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

Lupus, antiphospholipid syndrome, and stroke: An attempt to crossmatch

Cerebrovascular accidents (CVAs) or strokes are part of the common thrombotic manifestations of Systemic Lupus Erythematosus (SLEs) and Antiphospholipid syndrome (APS). Such neurological thrombotic events tend to occur in patients with SLE at a higher frequency when Antiphospholipid antibodies (aPLs) are present, and tend to involve the large cerebral vessels. The mechanism of stroke in SLE can be driven by complement deposition and neuroinflammation involving the blood-brain barrier although the traditional cardiovascular risk factors remain major contributing factors. Primary prevention with antiplatelet therapy and disease activity controlling agent is the basis of the management. Anticoagulation via warfarin had been a tool for secondary prevention, especially in stroke recurrence, although the debate continues regarding the target international normalized ratio (INR). The presence of either of the three criteria antiphospholipid antibodies (aPLs) and certain non-criteria aPL can be an independent risk factor for stroke. The exact mechanism for the involvement of the large cerebral arteries, especially in lupus anticoagulant (LAC) positive cases, is still to be deciphered. The data on the role of non-criteria aPL remain very limited and heterogenous, but IgA antibodies against β2GPI and the D4/5 subunit as well as aPS/PT IgG might have a contribution. Anticoagulation with warfarin has been recommended although the optimal dosing or the utility of combination with antiplatelet agents is still unknown. Minimal data is available for direct oral anticoagulants (DOACs).

Anti-Phosphatidylethanolamine and Anti-Phosphatidylserine Antibodies—Association with Renal Involvement, Atherosclerosis, Cardiovascular Manifestations, Raynaud Phenomenon and Disease Activity in Polish Patients with Systemic Lupus Erythematosus

Objective. To evaluate the association between anti-phosphatidylethanolamine (aPE) and anti-phosphatidylserine (aPS) antibodies and cardiovascular risk, organ involvement and disease activity in systemic lupus erythematosus (SLE) patients. Methods. We studied 93 SLE patients and 30 controls. We analyzed levels of anti-phospholipid antibodies, including aPS and aPE, the profiles of antinuclear, anti-neutrophil cytoplasmic (ANCA) and anti-endothelial antibodies, carotid intima-media thickness (cITM) and atherosclerotic plaque presence, ankle-brachial and high resistance indices, atherosclerotic risk factors, organ manifestations and treatment. Results. Levels of aPS and aPE were significantly higher in SLE patients in comparison with the controls (p = 0.038 and p = 0.044, respectively). aPS was associated with the risk of Raynaud’s phenomenon (p = 0.021) development. aPE increased the risk of renal involvement (p = 0.049), cerebral stroke (p = 0.050), high vlues of cIMT (p = 0.041) development as well as occurrence of selected serological markers associated with activity of the disease such as anti-double stranded DNA (p = 0.021). The long duration of regular smoking (p = 0.021) and the high number of cigarettes/day (p = 0.015) were significantly associated with the risk of aPE occurrence. Conclusions. Patients with aPS and aPE are at risk of vascular involvement. Especially the presence of aPE may significantly increase the risk of thrombotic complications development in SLE patients without classical serological markers of APS. Finally, aPE might be used as a marker of disease activity and risk of renal injury development in this patient group. The classical atherosclerotic markers including lipid indices play an important role in complex analysis of cardiovascular risk in lupus patients and enable to identify patients at the highest risk and implement effective preventive, diagnostic and therapeutic procedures.

IgA Antiphospholipid Antibodies in Antiphospholipid Syndrome and Systemic Lupus Erythematosus

Objective: To define the role of IgA antibodies to cardiolipin (aCL) and IgA antibodies to beta-2 glycoprotein 1 (anti-β2-GP1) in the development of vascular complications in patients with antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE). Material and methods: A total of 187 patients with one of the following diagnoses: primary APS (PAPS), probable APS, SLE with APS, and SLE without APS. The comparison group consisted of 49 patients with other rheumatic diseases (RD), the control group included 100 relatively healthy individuals (without RD, oncological pathology, and infectious diseases). All patients underwent standard clinical, laboratory, and instrumental examinations before being included in the study and during follow-up. The aPL study included the determination of IgG/IgM aCL, IgG/IgM anti-β2-GP1 by enzyme-linked immunosorbent assay (ELISA), IgG/IgM/IgA aCL, IgG/IgM/IgA anti-β2-GP1 by chemiluminescence analysis (CLA), and lupus anticoagulant (LA). Results: IgA aCL were detected in 75 (40%) of the 187 patients with APS and SLE, in none of the comparison group, and in 2 (2%) of the control one. IgA anti-β2-GP1 were detected in 63 (34%) of the 187 patients with APS and SLE, in none of the patients in the comparison group, and in one (1%) of the control group. The prevalence of IgA aCL and IgA anti-β2-GP1 and their levels were statistically significantly higher in patients with APS (PAPS and SLE + APS) than the levels in patients with SLE and those of the comparison and control groups (p < 0.05). IgA aCL and IgA anti-β2-GP1 were significantly associated with thrombosis in APS (χ2 = 4.96; p = 0.02 and χ2 = 4.37; p = 0.04, respectively). The risk of thrombosis was 2.04 times higher in patients with positive IgA aCL than in patients without these antibodies, as well as in patients with positive IgA anti-β2-GP1; it was twice as high as in patients without antibodies. There was a high specificity of IgA aCL and IgA anti-β2-GP1 for both the diagnosis of APS and its clinical manifestations, despite a low sensitivity. Conclusions: The study revealed a relationship of thrombosis and APS with IgA aCL and IgA anti-β2-GP1. There was a high specificity of IgA aCL and IgA anti-β2-GP1 (95% and 93%, respectively) for the diagnosis of APS with a low sensitivity (54% and 44%, respectively). There were no patients with isolated positivity of IgA aCL and IgA anti-β2-GP1.

Immunoglobulin A Isotype of Antiphospholipid Antibodies Does Not Provide Added Value for the Diagnosis of Antiphospholipid Syndrome in a Chinese Population

Objective

Antiphospholipid syndrome (APS) is characterized by the presence of anti-phospholipid (aPL) antibodies. However, the relationship between the immunoglobulin (Ig) A isotype of aPL positivity and its clinical utility in APS diagnosis is controversial. Presently, we determine the clinical utility of IgA-aPL from consecutive patients in a large cohort from the Chinese population and patients with APS whose aPL profiles were obtained.

Methods

The detection of anticardiolipin (aCL) and anti-β₂ glycoprotein-Ⅰ (aβ₂GPⅠ) antibodies of the IgA/IgG/IgM isotype by paramagnetic particle chemiluminescent immunoassay was carried out in sera from 7293 subjects. 153 primary APS (PAPS) patients and 59 patients with secondary APS (SAPS) were included in this study.

Results

In total, 1,082 out of 7,293 (2.55%) subjects had a positive IgA-aPL test, and the prevalence of isolated IgA-aPL was 0.29% (21/7,293) in the general population. The prevalence of IgA-aPL in the PAPS patients was 12.42% (19/153); however, only one patient (0.65%) presented with isolated IgA-aPL. Fifty (25.9%) of the SAPS had IgA-aPL, none of whom lacked IgG/IgM-aPL. The combination of the IgA isotype and the IgG/IgM isotype did not increase the diagnostic performance when compared with the IgG/IgM isotype of aCL or aβ₂GPⅠ, respectively. IgA-aPL was not associated with clinical manifestation in patients with APS.

Conclusion

Isolated IgA-aPL is rare in the general population as well as in patients with APS. Whether in the laboratory or in clinical practice, the presence of IgA-aPL does not provide added value for the diagnosis of APS in the Chinese population.

Cognitive impairment in elderly patients with rheumatic disease and the effect of disease-modifying anti-rheumatic drugs

Recent development of biologic disease-modifying anti-rheumatic drugs (DMARDs) has led to better control of disease activity among patients with chronic rheumatological diseases. Many patients with rheumatic disease are living longer, adding to the growing elderly population. Rheumatic diseases, most notably rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), are known to increase the risk of cognitive impairment. Systemic inflammation associated with chronic rheumatological diseases has been postulated to be key driver of cognitive decline. Recent development of classic and biologic DMARDs have led to better control of disease activity among patients with rheumatic conditions. It is proposed that strict control of systemic inflammation will significantly lower the risk of cognitive impairment among patients with rheumatic disease. The impact of classic DMARDs on cognitive function appears to be variable. On the other hand, biologic DMARDs, specifically antitumor necrosis factor (TNF) drugs (i.e., etanercept), have been shown to significantly lower the risk of dementia. Experimental studies on IL-1, IL-6, and B and T cell blockade are promising. However, clinical data is limited. Preclinical studies on targeted therapies, specifically JAK/STAT inhibitors, also show promising results. Additional studies are necessary to better understand the impact of these newer biologic agents on cognitive function in elderly patients with rheumatic disease. Key points • Patients with chronic rheumatic conditions are beginning to live longer, adding to the elderly population. • Patients with chronic rheumatologic disease are at increased risk of cognitive impairment compared to the general population. • Recent development of biologic (i.e., TNF, IL-1, IL-6) and targeted drugs (i.e., Janus kinase inhibitors) have led to better control of disease activity. • Current evidence suggests that TNF inhibitors may have beneficial effects on cognitive function. However, evidence on newer biologic and targeted therapies is limited.

[Which place of antiphosphatidylethanolamine antibodies research in seronegative antiphospholipid syndrome suspicion?]

PURPOSE

Antiphospholipid syndrome (APS) is a clinico-biological syndrome, which associates vascular injury and persisting antiphospholipid antibodies (aPL). Patients with clinical symptoms of APS but without aPL are defined as "seronegative APS" (SNAPS). The aim of this study was to evaluate antiphosphatidylethanolamine antibody (aPE) investigation in patients with SNAPS suspicion.

METHODS

This retrospective study was conducted in patients with SNAPS suspicion. A homemade enzyme-linked immunosorbent assay (ELISA) was used to search for aPE. The results of this homemade method were compared with those from a global screening ELISA.

RESULTS

Two hundred twenty-eight patients with SNAPS suspicion were included. Among them, 58.3% had a thrombotic event. The homemade ELISA found positive persisting aPE in 23 patients (10%): 15 with a thrombotic event, 6 with obstetrical morbidity and 2 with a combined event. The global screening ELISA was positive in only 11 of these 23 patients (47.8%).

CONCLUSION

These results suggest the implication of aPE in SNAPS.

Rheumatic diseases and autoimmune vascular dementia

Vascular dementia (VD) comes second after Alzheimer's disease (AD) as a cause of impaired cognition. VD is not a specific nosological entity, but rather a syndrome encompassing a number of diseases caused by impaired supply of blood to the brain. Systemic autoimmune disorders such as systemic lupus erythematosus, rheumatoid arthritis, vasculitis and antiphospholipid syndrome (APS) can be associated with dementia. VD is often related to the presence of traditional cardiovascular risk factors, but it may also be associated with a host of disorders affecting the brain blood vessels, neuronal cells, or both. It is important to entertain in the differential diagnosis of VD, to recognize and to cure them accurately in order to preserve life's quality of our patients.

Increased Risk of Dementia in Patients With Systemic Lupus Erythematosus: A Nationwide Population-Based Cohort Study

OBJECTIVE

Systemic lupus erythematosus (SLE) is a systemic autoimmune disorder characterized by varied clinical symptoms and can be comorbid with neuropsychiatric disorders. However, the association between SLE and dementia risk in patients with SLE remains unclear. In this study, we evaluated the incidence of dementia in patients with SLE.

METHODS

Patients were recruited from a nationwide cohort in 2004-2008 and categorized as SLE (n = 1,074; patients diagnosed with SLE) or non-SLE (n = 5,370; age- and sex-matched controls). Each patient was followed for up to 7 years, until either receiving a diagnosis of dementia or until December 31, 2010. Data were analyzed using the Kaplan-Meier method and Cox regression analysis.

RESULTS

The incidence rate of dementia was higher in the SLE cohort (357 per 100,000 person-years) than in the non-SLE cohort (180 per 100,000 person-years). Patients with SLE had a higher risk of dementia than did those without SLE (crude hazard ratio [HR] 1.92; P < 0.05). Cox regression analysis revealed an adjusted HR for dementia in the SLE cohort of 2.14 (P < 0.001), after adjustment for other comorbid diseases and variables.

CONCLUSION

Patients with SLE have a higher risk of dementia.

The outcome of ELISA for antiphosphatidylethanolamine antibodies is dependent on the composition of phosphatidylethanolamine

OBJECTIVE

The presence of circulating autoantibodies against phosphatidylethanolamine (PE) has been shown to be positively associated with symptoms of antiphospholipid syndromes (APS). However, the current ELISA-based tests for antiphosphatidylethanolamine (aPE) antibodies remain inconsistent and controversial. The term PE refers to a collection of phospholipids that have phosphorylethanolamine head group as a common structural feature, but can vary in fatty acids with diverse physicochemical properties. The present study was to investigate, using synthetic positionally symmetrical PE species as a model system, the impact of PE structural variations on aPE ELISA.

METHODS

Single and combinations of synthetic PE species, including 16:0 (fatty acid length:degree of unsaturation), 18:0, 18:1, 20:4 and 22:6, were screened with ELISA using serum samples from aPE patients and compared with chicken egg PE. There were a total of 37 aPE patient serum samples, including 11 cofactor-independent IgM, 14 ABP-independent IgG and 12 ABP-dependent aPE serum samples (3 IgM, 8 IgG and 1 IgA). The ELISA conditions were investigated for different isotypes and cofactor dependence. Based on the initial screening, adjustments in phospholipid compositions were made for achieving optimal OD readings. Finally, we isolated total IgG from aPE sera to validate different antigenic preferences.

RESULTS

The antigenic preference was different among immunoglobulin isotypes and between cofactor-dependent versus cofactor-independent aPE antibodies. More specifically, 18:1 PE was a preferred antigen for cofactor-dependent aPE, whereas 20:4 PE was the preferred antigen for cofactor-independent IgG aPE. In contrast, cofactor-independent IgM aPE appeared to have a general preference for a more complex PE combination with longer fatty acids and a higher degree of unsaturation.

CONCLUSION

The present data indicated that the outcome of aPE ELISA was dependent on the composition and physicochemical properties of PE antigens. The discovery that aPE antibodies may have different antigenic preferences could shed light on the nature of their binding interactions.

Risk of stroke in patients with rheumatism: a nationwide longitudinal population-based study

The aim of this study was to investigate rheumatoid arthritis (RA), and systemic lupus erythematous (SLE) as risk factors for stroke. The study was analyzed by Using the Taiwan Longitudinal Health Insurance Database 2005 (LHID2005), this cohort study investigated patients with a recorded diagnosis of RA (N = 6114), and SLE (N = 621) between January 1, 2004, and December 31, 2007, with age-matched controls (1:4) (for RA, N = 24456; SLE, N = 2484). We used Cox proportional-hazard regressions to evaluate the hazard ratios (HRs) after adjusting confounding factors. Our study found 383 of 6114 RA patients, experienced stroke during the 20267 person-year follow-up period. The adjusted HR of stroke for RA patients was 1.24 (95% CI, 1.11 to 1.39), and for SLE patients was 1.88 (95% CI, 1.08 to 3.27). When steroid was added as additional confounding factor, the adjusted HR of ischemic stroke for RA patients was 1.32 (95% CI, 1.15 to 1.50), and for SLE patients was 1.31 (95% CI, 0.51 to 3.34). In conclusion, the rheumatic diseases of RA, and SLE are all risk factors for stroke. After controlled the effect of steroid prescription, RA is risk factor for ischemic stroke.

14th International Congress on Antiphospholipid Antibodies Task Force. Report on antiphospholipid syndrome laboratory diagnostics and trends

Current classification criteria for definite Antiphospholipid Syndrome (APS) require the use of three laboratory assays to detect antiphospholipid antibodies (aCL, anti-β2GPI and LA) in the presence of at least one of the two major clinical manifestations (i.e. thrombosis or pregnancy morbidity) of the syndrome. However, several other autoantibodies shown to be directed to other proteins or their complex with phospholipids have been proposed to be relevant to APS but their clinical utility and their diagnostic value remains elusive. This report summarizes the findings, conclusions and recommendations of the "APS Task Force 3-Laboratory Diagnostics and Trends" meeting that took place during the 14th International Congress on Antiphospholipid Antibodies (APLA 2013, September 18-21, Rio de Janeiro, RJ, Brazil).

The contribution of antiphosphatidylethanolamine antibodies in the diagnosis of the antiphospholipid syndrome

The diagnosis of seronegative antiphospholipid syndrome (APS) has been proposed for patients with well-defined clinical APS but persistently negative for the routinely tested antiphospholipid antibodies (aPLs): antibodies to cardiolipin (aCL) and to β(2) glycoprotein I (aβ(2)GPI) and lupus anticoagulant (LA). Antibodies directed to phosphatidylethanolamine (aPE) have been described as the sole aPLs in some patients with clinical manifestations of APS. Here, we briefly summarize the available data on the clinical associations of aPEs and propose their investigation in patients with a clinical profile highly suggestive of seronegative APS.

The clinical relevance of IgA anticardiolipin and IgA anti-β2 glycoprotein I antiphospholipid antibodies: a systematic review

The antiphospholipid syndrome (APS) is diagnosed in patients with thromboembolic events and/or pregnancy loss in the presence of persistent laboratory evidence for antiphospholipid antibodies (aPL). Diagnostic tests for the detection of antiphospholipid antibodies include laboratory assays that detect anticardiolipin antibodies, lupus anticoagulants, and anti-β(2)-glycoprotein I antibodies. Most studies on aPL have mainly focused on the estimation of the IgG and IgM isotypes, with only a few studies reporting on the pathogenic significance of IgA aPL. In this review we aimed to summarize and analyze the evidence published in the literature on the prevalence and the clinical significance of IgA aPL.

Increased risk of ischemic stroke in patients with systemic lupus erythematosus: a nationwide population-based study

BACKGROUND

Systemic lupus erythematosus (SLE) has been reported to be associated with an increased risk of cardiovascular disease. However, most studies have been criticized for either a small sample size or the lack of a prospective control. Our study investigated the relationship of SLE and the subsequent development of ischemic stroke using a nationwide, population-based database in an Asian population.

METHODS

From 2000 to 2007, we identified a study cohort consisting of a total of 11,637 newly diagnosed SLE patients using the National Health Insurance Research Database in Taiwan. A control cohort of 58,185 subjects without SLE, matched for age, gender, and comorbidities were selected for comparison to observe the occurrence of ischemic stroke in these two groups.

RESULTS

During a follow-up period of up to 7 years, ischemic stroke developed in 258 (2.22%) of the patients with SLE and in 873 (1.5%) of patients in the comparison cohort. Kaplan-Meier analysis also revealed a tendency of SLE patients toward ischemic stroke development (log rank test, p = 0.001). After Cox model adjustment for patients' demographic characteristics and selected comorbidities, patients with SLE were found to have a 1.67-fold (95% CI, 1.45 to 1.91) higher risk of developing ischemic stroke.

CONCLUSION

Patients with SLE have an increased risk of stroke.

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

BACKGROUND

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

OBJECTIVES

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

PATIENTS/METHODS

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

RESULTS

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

CONCLUSIONS

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

Antiphospholipid antibodies: discovery, definitions, detection and disease

Antiphospholipid antibodies (aPL) are immunoglobulins of IgG, IgM and IgA isotypes that target phospholipid (PL) and/or PL-binding plasma proteins. Detection of aPL in the laboratory is done currently by both immunoassays and functional coagulation tests. Convention defines aPL specificity in immunoassays according to the particular PL substrate present, for example aPS represents antiphosphatidylserine antibodies. This may be technically incorrect inasmuch as a particular PL may be responsible for binding and highly concentrating a specific plasma protein, the latter then becomes the target for the aPL. The binding of beta(2)GP-I (apolipoprotein H) to the negatively charged PL, cardiolipin (CL) provides a good example of this circumstance. In contrast, aPL which specifically prolong coagulation times in in vitro are called lupus anticoagulants (LA). The precise PL target(s) of the aPL responsible for LA activities are unknown and often debated. The persistent finding of aPL in patients in association with abnormal blood clotting and a myriad of neurological, obstetrical and rheumatic disorders often compounded by autoimmune diseases has led to an established clinical diagnosis termed antiphospholipid syndrome (APS). The common denominator for these APS patients is the presence of circulating aPL on two or more occasions and the observation of events attributable to abnormal or accelerated blood clotting somewhere in vivo. The purpose of this review is to collect, collate, and consolidate information concerning aPL.