A perturbation of antithrombin-III and protein C coupling associates with an increase of anti-beta2-glycoprotein I antibody in non-antiphospholipid antibody syndrome 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 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.

Hyperhomocysteinemia Relates to the Subtype of Antiphospholipid Antibodies in Non-SLE Patients

Abnormal increases of antiphospholipid antibody and plasma homocysteine levels are recently emerging as nonlipidic risk factors for cerebral atherogenesis and thrombosis. Both antiphospholipid antibody and homocysteine share many similar bioeffects in hemostasis, but their interaction is still inconsistent. In this study, we examined the relation between the plasma homocysteine level and lupus anticoagulant, anticardiolipin antibody, and anti-β2-glycoprotein I antibody in patients with noncardiac cerebral ischemia. Systemic lupus erythrematosus patients were excluded. The results showed a higher frequency of moderate hyperhomocysteinemia in patients with an abnormal increase of lupus anticoagulant only. Neither the serum folate and cobalamin levels nor methylenetetrahydrofolate reductase allele mutation contributes to this result. Accordingly, homocysteine interacts with lupus anticoagulant to promote cerebral atherosclerosis and ischemia. The role of vasculopathic or prothrombotic autoantibody generation in response to specific pathological change such as hyperhomocysteinemia warrants further investigation.

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.

Anti-beta2-Glycoprotein I Antibody and Hypertension in Cerebral Ischemia

Hypertension is known as a cause of endothelial cell damage and it activates humoral immunity. Therefore, it may modulate the anti-beta2-glycoprotein I antibody (aβGPI) to commit for thrombosis. To elucidate the relation between aβGPI and hypertension in cerebral ischemia, the blood aβGPI level was examined in healthy subjects, hypertensive subjects, and patients with cerebral ischemia with and without hypertension, respectively. The results showed that the blood aβGPI level increased in cerebral ischemia patients with hypertension rather than hypertensive subjects, and patients without hypertension rather than healthy individuals. However, the blood aβGPI level showed no difference between healthy individuals and hypertensive subjects, nor cerebral ischemia patients with and without hypertension. The serum globulin level did not change among them. Therefore, aβGPI displays a vital role for cerebral ischemia in both hypertensive and normotensive subjects. An activation of humoral immunity involving aβGPI warrants further investigation in cerebral ischemia.

Anti-prothrombin (aPT) and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies and the risk of thrombosis in the antiphospholipid syndrome. A systematic review

Antibodies to prothrombin are detected by directly coating prothrombin on irradiated ELISA plates (aPT) or by using the phosphatidylserine/prothrombin complex as antigen (aPS/PT). Although these antibodies have both been associated with antiphospholipid syndrome (APS) and a correlation between the two assays have been reported, it seems that aPT and aPS/PT belong to different populations of autoantibodies. It was our objective to systematically review the available evidence on aPT and aPS/PT antibodies and the risk of thrombosis in APS. Medline-reports published between 1988 and 2013 investigating aPT and aPS/PT as a risk factor for thrombosis were included. Whenever possible, antibody isotype(s) and site of thrombosis were analysed. This systematic review is based on available data from more than 7,000 patients and controls from 38 studies analysing aPT and 10 aPS/PT. Antibodies to prothrombin (both aPT and aPS/PT) increased the risk of thrombosis (odds ratio [OR] 2.3; 95% confidence interval [CI] 1.72-3.5). aPS/PT seemed to represent a stronger risk factor for thrombosis, both arterial and/or venous than aPT (OR 5.11; 95%CI 4.2-6.3 and OR 1.82; 95%CI 1.44-2.75, respectively). In conclusion, routine measurement of aPS/PT (but not aPT) might be useful in establishing the thrombotic risk of patients with previous thrombosis and/or systemic lupus erythematosus. Their inclusion as laboratory criteria for the APS should be indisputably further explored.

Delayed catastrophic antiphospholipid syndrome after massive cerebral infarction

INTRODUCTION

Catastrophic antiphospholipid syndrome (CAPS) is a life-threatening disorder urgent for aggressive treatment, and its characterized systemic thromboses and coagulopathy prompt for a rapid diagnosis.

CASE REPORT

A woman fell into unconsciousness two weeks after a stable course of massive cerebral ischemia was identified due to CAPS with Sjogren syndrome. Her thrombocyte count and coagulation times were was normal at initial. A high blood anti-beta(2)-glycoprotein I antibody level was found. Plasmapheresis rapidly reversed her consciousness and coagulation function.

CONCLUSIONS

A normal hemostatic parameters should not exclude CAPS. A favorable prognosis depends on the rapidity of appropriate treatment.

An increase of anticardiolipin antibody in association with stroke and chronic chemical exposure

A chemical worker working with urea-formaldehyde resin hazard for 20 years suffered cerebral ischemia in association with an increase of blood beta2-glycoprotein I-dependent anticardiolipin antibody (aCL)-IgG and IgM isotype, and a prolongation of activated partial thromboplastin time (aPTT). Major histocompatibility complex antigen showed DR4 positivity. On follow-up for over 6 years, aCL-IgG and aPTT decreased to reference range but aCL-IgM was still abnormally high despite a cessation of exposure. This patient highlights the induction of antibody-mediated thrombosis in chronic chemical exposure, especially in an individual with subclinical autoimmune disorder. The role of environment for coagulopathic vascular thrombosis is warranted for investigation.

Thrombophilia in ischemic stroke subtypes: implications for treatment

The current understanding of thrombogenesis is modeled on Virchow's triad: stasis, hypercoagulability, and vessel wall injury. There is a dynamic (always changing) nonlinear interaction between the vascular wall, blood components, and flow, which at times defined "pathologic" leads to thrombosis or hemorrhage, at other times called "healthy" to normal hemostasis. The triad named after Virchow was not designated as such in Virchow's work. Instead, Virchow showed that thrombosis itself leads to endothelial damage, hypercoagulability, and stasis. Thus, cause and effect regarding the elements of Virchow's triad and thrombosis become indistinguishable if linearity is considered mandatory. Considering a nonlinear relation solves this problem. In the real patient, each element is present to a degree. At every moment in time, the direction of coagulation (toward hemostasis, thrombosis, or hemorrhage) and the dynamic of interaction of the elements of the triad change. The complexity and nonlinearity of the thrombotic context is evident. These facts suggest a new venue for diagnostic classification of stroke (ischemic and hemorrhagic) by causation and have implications for its prevention and treatment. Clinical and laboratory evidence can be gathered for the elements of Virchow's triad as well as for fibrinolysis and thrombosis. Mathematical methods other than probability-based statistics can represent the measured presence of these elements to a degree and their nonlinear relationship. These include, but may not be limited to, Riemannian geometry, fuzzy logic, cellular automata, and infinitesimals, all proscribed by evidence-based medicine. However, by using these methods, diagnosis and treatment measures for stroke can be built on a causal rather than risk methodology, individualizing medical decisions to the patient. All current clinical guidelines are based on linear methods of probability-based statistics and group-based data. The therapeutic choice of antithrombotic therapy in the individual patient for whom measured elements of thrombogenesis are available rests on the knowledge and expertise of the treating physician.

Concurrent cerebral and axillary artery occlusion: a possible source of cerebral embolization from peripheral artery thrombosis

Intracranial embolization usually arises from heart, precerebral artery or aorta but rarely the peripheral artery as retrograde upstream of embolus should be overcome. We encountered a woman who experienced a transient right acronumbness followed by a sudden onset of left hemiplegia and conscious change concurrently. Cranial computerized tomography revealed a hemorrhagic infarct at right lentiform nucleus. Angiography disclosed right axillary artery occlusion at the proximal portion without collateral circulation. Cardioaortic survey and coagulation profile were normal. Thrombectomy was done and radial flow was corrected rapidly. Post-thrombectomic heparinization did not bring complication. Therefore, a distant embolism from peripheral artery at the upper limb should be alerted for cerebral ischemia. A lower density of embolus and no-flow condition in her occluded axillary artery may facilitate the upstreamed embolization. Heparinization, under closed monitor, is not contraindicated for preventing restenosis after thrombectomy in case of hemorrhagic transformation in brain.

Chondrosarcoma, lupus anticoagulant and cerebral ischaemia

Chondrosarcoma is a malignant disease of cartilage. Systemic embolisation usually arises from cancerous invasion of pulmonary vessels or the left atrium but cerebral embolisation or ischaemia is rarely recognised. We report a man with left leg amputation for tibial myxoid chondrosarcoma who suffered multiple cerebral embolisms one year later. Cerebral angiography and aortogram did not reveal luminal stenosis and a cardiac survey was normal. Lupus anticoagulant (LAC) and a prolonged activated partial thromboplastin time were detected. A molecular mimicry between prothrombin and paracrine hormones may have accounted for his LAC. A procoagulant autoantibody reacting against metastatic cancer cells may contribute to cancerous thrombosis, such as in chondrosarcoma.

An increase of blood anti-beta2-glycoprotein I antibody in Japanese encephalitis associated with cerebral ischemia

The role of humoral autoimmunity in virus-induced vascular thrombosis is still not clear. We encountered a patient who experienced cerebral ischemia in his early course of Japanese encephalitis. At the beginning, an increase of blood immunoglobulin G isotype of anti-beta2-glycoprotein I antibody, a prolonged activated partial thromboplastin time and thrombocytopenia resembling antiphospholipid antibody syndrome were found, and these abnormalities disappeared when the patient recovered later. A molecular mimicry between the T(2688)LRVLE in Japanese encephalitis virus and hexapeptide-TLRVYK may contribute for the patient's anti-beta2-glycoprotein I antibody generation. Therefore, an increase of procoagulative antibody, such as anti-beta2-glycoprotein I antibody, may display a crucial role for cerebral thrombosis associated with infectious pathogens such as Japanese encephalitis virus. The interaction between autoimmunity induction by infectious agents and procoagulation in the occurrence of vascular thrombosis may be more important than has been understood in previous studies.

The prevalence of protein C, protein S, and antithrombin III deficiency in non-APS/SLE Chinese adults with noncardiac cerebral ischemia

Protein C (PC), protein S (PS), and antithrombin III (AT-III) are vital thrombin antagonists in circulation. However, the prevalence of these natural inhibitors for cerebral ischemia is barely mentioned in the Chinese population. The prevalence of PC, PS, and AT-III deficiency in Chinese adults with cerebral ischemia is reported. The study subjects were free of antiphospholipid antibody syndrome or systemic lupus erythematosus. Cardiac, liver, and renal function were normal. An overall rate of thrombophilia was 27%. PS deficiency was the most common disorder, followed by PC with PS and PC deficiency. There was only one patient with AT-III deficiency. No gender was specific for thrombophilia. However, PS deficiency was predilected in young adults. A positive correlation between PC and AT-III was achieved in patients with a normal PC activity but not PC deficiency. There was no correlation between AT-III or PS. The odds ratios of PC and PS were 5.29 and 2.86, respectively. Accordingly, an inability for thrombin antagonization by the PC/PS axis may relate to the occurrence of cerebral ischemia in the Chinese population. AT-III seems to display a minor role only.