Damage measured by Damage Index for Antiphospholipid Syndrome (DIAPS) in antiphospholipid antibody-positive patients included in the APS ACTION registry.

OBJECTIVES: Our primary objective was to quantify damage burden measured by Damage Index for Antiphospholipid Syndrome (DIAPS) in aPL-positive patients with or without a history of thrombosis in an international cohort (the APS ACTION cohort). Secondly, we aimed to identify clinical and laboratory characteristics associated with damage in aPL-positive patients. METHODS: In this cross-sectional study, we analysed the baseline damage in aPL-positive patients with or without APS classification. We excluded patients with other autoimmune diseases. We analysed the demographic, clinical and laboratory characteristics based on two subgroups: (i) thrombotic APS patients with high vs low damage; and (ii) non-thrombotic aPL-positive patients with vs without damage. RESULTS: Of the 826 aPL-positive patients included in the registry as of April 2020, 586 with no other systemic autoimmune diseases were included in the analysis (412 thrombotic and 174 non-thrombotic). In the thrombotic group, hyperlipidaemia (odds ratio [OR] 1.82; 95% CI 1.05, 3.15; adjusted P = 0.032), obesity (OR 2.14; 95% CI 1.23, 3.71; adjusted P = 0.007), aß2GPI high titres (OR 2.33; 95% CI 1.36, 4.02; adjusted P = 0.002) and corticosteroid use (ever) (OR 3.73; 95% CI 1.80, 7.75; adjusted P < 0.001) were independently associated with high damage at baseline. In the non-thrombotic group, hypertension (OR 4.55; 95% CI 1.82, 11.35; adjusted P = 0.001) and hyperlipidaemia (OR 4.32; 95% CI 1.37, 13.65; adjusted P = 0.013) were independent predictors of damage at baseline; conversely, single aPL positivity was inversely correlated with damage (OR 0.24; 95% CI 0.075, 0.77; adjusted P = 0.016). CONCLUSIONS: DIAPS indicates substantial damage in aPL-positive patients in the APS ACTION cohort. Selected traditional cardiovascular risk factors, steroids use and specific aPL profiles may help to identify patients more prone to present with a higher damage burden.

Associations Among Antiphospholipid Antibody Types, Isotypes, and Titers: An AntiPhospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking (APS ACTION) Study.

Several antiphospholipid antibody (aPL) profiles ("triple" and lupus anticoagulant [LA] positivity) are associated with a higher risk for clinical manifestations of antiphospholipid syndrome (APS). Further risk is correlated with higher levels of anticardiolipin antibody (aCL) and anti-ß2 glycoprotein-I antibody (aß2GPI), and with aPL persistence. Given that the 3 aPL tests detect partially overlapping sets of antibodies, the primary goal of this study was to characterize the associations among aPL tests using AntiPhospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking (APS ACTION) core laboratory data. The APS ACTION Registry includes annually followed adult patients with positive aPL based on the Revised Sapporo Classification Criteria. We analyzed baseline and prospective core laboratory data of the registry for associations among aPL tests using the Spearman rank correlation with Bonferroni-adjusted significance level for multiple comparisons. An aPL Load was calculated based on 6 tests (aCL IgG/IgM/IgA and aß2GPI IgG/IgM/IgA); a receiver operating characteristic curve was used to evaluate the diagnostic performance of the aPL Load in predicting LA positivity. In 351 patients simultaneously tested for LA, aCL, and aß2GPI, the frequency of moderate-to-high (≥40 U) titers of aCL and aß2GPI IgG/IgM/IgA was higher in patients who were positive for LA vs those who were negative. An aPL Load was calculated for each patient to assess the overall aPL burden. For every 1-point increase in the aPL Load, the possibility of a positive LA test increased by 32% (odds ratio, 1.32; 95% CI, 1.2-1.5; P < .001). Based on core laboratory data from a large international registry, most aPL enzyme-linked immunosorbent assay ≥40 U and a high calculated aPL Load combining 6 aPL enzyme-linked immunosorbent assays were predictive of a positive LA. These data suggest that the combined quantitative burden of aPL may provide a mechanistic explanation of a positive LA.

Immunosuppression use in primary antiphospholipid antibody-positive patients: Descriptive analysis of the AntiPhospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking (APS ACTION) Clinical Database and Repository ("Registry").

BACKGROUND/PURPOSE: APS ACTION Registry was created to study the outcomes of patients with persistently positive antiphospholipid antibodies (aPL) with or without other systemic autoimmune disease (SAIDx). Given that immunosuppression (IS) is used for certain aPL manifestations, for example, thrombocytopenia (TP), our primary objective was to describe the indications for IS in aPL-positive patients without other SAIDx. Secondly, we report the type of IS used in patients with selected microvascular or non-thrombotic aPL manifestations. METHODS: An online database is used to collect clinical data. The inclusion criteria are positive aPL based on the laboratory section of the APS Classification Criteria, tested at least twice within one year prior to enrollment. Patients are followed every 12 ± 3 months. For this descriptive retrospective and prospective analysis, we included aPL-positive patients without other SAIDx and excluded those with new SAIDx classification during follow-up. For each patient, we retrieved clinical data at baseline and follow-up including selected aPL manifestations (diffuse alveolar hemorrhage [DAH], antiphospholipid-nephropathy [aPL-N], livedoid vasculopathy [LV]-related skin ulcers, TP, autoimmune hemolytic anemia [AIHA], cardiac valve disease [VD]), and IS medications. RESULTS: Of 899 patients enrolled, 537 were included in this analysis (mean age 45 ± 13 years, female 377 [70%], APS Classification in 438 [82%], and at least one selected microvascular or non-thrombotic aPL manifestation in 141 (26%)). Of 537 patients, 76 (14%) were reported to use IS (ever), and 41/76 (54%) received IS primarily for selected aPL manifestation. In six of 8 (75%) DAH patients, 6/19 (32%) aPL-N, 4/28 (14%) LV, 25/88 (28%) TP, 6/11 (55%) AIHA, and 1/43 (2%) VD, the IS (excluding corticosteroids/hydroxychloroquine) indication was specific for selected aPL manifestation. CONCLUSION: In our international cohort, 14% of aPL-positive patients without other SAIDx were reported to receive IS; the indication was at least one of the selected microvascular and/or non-thrombotic aPL-related manifestations in half. Thrombocytopenia was the most frequent among those selected aPL-related manifestations; however, approximately one-third received IS specifically for that indication. Diffuse alveolar hemorrhage was frequently treated with IS followed by AIHA and aPL-N. Systematic controlled studies are urgently needed to better define the role of IS in APS.

16th International Congress on Antiphospholipid Antibodies Task Force Report on Antiphospholipid Syndrome Treatment Trends.

Antiphospholipid syndrome (APS), an acquired autoimmune thrombophilia, is characterised by thrombosis and/or pregnancy morbidity in association with persistent antiphospholipid antibodies. The 16th International Congress on Antiphospholipid Antibodies Task Force on APS Treatment Trends reviewed the current status with regard to existing and novel treatment trends for APS, which is the focus of this Task Force report. The report addresses current treatments and developments since the last report, on the use of direct oral anticoagulants in patients with APS, antiplatelet agents, adjunctive therapies (hydroxychloroquine, statins and vitamin D), targeted treatment including rituximab, belimumab, and anti-TNF agents, complement inhibition and drugs based on peptides of beta-2-glycoprotein I. In addition, the report summarises potential new players, including coenzyme Q10, adenosine receptor agonists and adenosine potentiation. In each case, the report provides recommendations for clinicians, based on the current state of the art, and suggests a clinical research agenda. The initiation and development of appropriate clinical studies requires a focus on devising suitable outcome measures, including a disease activity index, an optimal damage index, and a specific quality of life index.

Cluster analysis for the identification of clinical phenotypes among antiphospholipid antibody-positive patients from the APS ACTION Registry.

OBJECTIVE: This study aimed to use cluster analysis (CA) to identify different clinical phenotypes among antiphospholipid antibodies (aPL)-positive patients. METHODS: The Alliance for Clinical Trials and International Networking (APS ACTION) Registry includes persistently positive aPL of any isotype based on the Sydney antiphospholipid syndrome (APS) classification criteria. We performed CA on the baseline characteristics collected retrospectively at the time of the registry entry of the first 500 patients included in the registry. A total of 30 clinical data points were included in the primary CA to cover the broad spectrum of aPL-positive patients. RESULTS: A total of 497 patients from international centres were analysed, resulting in three main exclusive clusters: (a) female patients with no other autoimmune diseases but with venous thromboembolism (VTE) and triple-aPL positivity; (b) female patients with systemic lupus erythematosus, VTE, aPL nephropathy, thrombocytopaenia, haemolytic anaemia and a positive lupus anticoagulant test; and (c) older men with arterial thrombosis, heart valve disease, livedo, skin ulcers, neurological manifestations and cardiovascular disease (CVD) risk factors. CONCLUSIONS: Based on our hierarchical cluster analysis, we identified different clinical phenotypes of aPL-positive patients discriminated by aPL profile, lupus or CVD risk factors. Our results, while supporting the heterogeneity of aPL-positive patients, also provide a foundation to understand disease mechanisms, create new approaches for APS classification and ultimately develop new management approaches.

Oral administration of Domain-I of beta-2glycoprotein-I induces immunological tolerance in experimental murine antiphospholipid syndrome.

It is well established that the humoral immunity in antiphospholipid syndrome (APS) is presented by circulating pathogenic anti-ß2GPI autoantibodies targeting mainly domain I of the ß2GPI protein, playing a major role in the disease pathogenesis. Previously, we have demonstrated that treatment of experimental APS mice with tolerogenic dendritic cells loaded with domain-I was more efficient in tolerance induction than with the whole molecule or domain-V. In the current study we had orally administered a domain-I derivative of the ß2GPI molecule, as a new therapeutic approach to induce oral tolerance in this mouse model of APS. BALB/c mice immunized with ß2GPI, were fed with either domain-I, domain-V derivative or the complete ß2GPI protein. ß2GPI immunized mice developed experimental APS which were fed with domain-I significantly had decreased fetal loss (p < 0.004), a lower size of thrombi (p < 0.001) and lower circulating anti-ß2GPI Abs in comparison to mice fed with domain-V or PBS (p < 0.002). Likewise, Domain-I fed mice had a lowered inflammatory response, exhibited by decreased expression of inflammatory cytokines (IFNγ, IL-6, IL-17) and elevated production of IL-10 anti-inflammatory cytokine by splenocytes. Moreover, the anti-inflammatory response in the domain-I fed APS mice was associated with increased circulating miRNA variations (155, 146, 182, 98) by RT-PCR, which are associated with immunomodulation of the immune network. We propose that oral tolerance with domain-I can be a novel therapy for patients with APS.

The journey of antiphospholipid antibodies from cellular activation to antiphospholipid syndrome.

Pathogenic antiphospholipid antibodies (aPL) are the driving factors of recurrent pregnancy loss and thrombosis that characterize antiphospholipid syndrome (APS). Current evidence indicates that aPL induce a procoagulant phenotype in the vasculature and abnormal cellular proliferation and differentiation in placental tissues to cause the typical clinical features; however, the molecular mechanisms underlying these processes remain incompletely understood. Inflammation serves as a necessary link between the observed procoagulant phenotype and actual thrombus development and is an important mediator of the placental injury in APS patients. However, the underlying mechanisms for these events have also not been fully elucidated. In this review, we will outline the available data that give us our current understanding of the pathophysiology of APS, especially as it relates to the development of thromboembolic and obstetric pathological phenomena in these patients. We will also describe the intracellular signaling pathways activated by aPL in various cellular subtypes and outline the current evidence linking these pathways to clinical phenotypes. Finally, we will discuss the implications of distinct molecular patterns defining clinical phenotypes of APS patients.

A prospective open-label pilot study of fluvastatin on proinflammatory and prothrombotic biomarkers in antiphospholipid antibody positive patients.

OBJECTIVE: To determine if proinflammatory and prothrombotic biomarkers are differentially upregulated in persistently antiphospholipid antibody (aPL)-positive patients, and to examine the effects of fluvastatin on these biomarkers. METHODS: Four groups of patients (age 18-65) were recruited: (a) primary antiphospholipid syndrome; (b) systemic lupus erythematosus (SLE) with antiphospholipid syndrome (APS) (SLE/APS); (c) persistent aPL positivity without SLE or APS (Primary aPL); and (d) persistent aPL positivity with SLE but no APS (SLE/aPL). The frequency-matched control group, used for baseline data comparison, was identified from a databank of healthy persons. Patients received fluvastatin 40 mg daily for 3 months. At 3 months, patients stopped the study medication and they were followed for another 3 months. Blood samples for 12 proinflammatory and prothrombotic biomarkers were collected monthly for 6 months. RESULTS: Based on the comparison of the baseline samples of 41 aPL-positive patients with 30 healthy controls, 9/12 (75%) biomarkers (interleukin (IL)-6, IL1ß, vascular endothelial growth factor (VEGF), tumour necrosis factor (TNF)-α, interferon (IFN)-α, inducible protein-10 (IP10), soluble CD40 ligand (sCD40L), soluble tissue factor (sTF) and intracellular cellular adhesion molecule (ICAM)-1) were significantly elevated. Twenty-four patients completed the study; fluvastatin significantly and reversibly reduced the levels of 6/12 (50%) biomarkers (IL1ß, VEGF, TNFα, IP10, sCD40L and sTF). CONCLUSIONS: Our prospective mechanistic study demonstrates that proinflammatory and prothrombotic biomarkers, which are differentially upregulated in persistently aPL-positive patients, can be reversibly reduced by fluvastatin. Thus, statin-induced modulation of the aPL effects on target cells can be a valuable future approach in the management of aPL-positive patients.

Standardization of antiphospholipid antibody testing--historical perspectives and ongoing initiatives.

The measurement of antiphospholipid antibodies (aPL) has been an important aspect of antiphospholipid syndrome (APS) characterization since the disease was first described in the 1980s. Despite significant efforts geared toward the standardization of immunoassays that measure anticardiolipin antibodies and anti-ß2-glycoprotein I spanning three decades, there are still reports of significant interassay and interlaboratory variation in the results of these assays. At the recent 13th International Congress on Antiphospholipid Antibodies (APLA 2010, April 13-16, 2010, Galveston, TX), a task force composed of internationally recognized experts in the field of APS was formed to address these issues. In this review, we discuss approaches that have been used in the past to achieve harmonization among aPL immunoassays as well as the ongoing efforts of the APLA task force. Our review also highlights the importance of cutoff determination in aPL assays and the clinical significance of positive aPL results of varying magnitudes.

Value of isolated IgA anti-ß2 -glycoprotein I positivity in the diagnosis of the antiphospholipid syndrome.

OBJECTIVE: To examine the prevalence of isolated IgA anti-ß2 -glycoprotein I (anti-ß2 GPI) positivity and the association of these antibodies, and a subgroup that bind specifically to domain IV/V of ß2 GPI, with clinical manifestations of the antiphospholipid syndrome (APS) in 3 patient groups and to evaluate the pathogenicity of IgA anti-ß2 GPI in a mouse model of thrombosis. METHODS: Patients with systemic lupus erythematosus (SLE) from a multiethnic, multicenter cohort (LUpus in MInorities, NAture versus nurture [LUMINA]) (n = 558), patients with SLE from the Hopkins Lupus Cohort (n = 215), and serum samples referred to the Antiphospholipid Standardization Laboratory (APLS) (n = 5,098) were evaluated. IgA anti-ß2 GPI titers and binding to domain IV/V of ß2 GPI were examined by enzyme-linked immunosorbent assay (ELISA). CD1 mice were inoculated with purified IgA anti-ß2 GPI antibodies, and surgical procedures and ELISAs were performed to evaluate thrombus development and tissue factor (TF) activity. RESULTS: A total of 198 patients were found to be positive for IgA anti-ß2 GPI isotype, and 57 patients were positive exclusively for IgA anti-ß2 GPI antibodies. Of these, 13 of 23 patients (56.5%) in the LUMINA cohort, 17 of 17 patients (100%) in the Hopkins cohort, and 10 of 17 patients (58.9%) referred to APLS had at least one APS-related clinical manifestation. Fifty-four percent of all the IgA anti-ß2 GPI-positive serum samples reacted with domain IV/V of anti-ß2 GPI, and 77% of those had clinical features of APS. Isolated IgA anti-ß2 GPI positivity was associated with an increased risk of arterial thrombosis (P < 0.001), venous thrombosis (P = 0.015), and all thrombosis (P < 0.001). The association between isolated IgA anti-ß2 GPI and arterial thrombosis (P = 0.0003) and all thrombosis (P = 0.0003) remained significant after adjusting for other risk factors for thrombosis. In vivo mouse studies demonstrated that IgA anti-ß2 GPI antibodies induced significantly larger thrombi and higher TF levels compared to controls. CONCLUSION: Isolated IgA anti-ß2 GPI-positive titers may identify additional patients with clinical features of APS. Testing for these antibodies when other antiphospholipid tests are negative and APS is suspected is recommended. IgA anti-ß2 GPI antibodies directed to domain IV/V of ß2 GPI represent an important subgroup of clinically relevant antiphospholipids.

Deciphering the clinical significance of longitudinal antiphospholipid antibody titers.

In antiphospholipid syndrome (APS), the risk of clinical manifestations increases with higher titers of antiphospholipid antibodies (aPL). Despite the adoption of aPL titers in the classification approach to aPL-positive subjects, the value of longitudinal monitoring of those titers in the follow-up is still debated, being well studied only in systemic lupus erythematosus (SLE). The literature suggests that the rate of aPL positivity decreases during follow-up in primary APS, estimating that seroconversion occurs in between 8.9 and 59% of patients over time. Negativisation of aPL occurs more frequently in asymptomatic aPL carriers than in patients with full-blown APS as well as in subjects with single aPL positivity or low aPL antibody titers. In patients with SLE, aPL typically behave fluctuating from positive to negative and back again in the course of follow-up. The few studies assessing the longitudinal course of aPL positivity with no associated systemic connective tissue disease reported a progressive decrement of aPL titers over time, in particular of antibodies against ß2 glycoprotein I (antiß2GPI) and cardiolipin (aCL) of IgG isotype. After a thrombotic event, aPL titers tend to decrease, as emerged from cohorts of both primary and secondary APS. Hydroxychloroquine has been identified as the most effective pharmacological agent to reduce aPL titers, with multiple studies demonstrating a parallel reduction in thrombosis rate. This review addresses available evidence on the significance of aPL titer fluctuation from clinical, therapeutic and pathogenic perspectives.

Thrombosis recurrence and major bleeding in non-anticoagulated thrombotic antiphospholipid syndrome patients: Prospective study from antiphospholipid syndrome alliance for clinical trials and international networking (APS ACTION) clinical database and repository ("Registry").

BACKGROUND: Long-term anticoagulant therapy is generally recommended for thrombotic antiphospholipid syndrome (TAPS) patients, however it may be withdrawn or not introduced in routine practice. OBJECTIVES: To prospectively evaluate the risk of thrombosis recurrence and major bleeding in non-anticoagulated TAPS patients, compared to anticoagulated TAPS, and secondly, to identify different features between those two groups. PATIENTS/METHODS: Using an international registry, we identified non-anticoagulated TAPS patients at baseline, and matched them with anticoagulated TAPS patients based on gender, age, type of previous thrombosis, and associated autoimmune disease. Thrombosis recurrence and major bleeding were prospectively analyzed using Kaplan-Meier method and compared using a marginal Cox's regression model. RESULTS: As of June 2022, 94 (14 %) of the 662 TAPS patients were not anticoagulated; and 93 of them were matched with 181 anticoagulated TAPS patients (median follow-up 5 years [interquartile range 3 to 8]). The 5-year thrombosis recurrence and major bleeding rates were 12 % versus 10 %, and 6 % versus 7 %, respectively (hazard ratio [HR] 1.38, 95 % confidence interval [CI] 0.53 to 3.56, p = 0.50 and HR 0.53; 95 % CI 0.15 to 1.86; p = 0.32, respectively). Non-anticoagulated patients were more likely to receive antiplatelet therapy (p < 0.001), and less likely to have more than one previous thrombosis (p < 0.001) and lupus anticoagulant positivity (p = 0.01). CONCLUSION: Fourteen percent of the TAPS patients were not anticoagulated at recruitment. Their recurrent thrombosis risk did not differ compared to matched anticoagulated TAPS patients, supporting the pressing need for risk-stratified secondary thrombosis prevention trials in APS investigating strategies other than anticoagulation.

Reporting and Establishment of Reference Intervals for Antiphospholipid Antibody Immunoassays: A Survey of Participants in the College of American Pathologists Proficiency Testing Program.

CONTEXT.­: Misdiagnosis of antiphospholipid syndrome can occur owing to the wide diversity of antiphospholipid (aPL) assays and a lack of international calibrators and harmonized reference intervals. OBJECTIVE.­: To assess laboratory practices regarding reporting and establishing reference intervals for immunoglobulin (Ig) G/IgM anti-cardiolipin (aCL) and anti-beta-2 glycoprotein I (anti-ß2GPI) assays. DESIGN.­: Supplemental questions related to reporting and establishing reference ranges for aPL assays were sent as part of the Antiphospholipid Antibody (ACL)-B 2019 College of American Pathologists (CAP) proficiency testing survey. The response rate and methods assessment details were determined, as well as qualitative and quantitative results for 3 test samples. RESULTS.­: The number of participants reporting results for IgG aCL (n = 489), IgM aCL (n = 476), IgG anti-ß2GPI (n = 354), and IgM anti-ß2GPI (n = 331) varied by antibody type. The enzyme-linked immunosorbent assay (ELISA) (up to 58.6%, 260 of 444) was the most used method; others included multiplex (from 18.9% to 23.9%), fluorescence enzyme immunoassay (14.4%-17.6%), and chemiluminescence immunoassay (6.5%-9.0%). More respondents reported quantitative than qualitative results and manufacturer cutoff ranges were used by 92.9% and 94.2% of respondents for aCL and anti-ß2GPI, respectively. Despite variation in the use of semiquantitative ranges, qualitative negative/positive reporting of the test samples achieved almost 100% consensus. Qualitative consensus was met in contrast to the wide range of quantitative results obtained for each analyte across different kits. CONCLUSIONS.­: ELISA remains the most used method for detecting aPL antibodies with most laboratories reporting quantitative results based on manufacturers' suggested reference ranges. The categorization of quantitative results as equivocal, weak positive, or positive for responders using kits from the same manufacturer was variable.

Fluctuation of Anti-Domain 1 and Anti-ß2 -Glycoprotein I Antibody Titers Over Time in Patients With Persistently Positive Antiphospholipid Antibodies.

OBJECTIVE: The present study was undertaken to longitudinally evaluate titers of antibodies against ß2 -glycoprotein I (anti-ß2 GPI) and domain 1 (anti-D1), to identify predictors of variations in anti-ß2 GPI and anti-D1 titers, and to clarify whether antibody titer fluctuations predict thrombosis in a large international cohort of patients who were persistently positive for antiphospholipid antibodies (aPL) in the APS ACTION Registry. METHODS: Patients with available blood samples from at least 4 time points (at baseline [year 1] and at years 2-4 of follow-up) were included. Detection of anti-ß2 GPI and anti-D1 IgG antibodies was performed using chemiluminescence (BIO-FLASH; INOVA Diagnostics). RESULTS: Among 230 patients in the study cohort, anti-D1 and anti-ß2 GPI titers decreased significantly over time (P < 0.0001 and P = 0.010, respectively). After adjustment for age, sex, and number of positive aPL tests, we found that the fluctuations in anti-D1 and anti-ß2 GPI titer levels were associated with treatment with hydroxychloroquine (HCQ) at each time point. Treatment with HCQ, but not immunosuppressive agents, was associated with 1.3-fold and 1.4-fold decreases in anti-D1 and anti-ß2 GPI titers, respectively. Incident vascular events were associated with 1.9-fold and 2.1-fold increases in anti-D1 and anti-ß2 GPI titers, respectively. Anti-D1 and anti-ß2 GPI titers at the time of thrombosis were lower compared to titers at other time points. A 1.6-fold decrease in anti-D1 titers and a 2-fold decrease in anti-ß2 GPI titers conferred odds ratios for incident thrombosis of 6.0 (95% confidence interval [95% CI] 0.62-59.3) and 9.4 (95% CI 1.1-80.2), respectively. CONCLUSION: Treatment with HCQ and incident vascular events in aPL-positive patients predicted significant anti-D1 and anti-ß2 GPI titer fluctuations over time. Both anti-D1 and anti-ß2 GPI titers decreased around the time of thrombosis, with potential clinical relevance.

Anti-Neutrophil Extracellular Trap Antibodies in Antiphospholipid Antibody-Positive Patients: Results From the Antiphospholipid Syndrome Alliance for Clinical Trials and InternatiOnal Networking Clinical Database and Repository.

OBJECTIVE: This study aimed to elucidate the presence, antigen specificities, and potential clinical associations of anti-neutrophil extracellular trap (anti-NET) antibodies in a multinational cohort of antiphospholipid (aPL) antibody-positive patients who did not have lupus. METHODS: Anti-NET IgG/IgM levels were measured in serum samples from 389 aPL-positive patients; 308 patients met the classification criteria for antiphospholipid syndrome. Multivariate logistic regression with best variable model selection was used to determine clinical associations. For a subset of the patients (n = 214), we profiled autoantibodies using an autoantigen microarray platform. RESULTS: We found elevated levels of anti-NET IgG and/or IgM in 45% of the aPL-positive patients. High anti-NET antibody levels are associated with more circulating myeloperoxidase (MPO)-DNA complexes, which are a biomarker of NETs. When considering clinical manifestations, positive anti-NET IgG was associated with lesions affecting the white matter of the brain, even after adjusting for demographic variables and aPL profiles. Anti-NET IgM tracked with complement consumption after controlling for aPL profiles; furthermore, patient serum samples containing high levels of anti-NET IgM efficiently deposited complement C3d on NETs. As determined by autoantigen microarray, positive testing for anti-NET IgG was significantly associated with several autoantibodies, including those recognizing citrullinated histones, heparan sulfate proteoglycan, laminin, MPO-DNA complexes, and nucleosomes. Anti-NET IgM positivity was associated with autoantibodies targeting single-stranded DNA, double-stranded DNA, and proliferating cell nuclear antigen. CONCLUSION: These data reveal high levels of anti-NET antibodies in 45% of aPL-positive patients, where they potentially activate the complement cascade. While anti-NET IgM may especially recognize DNA in NETs, anti-NET IgG species appear to be more likely to target NET-associated protein antigens.

Current international initiatives in antiphospholipid antibody testing.

Positive results in the anticardiolipin antibody (aCL), anti-ß2-glycoprotein I antibody (aß2GPI), and/or lupus anticoagulant (LA) assays constitute the laboratory criteria for the definite diagnosis of the antiphospholipid syndrome (APS). These tests became available from as early as the1980s, and since then several novel assays have become available that have varied usefulness in the diagnosis and prognosis of APS patients. For almost three decades there has been an ongoing effort to standardize the aCL, aß2GPI, and LA assays, but there are still reports of significant intra- and interlaboratory variation in the results of all three assays. There have also been numerous issues with the implementation of novel (noncriteria) antiphospholipid antibody (aPL) tests in standard testing panels, due to either lack of standardized testing methods or limited evidence of their clinical utility in APS patients. At the recent 13th International Congress on Antiphospholipid Antibodies (APLA 2010, 13-16 April 2010, Galveston, TX), two task forces were set up to address these problems. This review gives a general description of current problems hindering the standardization of aPL tests and the implementation of novel assays as standard components of aPL testing panels. It also highlights the approach used by APLA 2010 Task Forces to address these problems and presents their recommendations.

Pathogenesis of the antiphospholipid syndrome.

The presence of pathogenic antiphospholipid antibodies (aPL) is the characterizing feature of the antiphospholipid syndrome (APS), mediating the recurrent pregnancy loss and thrombosis typical of the disease, through their action on various antigenic targets. Despite the available knowledge regarding the mechanisms by which aPL induce a procoagulant phenotype in the vasculature and abnormal cellular proliferation and differentiation in placental tissues to cause the typical clinical features, these processes still remain incompletely understood. It is also known that inflammation serves as a necessary link between the observed procoagulant phenotype and actual thrombus development, and is an important mediator of the placental injury in APS patients. Even less well understood are the processes underlying the ontogeny of these pathogenic antibodies. This review seeks to highlight what is known about the mechanisms that contribute to the origin of pathogenic aPL and to the action of these antibodies on target antigens that produce the pathological features of APS. We will also examine the feasibility of classifying patients in clinical phenotypes related to underlying pathophysiological mechanisms, and how this could impact the management of patients with novel "targeted" therapeutic strategies.

Knowledge, Practice and Attitudes to the Management of Sepsis in Jamaica.

Introduction: Sepsis is a life-threatening dysfunction resulting from the dysregulated host response to infection. The mortality of sepsis in Jamaica remains high amid the proven efficacy of the Surviving Sepsis Guidelines implementation in some countries. Aim of study: To evaluate the inter-relationship of healthcare workers' attitude towards, knowledge of and practice of sepsis management in Jamaica. Material and methods: A survey was done using an anonymous self-administered validated questionnaire to healthcare workers across Jamaica. Questions on knowledge, attitude, and practice of sepsis within private and public hospitals were answered. Results: A total of 616 healthcare workers were eligible for analysis. Most respondents agree that healthcare workers need more training on sepsis (93.7%) and that formal sepsis training modules should be implemented at their hospitals or practice (93.2%). Several signs of sepsis as outlined by qSOFA were correctly identified as such by most respondents (60.6% to 76.4%), with the exception of a low PaCO2 (34.9%), which was correctly identified by a minority of respondents. While a majority (69.3%) were able to correctly define sepsis, only 8.8% of respondents knew the annual sepsis mortality rate. Postgraduate training (p<0.01) and formal sepsis training (p<0.05) were both predictive of high correct knowledge and practice scores. Specialization in Anaesthesia/ Critical Care Medicine (p<0.05) or Emergency Medicine (p<0.05) was predictive of high knowledge scores and Internal Medicine predictive of high practice scores (p<0.01). Conclusions: This study revealed that education for healthcare workers on sepsis and the implementation of SSC is needed in Jamaica.