Value of immunologic testing in stroke patients. A prospective multicenter study

Combined brain/heart magnetic resonance imaging in antiphospholipid syndrome-two sides of the same coin

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by arterial, venous, and/or small vessel thrombosis, pregnancy morbidity, and persistently elevated levels of antiphospholipid antibodies (aPL). Cardiovascular disease (CVD) in APS can present as heart valvular disease (HVD), macro-micro-coronary artery disease (CAD), myocardial dysfunction, cardiac thrombi, or pulmonary hypertension. Brain disease presents as stroke or transient ischemic attack (TIA) and less frequently as cerebral venous thrombosis, seizures, cognitive dysfunction, multiple sclerosis (MS)-like syndrome, or chorea. Infarcts and focal white matter hyperenhancement are the commonest brain (MRI) abnormalities, while myocardial ischemia/fibrosis, valvular stenosis/regurgitation, or cardiac thrombi are the main abnormalities detected by cardiovascular magnetic resonance. This review aims to present the existing evidence on brain/heart involvement and their interrelationship in APS and the role of brain/heart MRI in their evaluation. Embolic brain disease, due to HVD, CAD, and/or cardiac thrombus, or brain hypo-perfusion, due to myocardial dysfunction, are among the main brain/heart interactions in APS and they are considered determinants of morbidity and mortality. Currently, there is no evidence to support the use of combined brain/heart MRI in asymptomatic APS patients. Until more data will be available, this approach may be considered in APS patients at high risk for CVD/stroke, such as systemic lupus erythematosus with high-risk aPL profile or high scores in CVD risk prediction models; APS patients with HVD/thrombus, CAD, or heart failure; those with classic and non-criteria neurologic APS manifestations (seizures, cognitive dysfunction, MS-like syndrome); or with aggressive multi-organ disease. Key Points • Cardiovascular disease (CVD) in antiphospholipid syndrome (APS) can present as heart valvular disease (HVD), macro-micro-coronary artery disease (CAD), myocardial dysfunction, cardiac thrombi, or pulmonary hypertension. • Brain disease presents as stroke or transient ischemic attack (TIA), and less frequently as cerebral venous thrombosis, seizures, cognitive dysfunction, and multiple sclerosis (MS). • A combined brain/heart MRI may be considered in APS patients at high risk for CVD/stroke, such as systemic lupus erythematosus with high-risk aPL profile or high scores in CVD risks; APS patients with HVD/thrombus, CAD, or heart failure; those with classic and non-criteria neurologic APS manifestations (seizures, cognitive dysfunction, MS-like syndrome); or with aggressive multi-organ disease.

Anticardiolipin antibodies in various diseases in Taiwan: a retrospective analysis

The goals of this study are to determine the frequency of anticardiolipinantibodies (ACA) in patients with various diseases and to evaluate the clinical significance of ACA in Taiwan. We collected 690 patients from ACA laboratory records. They were divided into eight groups in order to compare ACA percentages. Positive rates of ACA in different disease groups were below 20%, except for 38.2% in autoimmune diseases with vascular thrombosis. Compared with old stroke, the ACA positivity in young stroke was not significantly different (P 0.482). The positive percentage of lupus anticoagulant (LA) (2.86%) was lower than that of ACA (15.66%) in young stroke (P 0.015). Among patients with pregnancy loss or prematurity, the ACA positivity in lupus patients (44.44%) was higher than without lupus (9.76%; P 0.01). The prevalence of ACA is higher in patients with vascular thrombosis complicated by autoimmune diseases than with thrombosis alone in Taiwan. Young and old stroke do not differ in ACA positivity. Moreover, ACA is more prevalent than LA for young stroke related coagulation.The ACA positivity for pregnancy loss or prematurity is very low in Taiwan. In summary, this is the first report on the frequency of ACA and other coagulation factors in various diseases in Taiwan.

The Increase of Blood Anticardiolipin Antibody Depends on the Underlying Etiology in Cerebral Ischemia

Although anticardiolipin antibody (aCL) has been suggested to be a potent risk factor for thrombosis and atherosclerosis in multiple arterial beds, conflicting results exist between aCL and cerebral ischemia in the general stroke population. To elucidate if this discrepancy relates to the heterogeneity of underlying etiologies, the blood beta2-glycoprotein I dependent-aCL in 432 Taiwanese adults was examined. The associated cerebral ischemia in these patients was classified into five subtypes according to the cause of cerebral ischemia. The results were compared with those in 100 healthy controls. A definite increase of aCL-IgG isotype was found in 41 patients (9.35%) and four controls (4.0%). The relative risk was 2.52. The frequency of increased aCL-IgG was 12.2%, 12.8%, 8.8%, 3.9%, and 3.5% in patients with large-artery atherosclerotic disease, stroke of unknown etiology, small-artery occlusive disease, cardioembolism, and stroke of other known etiology, respectively. Only patients with large-artery atherosclerotic disease (p<0.025) and stroke of unknown etiology (p<0.05) had higher frequencies of increased aCL than those in control subjects. The frequencies of abnormal results of activated partial thromboplastin time, antinuclear factor, Coombs’ test, and venereal disease research laboratory were 2.84%, 1.22%, 1.02%, and 1.34% in these 41 patients, respectively. Accordingly, aCL-IgG selectively increases in patients with large-artery atherosclerosis and stroke of unknown etiology, reflecting selective activation of humoral immunity for aCL in the pathogenesis of cerebral ischemia.

The Increase of Blood Anticardiolipin Antibody Depends on the Underlying Etiology in Cerebral Ischemia

Although anticardiolipin antibody (aCL) has been suggested to be a potent risk factor for thrombosis and atherosclerosis in multiple arterial beds, conflicting results still exist between aCL and cerebral ischemia in the general stroke population. To elucidate if this discrepancy relates to the heterogeneity of underlying etiologies, blood beta2-glycoprotein I dependent-aCL was evaluated in 432 Taiwanese adults associated with cerebral ischemia who were classified into five subtypes according to their causes of cerebral ischemia. The results were compared with those in 100 healthy controls. A definite increase of aCL-IgG isotype was found in 41 patients (9.35%) and four controls (4.0%). The relative risk was 2.52. The frequency of increased aCL-IgG was 12.2%, 12.8%, 8.8%, 3.9%, and 3.5% in patients with large-artery atherosclerotic disease, stroke of unknown etiology, small-artery occlusive disease, cardioembolism, and stroke of other known etiology, respectively. Only patient with large-artery atherosclerotic disease (p<0.025) and stroke of unknown etiology (p<0.05) had a higher frequency of increased aCL than control. The frequencies of abnormal result of activated partial thromboplastin time, antinuclear factor, Coombs’ test, and venereal disease research laboratory were 2.84%, 1.22%, 1.02%, and 1.34% in these 41 patients, respectively. Accordingly, aCL-IgG selectively increases in patients with large-artery atherosclerosis and stroke of unknown etiology, reflecting selective activation of humoral immunity for aCL in the pathogenesis of cerebral ischemia.

Antiphospholipid syndrome and central nervous system

Classification criteria, etiology, pathogenesis, major central nervous system (CNS) manifestations of the antiphospholipid syndrome (APS), as well as diagnostic and therapeutic approach are discussed in the article, supported by several MRI findings to illustrate differential complexity of selected topics. Close interplay of inflammation, autoimmunity, coagulation cascade, vasculature bed, neuron physiology and demyelinization in APS is elaborated. Cerebrovascular disease, multiple sclerosis-like syndrome, seizures, cognitive disfunction, headache and migraine, chorea and catastrophic antiphospholipid syndrome (CAPS) are discussed as the most prominent CNS manifestations of the APS.

Antinuclear antibody, is it a risk factor for cerebral ischemia? Magnetic resonance image analysis, a preliminary study

Magnetic resonance images (MRI) of 103 patients were examined to reveal whether positive antinuclear antibody is a risk factor for cerebral ischemia. The most common MRI formation was the presence of small high-intensity spots. The prevalence of hypertension and diabetes mellitus was significantly low. Although seven cases had no medical risk factors; they showed an abnormal MRI reading. Eleven cases exhibited signs of cerebral stroke. Positive antinuclear antibody cases are suggested to be part of the antiphospholipid antibody syndrome. Various types of cerebral arterial occlusion may occur, showing lacuna, atheroma generation, and a recurrent major vessel occlusion.

Hughes syndrome (the antiphospholipid syndrome): 25 years old

The antiphospholipid (Hughes) syndrome (APS) is a unique thrombotic disorder, causing both arterial and venous thrombosis, linked to the presence of antibodies directed against phospholipid-protein complexes. The first papers describing the syndrome were published in 1983 and, over the next two years, a series of publications described in detail the various clinical manifestations of the syndrome. Laboratory standardisation workshops were also set up and, in 1984, the first "world" symposium on APS was held. The international APS conferences have continued to grow in numbers and in stature. The APS has already had an impact in obstetrics, in medicine, in psychiatry, and in surgery. The approximate figure of 1 in 5 is a useful guide -- 1 in 5 of all young strokes, 1 in 5 recurrent miscarriages, 1 in 5 DVTs. More precise data will become available in the worlds of epilepsy, migraine, Alzheimer's, and MS. The advent of newer "biologic" immunosuppressives such as rituximab may offer help in selected cases. Intravenous immunoglobulin has proved successful, especially in the emergency setting.

Cerebral Manifestations in the Antiphospholipid (Hughes) Syndrome

The importance of cerebral disease in patients with the Hughes syndrome is now becoming more widely recognized. The range of neuropsychiatric manifestations of APS is comprehensive, and includes focal symptoms attributable to lesions in a specific area of the brain as well as diffuse or global dysfunction. Patients with APS frequently present with strokes and TIA, but a wide spectrum of other neurologic features-also including non thrombotic neurologic syndromes-has been described in association with the presence of aPL. The recognition of APS has had a profound impact on the understanding and management of the treatment of CNS manifestations associated with connective tissue diseases, in particular, SLE. Many patients with focal neurologic manifestations and aPL, who a few years ago would have received high-dose corticosteroids or immunosuppression, are often successfully treated with anticoagulation. In our opinion, testing for aPL may have a major diagnostic and therapeutic impact not only in patients with autoimmune diseases and neuropsychiatric manifestations, but also in young individuals who develop cerebral ischemia, in those with atypical multiple sclerosis, transverse myelitis, and atypical seizures. We would also recommend testing for aPL for young individuals found with multiple hyperintensity lesions on brain MRI in the absence of other possible causes,especially when under the age of 40 years. It is our practice to anticoagulate patients with aPL suffering from cerebral ischemia with a target INR of 3.0 to prevent recurrences. Low-dose aspirin alone (with occasional exceptions)does not seem helpful to prevent recurrent thrombosis in these patients. Our recommendation, once the patient has had a proven thrombosis associated with aPL, is long-term (possibly life-long) warfarin therapy. Oral anti coagulation carries a risk of hemorrhage, but in our experience the risk of serious bleeding in patients with APS and previous thrombosis treated with oral anticoagulation to a target INR of 3.5 was similar to that in groups of patients treated with lower target ratios. Although a double-blind crossover trial comparing low molecular weight heparin with placebo in patients with aPL and chronic headaches did not show a significant difference in the beneficial effect of low molecular weight heparin versus placebo, in our experience selected patients with aPL and neuropsychiatric manifestations such as seizures, severe cognitive dys-function, and intractable headaches unresponsive to conventional treatment may respond to anticoagulant treatment. The neurologic ramifications of Hughes syndrome are extensive, and it behoves clinicians in all specialties to be aware of this syndrome because treatment with anticoagulation may profoundly change the outlook for these patients.

Diagnosis of antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by recurrent vascular thrombosis and pregnancy losses. Laboratory diagnosis of APS relies on the demonstration of a positive anticardiolipin antibody test by an in-house or commercially available enzyme-linked immunosorbent assay, or on the presence of lupus anticoagulant by a coagulation-based test. Persistence of the positive results must be demonstrated, and other causes and underlying factors considered. Although it is universally recognized that the routine screening tests (anticardiolipin antibody or lupus anticoagulant) might miss some cases of APS, careful differential diagnosis and repeat testing are mandatory before the diagnosis of 'seronegative APS' can be made. Correct identification of patients with APS is important because prophylactic anticoagulant therapy can prevent thrombosis from recurring and treatment of affected women during pregnancy can improve fetal and maternal outcome.

Non-Atherosclerotic Vascular Disease in the Young

There are a large variety of non-atherosclerotic causes of ischemic stroke in the young. Arterial dissection, most commonly associated with non-traumatic causes, is among the most common. Both the carotid and vertebrobasilar circulations can be affected. The vasculitidies represent a rare, but potentially treatable series of conditions that can lead to stroke through diverse mechanisms. Moyamoya is a nonatherosclerotic, noninflammatory, nonamyloid vasculopathy characterized by chronic progressive stenosis or occlusion of the distal internal carotid arteries and/or proximal portions of the middle and/or anterior cerebral arteries. Moyamoya can be idiopathic (moyamoya disease) or the result of other conditions. An appreciation of the unusual causes of stroke in the young is important when considering secondary prevention measures.

APS and the brain

Antiphospholipid antibody syndrome (APS) may present with neurological syndromes. Cerebrovascular disease, chorea/ballismus, epileptic seizures, headache, cognitive impairment, transverse myelopathy, Devic's syndrome and multiple sclerosis-like presentations feature among others. Cerebrovascular disease is one of the most common presenting symptoms of APS, second only to deep vein thrombosis, and accounts for half of neurological manifestations in patients with APS; accelerated atherogenesis and cardioembolism are the most likely mechanisms implicated. Though infrequent, chorea is consistently associated with APS; the pathogenetic role of antiphospholipid antibodies (APLab) in this case might be routed through cerebrovascular disease in some cases and through purely immunological pathways in others. Both ischemic and immunological mechanisms have been demonstrated in the pathogenesis of epileptic seizures, which may account for 7% of neurological manifestations in APS. Although frequent in APS, a causative link between APLab and most common types of headache (migraine and tension-type headache) is more than dubious. Cognitive impairment may derive from a well-defined clinical tableau of multi-infarct dementia. Nevertheless, (highly frequent) less severe cognitive impairment has also been associated with the presence of APLab in the absence of magnetic resonance findings. A relationship between APS and transverse myelopathy seems likely but small numbers in the studies published to date preclude definite statements; routinely testing for APLab patients with neurological manifestations suggestive of multiple sclerosis seems to be unrecommended at the present time.

Inflammation and infection in clinical stroke

Stroke has enormous clinical, social, and economic implications, and demands a significant effort from both basic and clinical science in the search for successful therapies. Atherosclerosis, the pathologic process underlying most coronary artery disease and the majority of ischemic stroke in humans, is an inflammatory process. Complex interactions occur between the classic risk factors for atherosclerosis and its clinical consequences. These interactions appear to involve inflammatory mechanisms both in the periphery and in the CNS. Central nervous system inflammation is important in the pathophysiologic processes occurring after the onset of cerebral ischemia in ischemic stroke, subarachnoid hemorrhage, and head injury. In addition, inflammation in the CNS or in the periphery may be a risk factor for the initial development of cerebral ischemia. Peripheral infection and inflammatory processes are likely to be important in this respect. Thus, it appears that inflammation may be important both before, in predisposing to a stroke, and afterwards, where it is important in the mechanisms of cerebral injury and repair. Inflammation is mediated by both molecular components, including cytokines, and cellular components, such as leukocytes and microglia, many of which possess pro- and/or antiinflammatory properties, with harmful or beneficial effects. Classic acute-phase reactants and body temperature are also modified in stroke, and may be useful in the prediction of events, outcome, and as therapeutic targets. New imaging techniques are important clinically because they facilitate dynamic evaluation of tissue damage in relation to outcome. Inflammatory conditions such as giant cell arteritis and systemic lupus erythematosus predispose to stroke, as do a range of acute and chronic infections, principally respiratory. Diverse mechanisms have been proposed to account for inflammation and infection-associated stroke, ranging from classic risk factors to disturbances of the immune and coagulation systems. Considerable opportunities therefore exist for the development of novel therapies. It seems likely that drugs currently used in the treatment of stroke, such as aspirin, statins, and modulators of the renin-angiotensin-aldosterone system, act at least partly via antiinflammatory mechanisms. Newer approaches have included antimicrobial and antileukocyte strategies. One of the most promising avenues may be the use of cytokine antagonism, for example, interleukin-1 receptor antagonist.

Hughes (antiphospholipid) syndrome. Clinical features

Hughes (antiphospholipid) syndrome is a noninflammatory autoimmune disease. The most critical pathologic process is thrombosis, which results in most of the clinical features suffered by these patients. Recurrent thrombosis together with an adverse pregnancy history and the presence of antiphospholipid antibodies defines the syndrome.

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.

Neurological manifestations of antiphospholipid antibody syndrome

Thrombosis, thrombocytopenia, recurrent fetal loss and a variety of non-thrombotic neurological disorders have all been associated with antiphospholipid antibodies (aPL). Cerebral ischemia associated with aPL is the most common arterial thrombotic manifestation. Depression, cognitive dysfunction, depression and psychosis have all been associated with aPL. The presumed pathophysiologic mechanism underlying these manifestations is thought to be a result of cerebral ischemia in some, but not all cases. Seizures, chorea and transverse myelitis all appear to be associated with aPL. An interaction between aPL and central nervous system cellular elements rather than aPL-associated thrombosis seems to be a more plausible mechanism for these clinical manifestations. Migraine on the other hand, does not appear to be associated with aPL in either lupus or non-lupus populations. Neuroimaging studies show an increased frequency of brain abnormalities in patients with aPL, but none appear to be specific. The best treatment strategy for preventing neurological manifestations of aPL is not fully defined. For thrombotic manifestations, both antiplatelet and anticoagulant therapies have been suggested. In some patients, immunosuppressant therapy has been used. For non-thrombotic manifestations, some combination of immunosuppressant therapy and symptomatic treatment may be warranted.

Anticardiolipin antibodies in ischemic stroke in the young: Indian experience

Anticardiolipin antibodies (aCL) have been recognised as a marker for an increased risk of thrombosis. The prevalence of these antibodies in young Indian ischemic stroke population is not known. Our study establishes the prevalence of these antibodies and evaluates their clinical significance in 60 patients aged 40 years or less who presented with completed ischemic stroke. Immunoglobulin G and immunoglobulin M class antibodies to anticardiolipin were determined using a standardized enzyme-linked immunosorbent assay. The prevalence of these antibodies in stroke patients was 23% compared to 3.2% in the controls. All patients studied had no overt evidence of systemic lupus erythematosus or related autoimmune disorders. The aCL-positive stroke patients did not differ significantly from aCL-negative stroke patients with regard to demographic characteristics, risk factor profile, and radiological features. Prior transient ischemic attacks, ischemic retinopathy, and asymptomatic infection were more frequent in the aCL-positive group. The role of anticardiolipin antibodies as a disease marker for ischemic stroke is under-recognised in India and warrants further investigation.

Neurological aspects of antiphospholipid antibody syndrome

Antiphospholipid antibodies (aPL) have been associated with a variety of neurological disorders, mostly linked to focal neuroparenchymal ischemia or infarction. Cerebral ischemia associated with the antiphospholipid syndrome (APS) occurs at a younger age than typical atherothrombotic cerebrovascular disease, is often recurrent, and high positive GPL values are usually linked to the presence of a lupus anticoagulant. When other features of the syndrome are not present and cerebral ischemia occurs only associated with anticardiolipin immunoreactivity, there appears to be no discerning features of these patients unless GPL > 40 for which recurrent thrombo-occlusive events appear to occur more frequently. Other neurological manifestations associated with aPL include cerebral venous sinus thrombosis, ocular ischemia, dementia, including ischemic encephalopathy, and chorea. The role of aPL in migrainous events is controversial and may not play a role in recent, large case-controlled studies. Most seizures in patients harboring aPL are associated with focal brain infarction.

Hematologic disorders associated with ischemic stroke

Hematological disorders underlie a small proportion of all ischemic strokes. The association of these coagulation abnormalities with ischemic stroke is not always clear. The etiology of stroke still remains uncertain in a large number of cases and proper screening for coagulation abnormalities and the discovery of new coagulation disorders will probably increase the rate of strokes attributable to these causes. Since large case-control studies with unselected and consecutive stroke patients from different ethnic origins have not yet been performed to determine the role of coagulation abnormalities in ischemic stroke, our knowledge is dependent on case reports and small series of mostly younger patients. Extensive hematologic evaluation of unselected stroke patients will likely yield little useful information and be too expensive. Every stroke patients needs a careful evaluation, and in selected cases, this should include coagulation parameters. Patients with unexplained strokes after a careful evaluation, previous thrombotic episodes, or a positive family history for thrombosis, are good candidates for further coagulation studies. As long as the hypercoagulable state persists, both arterial and venous thromboembolic recurrences can be expected. Many of these patients may benefit from anticoagulants. In patients with hereditary coagulation disorders, studies should be extended to close relatives. Since some coagulation tests are fairly expensive, provide only equivocal data, and are not widely available, we advise a step-by-step approach starting with the patient and family history.

Stroke is an emergency

Stroke is an emergency. Ischemic stroke is similar to myocardial infarction in that the pathogenesis is loss of blood supply to the tissue, which can result in irreversible damage if blood flow is not restored quickly. Public education is needed to emphasize the warning signs of stroke. Patients should seek medical help immediately, using emergency transport systems. Therapy geared toward minimizing the damage from an acute stroke should be started without delay in the emergency room. This includes measures to protect brain tissue, support perfusion pressure, and minimize cerebral edema. Strategies for improving recovery should also begin immediately. All major medical centers need stroke teams and stroke units. Stroke prevention should be given high priority as a public health strategy. Risk factor management should be part of general health care and should begin in childhood, with emphasis on nutrition, exercise, weight control, and avoidance of tobacco. Health screening and early treatment of hypertension and hypercholesterolemia has decreased the incidence of stroke and heart disease, but these efforts need to be expanded to reach all segments of the population. Basic research has opened the door to new therapies aimed at re-establishing blood flow and limiting tissue damage. Clinical trials have already led to changes in stroke prevention, including studies of carotid endarterectomy and ticlopidine and warfarin therapy (for patients with atrial fibrillation). Trials in progress are testing the usefulness of ancrod, neuroprotective agents, antioxidant agents, anti-inflammatory agents, low-molecular-weight heparin, thrombolytic drugs, and angioplasty. Any delay starting therapy after an acute stroke will result in progressive, irreversible loss of brain tissue. Clinicians should remember that for a stroke patient, time is brain tissue.