Primary Antiphospholipid Syndrome Research Articles

Whole blood transcriptome identifies interferon-regulated genes as key drivers in thrombotic primary antiphospholipid syndrome

ObjectivePathogenesis of antiphospholipid syndrome (APS) isn't fully elucidated. We aimed to identify gene signatures characterizing thrombotic primary APS (thrPAPS) and subgroups at high risk for worse outcomes. MethodsWe performed whole blood next-generation RNA-sequencing in 62 patients with thrPAPS and 29 age-/sex-matched healthy controls (HCs), followed by differential gene expression analysis (DGEA) and enrichment analysis. We trained models on transcriptomics data using machine learning. ResultsDGEA of 12.306 genes revealed 34 deregulated genes in thrPAPS versus HCs; 33 were upregulated by at least 2-fold, and 14/33 were type I and II interferon-regulated genes (IRGs) as determined by interferome database. Machine learning applied to deregulated genes returned 79% accuracy to discriminate thrPAPS from HCs, which increased to 82% when only the most informative IRGs were analyzed. Comparison of thrPAPS subgroups versus HCs showed an increased presence of IRGs among upregulated genes in venous thrombosis (21/23, 91%), triple-antiphospholipid antibody (aPL) positive (30/50, 60%), and recurrent thrombosis (19/42, 45%) subgroups. Enrichment analysis of upregulated genes in triple-aPL positive patients revealed terms related to ‘type I interferon signaling pathway’ and ‘innate immune response’. DGEA among thrPAPS subgroups revealed upregulated genes, including IRGs, in patients with venous versus arterial thrombosis (n = 11, 9 IRGs), triple-aPL versus non-triple aPL (n = 10, 9 IRGs), and recurrent versus non-recurrent thrombosis (n = 10, 3 IRGs). ConclusionUpregulated IRGs may better discriminate thrPAPS from HCs than all deregulated genes in peripheral blood. Taken together with DGEA data, IRGs are highly expressed in thrPAPS and high-risk subgroups of triple-aPL and recurrent thrombosis, with potential treatment implications.

B-Cells and BAFF in Primary Antiphospholipid Syndrome, Targets for Therapy?

Primary antiphospholipid syndrome (PAPS) is a systemic autoimmune disease characterized by thrombosis, pregnancy morbidity, and the presence of antiphospholipid antibodies (aPL). Anticoagulants form the mainstay of treatment in PAPS. A growing number of studies suggest a previously underappreciated role of the immune system in the pathophysiology of PAPS. Although B-cells are strongly implicated in the pathophysiology of other autoimmune diseases such as systemic lupus erythematosus (SLE), little is known about the role of B-cells in PAPS. Shifts in B-cell subsets including increases in plasmablasts and higher levels of BAFF are present in patients with PAPS. However, while treatment with rituximab and belimumab may ameliorate thrombotic and non-thrombotic manifestations of PAPS, these treatments do not reduce aPL serum levels, suggesting that B-cells contribute to the pathophysiology of APS beyond the production of autoantibodies.

Predictors and Interrelationship of Patient-Reported Outcomes in Antiphospholipid Syndrome: A Cross-Sectional Study.

This study assessed patient-reported outcomes (PROs) in individuals with persistently positive antiphospholipid antibodies (aPL) to better understand how living with aPL may affect their quality of life. Patients completed Patient-Reported Outcomes Measurement Information System Physical Function (PF) and Cognitive Function (CF) Short Forms as well as the pain intensity (PI) rating (scale of 1-10). Patients were characterized for demographics, clinical manifestations of antiphospholipid syndrome (APS), cardiovascular risk factors, laboratory test results, and medication usage. Multivariate modeling was done via linear regression. Of 139 patients, 89 had primary APS, 21 had secondary APS, and 29 had persistent aPL without meeting clinical criteria for APS. The average T scores (±SD) for PF and CF were 45.4 ± 9.2 and 48.6 ± 11.6, respectively; the average for PI was 3.0 ± 2.6. Approximately half of the patients (47%) endorsed at least mild impairment in PF (T score < 45). Mean PF, CF, and PI did not differ between diagnostic groups. Individuals who endorsed more impairment on one measure also tended to endorse more impairment on another (Pearson r= 0.43-0.59). In the multivariate models, age, smoking, pain medications, and serotonergic medications were associated with impairment in at least one PRO domain. The Damage Index for APS was significantly correlated with both PF and CF. Individuals living with APS endorsed more impairment in PF (and potentially CF) than expected for the general population. The relationship between certain medications and PROs warrants further study, as does the longitudinal trajectory of these and other PROs.

Low Folate Levels are Associated with Strokes and Less Venous Thromboses in Primary Antiphospholipid Syndrome.

Low Folate Levels are Associated with Strokes and Less Venous Thromboses in Primary Antiphospholipid Syndrome.

Ocular involvement in primary antiphospholipid syndrome: results of an extensive ophthalmological evaluation performed in the APS-Rio cohort.

To study ophthalmological manifestations in a well-characterized primary antiphospholipid syndrome (PAPS) cohort (APS-Rio) and compare them with a healthy control group. We examined PAPS patients and controls with an extensive ophthalmological evaluation, which included anamnesis, visual acuity, slit-lamp biomicroscopy, binocular indirect ophthalmoscopy, and retinography of the anterior and posterior segments of the eye. PAPS group also underwent angiography exam and optical coherence tomography using spectral domain technology (SD-OCT). 98 PAPS patients and 102 controls were included. The most common symptom in PAPS was amaurosis fugax (34.7% vs. 6.9%; p = .001). In the multivariate analyses, Raynaud's phenomenon was associated with amaurosis fugax (OR 3.71, CI:1.33-10.32; p = .012), and livedo correlated with hemianopia (OR 6.96, CI:1.11-43.72, p = .038) and diplopia (OR 3.49, CI:1.02-11.53, p = .047). After ophthalmological evaluation, 84 PAPS patients had ocular involvement (1.0% glaucoma, 94.0% posterior findings, 62.7% anterior findings, and 56.6% both posterior and anterior findings). Vascular tortuosity was more frequent in the PAPS group (63.2% vs. 42.2%; p = .002), as well as peripheral tortuosity (29.6% vs. 7.8%; p < .001). After excluding patients with atherosclerotic risk factors, peripheral vascular tortuosity was still statistically associated with PAPS (35.0 vs. 7.8%, p < .001). Triple positivity was more frequent in PAPS patients with peripheral vascular tortuosity than in those without this ocular finding (34.5% vs. 15.9%, p = .041). Vasomotor phenomena are importantly related to ocular symptoms in PAPS. Vascular tortuosity was a frequent finding in PAPS patients. Peripheral vascular tortuosity was associated with triple positivity and might be a biomarker of ischemic microvascular retinopathy due to PAPS.

Hémorragie bilatérale des surrénales sous apixaban dans le syndrome primaire des antiphospholipides

Adrenal hemorrhage is a classical but rare complication of antiphospholipid syndrome, revealing diagnosis in one third of the cases. Anti-vitamin K therapy is the standard treatment but direct oral anticoagulants are discussed as an alternative. In the latest recommendations, it is advised not to use direct oral anticoagulants in the setting of antiphospholipid syndrome.We present a case of bilateral adrenal hemorrhage revealing primary antiphospholipid syndrome with triple positive antibody profile, in 53-year-old women treated by apixaban for previous venous thromboembolism.

Evaluation of a Gene Signature Related to Thrombotic Manifestations in Antiphospholipid Syndrome

Introduction: Whether different manifestations of thrombotic antiphospholipid syndrome (APS) share pathological mechanisms has not been established. Transcriptome analysis may constitute a new approach to evaluate the mechanisms behind thrombotic manifestations in APS. Aim: To determine in patients with primary thrombotic APS (t-PAPS) and aPL asymptomatic (individuals carrying the antibodies but without clinical manifestation) the expression of genes already related to venous and arterial thrombosis in general population compared with control. Method: mRNA was obtained from total leucocyte and gene expression was measured by qPCR and the results were analyzed by QuantStudio™ Software. Results: 100 t-PAPS, 17 asymptomatic aPL carriers and 100 control individuals were included. The group of t-PAPS were 63.73% female, and the median age was 40 years (IQR 31-53). Asymptomatic aPL carriers were mostly female (82.36%) and the median age was 36 years (IQR 24-59). Controls were mostly female (67%) and their median was 39 years (IQR 29-49). No significant demographic differences between the groups was observed. Cardiovascular risk factors were more prevalent among t-PAPS than among asymptomatic aPL carriers and controls (37.25%, 5.88% and 9% respectively). ANXA3 (P=0.0292) and TNFAIP6 (P=0.0006) mRNA were up-regulated while TXK (P=< 0.0001), BACH2 (P=0.0085) and SERPINB2 (P=0.0491) were down-regulated in t-PAPS when compared to controls. In aPL carriers, the relative expression levels of TNFAIP6 were similar to t-PAPS while that of BACH was similar to controls; as shown in Figure 1. In a subgroup analysis, ANXA3 and TNFAIP6 mRNA expression was more pronounced in t-PAPS with multiple thrombosis (P= 0.0027 and P=< 0.0001 respectively), while TXK mRNA expression was lower in all t-PAPS subgroups in comparison with controls, being particularly lower in patients who had first thrombotic event and non-triple positivity (P=< 0.0001 and P= < 0.0001 respectively), BACH2 mRNA expression was lower in t-PAPS subgroup with first thrombotic event (P= 0.0019) compared to the control group and SERPINB2 mRNA expression was only significantly lower in t-PAPS with first thrombotic event (P= 0.0071). Table 1 demonstrates fold changes by different manifestations of t-PAPS. Discussion: We observed a dysregulation of genes related to hemostasis (ANXA3 and SERPINB2) and inflammation (TNFAIP6, TXK and BACH2) in t-PAPS, when compared to controls. ANXA3 plays a role in cell growth regulation and signal transduction pathways, and has previously been linked to stroke in animal studies. TNFAIP6 is involved in cell-cell and cell-matrix interactions during inflammation and tumorigenesis. Among TXK related pathways are the transmigration of immune cells and plays a role in regulating the adaptive immune response. BACH2 is responsible for immune regulation, mainly related to the adaptive immune response and has been implicated in B cell. SERPINB2 regulates the production of the plasminogen activator inhibitor-2 (PAI-2), being directly related to the hemostasis pathways. Such mechanisms were not evident among asymptomatic aPL carriers. In subgroup analysis, the relative expression of genes related to innate immunity has also been associated with signs of disease severity, such as multiple thrombosis and triple positivity. Conclusions: Our results showed that innate immunity and hemostasis pathways are associated with t-PAPS at a transcriptome level and innate immunity may play a role in disease severity. Acknowledgements: São Paulo Research Foundation FAPESP (2019/20136-0) Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

A Role of Immunothrombosis in Acquired Antibody-Mediated Thrombophilia's: Classical Complement and Neutrophil Activation in APS and HIT

Introduction: Heparin induced thrombocytopenia (HIT) and APS (antiphospholipid syndrome) are acquired thrombophilia's characterized by both arterial and venous thromboembolic events (TE). As a common feature APS and HIT share the presence of pathological antibodies, which play a crucial role in disease pathogenesis. In HIT, antibodies are directed to platelet factor (PF) 4 and heparin, respectively, and in APS, antibodies target anti-phospholipids (anti-cardiolipin antibody, anti-Beta2- glycoprotein I and lupus anticoagulant). There is growing evidence that complement- and neutrophil activation in the form of neutrophil extracellular traps (NETs) play an important role in the pathogenesis of thrombosis, the so-called "immunothrombosis". Insufficient control with subsequent unrestrained complement activation results in thrombosis as seen in patients with paroxysmal nocturnal hemoglobinuria (PNH). Therapeutic inhibition of complement activation abrogates thrombosis in these patients, emphasizing the important role of complement activation in the pathogenesis of thrombosis. It has been demonstrated, that complement activation products efficiently induce neutrophil activation, and therapeutic complement inhibition in sepsis and PNH prevents neutrophil activation. Here, we investigate the role of complement activation and neutrophil activation in patients with APS and HIT, respectively. Methods To assess the association of complement activation and NET Formation, we measured complement activation products (C4bc, C3bc) and marks for neutrophil activation, such as nucleosomes and human neutrophil elastase-α1- antitrypsin complexes (HNE) by ELISA in plasma of 34 primary APS- and 26 HIT- patients and 31 healthy controls. Groups have been compared using the Mann- Whitney-Rank Test. Values are indicated as median and range, p<0.05 is considered statistically significant. Results Patients with APS and HIT showed sign. higher levels of complement activation products as compared to healthy controls. Complement activation mainly of the classical (C4b/c) and alternate pathway (C3b/c) in APS (11 nM and 263 nM) and in HIT (33 nM and 324 nM) were sign. higher (p<0.0001) as compared to the healthy controls (7 nM and 19 nM). C4bc levels were sign. higher in HIT as compared to APS patients (p<0001), but there was no difference in C3b/c levels between these two groups (see figure 1). Patients with HIT had a sig. (p<0.0001) higher nucleosomes (440 U/ml) and HNE (121 ng/ml) as compared to healthy controls (12 U/ml and 26 ng/ml). HNE levels were sign. (p<0.001) higher in APS patients (37 ng/ml) as compared to healthy controls (26 ng/ml), however no difference was observed in nucleosome levels (12 U/ml vs 14 U/ml) (see figure 2). Based on the number of positive antibodies, eleven APS patients have been stratified as high-risk and 24 APS patients as low- to intermediate risk. C4bc levels were sign. increased in the high-risk patients as compared to the low- to intermediate risk group, whereas no difference in C3b/c levels could be observed between the 2 groups. Similarly, HNE complexes sign. increased in the high-risk patients as compared to the low- to intermediate risk group, whereas no difference in nucleosome levels could be observed between the 2 groups. Six HIT patients (22%) had a diagnosed TE event whereas 17 patients (63%) had no diagnosed TE. In four patients (15%) no clinical data were available, and they have been excluded from subgroup analysis. Interestingly, the measured markers for complement - and neutrophil activation in HIT patient with and without thrombosis were not different. Conclusions We demonstrate complement activation in patients with HIT and APS. Based on the simultaneous raise in nucleosomes and HNE, there is evidence of NET formation in HIT, whereas only weak neutrophil activation can be found in APS. In APS classical complement activation and neutrophil activation correlates with APS risk stratification. Our results demonstrate classical complement pathway- and neutrophil activation in HIT and APS patients. These findings may form the base for new therapeutic strategies targeting complement and neutrophil activation. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

LncRNAs dysregulation in monocytes from primary antiphospholipid syndrome patients: a bioinformatic and an experimental proof-of-concept approach.

Antiphospholipid syndrome (APS) is the main cause of acquired thrombophilia where peripheral circulating cells such as monocytes have a key role. Currently, several studies have linked long non-coding RNAs (lncRNAs) in different inflammatory and autoimmune processes, including lupus. However, the role of lncRNAs in antiphospholipid syndrome is unknown, therefore, we aimed to select and measure expression levels of three lncRNAs based on its abundancein monocytes from APS patients. Selection of lncRNAs candidates were carried out based on its abundancein monocytes and their relationship with Perez-Sanchez miRNA signature by using miRNet 2.0 bioinformatic tool, then lncRNAs expression levels was measured in monocytes by RT-qPCR. This is the first study to report that lncRNAs: FGD5-AS1, OIP5-AS1 and GAS5 are promising candidates for play a role on APS monocytes and they are expressed differently between patients and controls. OIP5-AS1, FGD5-AS1 and GAS5 are downregulated on monocytes from APS patients.

Primary Anti-Phospholipid Antibody Syndrome: Real-World Defining Features of Rethrombosis in the Course of Disease.

We aimed to identify features that allow differentiation of primary antiphospholipid syndrome (PAPS) patients that suffer recurrent thrombotic events (RTE) despite anticoagulation, from the other diagnosed PAPS patients. This was an exploratory study of anticoagulated PAPS patients attending an Autoimmune Diseases Unit (1998-2018). From 2016, anti-phospholipid antibodies and lupus anticoagulant were determined for each patient at consecutive visits, collected together with retrospective clinical characteristics, laboratory, and therapeutic markers and compared according to the occurrence of thrombotic events during follow-up. Overall, two thirds of the patients were female, 93% were Caucasian, with a median age of 40 years at diagnosis, for a median time of 11.5 years in follow-up. Out of 54 patients, 10 were identified with RTE. There were no significant differences among the RTE and non-RTE patients as far as classical risk factors for clotting disorders. The RTE group was characterized by a higher proportion of younger patients, male sex and positivity for all laboratory markers, and initially and over follow-up as well as a sustained high-risk profile based on APS laboratory markers. Anticardiolipin IgG at onset was the only statistically significant marker of the RTE group. At the end of follow-up, consistent reversion to negative status was a rare event, observed in 20% of RTE vs. 25% of non-RTE patients. Despite therapy, we were able to identify features associated to thrombotic events in patients with PAPS. Prospectively regular clinical and laboratory monitoring might be warranted in order to treat APS more assertively.

Genetic variation in toll-like receptor 4 gene with primary antiphospholipid syndrome susceptibility: a cohort of Egyptian patients

BackgroundAs toll-like receptor 4 (TLR4) plays important roles in cellular immunity and TLR4 polymorphisms have been shown to be associated with susceptibility to a range of diseases, the present study aimed to investigate the association between TLR4 gene polymorphisms and the incidence of primary antiphospholipid syndrome (PAPS).MethodsTwo TLR4 single nucleotide polymorphisms (rs4986790 and rs4986791) were assessed in 110 subjects of Egyptian ethnicity, including 65 female patients with PAPS and 45 matched healthy controls, using polymerase chain reaction-restriction fragment length polymorphism. Results were verified using automated sequencing.ResultsThe homozygous wild-type (AA, aspartic acid) rs4986790 variant and (CC, threonine) rs4986791 variant were the predominant genotypes in the control and PAPS groups.ConclusionThe results of this preliminary study of TLR4 gene variants among patients with PAPS in an Egyptian population found no association between the rs4986790 and rs4986791 variants and susceptibility to PAPS.

Primary Antiphospholipid Syndrome with Livedo Reticularis is Linked to Female Sex and Stroke and Negatively Associated with Thyroid Disease.

To study the clinical and laboratory findings between patients with primary Antiphospholipid Syndrome (pAPS) with and without LR. Livedo Reticularis (LR) is a common manifestation of Antiphospholipid Syndrome (APS). Although no previous study evaluated patients with and without LR. A transversal study including 66 pAPS patients was performed. Demographical, anthropometric, medication use, antiphospholipid antibodies profile data were evaluated, and LR's clinical and laboratory features. Patients were subdivided into one of two groups: pAPS with LR and pAPS without LR. Both groups were alike concerning demographics and anthropometrics. Interestingly, the frequency of stroke (28.5 vs. 7.5%, p=0.04), as well as of Sneddon's syndrome (100 vs. 30.0%, p<0.0001), were higher in pAPS with LR than the other group. Conversely, patients in the pAPS without LR group had more thyroidopathy than those in the pAPS with LR group (80% vs. 50% %, p=0.03). Patients with pAPS and LR have more stroke and seem to be protected from thyroidopathy. Careful follow-up of these patients is therefore advised.

PSAT040 Bilateral Adrenal Infarcts: Initial Presentation in Concurrent Myelodysplastic Syndrome and Anti-Phospholipid Syndrome

Abstract Introduction Bilateral adrenal hemorrhage (BAH) has been noted in several conditions. Bilateral adrenal infarcts (BAI) are rarer but have been seen in anti-phospholipid syndrome (APS). Adrenal insults are not commonly associated with myelodysplastic syndrome (MDS). We present a patient who developed BAI as initial presentation of APS in the setting of MDS and discuss management considerations. Case A 58-year-old female with MDS diagnosed one month prior presented with abdominal pain, present for one year but acutely worse in the past week. CT A/P showed nodularity of bilateral adrenal glands. She was treated conservatively but continued to experience nausea, vomiting, and abdominal pain – repeat CT A/P one month later was suspicious for bilateral peri-adrenal hemorrhages. MRI with adrenal protocol demonstrated bilateral non-hemorrhagic adrenal infarcts. VS were negative for hypothermia or hypotension. Labs showed Na 136 (135-145 mmol/L), K 3.5 (3.4-5.1 mmol/L), BG 108 (mg/dL), DHEA-S 9.3 (8.0-391 mcg/dL), renin 6.7 (0.5-4.0 ng/mL/hr), aldosterone 6.2 (&amp;lt;31.0 ng/dL), 60-minute cortisol after ACTH stimulation test 34.3 (5.2-22.5 mcg/dL), plasma metanephrines &amp;lt;0.10 (0.00-0.49 nmol/L), plasma normetanephrines 0.34 (0.00-0.89 nmol/L), Hgb 11.8 (12.0-15.5 g/dL), and plts 129K (140-450 K/mcL). No history of anticoagulant use, trauma, or VTE. COVID-19 PCR was negative on two separate tests. Hypercoagulability testing noted positive lupus anticoagulant. Anticoagulation was deferred due to underlying bone marrow abnormalities and thrombocytopenia; aspirin was recommended instead by hematology. Outpatient testing revealed 12pm cortisol of 12.6 (5.2-22.5 mcg/dL), ACTH 108.3 (7.2-63.0 pg/mL), and DHEA-S 6.2 (8.0-391 mcg/dL). Patient was empirically started on hydrocortisone for glucocorticoid replacement therapy. Conclusion BAI is not typically associated with MDS but can occur in the setting of a concurrent hypercoagulable process such as APS. The adrenal glands are the most commonly involved glands in APS. Patients often present in adrenal crisis but can present in stable condition as in this case. The adrenal glands are particularly vulnerable due to the "vascular dam" near the zona reticularis. Imaging and laboratory investigation can clarify the nature of the adrenal insult and guide management. Treatment strategy may include anticoagulation to prevent further VTE events, but bleeding risk must be considered. Both glucocorticoid and mineralocorticoid replacement should be considered until residual adrenal reserve can be fully elucidated, which may take several months from initial diagnosis. References Rao RH. Bilateral massive adrenal hemorrhage. Med Clin North Am 1995; 79(1): 107-29. Aron DC, Findling JW, Tyrrell JB. Glucocorticoids and adrenal androgens. In: Greenspan's Basic and Clinical Endocrinology. Gardner DG, Shoback D (eds). Mc Graw Hill 2007; pp 367-378. Caron P, Chabannier MH, Cambus JP, Fortenfant F, Otal P, Suc JM. Definitive adrenal insufficiency due to bilateral adrenal hemorrhage and primary antiphospholipid syndrome. J Clin Endocrinol Metab 1998; 83(5): 1437-9. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Antiphospholipid syndrome and lupus anticoagulant-hypoprothrombinemia.

Lupus anticoagulant-hypoprothrombinemia syndrome is a rare cause of hemorrhage. In this syndrome, antiphospholipid antibodies bind to the FII epitope in its carboxy-terminal portion and form antigen-antibody complexes that are rapidly cleared by the reticuloendothelial system, conditioning hypoprothrombinemia and thus a bleeding tendency. Lupus anticoagulant-hypoprothrombinemia syndrome is associated with autoimmune diseases, mainly systemic lupus erythematosus, and less frequently with primary antiphospholipid syndrome, discoid lupus, drugs, celiac disease, and haemato-oncological diseases. Immunosuppressants, mainly steroids, are the mainstay treatment, nevertheless, there is still a concern about the right treatment for this entity since there have been described less than 200 cases around the world. We describe the case of a male patient with a history of primary antiphospholipid syndrome that comes to our hospital with a severe headache due to intracranial hemorrhage, secondary to Lupus anticoagulant-hypoprothrombinemia.

Ocular findings in asymptomatic patients with primary antiphospholipid syndrome.

Primary antiphospholipid syndrome (PAPS) is characterized by the presence of antiphospholipid antibodies (aPL), repetitive fetal loss, and arterial/venous thrombosis and no association with other autoimmune rheumatic disease. Ocular involvement can also occur including retinal vascular thrombosis and neuro-ophthalmological manifestations, such as optic neuropathy and amaurosis fugax. Early detection of ocular changes is crucial to minimize functional loss. To perform a multimodal evaluation, including the use of Optical Coherence Angiotomography (OCTA), in patients with PAPS without ocular complaints and compare with healthy individuals. We performed a complete structural and functional ophthalmological evaluation using OCTA and microperimetry exam in patients with PAPS, followed at a tertiary Rheumatology outpatient clinic. We included 104 eyes of 52 subjects [PAPS without ocular complaints (N = 26) and healthy individuals (N = 26)]. Among PAPS patients, 21 were female (80.8%) and 21 (80.8%) were Caucasians. PAPS manifestations were venous (65.4%), arterial thrombosis (34.6%), and obstetrical (34.6%) and all of them had lupus anticoagulant. Ophthalmologic findings were more frequent in PAPS compared to healthy individuals (19.2% vs. 0%, p = 0.05). The most common retinal change was paracentral acute middle maculopathy (PAMM) (3 patients, 5 eyes), followed by drusen (1 patient, 2 eyes) and pachychoroid pigment epitheliopathy (PPE) (1 patient, 1 eye). Hypertension and hyperlipidemia were present in 100% of the PAPS patients with PAMM, while only six patients (26.1%) with PAPS without PAMM presented these two risk factors together (p = 0.03). We provide novel evidence that approximately 20% of our asymptomatic PAPS patients without ocular symptoms have ophthalmologic findings that require early identification and careful surveillance focusing on minimizing systemic and vascular risk factors.

Asymmetric Dimethylarginine Is a Marker of Endothelial Dysfunction in Thrombotic Antiphospholipid Syndrome Patients.

Objective: The potential contribution of asymmetric dimethylarginine (ADMA) and high-sensitivity C reactive protein (hsCRP) to endothelial dysfunction in APS patients has not been studied in detail, until now. The study involved 105 APS patients (59 diagnosed with primary APS (PAPS) and 46 APS associated with systemic lupus erythematosus (SAPS)) who were compared to 40 controls. Endothelial dysfunction was assessed by measurement of flow-mediated dilatation (FMD) and glyceryl trinitrate dilatation (NMD) of the brachial artery. ADMA (micromol/L) was analyzed by ELISA. Results: FMD in patients with APS was significantly lower than that of the controls (p < 0.001), with no difference between the PAPS and the SAPS groups. ADMA and hsCRP concentrations were significantly higher in the patient cohort than in the control group (p < 0.001, p = 0.006, respectively), as was the case with the SAPS group as compared to the PAPS group (p < 0.001, p = 0.022, respectively). FMD impairment correlated to ADMA (ρ 0.472, p < 0.001) and to hsCRP (ρ 0.181, p = 0.033). In the regression model, the ADMA concentration confirmed the strength of its association (B 0.518, SE 0.183, Wald 8.041, p = 0.005, Exp(B) 1.679, 95% CI 1.174–2.402) to FMD impairment. The synergistic probability model of ADMA and hsCRP caused FMD impairment when the positivity of β2GPIIgG was added. ADMA may be used as a simple and low-cost tool for verifying the presence of endothelial dysfunction in APS patients. According to the results of the study, we could presume that hsCRP, together with aPL, has a preparatory effect on the endothelium in causing endothelial dysfunction.

EVALUATION OF A GENE SIGNATURE RELATED TO THROMBOTIC MANIFESTATIONS IN ANTIPHOSPHOLIPID SYNDROME

Whether different manifestations of thrombotic antiphospholipid syndrome (APS) share pathological mechanisms has not been established. Transcriptome analysis may constitute a new approach to evaluating the mechanisms behind thrombotic manifestations in APS. To determine in patients with primary thrombotic APS (t-PAPS) and aPL asymptomatic (individuals carrying the antibodies but without clinical manifestation) the expression of genes already related to venous and arterial thrombosis in the general population compared with control. Method: mRNA was obtained from total leucocytes, gene expression was measured by qPCR, and the results were analyzed by QuantStudio™Software. 100 t-PAPS, 17 asymptomatic aPL carriers, and 100 control individuals were included. The group of t-PAPS was 63.73% female, and the median age was 40 years (IQR 31-53). Asymptomatic aPL carriers were predominantly female (82.36%) and the median age was 36 years (IQR 24-59). Controls were mostly female (67%) and their median was 39 years (IQR 29-49). No significant demographic differences between the groups were observed. Cardiovascular risk factors were more prevalent among t-PAPS than among asymptomatic aPL carriers and controls (37.25%, 5.88%, and 9% respectively). ANXA3 (p = 0.0292) and TNFAIP6 (p = 0.0006) mRNA were up-regulated while TXK (p = < 0.0001), BACH2 (p = 0.0085) and SERPINB2 (p = 0.0491) were down-regulated in t-PAPS when compared to controls. In aPL carriers, the relative expression levels of TNFAIP6 were similar to t-PAPS while that of BACH was similar to controls; as shown in Figure 1. In a subgroup analysis, ANXA3 and TNFAIP6 mRNA expression were more pronounced in t-PAPS with multiple thrombosis (P = 0.0027 and P = < 0.0001 respectively), while TXK mRNA expression was lower in all t-PAPS subgroups in comparison with controls, being particularly lower in patients who had first thrombotic event and non-triple positivity (p = < 0.0001 and p = < 0.0001 respectively), BACH2 mRNA expression was lower in t-PAPS subgroup with first thrombotic event (P = 0.0019) compared to the control group and SERPINB2 mRNA expression was only significantly lower in t-PAPS with first thrombotic event (p = 0.0071). Table 1 demonstrates fold changes by different manifestations of t-PAPS. We observed dysregulation of genes related to hemostasis ( ANXA3 and SERPINB2 ) and inflammation ( TNFAIP6 , TXK, and BACH2 ) in t-PAPS when compared to controls. ANXA3 plays a role in cell growth regulation and signal transduction pathways, and has previously been linked to stroke in animal studies. TNFAIP6 is involved in cell-cell and cell-matrix interactions during inflammation and tumorigenesis. Among TXK-related pathways is the transmigration of immune cells which plays a role in regulating the adaptive immune response. BACH2 is responsible for immune regulation, mainly related to the adaptive immune response, and has been implicated in B cell. SERPINB2 regulates the production of the plasminogen activator inhibitor-2 (PAI-2), directly related to the hemostasis pathways. Such mechanisms were not evident among asymptomatic aPL carriers. In subgroup analysis, the relative expression of genes related to innate immunity has also been associated with signs of disease severity, such as multiple thrombosis and triple positivity. Our results showed that innate immunity and hemostasis pathways are associated with t-PAPS at a transcriptome level and innate immunity may play a role in disease severity.

Intracranial Bleeding as Primary Manifestation of Antiphospholipid Syndrome: Case Report

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder usually resulting in an increased risk of blood clots in the arterial-, venous-, or microvascular system. Various antibodies have been identified causing the activation and aggregation of thrombocytes and endothelial dysfunction resulting in a wide range of symptoms. Frequent manifestation may be arterial or venous clots in extremities or internal organs, neurological manifestation or pregnancy morbidities. Rarely, APS can manifest in the form of hemorrhage. We discuss the case of a 40-year-old male presenting with a severe headache, fatigue and fever. Head CT confirmed a subdural hematoma. Laboratory findings showed anemia, thrombocytopenia and elongated coagulation times. Immunoserology found the strong presence of lupus anticoagulant, anti-cardiolipin-, and anti-β2glycoprotein-I IgG antibodies confirming the diagnosis of primary antiphospholipid syndrome, specifically LA - hypoprothrombinemia syndrome. Following the administration of high dose glucocorticoids, we chose to give intravenous immunoglobulin followed by rituximab. Although his symptoms regressed and there was no further hemorrhaging, we chose to perform plasmapheresis due to continuously high concentration of anti- phospholipid antibodies to lower the antibody titer, which proved to be effective. Antithrombotic treatment can be challenging in such cases due to the co-occurrence of hypoprothrombinemia and prothrombotic antibodies. We decided to administer low-dose aspirin, with which the patient has no bleeding or blood clots for over 6 years. We find the case worth presenting due to the rare occurance of bleeding as primary manifestation of APS and due to the challenging treatment.

Extracellular vesicles released upon stimulation with antiphospholipid antibodies: An actual direct procoagulant mechanism or a new factor in the lupus anticoagulant paradox?

Antiphospholipid antibodies (aPL) lead to a hypercoagulable state in vivo. Paradoxically, some of these autoantibodies perform as inhibitors of the coagulation cascade in vitro (a phenomenon referred to as “lupus anticoagulant”). The presence of lupus anticoagulant has been related to an increased quantity of plasma extracellular vesicles, which may constitute a direct procoagulant mechanism in antiphospholipid syndrome. This study investigates whether or not endothelial cell-derived extracellular vesicles released upon stimulation with aPL (aPL-EDEVs) are related to a higher direct coagulation activity. Using an in vitro model of endothelium, flow cytometry and a recalcified plasma-based assay, we found that the coagulation activity of aPL-EDEVs is mainly conditioned by the lupus anticoagulant-like activity of autoantibodies. Nevertheless, in the presence of β2 glycoprotein I, a cofactor of aPL during the stimulation of endothelial cells, the coagulation activity of EDEVs is restored in a mitogen-activated protein kinase kinases 1 and 2 (MEK1/2)-dependent manner. This phenomenon was especially evident when using immunoglobulins G from patients with vascular and obstetric primary antiphospholipid syndrome who manifest refractoriness to treatment. Our findings suggest that the role of aPL-EDEVs in the antiphospholipid syndrome-related hypercoagulable state may not rely on their capacity to enhance clotting directly. While β2 glycoprotein I performs as a procoagulant cofactor and restores the coagulation activity of extracellular vesicles via MEK1/2 pathway, proportionally, autoantibodies interact with aPL-EDEVs and exhaust their coagulation properties. Further analysis is required to establish whether lupus anticoagulant-like autoantibodies opsonise extracellular vesicles and whether opsonised vesicles may lead to thrombosis by indirect means.

Circulating immune-complexes of IgG/IgM bound to B2-glycoprotein-I associated with complement consumption and thrombocytopenia in antiphospholipid syndrome.

BackgroundAntiphospholipid syndrome (APS) is a multisystemic autoimmune disorder characterized by thrombotic events and/or gestational morbidity in patients with antiphospholipid antibodies (aPL). In a previous single center study, APS-related clinical manifestations that were not included in the classification criteria (livedo reticularis, thrombocytopenia, leukopenia) were associated with the presence of circulating immune-complexes (CIC) formed by beta-2-glycoprotein-I (B2GP1) and anti-B2GP1 antibodies (B2-CIC). We have performed a multicenter study on APS features associated with the presence of B2-CIC.MethodsA multicenter, cross-sectional and observational study was conducted on 303 patients recruited from six European hospitals who fulfilled APS classification criteria: 165 patients had primary APS and 138 APS associated with other systemic autoimmune diseases (mainly systemic lupus erythematosus, N=112). Prevalence of B2-CIC (IgG/IgM isotypes) and its association with clinical manifestations and biomarkers related to the disease activity were evaluated.ResultsB2-CIC prevalence in APS patients was 39.3%. B2-CIC-positive patients with thrombotic APS presented a higher incidence of thrombocytopenia (OR: 2.32, p=0.007), heart valve thickening and dysfunction (OR: 9.06, p=0.015) and triple aPL positivity (OR: 1.83, p=0.027), as well as lower levels of C3, C4 and platelets (p-values: <0.001, <0.001 and 0.001) compared to B2-CIC-negative patients. B2-CIC of IgM isotype were significantly more prevalent in gestational than thrombotic APS.ConclusionsPatients with thrombotic events and positive for B2-CIC had lower platelet count and complement levels than those who were negative, suggesting a greater degree of platelet activation.