Catastrophic Antiphospholipid Syndrome: Candidate Therapies for a Potentially Lethal Disease

Antiphospholipid antibody carriers and patients with quiescent antiphospholipid syndrome show persistent subclinical complement activation

OBJECTIVES

Complement activation has been advocated as one mechanism by which aPLs can induce thrombosis. In patients with catastrophic APS or re-thrombosis, enhanced complement activation has been shown, even in the quiescent phase of the disease. We aimed to assess complement activation and to investigate its association with clinical variables in aPL-positive patients with a favourable disease course.

METHODS

Subjects with at least two consecutive positive aPL results obtained ≥12 weeks apart were enrolled. They were subjects without a history of thrombosis or pregnancy morbidity (aPL carriers), patients with pregnancy morbidity alone, i.e. obstetric APS patients (OAPS patients), and/or patients with arterial, venous, or small-vessel thrombotic APS (TAPS patients); for enrolment, all patients were required to have been free of symptoms for ≥2 years. Patients affected with systemic autoimmune diseases were excluded. Healthy age- and sex-matched subjects were included as controls. Plasma C5a and C5b-9 levels were assessed by commercially available ELISA assays. The non-parametric Mann-Whitney test and Spearman's correlation were applied.

RESULTS

Thirty-seven OAPS patients, 38 TAPS patients, 42 aPL carriers and 30 healthy subjects were enrolled. The median C5a and C5b-9 levels were significantly higher in quiescent aPL-positive patients (OAPS, TAPS, aPL carriers) compared with controls: C5a ng/ml 10.61 [interquartile range (IQR) 6.87-15.46] vs 4.06 (2.66-7.35), P < 0.001; C5b-9 ng/ml 283.95 (175.8-439.40) vs 165.90 (124.23-236.8), P < 0.001. Similar C5a and C5b-9 levels were observed in OAPS and TAPS patients and aPL carriers. A positive correlation between the median C5b-9 levels and the number of aPL-positive tests was found (P = 0.002).

CONCLUSION

The persistence of aPL antibodies is associated with a persistent subclinical activation of the complement cascade.

Diagnosis and Management of Catastrophic Antiphospholipid Syndrome and the Potential Impact of the 2023 ACR/EULAR Antiphospholipid Syndrome Classification Criteria

Catastrophic antiphospholipid syndrome (CAPS) is a rare and life-threatening condition characterized by the persistence of antiphospholipid antibodies and occurrence of multiple vascular occlusive events. CAPS currently remains a diagnostic challenge and requires urgent treatment. The diagnosis of CAPS is made difficult by classification criteria used as diagnostic criteria in clinical practice, knowledge derived from retrospective data and case reports, confounding clinical and biological features, and its rapid onset and mortality. The absence of prospective studies of CAPS limits the strength of evidence for guideline treatment protocols. This comprehensive review summarizes the current understanding of the disease, and discusses how the 2023 ACR/EULAR Antiphospholipid Syndrome Classification Criteria impact the definition and therapeutic management of CAPS, which is considered the most severe form of APS. The correct integration of 2023 ACR/EULAR APS classification criteria is poised to facilitate CAPS diagnosis, particularly in critical situations, offering a promising avenue for improved outcomes.

Neurologic Manifestations of Catastrophic Antiphospholipid Syndrome

PURPOSE OF REVIEW

Understanding of antiphospholipid antibody syndrome (APS), associated neurological manifestations, and disease-directed treatment has grown considerably over the last decade. Herein, we critically review the current and high-yield literature related to the pathophysiology, neurological presentations, and management of APS with particular emphasis on the rare and more fatal subset of APS, catastrophic antiphospholipid syndrome (CAPS).

RECENT FINDINGS

APS may manifest with a variety of neurologic syndromes, with cerebrovascular disease representing the most commonly encountered presentation. Diagnostic evaluation and treatment are often tailored to the specific presentation, with suspicion and testing for antiphospholipid antibodies recommended when neurologic presentations occur atypically or in younger individuals. In CAPS, which is more rapidly progressive with multiorgan involvement, potential alternative microangiopathic syndromes should be carefully considered in the differential diagnosis. To date, anticoagulation with vitamin K antagonists remains the mainstay of therapy in APS while triple therapy with anticoagulation, corticosteroids, and plasma exchange is standard of care in CAPS. Immunotherapy has shown early promise in refractory cases. APS is an autoimmune clinical syndrome with neurologic presentations classically characterized by vascular thrombosis, though recent understandings suggest additional direct immune-mediated phenomena. Our understanding of the underlying pathogenic mechanisms of APS continues to grow and will continue to influence our therapeutic approaches.

Pathogenesis, Diagnosis and Management of Obstetric Antiphospholipid Syndrome: A Comprehensive Review

Antiphospholipid syndrome is an autoimmune disorder characterized by vascular thrombosis and/or pregnancy morbidity associated with persistent antiphospholipid antibody positivity. Cases fulfilling the Sydney criteria for obstetric morbidity with no previous thrombosis are known as obstetric antiphospholipid syndrome (OAPS). OAPS is the most identified cause of recurrent pregnancy loss and late-pregnancy morbidity related to placental injury. Cases with incomplete clinical or laboratory data are classified as obstetric morbidity APS (OMAPS) and non-criteria OAPS (NC-OAPS), respectively. Inflammatory and thrombotic mechanisms are involved in the pathophysiology of OAPS. Trophoblasts, endothelium, platelets and innate immune cells are key cellular players. Complement activation plays a crucial pathogenic role. Secondary placental thrombosis appears by clot formation in response to tissue factor activation. New risk assessment tools could improve the prediction of obstetric complication recurrences or thromboses. The standard-of-care treatment consists of low-dose aspirin and prophylactic low molecular weight heparin. In refractory cases, the addition of hydroxychloroquine, low-dose prednisone or IVIG improve pregnancy outcomes. Statins and eculizumab are currently being tested for treating selected OAPS women. Finally, we revisited recent insights and concerns about the pathophysiology, diagnosis and management of OAPS.

Cost-effectiveness analysis of treatments for the first episode of catastrophic antiphospholipid syndrome: A study based on the catastrophic antiphospholipid syndrome registry

BACKGROUND

Treatments for catastrophic antiphospholipid syndrome (CAPS) rose from recommendations and consensus of international experts based on case series or case reports. We aimed to evaluate the treatment scheme with the best cost-effectiveness ratio associated with lower mortality as a high-impact clinical benefit.

METHODS

The CAPS Registry was used as our source of structured data on the different therapeutic strategies, their frequency, and their effectiveness (survival). Starting from around 50 different schemes, we identified those with a mortality of less than 33% within the 18 most frequently utilized. After applying the efficiency frontier method, we included two schemes to conduct a cost-effectiveness analysis from the Colombian healthcare sector perspective. Scheme 1 (Glucocorticoids + Anticoagulation + Anti-aggregation + Intravenous IgG immunoglobulin) and scheme 2 (Glucocorticoids + Anticoagulation + Anti-aggregation + Plasma exchange) were compared in terms of costs and survival. Deterministic and probabilistic sensitivity analyses (Monte Carlo simulation) were conducted to evaluate model robustness and uncertainty.

RESULTS

Our analysis uses the information corresponding to 427 cases from the CAPS registry, the majority being women (68.8%), with a mean age of 45.7 years and bearing general mortality of 38.17% (female: 38.4%, male: 37.5%). Scheme 2 was the cost-effective strategy over scheme 1. The results were robust on discrete sensitivity analysis and probability sensitivity analysis (Monte Carlo simulation).

CONCLUSION

To our knowledge, this is the first economic evaluation focused on the treatment of CAPS. For the Colombian health system, schemes 1 and 2 have similar behavior; nevertheless, scheme 2 represents the best cost-effectiveness ratio. This treatment approach is highly susceptible to the allocation of resources by the system and beneficial in terms of health outcomes.

Successful Treatment of Catastrophic Antiphospholipid Syndrome Using Rituximab: Case Report and Review of the Literature

BACKGROUND

Kidney involvement is a frequent complication of systemic lupus erythematosus (SLE) and kidney biopsy is essential in differentiating lupus nephritis (LN) from thrombotic microangiopathy (TMA) secondary to antiphospholipid autoantibodies (aPL). Association between antiphospholipid syndrome (APS) and acquired hemophilia due to inhibitors was very rarely described in SLE patients.

CASE PRESENTATION

We present the case of a 61-year-old male diagnosed with SLE who acquired deficiency of clotting factor VIII due to circulating inhibitors, admitted for acute kidney injury (AKI), microangiopathic hemolytic anemia, thrombocytopenia, and diplopia. Kidney biopsy showed TMA due to APS, but no signs of LN. Head computed tomography identified low dense areas in the white matter, suggesting small blood vessels' involvement. A diagnosis of probable catastrophic antiphospholipid syndrome (CAPS) was established and treatment with low molecular weight heparin, intravenous methylprednisolone, plasmapheresis, and rituximab was initiated, followed by resolution of AKI, diplopia, and TMA with complete depletion of CD19+B-lymphocytes (CD19+B-Ly) after one month. We further review the current knowledge regarding pathogenesis and management of CAPS in SLE patients.

CONCLUSIONS

Targeted therapy was possible after kidney biopsy, improving renal and general prognosis. CD19+B-Ly repopulation preceded biological relapse, so monitoring of CD19+B-Ly may serve as a tool to predict relapses and guide rituximab therapy.

Coronavirus disease 2019 (COVID-19) and immune-mediated inflammatory rheumatic diseases: at the crossroads of thromboinflammation and autoimmunity

Inflammation and coagulation are key basic mechanism of protection against all potentially pathogenic mechanical and biological factors targeting human organism from inner and outer environment. On the other hand, uncontrolled inflammation results in hypercoagulation, inhibition of anticoagulation and alteration of mechanisms responsible for resolution of inflammation, while production of “procoagulant” mediators (thrombin, tissue factor and others), activation of platelets and of vascular endothelial cells maintains inflammation. All factors taken together serve as the basis for a pathological process called thromboinflammation or immunothrombosis. Currently thromboinflammation is considered in the broad sense as a universal pathogenetic mechanism of numerous widespread acute and chronic conditions, including immune-mediated (autoimmune) inflammatory rheumatic diseases, oftentimes complicated by severe irreversible damage to vital organs. Thromboinflammation gained specific attention during СОVID-19 (coronavirus disease 2019) pandemic, caused by SARS-Cov-2 (severe acute respiratory syndrome Coronavirus-2). COVID-19 is considered currently as systemic thromboinflammation syndrome, manifesting via generalized thrombosis of arterial and venous macro- and microvasculature, termed as COVID-19-coagulopathy. The paper discusses common pathogenetic coagulopathy mechanisms in COVID-19 and immune-mediated (autoimmune) inflammatory rheumatic diseases (IMRDs), associated with overproduction of antiphospholipid antibodies, activation of the complement system, and dis-regulated synthesis of proinflammatory cytokines, etc. Delineating the autoimmune subtype of thromboinflammation, identification of genetic (i.e., genes encoding the complement system and others) and molecular-biologic biomarkers associated with higher occurrence of COVID-19-coagulopathy are the most relevant undertakings for the current practice. Gaining insights into mechanisms of thromboinflammation and converting them into potential pharmacotherapies of IMDs would facilitate and accelerate the drafting of effective therapeutic strategies for COVID-19. 

16th International Congress on Antiphospholipid Antibodies Task Force Report on Catastrophic Antiphospholipid Syndrome

The Task Force on Catastrophic Antiphospholipid Syndrome (CAPS) met again on occasion of the 16th International Congress on Antiphospholipid Antibodies (aPL) that was held in Manchester, England, in September 2019. Its aims were to assess the up-to-date knowledge on pathogenesis, clinical and laboratory features, diagnosis and classification, precipitating factors, and treatment of CAPS. This article summarizes the main aspects that were presented during the Task Force meeting at that Congress.

Is there a role for immunosuppression in antiphospholipid syndrome?

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by thrombosis, pregnancy morbidity, or nonthrombotic manifestations in patients with persistently positive antiphospholipid antibodies (aPL). Conventional APS treatment focuses on antithrombotic strategies, which are usually ineffective for the microvascular and nonthrombotic manifestations of aPL. Using a case-based presentation, this review focuses on the role of immunosuppression in nonobstetric APS, including B-cell inhibition (rituximab, belimumab, and bortezomib), complement inhibition (eculizumab), mechanistic target of rapamycin inhibition (sirolimus), vascular endothelial cell modulation (defibrotide), statins, and traditional rheumatologic disease-modifying agents (hydroxychloroquine, mycophenolate mofetil, azathioprine, and cyclophosphamide).

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Antiphospholipid syndrome: a clinical review

Antiphospholipid syndrome is characterised by recurrent thrombosis (arterial, venous, microvascular) and/or pregnancy complications in the presence of persistent antiphospholipid antibodies (lupus anticoagulant, anti-β2-glycoprotein 1 and anticardiolipin). It can be a primary disease or associated with another autoimmune disease (especially systemic lupus erythematosis). Testing for antiphospholipid antibodies should be considered in patients < 50 years of age with unprovoked venous or arterial thromboembolism, thrombosis at unusual sites or pregnancy complications. The mainstay of treatment is antithrombotic therapy and recommendations vary based on arterial, venous or pregnancy complications. If associated with systemic lupus erythematosis, hydroxychloroquine is recommended both as primary and secondary prophylaxis. Antithrombotic treatment is gold standard and effective.

Microthrombotic renal involvement in an SLE patient with concomitant catastrophic antiphospholipid syndrome: the beneficial effect of rituximab treatment

Antiphospholipid syndrome is characterized by multiple arterial and/or venous thrombotic events, recurrent fetal losses in the presence of antiphospholipid antibodies (aPL). Catastrophic antiphospholipid syndrome is a life-threatening, rare subset of antiphospholipid syndrome when the thrombotic events affect at least three organs, and clinical manifestations develop simultaneously or within a week. Diagnostically, small vessel occlusions can be detected by histopathology in the presence of aPL. Our case report describes an 18-year-old man who has been treated for antiphospholipid syndrome associated with systemic lupus erythematosus (SLE) since 2011. The clinical findings were dominated by recurrent deep vein thrombosis, and severe proteinuria caused by lupus nephritis, accompanied by mild serological and laboratory findings. The patient was hospitalized in March 2014 because of severe thrombocytopenia and infective diarrhoea. At this time the renal functions deteriorated rapidly. Simultaneously, left upper extremity paresis was observed; computed tomography showed ischaemic lesions in the territory of the middle cerebral artery. Abdominal discomfort and pain occurred. On computed tomography scan ischaemic lesions were seen in the spleen, the right kidney and the coeliac trunk. Laboratory and serological findings verified the presence of aPL and anti-DNA antibodies, anaemia and thrombocytopenia. Based on the above-mentioned clinical and laboratory findings, the diagnosis of catastrophic antiphospholipid syndrome was established. Anticoagulation, corticosteroids and plasma exchange treatment, as well as haemodiafiltration were initiated. Although the thrombotic cascade decelerated following these interventions, we could not see an improvement in the renal function. Rituximab treatment was started, leading to a significant improvement in renal function. After 5 weeks of treatment the patient was discharged from hospital.

Treatment of antiphospholipid syndrome beyond anticoagulation

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder marked by thrombosis and/or pregnancy morbidity in the presence of antiphospholipid antibodies (aPL). At the present time, treatment is primarily focused on anticoagulation. However, there is increasing awareness of the mechanisms involved in APS pathogenesis, which has led to the trial of novel therapies targeting those mechanisms. Following a brief review of the etiopathogenesis of and current management strategies in APS, this paper focuses on the evidence for these potential, targeted APS treatments, e.g., hydroxychloroquine, statins, rituximab, belimumab, eculizumab, defibrotide, sirolimus, and peptide therapy.

Therapeutic apheresis in the treatment of catastrophic antiphospholipid syndrome

Catastrophic thrombotic syndrome is characterized by occurrence of several thromboembolic occlusions which affect a variety of vascular beds over a short period of time. Catastrophic Antiphospholipid syndrome (CAPS) (1%) is regarded as a rare but severe variant of Antiphospholipid Syndrome. Treatment with anticoagulants, steroids and therapeutic plasma exchange has been shown to give the best results. However, to treat CAPS, the best substitute for plasma is still a debatable issue because there are no standard methods.

Catastrophic antiphospholipid syndrome and pregnancy

Catastrophic antiphospholipid syndrome (CAPS) is a rare but life-threatening condition that may be precipitated by pregnancy. The condition can be hard to diagnose since it mimics other thrombotic microangiopathies that are associated with pregnancy. Accurate and timely diagnosis is critical for effective treatment. In this review, we highlight pertinent clinical features of CAPS so that obstetricians will be able to recognize and treat the condition.

Antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of antiphospholipid antibodies, such as lupus anticoagulant, anticardiolipin antibodies and anti-β2-glycoprotein 1 antibodies. APS can present with a variety of clinical phenotypes, including thrombosis in the veins, arteries and microvasculature as well as obstetrical complications. The pathophysiological hallmark is thrombosis, but other factors such as complement activation might be important. Prevention of thrombotic manifestations associated with APS includes lifestyle changes and, in individuals at high risk, low-dose aspirin. Prevention and treatment of thrombotic events are dependent mainly on the use of vitamin K antagonists. Immunosuppression and anticomplement therapy have been used anecdotally but have not been adequately tested. Pregnancy morbidity includes unexplained recurrent early miscarriage, fetal death and late obstetrical manifestation such as pre-eclampsia, premature birth or fetal growth restriction associated with placental insufficiency. Current treatment to prevent obstetrical morbidity is based on low-dose aspirin and/or low-molecular-weight heparin and has improved pregnancy outcomes to achieve successful live birth in >70% of pregnancies. Although hydroxychloroquine and pravastatin might further improve pregnancy outcomes, prospective clinical trials are required to confirm these findings.