a connective tissue disorder, most frequently systemic lupus erythematosus (SLE). Damage to the nervous system is one of the most prominent clinical constellations of sequelae in APS and includes (i) arterial/ venous thrombotic events, (ii) psychiatric features and (iii) other non- thrombotic neurological syndromes. In this overview we compare the most important vascular ischemic (occlusive) disturbances (VIOD) with neuro-psychiatric symptomatics, together with complete, updated classifications and hypotheses for the etio-pathogenesis of APS with underlying clinical and laboratory criteria for optimal diagnosis and disease management.

Antiphospholipid antibodies in young adults with stroke

BACKGROUND

Antiphospholipid antibodies have been associated with a clinical syndrome consisting thrombosis and recurrent, unexplained fetal loss.

METHODS

The literature pertaining to stroke associated with antiphospholipid antibodies, with emphasis on stroke in young adults, was reviewed.

RESULTS

Antiphospholipid antibodies are an independent risk factor for stroke in young adults in five of six studies. Multiple antiphospholipid specificities or the Lupus Anticoagulant were tested in addition to anticardiolipin antibody in these studies. In the single study that found no increased risk for stroke, only anticardiolipin antibody was tested. Only one of these studies evaluated for risk of recurrent stroke in young adults with antiphospholipid antibodies and found it to be increased. No treatment trials have been conducted in young adults with antiphospholipid antibodies and stroke. In the single treatment trial comparing aspirin and low-INR producing doses of warfarin to prevent recurrent stroke, both were found to be equally effective.

CONCLUSIONS

Antiphospholipid antibodies, particularly Lupus Anticoagulant, is an independent risk factor for first and possibly recurrent ischemic stroke in young adults. The best therapeutic strategy for preventing antiphospholipid antibody-associated recurrent stroke is not clear.

Prevalence of antibodies against oxidised LDL in a cohort of 163 patients with positive anti-phospholipid antibodies and recent thrombosis

We evaluated the prevalence of anti-beta2-glycoprotein I (a-beta2-GPI), anti-phosphatidylserine/prothrombin (a-PP), anti-prothrombin (a-PT), and anti-oxidised low-density lipoprotein (a-oxLDL) antibodies in a cohort of patients with a recent thrombotic event. Among consecutive sera sent to an autoimmune laboratory for routine testing for anti-cardiolipin antibodies (aCL) 473 were found positive for IgG and/or IgM aCL. The referring physicians were requested for clinical information about thrombo-embolic events occurring within 6 months prior to testing. One hundred and sixty-three individuals of which 82 had suffered from cerebro-vascular infarction and 49 from deep venous thromboses or pulmonary emboli were included in the study. Ninety-four sera were positive for IgG aCL and 69 were negative. There was a strong correlation between the presence of IgG aCL and the three other phospholipid-related antibodies: a-beta2-GPI, a-PP, and a-PT. However, IgG a-oxLDL antibodies were almost equally distributed among sera positive and negative for IgG aCL. The presence of antibodies of all subgroups was most pronounced among patients with venous thrombo-embolic disease. In this cohort antibodies to beta2-GPI, PP, PT seem to coexist with aCL. However, a-oxLDL antibodies appear to define a subset of patients, who were older, had more arterial vascular disease, and with no apparent association to the presence of IgG aCL.

Phosphatidylserine IgG and beta-2-glycoprotein I IgA antibodies may be a risk factor for ischaemic stroke

OBJECTIVE

Antiphospholipid antibodies (APLA) are established risk factors for venous thrombosis but their role in the pathogenesis of cerebral ischaemia is unclear. The purpose of the present study was to evaluate the relevance of various APLA in patients with cryptogenic stroke (group A, n = 21) and determined causes of stroke (group B, n = 104) according to the TOAST classification in comparison with healthy volunteers without any thrombotic or ischaemic event in their history (group C, n = 84).

METHODS

Median ages were 52 yr (A), 60 yr (B) and 51 yr (C). Blood samples were tested for lupus anticoagulant (LA) using phospholipid-dependent coagulation tests (activated partial thromboplastin time, diluted Russell viper venom time). Confirmatory tests were performed if necessary. Furthermore, we assessed the presence of specific APLA and their antibody subclasses against cardiolipin (AclA), phosphatidylserine (ApsA), phosphatidylinositol (ApiA) and beta-2-glycoprotein I (Abeta2A) using enzyme-linked immunosorbent assay.

RESULTS

For ApsA IgG we found a significantly higher prevalence in stroke patients (57.7%) compared with normal subjects (4.8%; P < 0.001). Similarly, Abeta2A IgA was significantly more prevalent in stroke patients (20.8%) in comparison with normals (3.6%; P < 0.001). For all other APLAs tested, no significant differences emerged after adjustment for multiple comparisons. We did not find significant differences between stroke subtypes for any APLA.

CONCLUSION

The results of this study suggest a relevant role for antiphosphatidylserine IgG and anti-beta2-glycoprotein I IgA in stroke aetiology.

Antiphospholipid antibodies and stroke

Antiphospholipid antibodies are associated with venous and arterial thrombo-occlusive events, including stroke. They are a heterogeneous family of antibodies that react to negatively charged membrane-bound phospholipids or phospholipid-protein complexes. Despite much progress in the past decade, the precise mechanisms by which they promote thrombosis remain unknown. Increased risk of initial, but perhaps not recurrent, stroke has been associated with their presence. Antithrombotic regimens have been the mainstay of treatment, but the ideal therapeutic approach remains to be defined. This paper reviews the history, definition, associations, and treatment of this complex entity.

Management of the neurological manifestations of APS—what do the trials tell us?

PURPOSE

To systematically review evidence from clinical trials about the management of neurological manifestations of Antiphospholipid Syndrome (APS).

METHODS

Articles reporting case-control, cohort and prospective studies and treatment trials of primary or secondary stroke prevention in patients with aPL were identified in an OVID literature search from 1966 to 2004, using the keywords: APS, aPL and cerebrovascular disease. Articles were evaluated according to the standard system for assessing medical evidence to answer the following questions: (1) What is the role of aPL and recurrent stroke risk in both primary and secondary APS populations? (2) What is the evidence to support specific treatment strategies for secondary prevention of aPL-associated stroke? (3) What is the evidence to support specific treatment strategies for primary prevention of aPL-associated stroke?

CONCLUSIONS

(1) aPL are a risk factor for incident stroke (Grade A, established as useful for the given condition in the specified population). (2) The evidence to support the role of aPL in recurrent stroke is conflicting and, therefore, inconclusive. (3) Warfarin at moderate-intensity doses is equally effective in preventing a recurrent thrombotic event as warfarin at high-intensity doses in patients with APS (Grade A evidence, established as useful for the given condition in the specified population). (4) Warfarin, at moderate-intensity doses is as effective as aspirin (at a dose of 325 mg/day) in preventing recurrent thrombotic events in patients who are aPL-positive at the time of an initial stroke (Grade B evidence, probably useful for the given condition in the given population). (5) Currently there are no data to support the use of any prophylactic therapy in patients with aPL and no clinical manifestations for the purposes of preventing an incident stroke.

Stroke and the antiphospholipid syndrome: consensus meeting Taormina 2002

Ischaemic stroke is the only neurological manifestation accepted as a clinical diagnostic criterion for the antiphospholipid syndrome (APS). This association is reasonably well established in patients first diagnosed with APS but is less clear in randomly selected stroke patients who test positive on one occasion for antiphospholipid antibodies and who have no other evidence of systemic autoimmune disease. We propose a grading system that posits stroke to be definitely, likely or possibly associated with antiphospholipid antibodies (aPL). Further, there are limited prospective data to determine appropriate treatment. There is controversy as to whether the presence of aPL even increases risk of a recurrent stroke or other thromboembolic event, although data point to persistent medium-high titre aCL and/or LA as risk factors for recurrence. In the absence of data to guide clinicians on the best treatment, we cannot make strong recommnendations as to optimal therapy, nor can we propose clear consensus treatment guidelines.

Blood test detecting autoantibodies to N-methyl-D-aspartate neuroreceptors for evaluation of patients with transient ischemic attack and stroke

BACKGROUND

Stroke is a multisystemic disorder that includes mechanisms of thrombosis and neurotoxic coupling. Key metabolites of the molecular cascade following biochemical events appear simultaneously in brain tissue, the blood-brain barrier, and brain vessels, activating the immune system and generating autoantibodies (aAbs) to brain-specific antigens. We developed an ELISA blood test to measure aAbs to a subtype of N-methyl-D-aspartate (NMDA) receptors, which are the key markers of neurotoxicity underlying cerebral ischemia. We investigated the diagnostic accuracy of serum aAbs to NR2A/2B, a subtype of NMDA receptors, in assessing transient ischemic attack (TIA) and ischemic stroke (IS) and its ability to distinguish cerebral ischemia from intracerebral hemorrhage (ICH).

METHODS

Autoantibodies to NR2A/2B were measured in 360 serum samples: 105 from TIA/stroke patients and 255 from controls, including patients with controlled hypertension/atherosclerosis and gender- and age-matched healthy individuals.

RESULTS

Patients with TIA (n = 56) and acute IS (n = 31) had significantly higher NR2A/2B aAb concentrations than controls (P <0.0001). The test sensitivities for TIA and IS were 95% and 97%, respectively, and predictive values were 86% and 91% at a cutoff point of 2.0 micro g/L. The area under the ROC curve was 0.99. Monitoring NR2A/2B aAbs within 72 h differentiated IS and ICH (P <0.001) and was confirmed by magnetic resonance imaging and computed tomography.

CONCLUSIONS

NR2A/2B aAbs are independent and sensitive serologic markers capable of detecting TIA with a high posttest probability and, in conjunction with neurologic observation and neuroimaging, ruling out ICH. The test may help assess risk of TIA in routine general practice and may potentially be useful in assisting diagnosis of acute IS in the emergency setting.

Phospholipid autoantibodies: time for a new immuno-assay?

Antiphospholipid (aPL) antibodies are a wide and heterogeneous group of closely related immunoglobulins that have specificity for a number of phospholipids (PLs), PL-binding proteins, including beta2 glycoprotein I (beta2GP1), prothrombin, and PL-protein complexes. Antiphospholipid antibodies are currently detected by a standard solid-phase immunoassay such as anticardiolipin (aCL) antibodies. Although the association between aCL antibodies and thrombosis is well recognized, their role in stroke pathogenesis, and the possibility that they are an independent stroke risk factors in the general stroke population, remains to be determined. There are other negatively charged PL, largely represented within the cellular membrane and involved in the coagulation. Different studies have demonstrated a positive correlation among other aPL and stroke.

Neurological and neuroendocrine-cytokine inter-relationship in the antiphospholipid syndrome

Although many neurological deficits have been described in the antiphospholipid syndrome (APS), only stroke is well established and accepted as a diagnostic criterion in the disease. We presently review clinical data obtained from large series of cases regarding stroke, dementia, epilepsy, chorea, migraine, white-matter disease, and behavioral changes in APS, or linked-to-laboratory criteria such as antiphospholipid antibodies (aPL). The contribution of animal models to our understanding of these manifestations of APS is stressed, especially regarding the cognitive and behavioral aspects for which we have established model systems in the mouse. These models utilize immunization of mice with beta(2)-glycoprotein1, a central autoantigen in APS, which induces persistent high levels of aPLs. These mice develop hyperactive behavior after a period of four months, as well as deficits in learning and memory, and are potentially valuable as a system in which to study the pathogenesis and treatment of cognitive and behavioral aspects of APS. We have developed another model, in which IgGs from APS patients induce depolarization of brain synaptoneurosomes, and which may serve as a model for the pathogenesis of epilepsy in APS. Hormonal changes are another potential CNS manifestation of APS and this may be potentially linked to the systemic and central effects of cytokines such as interleukin-3. Better understanding of the link between APS and neurological or neuroendocrine manifestations other than stroke will reveal whether they can be used as clinical criteria for the diagnosis of APS and, it is hoped, lead to better treatment.

Spectrum of antiphospholipid antibodies (aPL) in patients with cerebrovascular disease

BACKGROUND

The association of stroke and antiphospholipid antibodies (aPL) other than anticardiolipin antibodies (aCL) is not well documented.

OBJECTIVE

To report the distribution of aCL, antiphosphatidylethanolamine (aPE), and antiphosphatidylserine (aPS) aPL among patients with symptomatic cerebrovascular disease evaluated by our Stroke Service at Indiana University Hospital from January 1997 to November 1999.

METHODS

We retrospectively reviewed medical records from 1997 to 1999 at Indiana University Hospital for all patients with symptomatic cerebrovascular disease using the International Statistical Classification of Diseases, 9th Revision, (ICD-9) codes. We identified patients with elevated titers of aPL. Sera from these patients were obtained within the first 30 days of the index event. We included only those patients for whom the serum samples were tested in a single laboratory by an in-house enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) immunoglobulin A (IgA) and immunoglobulin M (IgM) aCL, aPE, and aPS. We examined the clinical presentation, stroke risk factors, associated rheumatologic disorders, and distribution of aPL specificity and isotype.

RESULTS

Thirty-four of 185 patients, 26 women (76%), with a mean age of 46 years, and 8 men (24%) with a mean age of 46 years, had aPL. Nine patients had transient ischemic attacks (TIA), 25 suffered strokes, 23 had ischemic infarcts, and 2 had hemorrhagic infarcts (1 had a superior sagittal sinus thrombosis with bilateral hemispheric hemorrhagic infarcts, and one had bilateral hemorrhagic infarcts associated with systemic lupus erythematosus [SLE]). Six patients had SLE. The most common stroke risk factors were cigarette smoking (38%) and arterial hypertension (26%). Approximately two thirds (60%) of patients had a single positive aPL finding: aPE in 35%, aCL in 18%, and aPS in 6%. Multiple specificities were seen in 40%. IgA was the only aPL antibody isotype detected in 26% of the patients, IgG was the lone isotype in 24%, and IgM alone in 12%. Multiple aPL isotypes were detected in 38% of patients. Five patients (15%) presented with aPE IgA as the exclusive aPL.

CONCLUSION

In our series, aPE was the most frequent finding in stroke patients who were suspected to have an associated aPL syndrome. These specific types of aPL may be present relatively often in stroke patients and are often not assessed. Further studies are needed to determine how specific these aPL are in stroke versus other acute illnesses and versus healthy controls, and how these aPL are associated with stroke risk.

Neurologic manifestations of the antiphospholipid syndrome

Neurologic disorders are among the most prominent clinical manifestations associated with the antiphospholipid syndrome. Such neurologic disorders are predominantly related to focal central nervous system thrombo-occlusive events. This review summarizes the latest data regarding the clinical aspects of stroke and other neurologic manifestations associated with antiphospholipid antibodies.

Seasonal distribution of antiphospholipid antibodies

BACKGROUND AND PURPOSE

The purpose of this study was to determine if there was a seasonal variation in antiphospholipid antibody (aPL) titers and whether this variation differed between stroke cases and control subjects.

METHODS

IgG and IgM anticardiolipin and antiphosphatidyl serine antibody titers were obtained on serum samples from 884 stroke patients and 1024 control subjects over a 7-year period. Temporal distributions by month of blood draw were evaluated.

RESULTS

Marked seasonal differences in the proportion of positive titers were found for control subjects, but no seasonal variability among patients was noted. In control subjects, positive titers occurred less frequently in the summer months, mirroring the seasonal trends seen in respiratory track infections and rheumatic fever.

CONCLUSIONS

Our data suggest some aPL antibodies arise from different origins in patients and control subjects. The seasonality observed in the apparently normal population may be related to antibodies of infectious origin and is consistent with the reported lack of association with thrombosis of infection-related antibodies.

Update on ischemic stroke

Stroke is the second most common cause of death worldwide, exceeded only by heart disease. Epidemiologic studies have greatly enhanced our understanding of the factors that increase stroke risk. There have also been many recent developments in the understanding of the various etiologies of stroke as well as specific new treatments. The characteristic sudden onset and rapid tissue damage make stroke particularly challenging to treat. The most promising therapy for acute ischemic stroke is the use of a thrombolytic agent. This has been the focus of recent large trials and remains a challenging treatment for cerebral ischemic stroke as well as for retinal artery occlusion. Because neuro-ophthalmic symptoms and signs such as vision loss and diplopia are common in patients with stroke, patients are often seen by ophthalmologists prior to their primary care physicians or neurologists. The ophthalmologist should be aware of some of the new diagnostic and therapeutic issues in the management of patients with acute ischemic stroke. This review emphasizes some of the controversial topics published during the past few years.

Prothrombotic disorders and ischemic stroke in children

Childhood ischemic stroke, including arterial ischemic stroke (AIS) and sinovenous thrombosis (SVT), is relatively rare in children but can result in devastating morbidity and mortality. An understanding of the etiology of childhood stroke is important because strategies for primary and secondary prevention can be devised. Prothrombotic disorders may contribute to the etiology of childhood stroke, and include deficiencies of antithrombin, protein C, protein S, plasminogen, and presence of Factor V Leiden, Prothrombin gene G20210A, dysfibrinogenemia, antiphospholipid antibodies, hyperhomocysteinemia, and elevated lipoprotein (a). The overall incidence of prothrombotic disorders in childhood AIS is estimated to be 20% to 50% in most studies and, in childhood SVT, to be 33% to 99%. In addition, hyperlipidemia, polycythemia, iron deficiency anemia, and platelet disorders may result in a prothrombotic state associated with ischemic stroke. The etiologic contribution of these prothrombotic disorders to initial and recurrent stroke has not been clearly defined; however, additional risk factors are usually present in affected children. Given the prevalence of prothrombotic disorders in childhood stroke, and their likely causative role, children with stroke should be screened for prothrombotic disorders. Future prospective and multicenter studies will elucidate the contribution of specific prothrombotic disorders to initial and recurrent stroke, and optimal therapy.

Differential diagnosis of central nervous system manifestations of the antiphospholipid antibody syndrome

Anti-phospholipid antibodies (aPL) have been associated with a variety of neurologic manifestations. The evidence for an association between aPL and most of these is weak because (1) no association actually exists, (2) the manifestation is rare or (3) sufficiently powered studies have not been performed. The only neurologic manifestation that is considered to have sufficient evidence to justify it being a part of the criteria for the diagnosis of Anti-phospholipid Antibody Syndrome (APS) is cerebral ischemia. In this mini-review, most of the neurologic syndromes with an actual or suspected association with aPL are considered. The role of aPL in the differential diagnosis of these syndromes is considered as well.

Stroke risk factors

Despite advances in the treatment of acute cerebral infarction, the most effective method of reducing stroke morbidity and mortality is the identification and modification of stroke risk factors. Modifiable stroke risk factors include hypertension, atrial fibrillation, hypercholesterolemia, cigarette smoking, hyperhomocystinemia, and carotid stenosis. Improved identification of individuals at increased stroke risk due to these factors can reduce individual risk and the cost to society of the consequences of stroke.