Neurologic manifestations of the antiphospholipid syndrome

Prevalence of Anti-Nuclear Antibodies and Anti-Phospholipid Antibodies in an Egyptian Cohort with Schizophrenia: A Case-Control Study

BACKGROUND

Psychiatric disorders, including schizophrenia could herald other manifestation(s) of systemic lupus erythematosus (SLE) potentially hindering timely and optimal management. Moreover, schizophrenia is among the described 'extra-criteria' manifestations of anti-phospholipid syndrome (APS). Hence, screening schizophrenia patients for SLE and APS may pose diagnostic and therapeutic implications.

OBJECTIVES

Examine schizophrenia patients with no overt connective tissue disease(s) manifestation(s) for clinical and/or serologic evidence of SLE and/or APS.

METHODS

The study included 92 schizophrenia patients [61 (66.3%) males] and 100 age- and gender-matched healthy controls. Both groups were tested for anti-nuclear antibodies (ANAs), anti-double stranded deoxyribonucleic acid (anti-dsDNA) antibodies, complement 3 (C3) and C4, and criteria anti-phospholipid antibodies (aPL) [anticardiolipin Immunoglobulin (Ig) G and IgM, anti-beta-2-glycoprotein I IgG and IgM, and lupus anticoagulant (LAC)].

RESULTS

The patients' mean age and disease duration were 28.8 ± 8.1 and 5.7 ± 2.2 years, respectively. The prevalence of ANA positivity, height of titre, and pattern was comparable between patients and controls (p = 0.9, p = 0.8 and p = 0.1, respectively). Anti-dsDNA antibodies and hypocomplementemia were absent in both groups. A significantly higher frequency of positive LAC was observed among patients compared with controls (7.6 % vs. 1 %, p = 0.02), whereas other aPL were comparable between both groups. None of the patients or controls demonstrated clinically meaningful (medium or high) aPL titres.

CONCLUSION

In our study, schizophrenia was solely associated with LAC. Thus, in the absence of findings suggestive of SLE or APS, routine screening for both diseases is questionable.

Antiphospholipid Syndrome and the Neurologist: From Pathogenesis to Therapy

Antiphospholipid syndrome (APS) is an autoimmune antibody-mediated condition characterized by thrombotic events and/or pregnancy morbidity in association with persistent positivity to antiphospholipid antibodies (aPL). The nervous system is frequently affected, as intracranial vessels are the most frequent site of arterial pathology. Over the course of years, many other neurological conditions not included in the diagnostic criteria, have been associated with APS. The pathogenic mechanisms behind the syndrome are complex and not fully elucidated. aPL enhance thrombosis, interfering with different pathways. Nevertheless, ischemic injury is not always sufficient to explain clinical features of the syndrome and immune-mediated damage has been advocated. This may be particularly relevant in the context of neurological complications. The reason why only a subgroup of patients develop non-criteria nervous system disorders and what determines the clinical phenotype are questions that remain open. The double nature, thrombotic and immunologic, of APS is also reflected by therapeutic strategies. In this review we summarize known neurological manifestations of APS, revisiting pathogenesis and current treatment options.

Neurologic manifestations of antiphospholipid syndrome

Neurological involvement in antiphospholipid antibody syndrome (APS) is common, and its occurrence increases morbidity and mortality. Patients may present variable neurological involvement, such as cerebrovascular disease, cognitive dysfunction, headache, seizures, movement disorders, multiple sclerosis-like syndrome, transverse myelitis and ocular symptoms. Most neurological manifestations are associated with thrombosis of the microcirculation or of large vessels; nonetheless, there is compelling evidence suggesting that, in some cases, symptoms are secondary to an immune-mediated pathogenesis, with direct binding of aPL on neurons and glia. Herein we describe clinical characteristics and management of neurological APS manifestations.

Subtypes of Antiphospholipid Antibodies in Neurologic Disorders: An Observational Study

BACKGROUND AND OBJECTIVES

Concomitant neurologic manifestations and positive antiphospholipid antibodies (APAs) have been investigated in different manners. The present study aimed to investigate the association between neurologic manifestations and APAs.

MATERIALS AND METHODS

This cross-sectional descriptive study was conducted on 100 consecutive patients with selected neurological manifestations and at least one positive APAs within the age range of 20-50 years, referred to the Rheumatic Diseases Research Center from the Northeast Central Neurology Department of Iran during August 2012 to March 2014.

RESULTS

According to the results, 89% of the participants were persistently positive for APAs, including lupus anticoagulant, IgG anticardiolipin (aCL), IgM aCL, IgG β-2 glycoprotein 1 (β2- GP1), and IgM β2-GP1, observed in 16%, 41%, 42%, 17%, and 15% of the patients, respectively. Furthermore, 10% of the patients had concomitant lupus manifestations, and 37% of them showed anti-DNA. The IgG and IgM aCL were the most prevalent antibodies. Cerebral vascular accident (33%), retinal artery/vein occlusion (21%), and seizure (20%) were the most frequent presentations among the patients. In addition, the patients with multiple sclerosis (composing 3% of the subjects) were 100% positive for IgG and IgM aCL, as well as lupus anticoagulant. In addition, IgM anti-β2- GP1 was 100% positive in optic neuritis patients (composing 5% of the subjects) and was significantly associated with this neurologic disorder. IgM anti-β2-GP1 was also prevalent in the cases with Guillain-Barré syndrome. The most prevalent persistently positive antibody in the patients with cerebrovascular accident was IgM aCL.

CONCLUSION

The findings of this study revealed some associations between the subtypes of APAs and incidence of neurologic disorders. However, the exact correlation between those symptoms and APAs needs further investigations.

Bilateral Choroidal Occlusion in Antiphospholipid Syndrome Associated with Systemic Lupus Erythematosus

This article reports a rare case of bilateral choroidal occlusion that occurred in a 24-year-old woman with antiphospholipid syndrome (APS) associated with systemic lupus erythematosus (SLE). This young lady concurred with aorta ventralis thrombosis and bilateral iliac artery occlusion when presented, and experienced a rapid deterioration of vision. She also has a history of recurrent miscarriage. Corticosteroid, immunosuppression and anticoagulation therapy were administered. Patients with APS associated with SLE are at risk for thrombotic phenomena, which may affect the ocular vessels of all sizes, including choroidal vessel. Our case alerts ophthalmologists and rheumatologists that bilateral choroidal occlusion may indeed be developed in patients with APS associated with SLE, and is a potential cause of visual morbidity.

Epilepsy as part of systemic lupus erythematosus and systemic antiphospholipid syndrome (Hughes syndrome)

The antiphospholipid syndrome (APS) is defined by the presence of antiphospholipid antibodies (aPL), demonstrated by ELISAs for antibodies against phospholipids and associated phospholipid-binding cofactor proteins and/or a circulating lupus anticoagulant (LA) together with diverse systemic clinical manifestations such as thrombosis, and recurrent spontaneous abortions. According to the criteria set out in Sydney1 the only neurological manifestations that can be suitable as APS classification criteria are ischemic events (stroke and transient ischemic attacks). However, other neurological manifestations, including seizures in particular, have been repeatedly reported in APS patients.2

The present review will summarize recent research on the association of aPL, as well as other autoantibodies, with seizure disorders, with or without concomitant SLE.

Altered receptor binding densities in experimental antiphospholipid syndrome despite only moderately enhanced autoantibody levels and absence of behavioral features

Experimental antiphospholipid syndrome (eAPS) in Balb/c mice causes neuropsychiatric abnormalities including hyperactivity, increased explorative behavior and cognitive deficits. Recently, we have demonstrated that these behavioral changes were linked to an upregulation of serotonergic 5-HT1A receptor binding densities in cortical and hippocampal regions while excitatory and inhibitory neurotransmitter receptors remain largely unchanged. To examine whether the observed behavioral features depend on a critical antibody concentration, mice with only moderately enhanced antiphospholipid antibodies (aPL), about 50-80% of high levels, were analyzed and compared to controls. The staircase test was used to test animals for hyperactivity and explorative behavior. The brains were analyzed for tissue integrity and inflammation. Ligand binding densities of NMDA, AMPA, GABAA, 5-HT1A, M1 and M2 muscarinic acetylcholine receptors, respectively, were analyzed by in vitro receptor autoradiography and compared to brains of mice from our previous study with high levels of aPL. Mice with only moderately enhanced aPL did not develop significant behavioral changes. Brain parenchyma remained intact and neither inflammation nor glial activation was detectable. However, there was a significant decrease of NMDA receptor binding densities in the motor cortex as well as an increase in M1 binding densities in cortical and hippocampal regions, whereas the other receptors analyzed were not altered. Lack of neuropsychiatric symptoms may be due to modulations of receptors resulting in normal behavior. In conclusion, our results support the hypothesis that high levels of aPL are required for the manifestation of neuropsychiatric involvement while at lower antibody levels compensatory mechanisms may preserve normal behavior.

Ferritin in the antiphospholipid syndrome and its catastrophic variant (cAPS)

BACKGROUND

Ferritin is an iron storage protein considered also as an acute phase reactant with high levels in various inflammatory conditions. Recently, a plausible role for ferritin in the pathogenesis of immune-mediated and especially autoimmune diseases has been suggested. However, the link between ferritin and the antiphospholipid syndrome (APS) has been rarely explored. Therefore, in the current study we evaluated ferritin levels and their correlation to clinical and serological manifestations in patients with APS. We further analyzed ferritin levels among patients with the catastrophic variant of APS (cAPS).

METHODS

Ferritin levels were determined in serum samples of 176 APS patients and 98 matched healthy controls according to age and sex (LIAISON, DiaSorin, Italy). APS samples were further analyzed for antiphospholipid (anti-cardiolipin, anti- beta-2-glycoprotein, lupus anticoagulant) and anti-infectious antibodies (CMV, EBV, rubella, toxoplasma, HBV) (LIAISON, DiaSorin, Italy). Clinical, serological and demographic manifestations were recorded. An additional analysis of ferritin levels among 14 patients with cAPS was performed.

RESULTS

Hyperferritinemia was present in 9% vs. 0% of APS patients and controls, respectively (p < 0.001). Among patients with APS, ferritin levels correlated with venous thrombosis, cardiac, neurological, and hematological manifestations and the presence of anti-CMV-IgM antibodies. Hyperferritinemia was present in 71% of cAPS patients, and ferritin levels among this subgroup were significantly higher compared with APS-non-cAPS patients (816 ± 847 ng/ml vs. 120 ± 230 ng/ml, p < 0.001).

CONCLUSIONS

Herein, we found that hyperferritinemia correlates with the presence of APS, its clinical manifestations and specifically with the catastrophic variant of this disease. Hyperferritinemia was also linked with anti-CMV antibodies among patients with APS. These associations allude to a pathogenic role of ferritin in the pathogenesis of APS, and the plausible role of ferritin as a marker of ensuing cAPS, although further studies are needed to elucidate these associations.

Neurological impairment in experimental antiphospholipid syndrome is associated with increased ligand binding to hippocampal and cortical serotonergic 5-HT1A receptors

The antiphospholipid syndrome (APS) is an autoimmune disease where the presence of high titers of circulating autoantibodies causes thrombosis with consecutive infarcts. In experimental APS (eAPS), a mouse model of APS, behavioral abnormalities develop in the absence of vessel occlusion or infarcts. Using brain hemispheres of control and eAPS mice with documented neurological and cognitive deficits, we checked for lymphocytic infiltration, activation of glia and macrophages, as well as alterations of ligand binding densities of various neurotransmitter receptors to unravel the molecular basis of this abnormal behavior. Lymphocytic infiltrates were immunohistochemically characterized using antibodies against CD3, CD4, CD8 and forkhead box P3 (Foxp3), respectively. GFAP, Iba1 and CD68-immunohistochemistry was performed, to check for activation of astrocytes, microglia and macrophages. Ligand binding densities of NMDA, AMPA, GABAA and 5-HT1A receptors were analyzed by in vitro receptor autoradiography. No significant inflammatory reaction occurred in eAPS mice. There was neither activation of astrocytes or microglia nor accumulation of macrophages. Binding values of excitatory and inhibitory neurotransmitter receptors were largely unchanged. However, ligand binding densities of the modulatory serotonergic 5-HT1A receptors in the hippocampus and in the primary somatosensory cortex of eAPS mice were significantly upregulated which is suggested to induce the behavioral abnormalities observed.

Chorea in primary antiphospholipid syndrome is associated with rheumatic fever

The aim of the study is to evaluate the frequency of chorea in a cohort of primary antiphospholipid syndrome (PAPS) patients and their possible clinical and laboratory associations. The records of 88 PAPS patients, fulfilling Sapporo criteria, followed up at the rheumatology outpatient clinic, were analyzed in order to determine the frequency of chorea. Risk factors for chorea, clinical manifestations, associated comorbidities, serologic features and treatment strategies were analyzed. Eighty-eight PAPS patients were evaluated. Mean age was 40.6 ± 11.1 years, and 91% of them were Caucasian and 91% women. Four (4.5%) patients with chorea were identified: 2 of them (50%) had only one chorea episode and 2 (50%) had recurrent chorea. All patients had chorea onset before PAPS diagnosis. Mean age, gender and ethnical distribution were comparable in groups with or without seizures (P > 0.05). Interestingly, the comparison of the 4 PAPS patients with chorea with those without this abnormality (n = 84) demonstrated a lower BMI [21.1 (18-24.2) vs. 27.5 (17.5-40.9) kg/m(2), P = 0.049] and frequency of venous events (0 vs. 63.1%, P = 0.023) in the first group. A higher frequency of rheumatic fever (75% vs. 0, P < 0.001) and thrombocytopenia (75 vs. 21.4%, P = 0.041) was observed in PAPS individuals with chorea. Both groups were alike regarding the other clinical APS manifestations, disease duration, risk factors for cerebrovascular diseases, use of drugs and antiphospholipid antibodies (P > 0.05). This study demonstrated that 4.5% of PAPS patients had chorea, predominately before PAPS diagnosis, and this neurological abnormality was associated with rheumatic fever and thrombocytopenia. These data reinforce the need for RF diagnosis in those PAPS patients with chorea.

Neurological manifestations of antiphospholipid syndrome

BACKGROUND

Neurologic disorders are among the most common and important clinical manifestations associated with the antiphospholipid syndrome (APS). It is characterized by diverse neurological manifestations. These include stroke, transient ischaemic attack, Sneddon's syndrome, convulsions/epilepsy, dementia, cognitive deficits, headaches/migraine, chorea, multiple sclerosis-like, transverse myelitis, ocular symptoms and Guillain-Barré syndrome.

MATERIAL AND METHODS

We review the latest data about neurologic disorders and APS.

RESULTS

In patients under 45 years of age, 20% of strokes are potentially associated with APS. Our study group recently reported a correlation between primary APS and peripheral neuropathy. Only one study investigated the occurrence of peripheral neuropathy in patients diagnosed with PAPS through electrophysiological study and showed alterations in 35% of patients. The mechanism of nervous system involvement in APS is considered to be primarily thrombotic. However, other mechanisms have been described, such as antiphospholipid antibodies that bind to the neural tissue, deregulating their functions and having an immediate pathogenic effect.

CONCLUSIONS

This review summarizes the latest data regarding the clinical aspects, radiological and therapeutic of major neurologic manifestations associated with antiphospholipid antibodies.

Antibodies directed against ribosomal P proteins cross-react with phospholipids

Anti-ribosomal P protein (anti-P) antibodies are marker antibodies in systemic lupus erythematosus (SLE). Their association with psychiatric or neurological manifestations has been proposed, but remains controversial. Anti-phospholipid antibodies are the hallmark of a syndrome that may comprise a number of neurological manifestations. Thus, anti-P and anti-phospholipid antibodies have both been associated with central nervous system involvement and their co-existence in the same sera was reported. We verified the ability of purified anti-P antibodies to bind different phospholipids and phospholipid-binding proteins in solid-phase assays. Anti-P antibodies from five of eight patients bound cardiolipin (CL) when saturated with fetal calf serum (FCS); in three cases anti-CL antibodies were also detected in the flow-through. No anti-P eluate, nor any corresponding flow-through, bound beta(2)-glycoprotein I alone or prothrombin. Moreover, no anti-P eluate bound CL when the plates were blocked with bovine serum albumin in the absence of FCS. Anti-P antibodies with anti-CL activity bound both ssDNA and dsDNA and also nucleosomes in three patients. Our data indicate a great heterogeneity of anti-P antibodies that appear to be overlapped partially with the other autoantibody populations detected frequently in SLE.

Nodular regenerative hyperplasia (NRH) of the liver--a manifestation of 'organ-specific antiphospholipid syndrome'?

Nodular regenerative hyperplasia (NRH) of the liver is a local hyperplastic response of hepatocytes, probably due to vascular abnormalities. Since it was shown in a few case reports that NRH may be associated with antiphospholipid antibodies (APA) we wanted to analyze the relevance of APA in patients with this disease. Sera from 13 patients with histologically defined NRH were tested for APA by an in-house ELISA using as antigens cardiolipin (CL), beta2-glycoprotein I (beta2-gp I), phosphatidylserine (PS), and thromboplastin (TP), a mixture of different phospholipids and phospholipid-binding proteins. As controls, sera from patients with serologically and histologically defined autoimmune liver diseases (primary biliary cirrhosis n = 14; autoimmune hepatitis n = 14) without histological evidence for NRH as well as from 14 healthy blood donors were analyzed. 77% of the NRH patients had APA. In 46% they were directed against CL. In contrast, only 14% of the patients with autoimmune liver diseases and 14% of the healthy controls had anti-CL antibodies (p < 0,05). Antibodies to beta2-gp I and TP did not discriminate between NRH and autoimmune liver diseases. Anti-PS antibodies were not observed. These data indicate that determination of anti-CL antibodies in NRH may help to identify a subgroup of patients in whom an 'organ-specific antiphosholipid syndrome' of the liver may be involved in the pathogenesis.