The anti-phospholipid (Hughes) syndrome: a crossroads of autoimmunity and atherosclerosis

Kidney disease in primary anti-phospholipid antibody syndrome

APS is an autoimmune disease defined by the presence of arterial or venous thrombotic events and/or pregnancy morbidity in patients who test positive for aPL. APS can be isolated (primary APS) or associated with other autoimmune diseases. The kidney is a major target organ in APS, and renal thrombosis can occur at any level within the vasculature of the kidney (renal arteries, intrarenal vasculature and renal veins). Histological findings vary widely, including ischaemic glomeruli and thrombotic lesions without glomerular or arterial immune deposits on immunofluorescence. Renal involvement in patients with definite APS is treated with long-term anticoagulants as warfarin, but new treatments are being tried. The aim of this article is to review the links between primary APS and kidney disease.

Antiphospholipid (Hughes) syndrome and atheroma

The antiphospholipid syndrome (APS) is a prothrombotic disorder characterised by recurrent thrombotic events and pregnancy morbidity in the context of autoantibodies against phospholipid binding proteins. There is increasing evidence that these autoantibodies are associated with accelerated atherosclerosis. The presence of stenotic lesions radiologically and abnormalities of the ankle-brachial index, flow-mediated dilatation and carotid abnormalities supports this view and this clinical evidence is reviewed.

Immune Response to Dietary Proteins, Gliadin and Cerebellar Peptides in Children with Autism

The mechanisms behind autoimmune reaction to nervous system antigens in autism are not understood. We assessed the reactivity of sera from 50 autism patients and 50 healthy controls to specific peptides from gliadin and the cerebellum. A significant percentage of autism patients showed elevations in antibodies against gliadin and cerebellar peptides simultaneously. For examining cross-reaction between dietary proteins and cerebellar antigens, antibodies were prepared in rabbits, and binding of rabbit anti-gliadin, anti-cerebellar peptides, anti-MBP, anti-milk, anti-egg, anti-soy and anti-corn to either gliadin- or cerebellar-antigen-coated wells was measured. In comparison to anti-gliadin peptide binding to gliadin peptide at 100%, the reaction of anti-cerebellar peptide to gliadin peptide was 22%, whereas the binding of anti-myelin basic protein (MBP), anti-milk, anti-egg and anti-soy to gliadin was less than 10%. Further examination of rabbit anti-gliadin (EQVPLVQQ) and anti-cerebellar (EDVPLLED) 8 amino acid (AA) peptides with human serum albumin (HSA) and an unrelated peptide showed no binding, but the reaction of these antibodies with both the cerebellar and gliadin peptides was greater than 60%. This cross-reaction was further confirmed by DOT-immunoblot and inhibition studies. We conclude that a subgroup of patients with autism produce antibodies against Purkinje cells and gliadin peptides, which may be responsible for some of the neurological symptoms in autism.

The prevalence of abnormal pulse wave velocity, pulse contour analysis and ankle-brachial index in patients with livedo reticularis: a controlled study

OBJECTIVE

To evaluate the prevalence of abnormal pulse wave velocity (PWV), pulse contour analysis (PCA) and abnormal ankle-brachial pressure index (ABPI) in patients with livedo reticularis (livedo) and without livedo.

METHODS

We recruited 74 patients, of whom 41 had livedo: 16 APS, 9 APS with SLE and 16 with livedo (negative for aPL or lupus). The other group of 33 patients without livedo consisted of 10 APS, 8 APS with SLE and 15 with SLE only. Livedo was diagnosed and confirmed by a dermatologist. PWV was assessed in fasting patients by the Micro Medical PulseTrace analyser using a 4 MHz continuous-wave directional Doppler probe and digital PCA was analysed by Micro Medical PulseTrace by the same operator. Chi-square with Yates's correction was used for comparing results.

RESULTS

The median age of the livedo patients was 46 (29-71) years and of the non-livedo patients was 45 (25-68) years. Abnormal values of PWV in 10/41 (24.40%), ABPI in 4/41 (9.8%) and PCA in 10/41 (24.40%) patients were observed in the livedo group and in the non-livedo group abnormal values of PWV in 1/33 (P ≤ 0.025), ABPI in 0/33 (P = NS) and PCA in 5/33 (P = NS) were observed.

CONCLUSION

Patients with livedo reticularis are more likely to have abnormal PWV, indicating arterial stiffness.

The comparison of acute myocardial infarction serum anticardiolipin antibody with healthy subjects, in Gorgan (Northern Iran)

Arthrosclerosis considered one of the most important causes of morbidity and mortality in industrial and developing countries. The rate of myocardial infarction in some countries is about 2 million annually with 1/4 of them is leading to death. This study was a case-control research, which was carried out as cross-sectional project in two groups, healthy and case subjects. The mean age and standard deviation of patients and control groups were nearly equal (55 +/- 10). The ELISA technique was applied to measure the serum antibody level. The sample populations in each group were exactly the same (120 person in each group). The gender distribution in case and control group was 44 female, 76 male and 45 female and 75 male, respectively. The Mean +/- SD of IgM in case group and control groups were 3.10 +/- 2.54 and 1.54 +/- 1.00, respectively. The Mean +/- SD for IgG in case and control groups were 5.90 +/- 3.84 and 3.08 +/- 1.95, respectively. The differences, between the mean of IgM and IgG in two groups of cases and control statistically were significant (p = 0.0001). In case group the Mean +/- SD for IgM for men and woman were 2.98 +/- 1.97 and 3.17 +/- 2.83, respectively, which this differences statistically, were not significant. In case group the Mean +/- SD for IgG were 5.14 +/- 3.45 and 6.35. The above findings indicated that the average of both IgG and IgM are higher among men compared to women. Due to high prevalence of acute coronary syndrome in Iran, the determination of anticardiolipin antibody (IgG) are applied for suspected acute coronary syndrome patients and further prevention measure should be taken for patient with higher serum anticardiolipin antibody.

Hughes syndrome (the antiphospholipid syndrome): a disease of our time

A pro-thrombotic condition was described in 1983 which was characterised by the presence of circulating antiphospholipid antibodies, as well as peripheral thrombosis (e.g. DVT), a tendency to internal organ involvement, repeated miscarriage, and, occasionally, thrombocytopenia (aPL) (Hughes, Br Med J 287:1088-1089, 1983). Previously, there had been a number of observations, mainly in patients with lupus having "false positive" tests for syphilis, miscarriage and circulating lupus anticoagulants. The description in 1983 had three notable features (a) a detailed comprehensive clinical picture of the syndrome; (b) this description differed from other coagulopathies in showing a propensity for arterial thrombosis (e.g. stroke and heart attack); and (c) this was a syndrome quite independent from lupus. There are indications that the primary antiphospholipid syndrome will turn out to be more common than lupus, though this could still be a reflection of referral practice.

Ankle-brachial pressure index: a simple tool for assessing cardiovascular risk in patients with systemic vasculitis

OBJECTIVE

Cardiovascular disease may be increased in patients with systemic vasculitides (SV). The Ankle-Brachial Pressure Index (ABPI) is a non-invasive tool for the assessment of cardiovascular risk (CV). Our aim was to determine the prevalence of an abnormal ABPI in patients with SV and healthy controls and to correlate with clinical and serological parameters.

METHODS

We studied 54 consecutive vasculitis patients (20 males) attending the vasculitis clinic and 49 healthy subjects. Patients were classified according to the ACR 1990 criteria and the Chapel Hill Consensus definitions. There were 18 patients with Wegener's granulomatosis, eight with Behcet's disease, seven with Churg-Strauss Syndrome, three with Henoch-Schonlein purpura, three with polyarteritis nodosa, three with Takayasu's disease, three with p-ANCA associated vasculitis, three with urticarial vasculitis, two with cutaneous leucocytoclastic angiitis, one with microscopic polyangiitis, one with primary central nervous system angiitis, one giant cell arteritis and one with cutaneous vasculitis secondary to Sjogren's syndrome. Traditional risk factors as well as glucose, lipid profile, CRP, hsCRP, ANCA and aPL were assessed. ABPI was measured according to a consensus statement on the methodology.

RESULTS

The ABPI was abnormal in 11/54 (20.4%) of SV patients and 2/49 (4%) of the control group (chi(2) with Yates correction = 4.8, P <or= 0.03). CV events were more prevalent in the SV patients with abnormal ABPI (45.5% vs 11.6%, P <or= 0.01).

CONCLUSIONS

There is an increased prevalence of an abnormal ABPI in patients with systemic vasculitides implying an increased risk of cardiovascular disease. This simple tool may be clinically useful in identifying systemic vasculitis patients at risk of accelerated atherosclerosis.

Perceived work-related stress and early atherosclerotic changes in healthy employees

OBJECTIVE

This study was conducted to investigate the relationship between perceived work-related stress and preclinical atherosclerosis.

METHODS

A total of 100 managers and 50 office workers aged 35-65 participated in a questionnaire study. Individual, family and work-related stress risk factors and coping were evaluated in all the studied individuals. Serum levels of biochemical (total cholesterol, LDL, HDL, TG, glucose) and serological risk factors of atherosclerosis (anticardiolipin, anti-beta(2) GPI, anti-oxLDL, anti-HSP and anti-hsCRP antibodies) were evaluated. A computer analysis of B-mode ultrasound images was used to assess carotid artery intima-media thickness (IMT) and atherosclerotic plaque in carotid arteries. Statistical analysis was conducted with SPSS v. 11.5.

RESULTS

The studied individuals showed average ranges of both the global stress level and of coping results. In 71% no changes were found in the ultrasound image and in 29% of individuals (43) the presence of plaque was shown. The mean value of the IMT measure was 0.0618 +/- 0.013 mm. IMT and plaque correlated negatively with the level of global work-related stress (r = -0.26; P < 0.01; and r = -0.28; P < 0.01; respectively). No correlation was found either between work-related stress and coping, or between coping and IMT (P > 0.05), or between work-related stress and healthy lifestyle (no smoking, no excessive use of alcohol, high physical activity), or between healthy lifestyle and IMT (P > 0.05). Positive correlation between IMT and LDL and smoking did not result from higher stress reaction in the studied individuals.

CONCLUSIONS

The explanation of the negative correlation between perceived work-related stress and preclinical atherosclerosis was not confirmed either by the subjects under high stress undertaking healthy protective activities or by their escaping into unhealthy behaviour. The most probable interpretation of the results is that in individuals with a low level of perceived work-related stress, somatization of stress takes place.

Early atheroma in primary and secondary antiphospholipid syndrome: an intrinsic finding

OBJECTIVES

The relationship between atherosclerosis and the antiphospholipid syndrome (APS) is unclear. This study compared intima-media thickness (IMT), arterial stiffness, and presence of plaques in APS patients and controls to evaluate the risk of atherosclerosis in this patient population. The study also explored the relationship between these parameters and cardiovascular risk factors.

METHODS

Carotid and femoral IMT and stiffness were measured in 58 APS patients and 58 controls. In addition, antiphospholipid antibodies and cardiovascular risk factors were investigated and other systemic lupus erythematosus (SLE)-related serologic parameters were measured. Details of the patients' previous medical history and information regarding disease treatment were analyzed.

RESULTS

A significant difference was found between IMT, arterial stiffness, and the presence of plaques in patients and controls (P<0.05). All of these parameters were independent of cardiovascular risk factors. No differences in these parameters were found between patients with primary APS and those with secondary APS, or between patients with thrombosis and those with obstetric manifestations. There was no correlation between SLE disease activity and atheroma. Patients with plaques had taken a lower total dose of corticosteroids and/or hydroxychloroquine.

CONCLUSIONS

Some markers of early atherosclerosis could be detected in both primary and secondary APS, irrespective of clinical manifestations. These data suggest that atherosclerosis might be an intrinsic finding in APS patients, independent of cardiovascular risk factors, and that immunosuppressive treatment may prevent atherosclerosis.

Systemic lupus erythematosus

Systemic lupus erythematosus is an autoimmune connective-tissue disorder with a wide range of clinical features, which predominantly affects women, especially from certain ethnic groups. Diagnosis is based on clinical assessment supported by investigations, including the finding of autoantibodies. Treatments range from antimalarial agents to corticosteroids and immunosuppressive agents. This Seminar draws attention to advances in the epidemiology, genetics, cardiovascular risks, lupus nephritis, CNS disease, the antiphospholipid syndrome, assessment of disease activity and damage, and pregnancy related and quality of life issues. New therapeutic approaches, such as biological agents and mycophenolate mofetil, will also be discussed.

Stenosis in antiphospholipid syndrome: a new finding with clinical implications

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by a variety of clinical manifestations. Recent studies suggest arterial stenosis is involved in APS. Furthermore, arterial stenosis may be a relevant and treatable cause for hypertension, renal, CNS and gastrointestinal manifestations of APS. Our objective was to overview the published data regarding arterial stenosis in APS--the clinical presentation, diagnosis, suggested therapies and the possible mechanisms. We searched PUBMED (1951-2006) reference lists for the role of arterial stenosis in APS. APS patients might present with arterial stenosis. Its recognition has important diagnostic and therapeutic implications. Articles suggest that anticoagulation treatment with INR above three may reverse the artery stenosis and achieve subsequent clinical improvement. Currently, there are no specific guidelines for the management of APS patients with arterial stenosis. The exact mechanism of arterial stenosis in APS patients remains unclear.

Antiphospholipid syndrome and the kidneys

OBJECTIVES

To study the relationship between antiphospholipid antibodies and kidney diseases.

METHODS

We reviewed the medical literature from 1968 to 2005 using MEDLINE and the keywords antiphospholipid syndrome, anticardiolipin antibodies, lupus anticoagulant, hypertension, renal artery stenosis, renal vascular thrombosis, thrombotic microangiopathy, and glomerulonephritis.

RESULTS

The renal manifestations of the antiphospholipid syndrome may result from thrombosis occurring at any location within the renal vasculature, that is, in the renal artery trunk or branches, intraparenchymal arteries and arterioles, glomerular capillaries, and the renal veins. The spectrum of these manifestations includes renal artery stenosis and/or malignant hypertension, renal infarction, renal vein thrombosis, thrombotic microangiopathy, increased allograft vascular thrombosis, and reduced survival of renal allografts. More recently nonthrombotic conditions like glomerulonephritis have also been reported.

CONCLUSION

The kidney appears to be a major target organ in both primary and secondary APS. Early detection of renal involvement may improve the prognosis of these patients.

Risk factors for atherosclerosis in healthy employees-a multidisciplinary approach

BACKGROUND

The aim of the study was to investigate the prevalence of early atherosclerosis in healthy workers and the relationship between classical, psychological, and immunological risk factors and atherosclerosis, as well as their predictive value.

METHODS

One hundred healthy managers and 50 office workers aged 35-65 were studied. In all subjects, individual, family, and occupational stress/coping risk factors were evaluated, including plasma levels of biochemical (total cholesterol, LDL, HDL, TG, glucose) and inflammatory-immunological (aCL, anti-beta(2) GPI, oxLDL, HSP, HSCRP) parameters. Carotid artery intima-media thickness (IMT) and atherosclerotic plaques in carotid arteries were assessed with computer analysis of B-mode ultrasound images.

RESULTS

In 107 persons (71%) no changes were found in ultrasound images and in 43 individuals (29%) the presence of plaque was shown. The mean IMT value was 0.0618+/-0.013 mm. Cross-domain analysis showed that core predictors for IMT were age, LDL level, smoking, and occupation (being a manager) (beta=0.33, 0.30, 0.23, and 0.20, respectively); the core predictors for plaque were age, total cholesterol level, and an occupational stressor home-work balance (Wald=7, 6.7, and 5.6, respectively). Immunological factors were not independent predictors.

CONCLUSIONS

In atherosclerosis, not only traditional risk factors (age, lipid disorders, and lifestyle) but also occupational stress factors may play a role. Immunological factors do not seem to play a role in the development of atherosclerosis in a population of healthy workers. The interplay between occupational stress and atherosclerotic changes requires further investigation.

The Role of Endothelial Cell Reactive Antibodies in Peripheral Arterial Disease

OBJECTIVES

It is hypothesised that endothelial cell reactive antibodies (ECRA) play a role in the progression of PAD through activation of endothelial cells and the release of inflammatory cytokines. We aimed to test this hypothesis by assessing levels of ECRA, E-selectin and IL-6 in patients with PAD of varying severity in a case controlled study. DESIGN, MATERIALS, METHODS: Patients were assessed clinically and with ankle-brachial pressure indices. Patients with critical ischaemia (CI, n=30), stable claudicants (SC, n=30), and age-matched controls (AMC, n=20) were studied. Antibody, E-selectin and IL-6 levels were measured using ELISA.

RESULTS

ECRA levels were significantly raised in the CI group over AMC. IL-6 levels were significantly elevated in both SC and CI over the control group and in CI over SC. There were no significant differences in E-selectin levels between the AMC, SC and CI.

CONCLUSION

Our findings support the hypothesis that autoantibodies play a role in promoting PAD by elevating IL-6. The absence of an elevation in E-selectin in this study may be due to its short half-life, and casts doubt on its value as a marker of inflammation in atherosclerosis.

Defects in regulation of local immune responses resulting in atherosclerosis

Atherosclerosis is nowadays generally accepted as an inflammatory disease but the mechanism of its origin and development have not yet been fully clarified. The present review focuses on the role of the local immune system as one of the key players in the pathogenesis of the complex process. Its part represented by vascular-associated lymphoid tissue (VALT) within the arterial wall participates directly in the vascular wall's homeostatis. Its inordinate activation during ontogenic development of an individual, this formerly defensive and physiologic mechanism transform into a pathological process resulting in an impairing inflammation. Hsp60, CRP and oxidized or otherwise modified LDL are serious candidates for triggering these pathological changes. The principal role is played by anti-Hsp60 antibodies and by shear stress originating on the surface of endothelium due to blood flow. The experimental and clinical data supporting this immunological hypothesis of atherosclerosis are discussed.

The role of endothelial cell reactive antibodies in peripheral vascular disease

The mechanism by which a small but significant proportion of patients with peripheral vascular disease (PVD) rapidly progress to critical ischaemia is unclear. Both experimental and clinical data suggest a role for autoantibodies in the pathogenesis of atherosclerotic disease, particularly in the accelerated atherosclerosis seen in patients with systemic lupus erythematosus and the anti-phospholipid syndrome. This review examines the evidence for a role for endothelial cell reactive autoantibodies in PVD and the potential mechanisms by which these autoantibodies could contribute to the acceleration of atherosclerosis in a proportion of patients. The identification of such markers could lead to the identification of patients with PVD who are at risk of developing critical ischaemia and may warrant early and aggressive intervention.

Increased fibrin polymerization rate in patients with primary antiphospholipid syndrome and systemic lupus erythematosus

The main event in blood coagulation is the thrombincatalyzed conversion of fibrinogen into fibrin. This singular transformation of a soluble protein into an insoluble polymeric network occurs with faultless precision. Abnormalities of fibrin polymerization can lead to hemorragic and thrombotic disorders. Increased fibrinogen plasma concentration (Fg) and fibrin polymerization rate (FPR) could be additional risk factors associated with atherothrombosis in antiphospholipid syndrome (APS) and in systemic lupus erythematosus (SLE). Our objective was to investigate Fg and FPR in consecutive patients with APS and SLE. Thirty-nine patients and 31 age- and gender-matched healthy controls were studied. Sixteen patients had primary APS, 13 patients had SLE, and 10 patients had SLE plus APS. The mean of the FPR was significantly increased (0.2799 +/- 0.091) in patients with APS plus SLE as compared with the control group (0.2052 +/- 0.055) (p < 0.05). Fg was higher in APS plus SLE (3.15 g/L +/- 0.43) and in primary APS (3.03 g/L +/- 0.29) than in controls (2.87 g/L +/- 0.49). Our results demonstrated an increased FPR in patients with APS plus SLE. This phenomenon could be an additional risk factor for thrombosis in these autoimmune diseases.

Antiphospholipid antibodies: are they pro-atherogenic or an epiphenomenon of atherosclerosis?

Antiphospholipid antibodies are the hallmark of the antiphospholipid syndrome which is characterized by thrombosis. There are currently data supporting an association between these autoantibodies and atherosclerosis as well. Human studies suggest that anti-cardiolipin and anti-beta2-glycoprotein-I antibodies are elevated in patients having coronary artery disease compared with controls. Anti-cardiolipin antibodies are also associated with typical chest pain, significant coronary artery stenosis on angiography and prediction of myocardial infarction. Laboratory studies and murine models support the pro-atherogenic role of these autoantibodies, as they are involved in uptake of oxidized LDL into macrophages, and immunization of mice with them results in enhanced atherosclerosis. There is some evidence that high anti-beta2-glycoprotein-I antibodies can present a risk factor for atherosclerosis, but more epidemiological data are required in order to confirm whether the pro-atherogenic properties of anti-phospholipid antibodies signifies an independent risk factor for atherosclerosis and its complications.

Primary anti-phospholipid antibody syndrome (APS): current concepts

Primary anti-phospholipid syndrome (APS) is a thrombophilic state characterized by recurrent arterial and venous thrombosis, recurrent pregnancy loss, and the presence of circulating anti-phospholipid antibodies that may be responsible for thrombophilia and pregnancy morbidity. Ophthalmologic features are present in 15-88% of the patients with primary APS, thus ophthalmologists are one of the first physicians to whom the patient will present. An accurate diagnosis may save the patient from recurrent, potentially life-threatening thrombosis. In the U.S.A., an estimated 35,000 new cases of APS-related venous thrombosis occur each year in a population that is several decades younger than the patient population typically affected by thrombosis. Clinical features, such as chorea, transverse myelitis, cardiac valvular lesions, and accelerated atherosclerosis, are hypothesized to be due to a direct tissue-antibody interaction and cannot be explained purely by thrombosis. The use of recently proposed, well-defined diagnostic criteria, and better standardization of laboratory assays for the anti-phospholipid antibodies should help enable epidemiological surveys to establish the prevalence of these antibodies in patients with thrombosis and in the general population. Diagnosis of APS should be considered in all patients with recurrent systemic or ocular thrombosis in the absence of known risk factors. Several well-designed prospective studies show an increased risk of thrombosis in the presence of medium to high antibody level. With ocular involvement in as many as 88% of APS patients, an ophthalmic assessment should be an integral part of the clinical work-up of any patient with suspected or confirmed APS. The presence of isolated ocular thrombophilia with persistently elevated anti-phospholipid antibodies or lupus coagulant should confirm the diagnosis of APS. Management of these patients must be a multi-disciplinary effort with either a rheumatologist or a hematologist having the overall responsibility for coordinating treatment and monitoring the patient's immune status and anticoagulation. Treatment of isolated ocular thrombophilia in the presence of moderate to high titers of antiphospholipid antibodies should be on the same principles as patients with APS to prevent recurrent ocular or cerebral thrombosis.

[Antiphospholipid syndrome with only antiphosphatidylethanolamine antibodies: report of 20 cases]

PURPOSE

The association of antiphosphatidylethanolamine antibodies (aPE) as the only antiphospholipid antibody with antiphospholipid syndrome (APS) is discussed. The aPE was described as the sole antibody in many cases suggesting APS. aPE was not included in the Sapporo criteria for the classification of APS.

METHODS

We investigated the clinical features of 20 patients with aPE only; 17 patients had symptoms potentially related to APS (group 1) and three had other manifestations (group 2).

RESULTS

There were 15 women and five men, mean age was 35 +/- 12 years at the beginning. In group 1 (n = 17), ten patients presented arterial thrombosis, nine venous thrombosis (five had both), and six microvascular thrombosis (livedo reticularis, lacunar pathology). The aPE positivity was persistent in 13 patients. A subgroup of four patients (three women) presented arteriosclerosis with peripheral arteriopathy which started before 45 years of age. They had another atherosclerosis risk factor associated with aPE persistence. In group 2 (n = 3), there was no thrombotic event, one demyelinating pathology, one microvascular pathology, and one arterial dysplasia. The aPE positivity was never confirmed. Finally, 13 patients presented an APS with aPE only, confirmed at least 8 weeks later.

CONCLUSIONS

Our study points out that testing for aPE would be of interest for patients when symptoms were potentially related to APS, particularly when other antiphospholipid antibodies were negative. This description questions the enlargement of the APS biological criteria defined in Sapporo. The role of aPE in atherosclerosis is considered.

Atherosclerosis and autoimmunity

Novel risk factors for the progression of atherosclerosis such as C-reactive protein (CRP) and adhesion molecules have stimulated much recent interest in the role of inflammation in atherosclerotic disease. There is also evidence emerging that autoimmunity may have a role in the pathogenesis of atherosclerosis. In this article we explore the evidence for the role of autoimmunity in human atherosclerosis, both in the general population and in the context of the antiphospholipid syndrome. In particular we will focus on several autoantigens, review the evidence for their role in the process of atherosclerosis and the nature of the immune responses.

Heat shock protein 60/65, beta 2-glycoprotein I and oxidized LDL as players in murine atherosclerosis

We have made consecutive studies to prove that autoimmune factors can influence the progression of atherosclerosis in inbred and transgenic mice. C57BL/6 as well as LDL-receptor deficient mice were immunized with heat shock protein 65. LDL-RD and apolipoprotein E knockout (apoE KO) mice were immunized with human B-glycoprotein I. ApoE KO mice were immunized with oxidized LDL. In all immunized mice, a sustained humoral response to the provided antigen was elicited evident by high titers of antibodies by ELISA. A primary cellular immune response was also shown by thymidine incorporation studies employing the antigens in vitro. Immunization with hsp-65 and with beta 2-GPI served to enhance the progression atherosclerosis and led to an increase in the infiltration of CD3 in the subendothelial regions of the early plaques. Transfer of hsp-65 and beta 2-GPI reactive lymphocytes to syngenic mice led to enhancement of fatty streak formation. However, immunization with homologous oxLDL in apoE KO mice led to attenuation of lesion progression concomitant with the production of anti-oxLDL antibodies. Thus, autoimmune factors appear to influence early artherosclerosis progression in mice. If proven in humans these antigen specific responses may be harnessed for selective immunomodulation of the atherosclerotic plaque.

Autoimmune antiphospholipid antibodies and cryoglobulinemia

In addition to their role in the thrombotic manifestations of the antiphospholipid syndrome (APS), autoimmune antiphospholipid (aPL) antibodies may also be responsible for direct injury to the blood vessel wall, although the mechanism is unclear. Cryoglobulinemia has been reported infrequently in patients with APS and is one potential means of blood vessel injury. The aim of the present study was to determine if autoimmune aPL antibodies and their target antigens contribute to the formation of cryoprecipitates. Cryoglobulins were identified and isolated from 5 of 8 patients with autoimmune aPL antibodies. Using identical concentrations of immunoglobulins isolated from matched sera and washed cryoprecipitates there was a significant enrichment (at least 100%) of aCL antibodies in the cryoprecipitates from 4 of 5 patients. This involved IgG, IgM and IgA isotypes with specificity for both beta2-glycoprotein I (GPI) and prothrombin (PT). The target antigens were detected in cryoprecipitates from all 5 aPL positive patients and in cryoprecipitates from 3 controls. These results suggest that anti-beta2-GPI and anti-PT antibodies in association with their target antigens are integrally involved in the formation of cryoprecipitates in patients with autoimmune aPL antibodies and provide insight into a potential mechanism for blood vessel injury.

Autoimmunity in atherosclerosis: lessons from experimental models

The modern view of atherosclerosis is of a chronic inflammatory disorder. In accord with this paradigm, the process of uninhibited influx of fat to the vessel wall results from an 'adequate' response to various forms of injury (i.e. turbulence, infections, modified lipoproteins). This idea has been further extended by several groups, to assume that the atherosclerotic lesion can be the target of an autoimmune mediated attack. According to this hypothesis, the site of initiation of the plaque should bear/express the target autoantigen, whereas concomitantly a respective immune response is generated in the periphery. The examples illuminating this notion are beta2GPI as a target autoantigen, HSP60/65 an oxidized-LDL. Herein we present evidence to support the involvement of autoimmune mechanisms in atherogenesis based on the experience from experimental models and human studies.

High prevalence of anti-beta2 glycoprotein I antibodies in patients with ischemic heart disease

Ischemic cardiac manifestations have been reported in a various percentage of patients with anti-phospholipid antibodies. As concerns the relationship between anti-beta2 glycoprotein I antibodies (anti-beta2-GPI) and ischemic heart disease (IHD), it was investigated in only one coronary primary prevention study. We investigated the prevalence of anti-beta2-GPI in a well characterized group of patients with different clinical manifestation of IHD. Sera from 37 patients (mean age 62.7 +/- 9.9) with IHD (20 with unstable angina-UA and 17 with effort angina-EA) and from 40 healthy subjects, matched for age and sex, were tested for the presence of IgG and IgM anti-beta2-GPI using an ELISA technique. Eleven/37 patients (29.7%) resulted positive for anti-beta2-GPI. A positivity for IgG anti-beta2-GPI was found in 10 patients, 1 patient was positive for IgM and 1 for both isotypes. The prevalence of anti-beta2-GPI in the control group resulted significantly lower (2.5%; p < 0.005) than in patients with IHD. Positivity for anti-beta2-GPI was found in 9/20 (45%) patients with UA and only in 2/17 patients (11.8%) with EA (p = 0.0365). IgG anti-beta2-GPI levels (median 7.7U/ml, range 2.6-24.1) were significantly higher in patients with UA compared to patients with EA (median 4.6 U/ml, range 2.3-11.5; p = 0.02) and controls (median 3.15 U/ml, range 2.3-9.0; p < 0.0001); also IgM levels resulted higher in patients with unstable angina. A positivity for anti-beta2-GPI was observed in 4/13 patients (30.8%) with a previous myocardial infarction (MI) and in 7/24 (29.2%) patients without a previous MI. Our findings suggest that anti-beta2-GPI could represent an expression of the T-cell activation detectable in patients with unstable angina. The lack of a significant difference in the prevalence of these antibodies in patients with or without a previous MI suggests that anti-beta2-GPI are not induced by tissue necrosis.

Retinopathy in systemic lupus erythematosus: pathogenesis and approach to therapy

The starting point in the assessment of SLE-retinopathy is the clinical examination by ophthalmoscopy and retinal fluorescein angiography. It is noted that two major clinical forms of retinopathy may occur in SLE; (1st) the "classic" type characterized by cotton-wool spots with or without intraretinal hemorrhages, and (2nd) the thrombosis of larger retinal blood vessels, such as central or branch arteries/veins. However, a well-defined pathogenetic classification of SLE-retinopathy has still not been proposed as yet. A practical classification based on the pathogenesis could be of aid to commence a more appropriate treatment. The aims of this paper are; (1st) to focus on the most implicate mechanisms of retinal vascular disease in SLE, (2nd) to mention the most common features associated with the different forms of retinopathy, and finally (3rd) to assess the prevalence of retinopathy in SLE. In our opinion, it seems that two major types of retinopathy exist in SLE: firstly, the Hughes' retinopathy due to antiphospholipid-induced retinal vascular thrombosis, for which anticoagulation is the best treatment, and secondly, the "classic" retinopathy in which at least two major causes could be associated; vasculitis and accelerated atherosclerosis. In patients with "classic" retinopathy, the most appropriate treatment still needs to be established. If "classic" retinopathy is due to vasculitis, immunosuppressive drugs should be administered, while if atherosclerosis play an etiologic role, a prophylaxis with antioxidants or the use of low-dose aspirin should be assessed.

The clinico-ophthalmological spectrum of antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a hypercoagulable disorder with highly variable symptomatology including ocular manifestations. Antiphospholipid antibodies (aPL) are the serologic markers of this clinical entity. Our aim was to note the main associated ocular features of APS and elucidate which pathogenic mechanisms may participate. Retinal vascular thrombosis and different neuro-ophthalmologic manifestations, such as optic neuropathy and amaurosis fugax, may be considered as the ocular hallmarks of this syndrome. Ocular features due to aPL-induced thrombosis should be treated with anticoagulant drugs. Conversely, for the treatment of ocular features due to immunological mechanisms such as vasculitis, immunosuppressive regimes seem to be more appropriate.

Hughes' syndrome: the antiphospholipid syndrome. A historical view

In the 15 years since our description of the antiphospholipid syndrome, it has become recognised as an important disease, not only in the world of lupus but in the broader areas of obstetrics, neurology and vascular disease. Although advances have been made in the understanding of the interactions of antibodies, protein co-factors, clotting molecules, endothelium and platelets, much still needs to be learnt about management where strokes, in particular, continue to cause significant morbidity.

Towards improved criteria for the antiphospholipid syndrome

A workshop to be held in Sapporo will attempt to upgrade criteria for the antiphospholipid syndrome (APS). These criteria should probably be based on a scoring system using both clinical and biological items. Clinical criteria could be categorized between 'major', that is thrombosis or obstetrical criteria, and 'minor', to be selected among livedo, heart valve lesions, chorea, adrenal hemorrhage, thrombocytopenia, and others. A similar approach could be proposed for biological criteria, with persistent strong LA, high IgG aCL or antibodies to beta2GPI as major criteria if the workshop accepts antibodies directed to co-factors as APS criteria. Minor criteria could include IgM aCL, low/medium IgG aCL, and VDRL. Whether anti-prothrombin, anti-oxidised LDL, and M5 anti-mitochondrial antibodies should be added to the minor criteria, is open to discussion. In our mind, other parameters should be taken into account such as: young age--a method to avoid the questionable exclusion of arteriosclerosis in cases of arterial thrombosis--and the presence of personal and/or first-degree familial features of auto-immunity. Lastly, a differential diagnosis section is probably needed.