Antiphospholipid syndrome pathogenesis in 2023: an update of new mechanisms or just a reconsideration of the old ones?

Antibodies against phospholipid (aPL)-binding proteins, in particular, beta 2 glycoprotein I (ß2GPI), are diagnostic/classification and pathogenic antibodies in antiphospholipid syndrome (APS). ß2GPI-aPL recognize their target on endothelium and trigger a pro-thrombotic phenotype which is amplified by circulating monocytes, platelets and neutrophils. Complement activation is required as supported by the lack of aPL-mediated effects in animal models when the complement cascade is blocked. The final result is a localized clot. A strong generalized inflammatory response is associated with catastrophic APS, the clinical variant characterized by systemic thrombotic microangiopathy. A two-hit hypothesis was suggested to explain why persistent aPL are associated with acute events only when a second hit allows antibody/complement binding by modulating ß2GPI tissue presentation. ß2GPI/ß2GPI-aPL are also responsible for obstetric APS, being the molecule physiologically present in placental/decidual tissues. Additional mechanisms mediated by aPL with different characteristics have been reported, but their diagnostic/prognostic value is still a matter of research.

Inflammatory and vaso-occlusive ulcers: Part I - clinical presentation and diagnosis.

In this CME, we review two specific categories of ulcers: inflammatory (where inflammation is the primary pathologic process leading to ulceration) and vaso-occlusive (where occlusion is the primary process). Inflammatory ulcers include pyoderma gangrenosum and vasculitides, whereas livedoid vasculopathy, calciphylaxis and Martorell ulcers are vaso-occlusive ulcers. Determining the causes of ulcers in these conditions may require laboratory evaluation, biopsy and imaging.

Inflammatory and vaso-occlusive ulcers: Part II - Management.

In the second part of this CME, we present an approach for the management of inflammatory and vaso-occlusive ulcers and highlight the need for further research in this field. The three overarching principles for management are etiology-specific treatment, ulcer care, and consideration of patient comorbidities and risk factors for poor healing. Both etiology-specific treatment and management of patient comorbidities and risk factors often require collaboration with providers from other specialties. Ulcer care is governed by TIME, or tissue debridement, infection control, management of moisture imbalance and epithelial edge advancement. As wound healing is a dynamic process, management should be adapted to changes in the status of the ulcer.

Successful treatment with rituximab in anti-phospholipid syndrome nephropathy associated with systemic lupus erythematosus: A case report and literature review.

Anti-phospholipid syndrome (APS) nephropathy is an autoimmune disease that is sometimes accompanied by systemic lupus erythematosus (SLE). Here, we report the use of rituximab to treat a case of APS nephropathy in a SLE patient with recurrent vascular thrombosis. A 52-year-old woman, who had been diagnosed with SLE 11 years earlier, was referred to a nephrology clinic for evaluation of azotaemia and proteinuria. She had experienced spontaneous abortion at 35 years of age. The patient had been diagnosed with right popliteal thrombosis at 39 years of age, and with left pulmonary artery thrombosis and SLE at 41 years of age. Before admission, she was undergoing anticoagulant and immunosuppressive therapies, with follow-up in the rheumatology clinic. At her last outpatient clinic visit before admission, she exhibited mild bilateral lower-limb pitting oedema, impaired renal function and proteinuria. Renal biopsy revealed arteriolar wall thickening, with thrombi in the capillary lumina and marked inflammatory cell infiltration in the interstitium. The patient was treated with warfarin and high-dose corticosteroids. Intravenous rituximab (500 mg) was also administered twice at a 4-week interval. Her renal function did not worsen any further, and her proteinuria decreased. Here we report the successful use of rituximab to treat APS nephropathy in a patient with SLE, who had progressive renal insufficiency.

Anti-vimentin/cardiolipin IgA in the anti-phospholipid syndrome: A new tool for 'seronegative' diagnosis.

Anti-phospholipid syndrome (APS) is a systemic autoimmune disorder defined by the simultaneous presence of vascular clinical events, pregnancy morbidity and anti-phospholipid antibodies (aPL). In clinical practice, it is possible to find patients with APS who are persistently negative for the routine aPL tests (seronegative APS; SN-APS). Recently, the identification of aPL immunoglobulin (Ig)A and/or anti-ß2-glycoprotein-I (ß2-GPI) IgA was shown to represent a further test in SN-APS patients. In this study we analyzed the presence of anti-vimentin/cardiolipin (aVim/CL) IgA in a large cohort of patients with SN-APS, evaluating their possible association with clinical manifestations of the syndrome. This study includes 60 consecutive SN-APS patients, 30 patients with APS and 40 healthy donors. aVim/CL IgA were detected by enzyme-linked immunosorbent assay (ELISA). Results show that 12 of 30 APS patients (40%) and 16 of 60 SN-APS patients (26.7%) resulted positive for aVim/CL IgA. Interestingly, SN-APS patients who tested positive for aVim/CL IgA showed a higher prevalence of arterial thrombosis (p = 0.017, likelihood positive ratio = 5.7). This study demonstrates for the first time, to our knowledge, the presence of aVim/CL IgA in sera of patients with APS. In particular, they revealed a potential usefulness in identification of a significant proportion of SN-APS patients. Moreover, as patients tested positive for aVim/CL IgA reported a high likelihood ratio to have the clinical features of APS, this test may be considered a suitable approach in the clinical evaluation of SN-APS.

EUREKA algorithm predicts obstetric risk and response to treatment in women with different subsets of anti-phospholipid antibodies.

OBJECTIVES: aPL, the serum biomarkers of APS, are the most common acquired causes of pregnancy morbidity (PM). This study investigates the impact of aPL positivity fulfilling classification criteria ('criteria aPL') and at titres lower than thresholds considered by classification criteria ('low-titre aPL') on PM and assesses the effectiveness of low-dose aspirin (LDASA), low molecular weight heparin (LMWH) and HCQ in reducing the probability of PM (PPM). METHODS: Longitudinal data on 847 pregnancies in 155 women with persistent aPL at any titre and 226 women with autoimmune diseases and negative aPL were retrospectively collected. A generalized estimating equations model for repeated measures was applied to quantify PPM under different clinical situations. RESULTS: EUREKA is a novel algorithm that accurately predicts the risk of aPL-associated PM by considering aPL titres and profiles. aPL significantly impact PPM when at low titres and when fulfilling classification criteria. PPM was further stratified upon the aPL tests: aCL IgG/IgM and anti-ß2-glycoprotein I (ß2GPI) IgM, alone or combined, do not affect the basal risks of PPM, an increase occurs in case of positive LA or anti-ß2GPI IgG. LDASA significantly affects PPM exclusively in women with low-titre aPL without anti-ß2GPI IgG. The LDASA + LMWH combination significantly reduces PPM in all women with low-titre aPL and women with criteria aPL, except those carrying LA and anti-ß2GPI IgG. In this group, the addition of HCQ further reduces PPM, although not significantly. CONCLUSION: EUREKA allows a tailored therapeutic approach, impacting everyday clinical management of aPL-positive pregnant women.

Extrahepatic autoimmune diseases in primary biliary cholangitis: Prevalence and significance for clinical presentation and disease outcome.

BACKGROUND AND AIM: The prevalence and clinical significance of extrahepatic autoimmune diseases (EHAIDs) have not been evaluated in a large cohort of primary biliary cholangitis (PBC). METHODS: The medical records of 1554 patients with PBC from 20 international centers were retrospectively reviewed. Development of decompensated cirrhosis (ascites, variceal bleeding, and/or hepatic encephalopathy) and hepatocellular carcinoma were considered clinical endpoints. RESULTS: A total of 35 different EHAIDs were diagnosed in 440 (28.3%) patients with PBC. Patients with EHAIDs were more often female (92.5% vs 86.1%, P < 0.001) and seropositive for anti-mitochondrial antibodies (88% vs 84%, P = 0.05) and antinuclear antibodies and/or smooth muscle antibodies (53.8% vs 43.6%, P = 0.005). At presentation, patients with EHAIDs had significantly lower levels of alkaline phosphatase (1.76 vs 1.98 × upper limit of normal [ULN], P = 0.006), aspartate aminotransferase (1.29 vs 1.50 × ULN, P < 0.001), and total bilirubin (0.53 vs 0.58 × ULN, P = 0.002). Patients with EHAIDs and without EHAIDs had similar rates of GLOBE high-risk status (12.3% vs 16.1%, P = 0.07) and Paris II response (71.4% vs 69.4%, P = 0.59). Overall, event-free survival was not different in patients with and without EHAIDs (90.8% vs 90.7%, P = 0.53, log rank). Coexistence of each autoimmune thyroid diseases (10.6%), Sjögren disease (8.3%), systemic sclerosis (2.9%), rheumatoid arthritis (2.7%), systemic lupus erythematosus (1.7%), celiac disease (1.7%), psoriasis (1.5%), and inflammatory bowel diseases (1.3%) did not influence the outcome. CONCLUSIONS: Our study confirms that EHAIDs are frequently diagnosed in patients with PBC. The presence of EHAIDs may influence the clinical phenotype of PBC at presentation but has no impact on PBC outcome.

Antiphospholipid antibody levels in early systemic lupus erythematosus: are they associated with subsequent mortality and vascular events?

OBJECTIVES: aPL are present in between 20 and 30% of patients with SLE. They can cause vascular events (VE) or pregnancy morbidity. aCL and anti-beta-2-glycoprotein I (anti-ß2GPI) are measured in clinical practice. Domain I (DI) of ß2GPI is the main site for aPL binding. We investigated the prevalence of IgG anti-DI, aCL and anti-ß2GPI antibodies in early SLE and their association with mortality and development of VE. METHODS: Samples from 501 patients with SLE that had been obtained and stored early during their disease were tested for IgG anti-DI, aCL and anti-ß2GPI antibodies by ELISA. LA status and history of VE were obtained by reviewing medical records. Kaplan-Meier analysis was used to investigate mortality and occurrence of VE, comparing groups with and without aPL in early disease. RESULTS: Of 501 patients, 190 (38%) had at least one of these aPL, of whom 112 had anti-DI alone. Of 276 patients with complete vascular history, 83 had experienced VE. The 39 patients who were double or triple-ELISA-positive for any combination of the three aPL were more likely to have or develop lupus anticoagulant (P<0.0001) than those who were single-ELISA-positive or negative. In Kaplan-Meier analysis, they showed a trend towards developing more VE (P = 0.06). CONCLUSION: IgG anti-DI antibodies were present in early serum samples from 29% of patients and were more common than IgG aCL or anti-ß2GPI. There was some evidence suggesting that double or triple-ELISA-positivity for these antibodies identified a group with worse outcomes.

Prevalence of autoantibodies directed against prothrombin in unprovoked venous thromboembolism.

The anti-phospholipid syndrome (APS) is defined by the laboratory detection of at least one of three anti-phospholipid autoantibodies (lupus anticoagulant, or anti-cardiolipin or anti-ß2-glycoprotein I antibodies) in the clinical setting of thrombosis or pregnancy morbidity in a patient. Recognising APS and administering appropriate secondary thromboprophylaxis is important to reduce risk of recurrent thrombosis and/or pregnancy morbidity. In some instances, patients having clinical manifestations highly suggestive of APS are persistently negative for these antibodies but instead have other autoantibodies. Autoantibodies directed against prothrombin (PT) have been associated with increased thrombotic risk and comprise anti-prothrombin (aPT) and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies. Detection of aPT and aPS/PT may help stratify patients for more effective treatment, however, their prevalence among patients with unprovoked venous thromboembolism (VTE) is unknown and determination of their frequencies is the objective of this study. Sera from 148 patients with unprovoked VTE were analysed. Autoantibodies directed against PT collectively, aPT and aPS/PT were present in 24.3%, 14.9% and 13.5%, respectively. Prevalence of these autoantibodies in unprovoked VTE is much lower compared to cohorts comprising mainly patients with systemic autoimmune disorders. Detection of these autoantibodies in unprovoked VTE has potential therapeutic implications for patients including the duration of anticoagulation and administration, or otherwise, of direct oral anticoagulants. Data from this study will assist in the design of future clinical studies to estimate risk of recurrent VTE and to determine optimal management.

News and meta-analysis regarding anti-Beta 2 glycoprotein I antibodies and their determination.

Recent advances allow us to propose antibodies targeting beta-2-glycoprotein I (ß2-GPI) as the most specific antibodies associated with anti-phospholipid syndrome (APS). Therefore, there is now a crucial need for powerful biological assays to adequately monitor them. It is well established that these antibodies recognize mainly cryptic epitopes, which requires a great deal of consideration in the choice of laboratory tests to identify these antibodies. To this end, an update on the pathophysiological role of ß2-GPI and a meta-analysis were conducted providing an overview of the current progress towards anti-ß2-GPI detection.

Mitigating placental injuries through up-regulating DAF in experimental APS mice: new mechanism of progesterone.

Anti-phospholipid syndrome (APS) is characterized by recurrent pathological pregnancy, arterial or venous thrombosis in the presence of anti-phospholipid antibody (aPL). Complement activation is recognized as an intermediate link leading to placental thrombosis and placental inflammation in APS model mice. Decay accelerating factor (DAF, CD55), MAC-inhibitory protein (MAC-IP, CD59) and membrane co-factor protein (MCP, CD46) are important complement inhibitory proteins (CIPs) highly expressed in normal placenta to curb excessive complement activation and its mediated injuries. Anti-ß2 glycoprotein I (anti-ß2GPI) antibody is an important aPL. We found that placental DAF and CD46 decreased in ß2GPI passively immunized APS model mice, accompanied by C3 deposition, neutrophil infiltration and increased proinflammatory cytokine levels detected in its placenta. Progesterone supplement can up-regulate DAF but not CD46 expression, curb C3 activation and decrease proinflammatory cytokines levels to reduce fetal loss frequency. Progesterone receptor antagonist (mifepristone) or knock-down DAF with specific siRNA, above the protective effects of progesterone, were significantly weakened. Another sex hormone, oestrogen, has no significant effect on placental DAF and C3 contents and fetal loss frequency in the APS mice model. This may be an important mechanism by which progesterone induces maternal-fetal immune tolerance. At the same time, it may provide evidence for the use of progesterone in APS abortion patients.

Tissue factor over-expression in platelets of patients with anti-phospholipid syndrome: induction role of anti-ß2-GPI antibodies.

Anti-phospholipid syndrome (APS) is characterized by arterial and/or venous thrombosis and pregnancy morbidity. It is well known that in these patients thrombosis may be the result of a hypercoagulable state related to anti-ß2-glycoprotein I (ß2-GPI) antibodies. Moreover, platelets may play a role in thrombotic manifestations by binding of anti-ß2-GPI antibodies. Platelets express tissue factor (TF), the major initiator of the clotting cascade, after activation. We primarily analyzed whether anti-ß2-GPI antibodies may trigger a signal transduction pathway leading to TF expression in human platelets. Platelets from healthy donors were incubated with affinity purified anti-ß2-GPI antibodies for different times. Platelet lysates were analyzed for phospho-interleukin-1 receptor-associated kinase 1 (IRAK), phospho-p65 nuclear factor kappaB (NF-κB) and TF by Western blot. IRAK phosphorylation was observed as early as 10 min of anti-ß2-GPI treatment, with consequent NF-κB activation, whereas TF expression, detectable at 45 min, was significantly increased after 4 h of anti-ß2-GPI treatment. Virtually no activation was observed following treatment with control immunoglobulin IgG. We then analyzed TF expression in platelets from 20 APS patients and 20 healthy donors. We observed a significant increase of TF in APS patients versus control subjects (P < 0·0001). This work demonstrates that anti-ß2-GPI antibodies may trigger in vitro a signal transduction pathway in human platelets, which involves IRAK phosphorylation and NF-κB activation, followed by TF expression. Furthermore, ex vivo, platelets of APS patients showed a significantly increased expression of TF. These findings support the view that platelets may play a role in the pathogenesis of APS, with consequent release of different procoagulant mediators, including TF.

Anti-ß2 -glycoprotein I antibody with DNA binding activity enters living monocytes via cell surface DNA and induces tissue factor expression.

Autoantibodies characteristic for anti-phospholipid syndrome (APS) and systemic lupus erythematosus (SLE) are anti-ß2 -glycoprotein I (ß2 GPI) antibodies and anti-DNA antibodies, respectively, and almost half of APS cases occur in SLE. Anti-ß2 GPI antibodies are recognized to play a pivotal role in inducing a prothrombotic state, but the precise mechanism has not been fully elucidated. In a widely accepted view, binding of anti-ß2 GPI antibodies to cell surface ß2 GPI in monocytes and endothelial cells triggers the Toll-like receptor 4-myeloid differentiation primary response 88 (TLR)-4-MyD88) signaling pathway which leads to activation of p38 mitogen-activated protein kinase (MAPK), mitogen-activated protein kinase kinase 1/extracellular signal-regulated kinases (MEK-1/ERK) and/or nuclear factor kappa B (NF-κB) and expression of tissue factor (TF). However, resting cells do not express substantial amounts of TLR-4. Previously, we generated a mouse monoclonal anti-ß2 GPI antibody WB-6 and showed that it induced a prothrombotic state - including TF expression on circulating monocytes - in normal mice. In the current study, we aimed to clarify the mechanism of interaction between WB-6 and resting monocytes, and found that WB-6 exhibits binding activity to DNA and enters living monocytes or a monocytic cell line and, to a lesser extent, vascular endothelial cells. Treatment of the cells with DNase I reduced the internalization, suggesting the involvement of cell surface DNA in this phenomenon. Monocytes harboring internalized WB-6 expressed TF and tumor necrosis factor (TNF)-α which, in turn, stimulated endothelial cells to express intercellular adhesion molecule 1 (ICAM-I) and vascular cell adhesion molecule 1 (VCAM-I). These results suggest the possibility that a subset of anti-ß2 GPI antibodies with dual reactivity to DNA possesses ability to stimulate DNA sensors in the cytoplasm, in addition to the cell surface receptor-mediated pathways, leading to produce proinflammatory and prothrombotic states.

Use of combined hormonal contraceptives among women with systemic lupus erythematosus with and without medical contraindications to oestrogen.

OBJECTIVES: To assess the prevalence of combined hormonal contraceptives (CHCs) in reproductive-age women with SLE with and without possible contraindications and to determine factors associated with their use in the presence of possible contraindications. METHODS: This observational cohort study included premenopausal women ages 18-45 years enrolled in the SLICC Registry ⩽15 months after SLE onset, with annual assessments spanning 2000-2017. World Health Organization Category 3 or 4 contraindications to CHCs (e.g. hypertension, aPL) were assessed at each study visit. High disease activity (SLEDAI score >12 or use of >0.5 mg/kg/day of prednisone) was considered a relative contraindication. RESULTS: A total of 927 SLE women contributed 6315 visits, of which 3811 (60%) occurred in the presence of one or more possible contraindication to CHCs. Women used CHCs during 512 (8%) visits, of which 281 (55%) took place in the setting of one or more possible contraindication. The most frequently observed contraindications were aPL (52%), hypertension (34%) and migraine with aura (22%). Women with one or more contraindication were slightly less likely to be taking CHCs [7% of visits (95% CI 7, 8)] than women with no contraindications [9% (95% CI 8, 10)]. CONCLUSION: CHC use was low compared with general population estimates (>35%) and more than half of CHC users had at least one possible contraindication. Many yet unmeasured factors, including patient preferences, may have contributed to these observations. Further work should also aim to clarify outcomes associated with this exposure.

Anti-phospholipid antibody syndrome occurrence in patients with persistent anti-phospholipid antibodies.

We investigated the overall frequency of anti-phospholipid syndrome (APS) occurrence in Korean patients with consecutively detected anti-phospholipid antibodies with an interval of 12 weeks (persistent aPLs). We retrospectively reviewed the results of blood tests of aPLs in 14,889 patients in whom aPL tests were performed at Yonsei University College of Medicine, Severance Hospital, from January 2012 to August 2018, and included 833 patients with persistent aPLs. We obtained clinical and laboratory data including anti-cardiolipin antibodies IgM and IgG, anti-beta2 glycoprotein1 IgM and IgG, and lupus anticoagulant (LAC). Of 833 patients with persistent aPLs, 96 patients (11.5%) had APS (84 patients had thrombotic events and 12 had pregnancy morbidity). Among aPLs, LAC was detected in patients with APS more frequently than asymptomatic carriers of aPLs (46.9% vs. 25.9%, p < 0.001). Patients with LAC (relative risk (RR) 2.558, p < 0.001) and aPLs ≥ 2 (RR 1.731, p = 0.014) exhibited the higher rate of APS occurrence than those without. Moreover, patients with aPLs ≥ 3 and aPLs ≥ 4 exhibited the higher rates of APS occurrence than those without (RR 2.753, p < 0.001 and RR 3.209, p = 0.013). Meanwhile, patients with ANA, anti-dsDNA, anti-SSA/Ro, and SLE exhibited the increased frequency of LAC positivity, compared to those without (RR 3.304, p = 0.005, RR 4.269, p = 0.032, RR 3.750, p = 0.041 and RR 8.828, p < 0.001, respectively). APS occurs in 11.5% of Korean patients with persistent aPLs. LAC positivity and aPLs ≥ 2 were significantly associated with APS occurrence. SLE and SLE-related autoantibodies were associated with LAC positivity.

Clinical characteristics of patients with systemic lupus erythematosus showing a false-positive result of syphilis screening.

A false-positive result of syphilis screening test (FPST) is a characteristic finding in patients with systemic lupus erythematosus (SLE). We evaluated the clinical characteristics of SLE patients with FPST at SLE diagnosis. We reviewed the medical records of patients with SLE who underwent the Venereal Disease Research Laboratory or Rapid Plasma Reagin tests at SLE diagnosis at Severance Hospital between 2006 and 2016. The baseline characteristics and clinical outcomes were compared between patients with FPST and those with a negative result of syphilis screening test. Of 145 patients with SLE, 20 patients showed FPST and 125 patients showed a negative syphilis screening result. At SLE diagnosis, patients with a negative result had higher SLE disease activity index (5.0 vs. 8.0, P < 0.001) and were more commonly complicated with nephritis (15.0% vs. 41.6%, P = 0.026). High level of serum total protein (> 8 g/dL) and the presence of anti-cardiolipin antibodies were independently associated with FPST (P = 0.010 and 0.037, respectively). During the follow-up (median 61 months), 5 patients with FPST (20.0%) and 12 patients without FPST (9.6%) were finally diagnosed with APS. The long-term risk of de novo thrombosis was higher in the FPST group (n = 4/20, 20% vs n = 6/125, 4.8%, P = 0.041). However, all-cause mortality showed no difference between the FPST group and the negative group. Patients with SLE showing FPST showed lower disease activity at SLE diagnosis but higher thrombotic risk and similar overall survival compared to those without FPST.

Thrombotic risk assessment and analytical performance of the chemiluminescent analyzer IDS-iSYS for the detection of anti-cardiolipin and anti-beta 2 glycoprotein I autoantibodies.

Patients with antiphospholipid antibodies (APLA) are predisposed to develop thrombosis, however the standardization of anti-cardiolipin (aCL) and anti-beta 2 glycoprotein I (ß2-GPI) Ab assays are challenging. Therefore we decided to test the performance of a new chemiluminescent assay (CLIA), and assayed aCL and aß2-GPI IgG/M in serum from 120 healthy individuals, 108 patients with idiopathic venous thrombosis, 78 patients with antiphospholipid syndrome (APS), and 64 non-thrombotic APLA-carriers using CLIA IDS-iSYS. Very good (aCL/aß2-GPI IgG) to moderate (aCL/aß2-GPI IgM) agreement with a commercial and an in house ELISA assay were observed and, in particular, CLIA demonstrated the highest sensitivity in aß2-GPI IgG detection. Finally, aCL/aß2-GPI Ab capacity to predict the thrombotic risk was tested showing for CLIA a significant odds ratio (OR) when considering double positivity for aCL/aß2-GPI IgG, aCL IgG at high levels, and aß2-GPI IgG at high levels. In conclusion, CLIA improves aß2-GPI IgG detection and thrombotic risk assessment.

Immunoglobulin A anti-phospholipid antibodies in Swedish cases of systemic lupus erythematosus: associations with disease phenotypes, vascular events and damage accrual.

Immunoglobulin (Ig) G- and IgM-class anti-cardiolipin antibodies (aCL) and lupus anti-coagulant (LA) are included in the 1997 update of the American College of Rheumatology (ACR-97) systemic lupus erythematosus (SLE) criteria. Despite limited evidence, IgA-aCL and IgA anti-ß2 -glycoprotein-I (anti-ß2 GPI) were included in the 2012 Systemic Lupus International Collaborating Clinics criteria. The present study aimed to evaluate IgG-/IgA-/IgM-aCL and anti-ß2 GPI occurrence in relation to disease phenotype, smoking habits, pharmacotherapy, anti-phospholipid syndrome (APS) and organ damage among 526 Swedish SLE patients meeting ACR-97. Patients with rheumatoid arthritis (n = 100), primary Sjögren's syndrome (n = 50) and blood donors (n = 507) served as controls. Anti-phospholipid antibodies (aPL) were analysed by fluoroenzyme-immunoassays detecting aCL/anti-ß2 GPI. Seventy-six (14%) SLE cases fulfilled the Sydney APS-criteria, and ≥ 1 aCL/anti-ß2 GPI isotype (IgG/IgA/IgM) occurred in 138 SLE patients (26%). Forty-five (9%) of the SLE cases had IgA-aCL, 20 of whom (4%) lacked IgG-/IgM-aCL. Seventy-four (14%) tested positive for IgA anti-ß2 GPI, 34 (6%) being seronegative regarding IgG/IgM anti-ß2 GPI. Six (1%) had APS manifestations but were seropositive regarding IgA-aCL and/or IgA anti-ß2 GPI in the absence of IgG/IgM-aPL and LA. Positive LA and IgG-aPL tests were associated with most APS-related events and organ damage. Exclusive IgA anti-ß2 GPI occurrence associated inversely with Caucasian ethnicity [odds ratio (OR) = 0·21, 95% confidence interval (CI) = 0·06-0·72) and photosensitivity (OR = 0·19, 95% CI = 0·05-0·72). Nephritis, smoking, LA-positivity and statin/corticosteroid-medication associated strongly with organ damage, whereas hydroxychloroquine-medication was protective. In conclusion, IgA-aPL is not rare in SLE (16%) and IgA-aPL analysis may have additional value among SLE cases with suspected APS testing negative for other isotypes of aPL and LA.

The treatment of anti-phospholipid syndrome: A comprehensive clinical approach.

Anti-phospholipid syndrome (APS) is an acquired pro-thrombotic autoimmune disease that predisposes to thrombotic events and/or obstetric complications, in the persistent presence of anti-phospholipid antibodies (aPL). Life long moderate-intensity anticoagulation is the option of choice for aPL-positive patients with a previous thrombosis; critical issues concern the management of those with a history of arterial event due to the high rate of recurrence. Alternatives comprise anti-platelet agents and high-intensity anticoagulation. Low dose aspirin (LDASA) and low molecular weight heparin provide the mainstay of the treatment of obstetric APS, allowing a birth rate in 70% of cases. The management of refractory APS, thrombotic as well as obstetric, is highly debated, but an increasing burden of evidence points towards the beneficial effects of multiple treatments. Similarly, a management envisaging multiple drugs (anticoagulation, steroids, plasma exchange and/or intravenous immunoglobulins) is the most effective approach in catastrophic APS. Asymptomatic aPL carriers are at higher risk of thrombotic and obstetric complications compared to the general population, thus potentially benefitting of a pharmacological intervention. LDASA and hydroxychloroquine can be considered as options, in particular in case of high risk aPL profile, concomitant cardiovascular risk factors or associated autoimmune disease. APS is apparently a simple condition, but its multifaceted nature requires a complex and tailored treatment.

Beyond thrombosis: Anti-ß2GPI domain 1 antibodies identify late pregnancy morbidity in anti-phospholipid syndrome.

Antibodies against ß2 glycoprotein I (anti-ß2GPI) have been identified as the main pathogenic autoantibody subset in anti-phospholipid syndrome (APS); the most relevant epitope is a cryptic and conformation-dependent structure on ß2GPI domain (D) 1. Anti-ß2GPI domain profiling has been investigated in thrombotic APS, leading to the identification of antibodies targeting D1 as the main subpopulation. In contrast, scarce attention has been paid to obstetric APS, hence this study aimed at characterizing the domain reactivity with regards to pregnancy morbidity (PM). To this end, 135 women with persistently positive, medium/high titre anti-ß2GPI IgG, without any associated systemic autoimmune diseases and at least one previous pregnancy were included: 27 asymptomatic carriers; 53 women with obstetric APS; 20 women with thrombotic APS; and 35 women with both thrombotic and obstetric complications. Anti-D1 and anti-D4/5 antibodies were tested using a chemiluminescent immunoassay and a research ELISA assay, respectively (QUANTA Flash® ß2GPI Domain 1 IgG and QUANTA Lite® ß2GPI D4/5 IgG, Inova Diagnostics). Positivity for anti-D1 antibodies, but not anti-D4/5 antibodies, was differently distributed across the 4 subgroups of patients (p < 0.0001) and significantly correlated with thrombosis (χ2 = 17.28, p < 0.0001) and PM (χ2 = 4.28, p = 0.039). Patients with triple positivity for anti-phospholipid antibodies displayed higher anti-D1 titres and lower anti-D4/5 titres compared to women with one or two positive tests (p < 0.0001 and p = 0.005, respectively). Reactivity against D1 was identified as a predictor for PM (OR 2.4, 95% confidence interval [CI] 1.2-5.0, p = 0.017); in particular, anti-D1 antibodies were predictive of late PM, conveying an odds ratio of 7.3 (95% CI 2.1-25.5, p = 0.022). Positivity for anti-D1 antibodies was not associated with early pregnancy loss. Anti-D4/5 antibodies were not associated with clinical APS manifestations. As a whole, our data suggest that anti-D1 antibodies are significantly associated not only with thrombosis, but also with late PM, while positive anti-D4/5 antibodies are not predictive of thrombosis or PM.