Anti-Phosphatidylserine/Prothrombin Antibodies at Two Points: Correlation With Lupus Anticoagulant and Thrombotic Risk.

Antibodies to phospholipids (aPL) and associated proteins are a hallmark in the diagnosis of anti-phospholipid syndrome (APS). Those included in the classification criteria are the lupus anticoagulant (LA) and the IgG and IgM isotypes of anticardiolipin (aCL) and anti-beta-2 glycoprotein I (ß2GPI) antibodies. Non-classification criteria markers such as autoantibodies that recognize the phosphatidylserine/prothrombin (aPS/PT) complex have been proposed as biomarkers for APS. Studies of aPS/PT antibodies have shown a strong correlation to clinical manifestations and LA. We aimed to study the value and the persistence of aPS/PT IgG and IgM antibodies in a cohort of consecutive patients with clinical suspicion of APS and their utility as thrombotic risk markers. Our study, with 103 patients, demonstrates that persistently positive results for aPS/PT IgG antibodies were significantly associated with APS classification, thrombosis, triple aPL positivity, LA positive result, and the Global APS Score (GAPSS) > than 9 points (p < 0.01, for each condition). On the other hand, no association was seen with pregnancy morbidity (p = 0.56) and SLE (p = 0.07). Persistence of aPS/PT antibodies, defined according to the current laboratory classification criteria, likely improves the diagnosis and clinical assessment of patients with APS.

A retrospective study on the prevalence of anti-phospholipid antibodies, thrombotic events and cutaneous signs of vasculopathy in 173 hospitalized COVID-19 patients.

BACKGROUND: Hypercoagulability is a risk factor of thromboembolic events in COVID-19. Anti-phospholipid (aPL) antibodies have been hypothesized to be involved. Typical COVID-19 dermatological manifestations of livedo reticularis and digital ischemia may resemble cutaneous manifestations of anti-phospholipid syndrome (APS). OBJECTIVES: To investigate the association between aPL antibodies and thromboembolic events, COVID-19 severity, mortality, and cutaneous manifestations in patients with COVID-19. METHODS: aPL antibodies [anti-beta2-glycoprotein-1 (B2GP1) and anti-cardiolipin (aCL) antibodies] were titered in frozen serum samples from hospitalized COVID-19 patients and the patients' clinical records were retrospectively analyzed. RESULTS: 173 patients were enrolled. aPL antibodies were detected in 34.7% of patients, anti-B2GP1 antibodies in 30.1%, and aCL antibodies in 10.4%. Double positivity was observed in 5.2% of patients. Thromboembolic events occurred in 9.8% of patients, including 11 pulmonary embolisms, 1 case of celiac tripod thrombosis, and six arterial ischemic events affecting the cerebral, celiac, splenic, or femoral-popliteal arteries or the aorta. aPL antibodies were found in 52.9% of patients with vascular events, but thromboembolic events were not correlated to aPL antibodies (adjusted OR = 1.69, p = 0.502). Ten patients (5.8%) had cutaneous signs of vasculopathy: nine livedo reticularis and one acrocyanosis. No significant association was observed between the presence of cutaneous vasculopathy and aPL antibodies (p = 0.692). CONCLUSIONS: Anti-phospholipid antibodies cannot be considered responsible for hypercoagulability and thrombotic events in COVID-19 patients. In COVID-19 patients, livedo reticularis and acrocyanosis do not appear to be cutaneous manifestations of APS.

Therapeutic plasma exchange for anticoagulant-refractory antiphospholipid syndrome with severe ischemic and necrotic skin lesions: A case series.

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by clinical findings including thrombosis and/or obstetric complication and laboratory findings, e.g. ≥1 positive antiphospholipid antibodies (aPL) (lupus anticoagulant, anticardiolipin IgG/IgM and/or anti-ß2-glycoprotein IgG/IgM). A rare APS clinical entity is severe necrosis which is difficult to treat and often does not respond to anticoagulant therapy. Three consecutive patients with primary or secondary APS who presented with necrotic skin lesions secondary to APS were treated with therapeutic plasma exchange (TPE), glucocorticoids and low-molecular-weight heparin. All patients had a rapid-onset, either full or significant recovery of their APS-related necrotic lesions. Upon treatment, one patients showed resolution of lupus anticoagulant. Two patients had a decrease of at least 88 % in aPL titers after the initial treatment, and were kept on TPE maintenance every 5-6 weeks. None of the patients experienced significant side effects of the TPE. This is the first case series showing the clinical benefits of TPE in patients with ischemic and necrotic skin lesions due to severe anticoagulant-refractory vascular APS.

Antiphospholipid antibodies and cerebrovascular thrombosis in the pediatric population: Few answers to many questions.

Most of the knowledge in pediatric antiphospholipid syndrome (APS) is derived from studies performed on the adult population. As in adults, antiphospholipid antibodies (aPL) can contribute to thrombosis, especially cerebrovascular thrombosis, in neonates and children. Since aPL have the potential to cross the placental barrier, and since the pediatric population is prone to infections, re-testing for their positivity is essential to specify their role in cerebrovascular thrombosis.In this review, we aimed at assessing the prevalence of aPL, criteria or non-criteria, in neonatal and childhood ischemic stroke and sinovenous thrombosis trying to find an association between aPL and cerebrovascular thrombosis in the neonatal and pediatric population. Also, we looked into the effect of aPL and anticoagulants/antiplatelets on the long term neurological outcomes of affected neonates or children. The questions regarding the prevalence of aPL among pediatric patients with cerebrovascular thrombosis, the relationship between the titers of aPL and incidence and recurrence of cerebrovascular events, the predictability of the long term neurological outcomes, and the most optimal anticoagulation plan are still to be answered. However, it is crucial for clinicians to screen neonates and children with cerebrovascular thrombosis for aPL and confirm their presence if positive.

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.

Anticardiolipin and other antiphospholipid antibodies in critically ill COVID-19 positive and negative patients.

BACKGROUND: Reports of severe COVID-19 being associated with thrombosis, antiphospholipid antibodies (APLA), and antiphospholipid syndrome have yielded disparate conclusions. Studies comparing patients with COVID-19 with contemporaneous controls of similar severity are lacking. METHODS: 22 COVID-19+ and 20 COVID-19- patients with respiratory failure admitted to intensive care were studied longitudinally. Demographic and clinical data were obtained from the day of admission. APLA testing included anticardiolipin (aCL), anti-ß2glycoprotien 1 (ß2GP1), antidomain 1 ß2GP1 and antiphosphatidyl serine/prothrombin complex. Antinuclear antibodies (ANAs) were detected by immunofluorescence and antibodies to cytokines by a commercially available multiplexed array. Analysis of variance was used for continuous variables and Fisher's exact test was used for categorical variables with α=0.05 and the false discovery rate at q=0.05. RESULTS: APLAs were predominantly IgG aCL (48%), followed by IgM (21%) in all patients, with a tendency towards higher frequency among the COVID-19+. aCL was not associated with surrogate markers of thrombosis but IgG aCL was strongly associated with worse disease severity and higher ANA titres regardless of COVID-19 status. An association between aCL and anticytokine autoantibodies tended to be higher among the COVID-19+. CONCLUSIONS: Positive APLA serology was associated with more severe disease regardless of COVID-19 status. TRIAL REGISTRATION NUMBER: NCT04747782.

Association of antiphospholipid antibodies with clinical activity and renal pathological activity in patients with lupus nephritis.

OBJECTIVES: This study aimed to investigate the association of antiphospholipid antibodies (aPL) with clinical activity and renal pathological activity in patients with lupus nephritis (LN). METHODS: Levels of anticardiolipin () antibodies, anti-ß2-glycoprotein I (anti-ß2-GPI) antibodies and lupus anticoagulant (LAC) were measured, and other clinical and pathological data were also obtained during the same period before renal biopsy. RESULTS: A total of 83 patients with LN were included in this study, 40 patients (48.2%) in the s positive group and 43 patients in the aPL negative group. LN patients with positive aPL had significantly higher SLEDAI (p = 0.012), more hematuria (p = 0.043), lower serum C3 (p = 0.003) and C4 (p = 0.014), and a higher pathological activity index (p = 0.012), more micro-thrombosis (p = 0.046) and more C3 deposits (p = 0.038) in the glomerulus than patients with negative aPL The level of IgG- was significantly correlated with SLEDAI and serum level of C3 (r = 0.44, p < 0.001; r = -0.39, p = 0.003, respectively). The level of IgM- was significantly correlated with SLEDAI, and serum levels of C3 and C4 (r = 0.27, p = 0.014; r = -0.22, p = 0.041; r = -0.23, p = 0.035, respectively). CONCLUSIONS: Our work suggests that aPL, especially, are correlated with both clinical activity and renal pathological activity in patients with LN.

Autoantibodies Among HIV-1 Infected Individuals and the Effect of Anti-Retroviral Therapy (ART) on It.

BACKGROUND: Antiretroviral therapy (ART) has led to a decline in autoimmune diseases but lacks studies on its effect on autoantibodies. METHODS: It is a cross-sectional study with archived samples from 100 paired HIV-1 infected ART naïve and experienced individuals and 100 prospectively collected matched blood-donor controls. Antinuclear antibody, IgG anticardiolipin antibody, IgM and IgG ß2 glycoprotein-1 antibodies, and total IgG levels were detected. Results are expressed as mean with standard deviation (SD), median, percentage positivity, and a p<0.05 is considered significant. The study was approved by the Institutional Review Board. RESULTS: The median viral load of the treatment naïve samples was 4.34 Log copies/mL, while all were virally suppressed post ART with a median duration of treatment for 12 months (range: 3-36 months). The percentage of antinuclear antibody positivity was 5% among ART naïve and controls, with a decrease of 2% post ART (p= 0.441). The positivity for anti-cardiolipin antibody was 15% among ART naïve while none of the ART experienced or controls were positive (p<0.05). IgM ß2 glycoprotein-1 were 4%, 1% and 3% among ART naïve, treated and controls, respectively (p<0.05). IgG ß2 glycoprotein-1 was 2% among ART naïve while none of the treated and controls were positive (p<0.05). The mean total IgG level among ART naïve, experienced, and controls were 21.82 (SD 6.67), 16.91 (SD 3.38), 13.70 (SD 2.24) grams/Litre, respectively (p<0.05). CONCLUSION: ART has a significant effect on IgG anti-cardiolipin antibody and total IgG but only a marginal effect on ANA, IgM, and IgG ß2 glycoprotein-1 antibodies.

Clinical Relevance of Isolated Lupus Anticoagulant Positivity in Patients with Thrombotic Antiphospholipid Syndrome.

BACKGROUND: Patients positive for all three types of antiphospholipid antibodies (aPLs; triple positivity) have been identified for having a high risk for thrombotic events. However, the clinical significance of isolated lupus anticoagulant (LAC) positivity is debated. OBJECTIVES: To investigate the clinical relevance of isolated LAC. METHODS: A total of 456 patients were enrolled in this study; 66 antiphospholipid syndrome patients and 390 control patients. The control group consisted of autoimmune patients (n = 91), patients with thrombosis but without aPLs (n = 127), and normal controls (n = 172). LAC, anticardiolipin (anti-CL), and anti-ß2 glycoprotein I (anti-ß2GPI) immunoglobulin G (IgG) and immunoglobulin M (IgM) were determined according to the International Society on Thrombosis and Haemostasis (ISTH) guidelines. Anti-CL and anti-ß2GPI were measured by four different solid-phase platforms to overcome variability between test systems. The noncriteria IgA anti-CL and anti-ß2GPI, antidomain I of ß2GPI IgG, and antiphosphatidylserine/prothrombin antibodies (anti-PS/PT) IgG and IgM were detected according to the ISTH guidelines for solid-phase assays. RESULTS: In total, 70 patients were positive for LAC, of which 44 were negative for both anti-ß2GPI and anti-CL antibodies. We found that isolated LAC proved to be strongly associated with vascular thrombosis (odds ratio [OR]: 7.3; 95% confidence interval [CI]: 3.3-16.1), even better than triple-positive samples (OR: 4.3; 95% CI: 1.6-12.2). The titers of the anti-PS/PT IgG and IgM were significantly higher in triple-positivity samples compared with samples with isolated LAC positivity. The majority of single LAC positives were anti-PS/PT-negative. We observed that LAC positivity was weaker in isolated LAC-positive patients compared with LAC activity in triple-positive patients. CONCLUSION: Isolated LAC was highly associated with thrombosis. The presence of anti-PS/PT antibodies could not explain LAC positivity in isolated LAC. Isolated LAC showed a weaker LAC activity compared with triple-positive patients.

Identifying phenotypes of patients with antiphospholipid antibodies: results from a cluster analysis in a large cohort of patients.

OBJECTIVES: To identify the aggregation of patients with aPL into different subgroups sharing common features in terms of clinical and laboratory phenotypes. METHODS: We applied a hierarchical cluster analysis from the multiple correspondence analysis to determine subgroups of patients according to clinical and laboratory characteristics in a cohort of subjects with confirmed aPL positivity who presented to our outpatient clinics from 2006 to 2018. RESULTS: A total of 486 patients [403 women; age 41.7 years (26)] were included, resulting in five clusters. Cluster 1 (n= 150) presented with thrombotic events (65.3% with venous thrombosis), with triple aPL positivity found in 34.7% of them (the highest rate among the different clusters). All the patients from cluster 2 (n = 91) had a confirmed diagnosis of SLE and the highest rate of anti-dsDNA positivity (91.7%). Cluster 3 included 79 women with pregnancy morbidity. Triple positivity was present in 3.8%, significantly lower when compared with Cluster 1 (34.7% versus 3.8%, P <0.01). Cluster 4 included 67 patients, 28 (41.8%) of whom with APS. Thrombotic events were observed in 23.9% patients. Cluster 4 had the highest rate of cytopenia, with thrombocytopenia as high 41.8% with no anti-dsDNA antibodies. Cluster 5 included 94 asymptomatic aPL carriers. CONCLUSION: While clusters 1, 2, 3 and 5 corresponded to well-known entities, cluster 4 might represent a bridging condition between pure primary APS and defined SLE, with lower thrombotic risk when compared with primary APS but higher general features such as ANA and cytopenia (mainly thrombocytopenia).

Cerebral artery dissection secondary to antiphospholipid syndrome: A report of two cases and a literature review.

INTRODUCTION: Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by thromboembolic events, including ischemic stroke or complications in pregnancy, and the presence of antiphospholipid antibodies. Cervical artery dissection (CAD) is not an uncommon cause of stroke in young adults. The concomitant presence of APS and CAD is extremely rare. METHODS: Two cases with APS who developed acute ischemic strokes related to CAD are reported. A comprehensive systematic literature search using the PubMed database was also conducted. RESULTS: In Case 1, a 36-year-old woman who had been diagnosed with systemic lupus erythematosus and had been repeatedly positive for lupus anticoagulant tests developed an ischemic stroke caused by a vertebral artery dissection (VAD). After admission, she had a recurrent ischemic stroke, followed by considerable changes in steno-occlusive lesions of the vertebrobasilar artery system. In Case 2, a 36-year-old man developed multiple brain infarcts due to bilateral VAD with aneurysmal formations and associated with pulmonary embolism. The anticardiolipin antibody titer was repeatedly elevated after stroke. The literature review identified 8 patients with CAD associated with APS, involving the internal carotid artery in 6 patients and the middle cerebral artery and vertebral artery in 1 patient each. The patients were predominantly young and female, infrequently had atherosclerotic vascular risk factors, and were positive for various antiphospholipid antibodies. CONCLUSIONS: The current report described two rare cases of ischemic stroke caused by CAD secondary to APS, along with a review of the literature; the patients displayed characteristic clinical manifestations, implying specific mechanisms for cerebral artery disorders secondary to APS.

T Cell Proliferative Responses and IgG Antibodies to ß2GPI in Patients with Diabetes and Atherosclerosis.

BACKGROUND: Diabetes increases the risk of myocardial infarction (MI) by 2 to 3 folds. Tlymphocytes play a role in atherosclerosis, which is the main pathology behind MI. Cellular immune responses to beta-2 glycoprotein I (ß2GPI) are shown in carotid atherosclerosis. OBJECTIVE: To investigate the self-reactive, ß2GPI-specific T-lymphocytes in patients with and without diabetes and atherosclerosis. METHODS: Collectively, 164 subjects with and without diabetes that underwent coronary angiography were divided into four groups based on their diabetes status and coronary stenosis. Group I=Diabetic with ≥50% stenosis: A+D+ (n=66); Group II=Non-diabetic with ≥50% stenosis, A+D- (n=39); Group III=Diabetic with <50% stenosis: A-D+ (n=28); and Group IV=Non-diabetic with <50% stenosis: AD- (n=31). All groups were evaluated for anti-ß2GPI IgG antibody by ELISA method. Then, PBMCs were isolated from 18 subjects and were stimulated with ß2GPI-derived peptides to assess their proliferation in accordance with their HLA-DRB1 alleles. RESULTS: Mean ß2GPI IgG levels were higher in groups with ≥50% stenosis (A+) compared to those with <50% stenosis (A-), (P=0.02). The co-presence of diabetes in A+ individuals increased mean ß2GPI-specific IgG. Auto-reactive ß2GPI-specific T cells were detected in the repertoire of T-lymphocytes in all groups. ß2GPI-peptides showed promiscuous restriction by various HLADRB1. CONCLUSION: ß2GPI is the target of cellular and humoral immune responses in patients with atherosclerosis. Since the T cell responses but not antibodies were detectable in A-D+ and A-D- groups, it is reasonable to assume that cellular responses preceded the humoral responses. Post-translation modifications of ß2GPI under oxidative and glycemic stresses may have increased the IgG levels in patients with diabetes. Finally, identification of antigens that trigger immuno-pathogenesis in atherosclerosis and diabetes may help the development of immunomodulation methods to prevent or treat these debilitating diseases.

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.

Recurrent miscarriage is not associated with a higher prevalence of inherited and acquired thrombophilia.

PROBLEM: Although not being recommended in guidelines, many physicians perform routine screening for thrombophilia in RM patients suspecting a higher prevalence in these patients. The aim of this study was to analyze the prevalence of inherited and acquired thrombophilia in a large cohort of RM patients. METHOD OF STUDY: Within a multicenter case-control study, n = 820 RM patients and n = 141 controls were included. The prevalence of inherited and acquired thrombophilia including deficiency of protein C/S and antithrombin, elevation of factor VIII activity, APC resistance including mutation in the factor V Leiden gene, mutation in the prothrombin gene and antiphospholipid antibodies were assessed. Further, we performed a meta-analysis of the prevalence of thrombophilia in RM patients including studies between 01/2000 and 01/2020. RESULTS: An antiphospholipid syndrome (APLS) was only present in RM patients. Increased factor VIII concentration was significantly more prevalent in controls (RM vs controls: 5.8% vs 11.0%). None of the other thrombophilia did differ significantly between RM patients and controls. The meta-analysis revealed no significant difference in the occurrence of these thrombophilia between RM patients and controls. CONCLUSION: The prevalence of inherited thrombophilia does not differ between RM patients and controls. When analyzing rare events like thrombophilia, a high number of patients are needed to obtain reliable results, which might explain contradictory findings in previous studies analyzing small cohorts of RM patients. Despite being less prevalent than previously described, we still recommend screening for APLS as it is associated with severe pregnancy complications.

Anticardiolipin Positivity Is Highly Associated With Intrauterine Growth Restriction in Women With Antiphospholipid Syndrome.

The purpose of our study was to evaluate pregnancy outcomes of women with antiphospholipid antibodies (aPL) positivity and assess risk factors associated with adverse pregnancy outcomes. Pregnant women with aPL positivity were enrolled prospectively in China from January 2017 to March 2020. Treatment of low-dose aspirin and low molecular weight heparin were given. Pregnancy outcomes and coagulation function were recorded and compared with normal pregnancies. Multivariable logistic regression was performed to identify risk factors associated to intrauterine growth restriction (IUGR). 270 pregnant women, including 44 diagnosed as Antiphospholipid syndrome (APS), 91 as non-criteria APS (NCAPS) and 135 normal cases as control, were enrolled in the study. The live birth rate in aPL carriers and APS group was 97% and 95.5%, respectively. Adverse pregnancy outcomes did not show significant difference between aPL carriers and normal pregnancies, and between APS and NCAPS, except for IUGR. The incidence of IUGR was significantly higher in aPL carriers than normal pregnancies, and in APS patients than NCAPS (P < 0.05). After controlling for age, in vitro fertilization (IVF), pregnancy losses related to APS and treatment, anticardiolipin (aCL) positivity was the only variable significantly associated with IUGR, with an adjusted odds ratio of 4.601 (95% CI, 1.205-17.573). Better pregnant outcomes of aPL positive women, include APS and NCAPS, were achieved in our study with treatment based on low-dose aspirin (LDA) plus low molecular weight heparin (LMWH). The incidence of IUGR was still higher in them, and aCL positivity was the only one risk factor associated with IUGR.