Eculizumab therapy and complement regulation in a case of resistant catastrophic antiphospholipid syndrome.

Catastrophic antiphospholipid syndrome (CAPS) is a life-threatening form of antiphospholipid syndrome characterised by diffuse arterial and venous thrombosis, in the presence of positive antiphospholipid antibodies. The multiple sites of thrombosis in small, medium and large vessels progress to multiorgan failure, accounting for the high mortality rate associated with CAPS. Unregulated complement activation is increasingly recognised as critical to the pathogenesis of CAPS. Early diagnosis is essential to initiate prompt life-saving treatment with the triple therapy of anticoagulation, immunosuppression and either plasmapheresis or intravenous immunoglobulin. Among other immunosuppressive agents, eculizumab, a complement inhibitor has demonstrated efficacy in treatment-resistant cases.We report an instructive case of a woman presenting with both clinical and laboratory findings consistent with primary CAPS, resistant to initial treatment and responsive to eculizumab, with emphasis on genetic testing and implications for future therapy.

Anticoagulant and non-anticoagulant therapy in thrombotic antiphospholipid syndrome: old drugs and new treatment targets.

In this review, we discuss the current evidence on classic and newer oral anticoagulant therapy, older drugs such as HCQ and statins, and new potential treatment targets in APS. Vitamin K antagonists (VKAs) remain the cornerstone treatment for thrombotic events in APS. In patients fulfilling criteria for definite APS presenting with a first venous thrombosis, treatment with VKAs with a target international normalized ratio (INR) 2.0-3.0 is recommended. In patients with arterial thrombosis, treatment with VKA with target INR 2.0-3.0 or 3.0-4.0 is recommended by recent guidelines, considering the individual's bleeding and thrombosis recurrence risk. A combination of VKAs and low-dose aspirin (75-100 mg/daily) may also be considered. According to available evidence direct oral anticoagulants should be avoided in patients with arterial thrombosis and/or those with triple aPL positivity. Adjunctive treatment with HCQ and/or statins can be considered, especially in anticoagulation treatment-refractory APS. Potential targeted treatments in APS include B-cell targeting, complement inhibition, mammalian target of rapamycin inhibition, IFN targeting, adenosine receptors agonists, CD38 targeting or chimeric antigen receptor T-cell therapy. The safety and efficacy of these treatment targets needs to be examined in well-designed randomized controlled trials.

Antiphospholipid syndrome, thrombosis, and vaccination in the COVID-19 pandemic.

Thrombosis is one of the many signs of antiphospholipid syndrome (APS) and COVID-19 infection. Although the mechanisms contributing to thrombosis in APS and COVID-19 are relatively similar, this remains an open subject. Even now (when the COVID-19 pandemic has subsided), there is no conclusive solution to APS and COVID-19 co-occurrence. The presence of newly generated antiphospholipid antibodies (aPLs) in COVID-19 infection may or may not be connected to the diagnosis of APS. The prevalence of aPLs is substantial in severe COVID-19 but not related to thrombosis or a worse outcome. Adequate monitoring of antibody positivity over time is recommended for APL diagnosis. On the other hand, thrombosis and thrombocytopenia can rarely occur with vaccination with mRNA vaccines. Some studies have shown that COVID-19 immunization is well tolerated among APS patients who are triple-positive for aPL, which may comfort patients and referring physicians and lessen hesitation in unvaccinated APS/aPL-positive patients. In this narrative review, we will give an overview of the interaction between aPL-APS-COVID-19-thrombosis and related diagnostic insights learned during the pandemic.

A thrombin-driven neural net diagnoses the antiphospholipid syndrome without the need for interruption of anticoagulation.

ABSTRACT: Thrombosis is an important manifestation of the antiphospholipid syndrome (APS). The thrombin generation (TG) test is a global hemostasis assay, and increased TG is associated with thrombosis. APS is currently diagnosed based on clinical and laboratory criteria, the latter defined as anti-cardiolipin, anti-ß2-glycoprotein I antibodies, or lupus anticoagulant (LA). APS testing is often performed after a thrombotic episode and subsequent administration of anticoagulation, which might hamper the interpretation of clotting assays used for LA testing. We set out to develop an artificial neural network (NN) that can diagnose APS in patients who underwent vitamin K antagonist (VKA) treatment, based on TG test results. Five NNs were trained to diagnose APS in 48 VKA-treated patients with APS and 64 VKA-treated controls, using TG and thrombin dynamics parameters as inputs. The 2 best-performing NNs were selected (accuracy, 96%; sensitivity, 96%-98%; and specificity, 95%-97%) and further validated in an independent cohort of VKA-anticoagulated patients with APS (n = 33) and controls (n = 62). Independent clinical validation favored 1 of the 2 selected NNs, with a sensitivity of 88% and a specificity of 94% for the diagnosis of APS. In conclusion, the combined use of TG and NN methodology allowed for us to develop an NN that diagnoses APS with an accuracy of 92% in individuals with VKA anticoagulation (n = 95). After further clinical validation, the NN could serve as a screening and diagnostic tool for patients with thrombosis, especially because there is no need to interrupt anticoagulant therapy.

Chorea as an initial and solitary manifestation of systemic lupus erythematosus with antiphospholipid syndrome in an elderly man.

Chorea can be an initial manifestation of systemic lupus erythematosus (SLE) or antiphospholipid syndrome (APS). It has been mostly described in younger female adults in association with other manifestations of SLE. When chorea appears as an initial and only manifestation in SLE/APS patients, the establishment of the correct diagnosis is difficult, and it may be initially attributed to a more common aetiology. Here we report an elderly man who presented with a new onset of right-sided chorea without other clinical manifestations of SLE/APS. He started on steroids a year later, however, there was no improvement. His chorea was symptomatically managed along with aspirin, and hydroxychloroquine as he refused to be on additional immunosuppression. Anticoagulation was relatively contraindicated, and also not favoured by this patient; therefore, aspirin was initiated. Even in elderly patients, once the common etiologies of chorea have been worked up, we suggest doing a rheumatological evaluation. Early diagnosis and prompt treatment can prevent persistent neurological abnormality.

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

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

Ischemic Stroke with Positive Antiphospholipid Antibodies in Bloom Syndrome: A Case Report.

OBJECTIVE: Bloom syndrome is a chromosomal breakage disorder associated with immune deficiency, characterized by short stature, predisposition to early-onset cancer, and immune defects. Currently, there have been no reports of acute cerebral infarction in patients with Bloom syndrome. Here, we report a case of Bloom syndrome complicated by elevated antiphospholipid antibodies and acute cerebral infarction. MATERIALS AND METHODS: A 23-year-old male with a known genetic diagnosis of Bloom syndrome was admitted to the Respiratory Department due to pulmonary aspergillosis. The patient experienced sudden dizziness, and subsequent cranial MRI revealed a newly developed infarction in the right cerebellar hemisphere. RESULTS: Six days later, the patient presented with sudden right visual field loss, and a repeat cranial MRI showed new infarctions in the left occipital and temporal lobes. Positive lupus anticoagulant and prolonged activated partial thromboplastin time suggested elevated antiphospholipid antibodies causing thrombus formation. Unfortunately, anticoagulant treatment was not administered due to recurrent hemoptysis. CONCLUSION: This study reports the first case of a Bloom syndrome patient with elevated antiphospholipid antibodies and acute cerebral infarction, suggesting that the immune and coagulation abnormalities caused by Bloom syndrome may contribute to the development of acute cerebral infarction.

SAPHO syndrome complicated by multiple venous thrombosis of left lower limb: A case report and literature review.

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is an uncommon clinical syndrome with the signs of skin problems and osteoarthropathy as its main features. The pathogenesis of SAPHO syndrome has not been fully elucidated, and multiple complications may be present, including thrombosis. A 39-year-old male patient was diagnosed with SAPHO syndrome, complicated by multiple venous thrombosis of the left lower limb. We conducted a brief review of the current available literature on thrombosis in patients with SAPHO syndrome and speculated that the presence of lower extremity thrombosis in this patient with SAPHO syndrome may be related to physiological structure or antiphospholipid syndrome. Whether positive lupus anticoagulant has an effect on thrombosis in patients with SAPHO syndrome remains to be investigated.

The effects of hydroxychloroquine and its promising use in refractory obstetric antiphospholipid syndrome.

Hydroxychloroquine (HCQ) is obtained by hydroxylation of chloroquine (CQ) and the first indication was malaria. Nowadays, HCQ is commonly used in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) with favorable results. Antiphospholipid syndrome (APS) is an autoimmune disease characterized by thrombosis and/or pregnancy morbidity and persistent positivity of antiphospholipid antibodies. Around 20-30% of pregnant women with APS develop adverse pregnancy outcomes despite conventional treatment with aspirin and heparin, called refractory obstetric APS. Interestingly, HCQ has shown positive effects on top of the standard of care in some refractory obstetric APS patients. HCQ mechanisms of action in APS comprise its ability to bind sialic acid present in cell membranes, its capacity to block the binding of antiphospholipid antibodies to the cell and the induced increase of pH in extracellular and intracellular compartments. However, the precise mechanisms of HCQ in the specific situation of refractory APS still need to be fully clarified. Therefore, this review summarizes the known modulating effects of HCQ and CQ, their side effects and use in APS and different pathologies to understand the benefit effects and the mechanism of action of HCQ in refractory obstetric APS.

A Rare Case with Pulmonary Embolism and Literature Review.

BACKGROUND: Pulmonary embolism is rare in children, and most of them have high-risk factors, such as antiphospholipid syndrome, intravenous catheterization, fracture bed rest, etc. For children with pulmonary embolism without clear inducement, hereditary thrombophilia should be considered. Genetic protein S deficiency (PSD) is a kind of thrombophilia, which is caused by the mutation of PROS 1 gene, resulting in an increased tendency to thrombosis. METHODS: The diagnosis of the two cases was made after detecting based on Thrombophilia screening and Sanger sequencing in clinical laboratory. RESULTS: Sanger sequencing found that case 2 and case 1 genotypes were the same, case 1 sister and grandfather carried c.200a>c (p.e67a) mutation, and case 1 aunt and grandmother did not carry PROS1 gene mutation. Case 1 received anticoagulation therapy for 3 months, and case 2 also received anticoagulation therapy for 3 months. During the 1 year follow-up, no new thrombotic events and no adverse reactions such as bleeding were observed in both patients. CONCLUSIONS: For children with pulmonary embolism without clear risk factors, PSD should be considered, and protein S activity should be tested before receiving anticoagulant drugs.

Complement biomarkers in the antiphospholipid syndrome - Approaches to quantification and implications for clinical management.

Complement is a major driver of antiphospholipid syndrome (APS) and a promising therapeutic target in refractory and catastrophic APS. Complement testing in APS is largely limited to research settings, and reliable, rapid-turnaround biomarkers are needed to predict those at risk for adverse clinical outcomes and most likely to benefit from complement inhibition. We review complement biomarkers and their association with thrombosis and obstetric outcomes, including: (i) complement proteins and activation fragments in the fluid phase; (ii) assays that evaluate complement on cell membranes (e.g. in vivo cell-bound complement fragments, hemolytic assays, and ex vivo 'functional' cell-based assays, and (iii) sequencing of complement genes. Current studies highlight the inconsistencies in testing both between studies and various aPL/APS subgroups, suggesting that either cell-based testing or multiplex panels employing a combination of biomarkers simultaneously may be most clinically relevant. Standardization of complement assays is needed to ensure reproducibility and establish clinically relevant applications.

Tacrolimus shows adequate efficacy in patients with antiphospholipid antibodies associated thrombocytopenia: a retrospective cohort study.

Thrombocytopenia is a common manifestation associated with the presence of antiphospholipid antibodies (aPL). The aim of this study is to investigate the efficacy and safety of tacrolimus treatment in aPL associated thrombocytopenia. This is a single-center retrospective study. Patients who had persistent positive aPL and thrombocytopenia that was treated with tacrolimus were included. A total of 49 patients [38 females (77.6%)] were enrolled from Nov 2013 to Apr 2022 with a median treatment duration of 22 months. Seventeen fulfilled classification criteria of antiphospholipid syndrome (APS), 18 systemic lupus erythematosus (SLE). The median age of study patients was 37 years (IQR 31, 48). Forty-three (87.8%) patients were on concomitant use of glucocorticoids, 6 on tacrolimus monotherapy. The overall response rate in this cohort was 85.7% (n = 42), including 49% of complete responses (n = 24). The median time to achieve a response was 3 months. Nine (18.4%) patients with overall response experienced a loss of response. The response rate during follow-up in patients with monotherapy was noninferior. Patients with positive antinuclear antibody (ANA) showed the tendency of maintaining response (p = 0.028). The 19 patients who were on medium and high dosage of glucocorticoids (> 15 mg prednisone/d) managed to taper glucocorticoids rapidly. Side effects were reported in 12.2% (n = 6) of the patients (elevated creatinine, general malaise, elevated liver enzyme). Tacrolimus has adequate efficacy, steroid-sparing effect and is well tolerated for aPL associated thrombocytopenia. Patients with positive ANA might benefit the most from tacrolimus treatment.

Thrombosis and APS: Lessons Learned from Another Black Swan Tale.

Antiphospholipid syndrome (APS) is a chronic systemic autoimmune disease characterized by venous, arterial, and microvascular thromboses and/or recurrent pregnancy morbidity, that occur in the persistent presence of antiphospholipid antibodies (aPL). APS can present with a wide range of clinical manifestations often reffered as "extra-criteria". These features, although apparently less common, can severely impact patients' outcome. Here, we report the case of a patient with a newly diagnosed APS. He previously experienced a recurrence of venous thrombosis after discontinuation of anticoagulant therapy in association with cutaneous ulcerations as presenting symptoms. Interestingly, skin lesions did not improve with full anticoagulant treatment. Due to concomitant presence of thrombotic and microvascular involvement, immunomodulatory therapy with steroid pulses followed by intravenous injections of belimumab was started, with progressive and significant amelioration, leading to complete recovery. Following the presentation of the current case report, we highlight the importance of suspecting APS in young patients experiencing unprovoked thrombosis. We also emphasized the critical issue of testing aPL during anticoagulant treatment and focused on the need of aPL retesting in patients with positivity at high titers. We also highlight the double nature of aPL-mediated clinical manifestations. While most patients presented with pure thrombotic complications, one should always remember that APS is an autoimmune-mediated disease, which can benefit from alternative therapeutic approaches beyond anticoagulation.

Therapy with direct oral anticoagulants for secondary prevention of thromboembolic events in the antiphospholipid syndrome: a systematic review and meta-analysis of randomised trials.

OBJECTIVE: Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterised by venous thrombosis (VT) or arterial thrombosis (AT) and/or pregnancy morbidity and the presence of antiphospholipid antibodies. Direct oral anticoagulants (DOACs) hold several advantages to vitamin K antagonists (VKAs) for prevention of thrombosis and we wish to evaluate DOACs compared with VKAs in secondary prevention of thromboembolic events in patients with APS. METHODS: We conducted searches of the published literature using relevant data sources (MEDLINE, Embase and Cochrane CENTRAL), and of trial registers for unpublished data and ongoing trials. We included randomised trials examining individuals >18 years with APS classified according to the criteria valid when the trial was carried out. Randomised controlled trials had to examine any DOAC agent compared with any comparable drug. We tabulated all occurrences of events from all eligible randomised trials. Due to few events, ORs and 95% CIs were calculated using the Peto method. RESULTS: 5 randomised trials comprising 624 patients met the predefined eligibility criteria. The primary outcome measure was new thrombotic events, a composite endpoint of any VT or AT, during the VKA-controlled phase of treatment. According to the I2 inconsistency index, there was evidence of statistical heterogeneity across the studies (I2=60%). Across trials, 29 and 10 thrombotic events were observed in 305 and 319 patients with APS treated with DOAC and VKA, respectively, corresponding to a combined Peto OR of 3.01 (95% CI 1.56 to 5.78, p=0.001). There was a significantly increased risk of AT while treated with DOACs compared with VKA (OR 5.5 (2.5, 12.1) p<0.0001), but no difference in the risk of VT (p=0.87). We found no significant difference in risk of bleeding. CONCLUSIONS: DOACs were associated with a significant increase in the risk of a new thrombotic event, especially AT, favouring standard prophylaxis with warfarin. PROSPERO REGISTRATION NUMBER: CRD42019126720.

Identification of MARK2, CCDC71, GATA2, and KLRC3 as candidate diagnostic genes and potential therapeutic targets for repeated implantation failure with antiphospholipid syndrome by integrated bioinformatics analysis and machine learning.

Background: Antiphospholipid syndrome (APS) is a group of clinical syndromes of thrombosis or adverse pregnancy outcomes caused by antiphospholipid antibodies, which increase the incidence of in vitro fertilization failure in patients with infertility. However, the common mechanism of repeated implantation failure (RIF) with APS is unclear. This study aimed to search for potential diagnostic genes and potential therapeutic targets for RIF with APS. Methods: To obtain differentially expressed genes (DEGs), we downloaded the APS and RIF datasets separately from the public Gene Expression Omnibus database and performed differential expression analysis. We then identified the common DEGs of APS and RIF. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed, and we then generated protein-protein interaction. Furthermore, immune infiltration was investigated by using the CIBERSORT algorithm on the APS and RIF datasets. LASSO regression analysis was used to screen for candidate diagnostic genes. To evaluate the diagnostic value, we developed a nomogram and validated it with receiver operating characteristic curves, then analyzed these genes in the Comparative Toxicogenomics Database. Finally, the Drug Gene Interaction Database was searched for potential therapeutic drugs, and the interactions between drugs, genes, and immune cells were depicted with a Sankey diagram. Results: There were 11 common DEGs identified: four downregulated and seven upregulated. The common DEG analysis suggested that an imbalance of immune system-related cells and molecules may be a common feature in the pathophysiology of APS and RIF. Following validation, MARK2, CCDC71, GATA2, and KLRC3 were identified as candidate diagnostic genes. Finally, Acetaminophen and Fasudil were predicted as two candidate drugs. Conclusion: Four immune-associated candidate diagnostic genes (MARK2, CCDC71, GATA2, and KLRC3) were identified, and a nomogram for RIF with APS diagnosis was developed. Our findings may aid in the investigation of potential biological mechanisms linking APS and RIF, as well as potential targets for diagnosis and treatment.

Surface Geometry of Cargo-less Gold Nanoparticles Is a Driving Force for Selective Targeting of Activated Neutrophils to Reduce Thrombosis in Antiphospholipid Syndrome.

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by recurrent arterial, venous, and microvascular thrombosis where activated neutrophils play a determinant role. However, neutrophils are challenging to target given their short lifespan in circulation and spontaneous activation. Screening of a small library of gold nanoparticles (AuNPs) led to the discovery of a formulation capable of targeting activated neutrophil attachment and has demonstrated that star-shaped, anti-PSGL-1-antibody-coated AuNPs (aPSGL-1-AuNPs) were more efficacious compared with other shapes of AuNPs. Our findings further revealed an exciting and safe targeting mode toward activated neutrophils in the APS mouse model induced by human-patient-derived antiphospholipid IgGs. Our studies demonstrate that targeting is dependent on the specific topographical features of the highly segregated PSGL-1 on the activated neutrophil surface for which a high affinity shape-driven nanomedicine can be designed and implemented. As such, star-shaped aPSGL-1-AuNPs serve as a promising nanoimmunotherapy for immunothrombosis associated with neutrophil adhesion in APS.