The physiopathology of the catastrophic antiphospholipid (Asherson's) syndrome: compelling evidence

Pediatric antiphospholipid syndrome: is it the same as an adult?

IMPORTANCE

Antiphospholipid syndrome in neonates and children is a rare, but in some cases life-threatening condition with arterial and/or venous thrombosis and/or non-thrombotic neurological, skin, ophthalmological and other manifestations.

OBSERVATIONS

This review highlights the available information about the features of pediatric APS, including the rare catastrophic form, the differences between pediatric and adult APS, and the role of genetic thrombophilia in APS manifestation.

CONCLUSIONS AND RELEVANCE

The clinical manifestations and treatment options for APS in children may differ from those in adults, and prescribing therapy can be challenging due to the unique clinical and morphological characteristics of the pediatric patient. Pediatric APS may be a predictor of the development of certain autoimmune diseases and classic manifestations of APS in adulthood, therefore, a revision of the existing criteria for the diagnosis and treatment of APS in children is necessary.

Catastrophic antiphospholipid syndrome: a case report and literature review

Catatrophic antiphospholipid syndrome (CAPS), a rare variant of antiphospholipid syndrome (APS), is associated with rapid multiorgan failure. While APS is associated with single medium-to-large blood vessel occlusions, CAPS is most often associated with several, concurrent vascular occlusions of small vessels, commonly of the kidneys, heart, skin and brain. We present a case of a 21-year-old female patient with a history of immune thrombocytopenia purpura and APS, who eventually developed concurrent cerebral venous sinus thrombosis, diffuse alveolar haemorrhage, renal thrombotic microangiopathy, and a necrotic, vasculitic wound on her forearm. Despite hospitalisation and treatment, her condition worsened and the patient eventually died after succumbing to suspected CAPS.

Catastrophic Thrombosis: A Narrative Review

Catastrophic thrombosis is a severe condition characterized by a hypercoagulable tendency, leading to multiple thromboembolic events in different blood vessels, usually within a short timeframe. Several conditions have been associated with the development of catastrophic thrombosis, including the catastrophic antiphospholipid syndrome, thrombotic anti-platelet factor 4 immune disorders, thrombotic microangiopathies, cancers, the hyper-eosinophilic syndrome, pregnancy, infections, trauma, and drugs. Thrombotic storm represents a medical emergency whose management represents a serious challenge for physicians. Besides the prompt start of anticoagulation, a patient's prognosis depends on early recognition and possible treatment of the underlying condition. In this narrative review, we summarize the main characteristics of catastrophic thrombosis, analyzing the various conditions triggering such life-threatening complication. Finally, an algorithm with the diagnostic workup and the initial management of patients with catastrophic thrombosis is presented.

Catastrophic antiphospholipid syndrome: Lessons from the "CAPS Registry"

The catastrophic antiphospholipid syndrome (CAPS) is a rare life-threatening clinical condition that represents the most severe clinical presentation of the antiphospholipid syndrome (APS). It was first described in 1992 in a group of patients that presented with multiorgan involvement and microangiopathic features of APS. Most of the current knowledge of CAPS comes from the analysis of all cases collected at the "CAPS Registry" that was created in 2000 to perform studies on this condition. Most cases are triggered by a prothrombotic situation that leads to a multiorgan thrombosis and a cytokine storm. The analysis of cases included in the "CAPS Registry" has shown that the triple therapy with anticoagulation, glucocorticoids, and plasma exchange and/or intravenous immunoglobulins is associated to a better prognosis of CAPS. The improvement of the knowledge allowed a decrease from the 50% mortality rate reported in the first series to 25-30% in the most recent publications.

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.

What we know and what we don't know about catastrophic antiphospholipid syndrome

Catastrophic antiphospholipid syndrome (CAPS) is a severe condition with high mortality. Since its description in 1992, an important effort has been made to improve and disseminate knowledge on CAPS. Most of our current knowledge comes from the studies performed using the CAPS Registry, a database created in 2000 to gather as many cases as possible in order to better define this disease. It has demonstrated that this condition has multiple faces and is often triggered by a precipitating factor that leads to a thrombotic microangiopathy and cytokine storm involving almost any organ of the body. Analysis of the CAPS Registry has also shown that patients receiving anticoagulation, glucocorticoids and plasma exchange and/or IVIG have a better prognosis. However, there are still many unresolved questions. In this review we summarize what is known and what is still a matter of research in this condition.

Pulmonary involvement in catastrophic antiphospholipid syndrome: A descriptive analysis from the "CAPS Registry"

OBJECTIVES

To describe the pulmonary involvement in patients with catastrophic antiphospholipid syndrome (CAPS), focusing on its relationship with extrapulmonary involvement, laboratory, radiological, and pathological findings.

METHODS

This retrospective cross-sectional study includes all patients grouped in the "CAPS Registry". All cases were reviewed, and those with pulmonary thromboembolism (PE) and/or diffuse alveolar hemorrhage (DAH) were selected. Data on pulmonary and extrapulmonary clinical presentation, radiologic patterns, laboratory findings, associated autoimmune diseases, treatments, and outcomes were analyzed. Frequency distribution and measures of central tendency were used to describe the cohort. Comparison between groups regarding qualitative variables was undertaken by chi-square or Fisher exact test, while T-test for independent variables was used to compare groups regarding continuous variables. IBM-SPSS v.22 was used for data analysis.

RESULTS

PE was reported in 129 (48.6 %) episodes, DAH in 75 (28.3 %) episodes, and overlap (DAH plus PE) in 7 (2.6 %) episodes. Bronchoalveolar lavage (BAL) was performed in 35 (4.9 %) CAPS episodes, and lung pathology samples were obtained in 84 (10.5 %) episodes (including autopsies). A significant relationship was observed between DAH and laboratory features of thrombotic microangiopathy (TMA). A meaningful relationship was also found between triple antiphospholipid antibody positivity and pathological TMA (26.5 %) as well as hypocomplementemia and DAH (24 %).

CONCLUSIONS

Pulmonary involvement may include both TMA and non-thrombotic inflammation, which can be differentiated into three patterns: PE, DAH with systemic TMA with hypocomplementemia or DAH without systemic TMA with/without hypocomplementemia.

Autoimmune Connective Tissue Diseases: Systemic Lupus Erythematosus and Rheumatoid Arthritis

Systemic lupus erythematosus and rheumatoid arthritis are just 2 of several autoimmune connective tissue diseases that are primarily chronic in nature but can present to the emergency department by virtue of an acute exacerbation of disease. Beyond an acute exacerbation of disease, their predilection for invading multiple organ systems lends itself to the potential for patients presenting to the emergency department with either a single or isolated symptom or a myriad of signs and/or symptoms indicative of a degree of disease complexity and severity that warrant timely recognition and resuscitation.

Precipitating factors of catastrophic antiphospholipid syndrome: the role of anticoagulant treatment in a series of 112 patients

BACKGROUND

The prevention of catastrophic antiphospholipid syndrome (CAPS), a rare complication of antiphospholipid syndrome (APS), is a major goal.

OBJECTIVES

We analyzed its precipitating factors, focusing on anticoagulation immediately before CAPS episodes.

METHODS

We retrospectively analyzed patients in the French multicenter APS/systemic lupus erythematosus database with at least 1 CAPS episode. Then we compared each patient with known APS before CAPS with 2 patients with non-CAPS APS matched for age, sex, center, and APS phenotype.

RESULTS

We included 112 patients with CAPS (70% women; mean age, 43 ± 15 years). At least 1 standard precipitating factor of CAPS was observed for 67 patients (64%), which were mainly infections (n = 28, 27%), pregnancy (n = 23, 22%), and surgery (n = 16, 15%). Before the CAPS episode, 67 (60%) patients already had a diagnosis of APS. Of the 61 treated with anticoagulants, 32 (48%) received vitamin K antagonists (VKAs), 23 (34%) heparin, and 2 (3%) a direct oral anticoagulant. They were less likely than their matched patients with APS without CAPS to receive VKA (48% vs 66%, p = .001). Among those treated with VKA, 72% had a subtherapeutic international normalized ratio (ie, <2) versus 28% in patients with APS without CAPS (p < .001). Finally, excluding pregnant patients (n = 14) for whom we could not differentiate the effect of treatment from that of pregnancy, we were left with 47 cases, 32 (68%) of whom had recently begun a direct oral anticoagulant, planned bridging therapy, or had VKA treatment with international normalized ratio <2.

CONCLUSION

These results strongly suggest that suboptimal anticoagulation management can trigger CAPS in patients with thrombotic APS.

Autoimmune Connective Tissue Diseases: Systemic Lupus Erythematosus and Rheumatoid Arthritis

Systemic lupus erythematosus and rheumatoid arthritis are just 2 of several autoimmune connective tissue diseases that are primarily chronic in nature but can present to the emergency department by virtue of an acute exacerbation of disease. Beyond an acute exacerbation of disease, their predilection for invading multiple organ systems lends itself to the potential for patients presenting to the emergency department with either a single or isolated symptom or a myriad of signs and/or symptoms indicative of a degree of disease complexity and severity that warrant timely recognition and resuscitation.

Case Report: An Unusual Case of Acute Lower Limb Ischemia as Precursor of the Asherson's Syndrome

Introduction: Asherson's Syndrome, also defined as Catastrophic Antiphospholipid Syndrome (CAPS), represents the most severe manifestation of Antiphospholipid Antibody Syndrome. Rarely, the first CAPS diagnosis is based on macro-thrombotic event as acute limb ischemia. Case Presentation: We present a case of a 65-year-old woman admitted with an acute lower limb arterial ischemia with a complete occlusion of all the three tibial vessels. Three endovascular recanalization procedures were performed contemporary to 48 h intraarterial thrombolysis administration. The patency of tibial arteries was restored with a near-complete absence of digital arteries and microvessel perfusion of the foot. In the following days, an aggressive foot gangrene was established, leading to a major lower-limb amputation. Due to the general clinical status worsening and aggressiveness of ischemic condition, further investigations were performed leading to the diagnosis of an aggressive Asherson's Syndrome that was also complicated by a severe heparin-induced thrombocytopenia. Medical management with a high dose of intravenous steroids and nine sessions of plasma exchange led to a clinical condition stabilization. Conclusion: In our case, the presence of a "sine causa" acute arterial occlusion of a large vessel represented the first manifestation of an aggressive form of Asherson's Syndrome that could represent a fatal disease. Due to the extreme variety of manifestations, early clinical suspicion, diagnosis, and multidisciplinary management are essential to limit the life-threatening consequences of patients.

Plasma exchange in catastrophic antiphospholipid syndrome

Plasma exchange is a well-established therapeutic procedure commonly used in many autoimmune disorders. The beneficial effects of plasma exchange are thought to occur through the elimination of pathogenic mediators found in plasma, including autoantibodies, complement components, and cytokines. The catastrophic antiphsopholipid syndrome (CAPS) is a life-threatening variant of the antiphospholipid syndrome (APS) where several thrombosis take place in a short period of time in patients with circulating antiphospholipid antibodies. The triple therapy with anticoagulation, corticosteroids and plasma exchange or intravenous immunoglobulins has been proposed in CAPS. CAPS is a rare disease precluding the conduction of formal clinical trials. However, the observation of a better clinical course of patients who received this treatment supports their use. Plasma exchange has become an established therapeutic procedure in CAPS but there are no studies regarding the better approach and thus its use relies on the experience of the physicians in charge. The current article aims to review potential mechanisms of action of plasma exchange and the technical aspects of this procedure and will focus on its current role in CAPS, the experience published in treating this condition and the treatment protocol that we use in our institution.

Probable Catastrophic Antiphospholipid Syndrome with Intracerebral Hemorrhage Secondary to Epstein-Barr Viral Infection

BACKGROUND

Catastrophic antiphospholipid syndrome (CAPS) is a rare, severe variant of antiphospholipid syndrome with a high mortality rate. We report a unique case of CAPS secondary to Epstein-Barr viral (EBV) infection complicated by pulmonary and intracerebral hemorrhage. A review of the CAPS literature relevant to intensive care practice is used to outline a rational approach to diagnosis and management.

METHODS

All data are from a single patient admitted to the Neurosciences Critical Care Unit in Addenbrooke's Hospital, Cambridge, in March 2016. Medline, Web of Science, PubMed, and the Cochrane Library were searched through September 2016 without restrictions for cases of CAPS, management of CAPS in the intensive care unit, and hemorrhage complicating CAPS. The patient gave express written consent to access and publish these data.

RESULTS

This is only the second reported case of probable CAPS secondary to EBV infection. Furthermore, pulmonary and intracerebral hemorrhage is rare manifestations of this multisystem prothrombotic state which provided unique challenges to the management.

CONCLUSIONS

While rare, CAPS should be considered in any patient presenting with rapidly progressive multiorgan failure, evidence of thrombotic microangiopathy, and antiphospholipid antibodies. A high index of suspicion is required as early, aggressive, multimodal treatment with anticoagulation, and immunosuppression improves outcomes.

Eculizumab in a pregnant patient with laboratory onset of catastrophic antiphospholipid syndrome: A case report

RATIONALE

Hypercoagulability and pregnancy morbidity are hallmarks of the antiphospholipid syndrome (APS). Catastrophic antiphospholipid syndrome (CAPS) is a potentially life-threatening omplication of APS, with widespread acute thrombotic microangiopathy (TMA) that can be precipitated by pregnancy and delivery and result in multiorgan damage. Unrestrained activation of the complement cascade is involved, favoring endothelial activation, tissue factor expression by leukocytes, and platelet aggregation. The complement block, which interrupts this amplification cycle, could prevent CAPS in patients with early TMA who face precipitating events.

PATIENT CONCERNS

We present a nulliparous pregnant woman with APS at the 30 week of gestation who has developed thrombocytopenia, intravascular hemolysis, elevated creatinine, proteinuria, and hematuria.

DIAGNOSES

These featurs were compatible with the diagnosis of CAPS. Consensually, serum C3 protein levels were rapidly decreasing, reflecting complement consumption.

INTERVENTIONS

She was treated with eculizumab, a humanized monoclonal antibody against C5 that prevents the formation of the complement membrane attack complex.

OUTCOMES

Laboratory parameters improved and the patient did not develop thrombosis or detectable organ/tissue damage. The patient safely delivered by cesarean section at week 32 of gestation a healthy 1640 g male infant. After 5 days, she received additional eculizumab, with complete resolution of the clinical condition. Low complement activity was detectable in the infant blood for a week after delivery. No infectious complication occurred.

LESSONS

Inhibition of the terminal complement activation is safe and might be effective in patients with APS developing early TMA, enabling safe delivery and preventing thrombotic events both in the mother and in the newborn.

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.

Treatment of catastrophic antiphospholipid syndrome

PURPOSE OF REVIEW

Catastrophic antiphospholipid syndrome (CAPS) is a severe manifestation of antiphospholipid syndrome (APS). Although affecting only 1% of patients with APS, the condition is frequently fatal if not recognized and treated early. Here, we will review the current approach to diagnosis and treatment of CAPS.

RECENT FINDINGS

Data from the international 'CAPS registry', spearheaded by the European Forum on Antiphospholipid Antibodies, have improved our understanding of at-risk patients, typical clinical features, and precipitating diagnoses. Current guidelines also continue to support the role of anticoagulants and glucocorticoids as foundation therapy in all patients. Finally, new basic science and case series suggest that novel therapies, such as rituximab and eculizumab, warrant further study.

SUMMARY

Attention to associated diagnoses, such as infection and systemic lupus erythematosus (SLE), is critical at the time of diagnosis. All patients should be treated with anticoagulants, corticosteroids, and possibly plasma exchange. In patients with SLE, cyclophosphamide should be considered. In refractory or relapsing cases, new therapies, such as rituximab and possibly eculizumab, may be options, but need further study.

Catastrophic antiphospholipid syndrome (CAPS): Descriptive analysis of 500 patients from the International CAPS Registry

OBJECTIVE

To analyze the clinical and immunologic manifestations of patients with catastrophic antiphospholipid syndrome (CAPS) from the "CAPS Registry".

METHODS

The demographic, clinical and serological features of 500 patients included in the website-based "CAPS Registry" were analyzed. Frequency distribution and measures of central tendency were used to describe the cohort. Comparison between groups regarding qualitative variables was undertaken by chi-square or Fisher exact test while T-test for independent variables was used to compare groups regarding continuous variables.

RESULTS

500 patients (female: 343 [69%]; mean age 38±17) accounting for 522 episodes of CAPS were included in the analysis. Forty percent of patients had an associated autoimmune disease, mainly systemic lupus erythematosus (SLE) (75%). The majority of CAPS episodes were triggered by a precipitating factor (65%), mostly infections (49%). Clinically, CAPS was characterized by several organ involvement affecting kidneys (73%), lungs (60%), brain (56%), heart (50%), and skin (47%). Lupus anticoagulant, IgG anticardiolipin and IgG anti-β2-glycprotein antibodies were the most often implicated antiphospholipid antibodies (83%, 81% and 78% respectively). Mortality accounted for 37% of episodes of CAPS. Several clinical differences could be observed based on the age of presentation and its association to SLE. Those cases triggered by a malignancy tended to occur in older patients, while CAPS episodes in young patients were associated with an infectious trigger and peripheral vessels involvement. Additionally, CAPS associated with SLE were more likely to have severe cardiac and brain involvement leading to a higher mortality (48%).

CONCLUSION

Although the presentation of CAPS is characterized by multiorgan thrombosis and failure, clinical differences among patients exist based on age and underlying chronic diseases, e.g. malignancy and SLE.

Acute Respiratory Events in Connective Tissue Disorders

Subacute-acute, hyperacute, or even catastrophic and fulminant respiratory events occur in almost all classic connective tissue disorders (CTDs); they may share systemic life-threatening manifestations, may precipitously lead to respiratory failure requiring ventilatory support as well as a combination of specific therapeutic measures, and in most affected patients constitute the devastating end-of-life event. In CTDs, acute respiratory events may be related to any respiratory compartment including the airways, lung parenchyma, alveolar capillaries, lung vessels, pleura, and ventilatory muscles. Acute respiratory events may also precipitate disease-specific extrapulmonary organ involvement such as aspiration pneumonia and lead to digestive tract involvement and heart-related respiratory events. Finally, antirheumatic drug-related acute respiratory toxicity as well as lung infections related to the rheumatic disease and/or to immunosuppression complete the spectrum of acute respiratory events. Overall, in CTDs the lungs significantly contribute to morbidity and mortality, since they constitute a common site of disease involvement; a major site of infections related to the 'mater' disease; a major site of drug-related toxicity, and a common site of treatment-related infectious complications. The extreme spectrum of the abovementioned events, as well as the 'vicious' coexistence of most of the aforementioned manifestations, requires skills, specific diagnostic and therapeutic means, and most of all a multidisciplinary approach of adequately prepared and expert scientists. Avoiding lung disease might represent a major concern for future advancements in the treatment of autoimmune disorders.

Catastrophic Antiphospholipid Syndrome: Scintigraphic Demonstration With Correlated Cross-Sectional Imaging

We present the case of catastrophic antiphospholipid syndrome occurring in a 44-year-old woman with a recent history of coronary artery bypass surgery. Postoperatively, she was urgently readmitted for a left middle cerebral artery stroke, and during workup she was found with a left ventricular thrombus on echocardiogram. Subsequently, the patient was diagnosed with antiphospholipid syndrome. Multimodality imaging, including bone and myocardial perfusion scintigraphy, CT, and MR, during her hospitalization, depicted all the characteristic features constituting the catastrophic form of antiphospholipid syndrome, also known as Asherson syndrome.

Hyperferritinemic syndrome: Still's disease and catastrophic antiphospholipid syndrome triggered by fulminant Chikungunya infection: a case report of two patients

There are four medical conditions characterized by high levels of ferritin, the macrophage activation syndrome (MAS), adult onset Still' s disease (AOSD), catastrophic antiphospholipid syndrome (CAPS), and septic shock, that share similar clinical and laboratory features, suggesting a common pathogenic mechanism. This common syndrome entity is termed "the hyperferritinemic syndrome." Here, we describe two different cases of hyperferritinemic syndrome triggered by Chikungunya fever virus infection: a 21-year-old female with SLE and a 32-year-old male patient who developed AOSD after the coinfection of dengue and Chikungunya viruses.

Rheumatologic emergencies

Rheumatological conditions can sometimes present as emergencies. These can occur due to the disease process or infection; contrary to what many people think, rheumatologic emergencies like a pain, rheumatic crisis, or attack gout do not compromise the patient's life. This article mentioned only true emergencies: catastrophic antiphospholipid syndrome (cAPS), kidney-lung syndrome, central nervous system (CNS) vasculitis, anti-Ro syndrome (neonatal lupus), and macrophage activation syndrome (MAS). The management of above emergencies includes critical care, immunosuppression when indicated, and use of a diagnostic flowchart as well as fast laboratory profile for making decisions. Anticoagulants have to be used in the management of antiphospholipid syndrome. A good understanding of these conditions is of paramount importance for proper management.

The

The addition of the word “catastrophic” to the term antiphospholipid syndrome (APS) was proposed 20 years ago by Ronald Asherson when he published an editorial in The Journal of Rheumatology describing a group of patients who develop multiple thrombosis in a short period of time and with a much worse prognosis than that attributed to patients with classic APS [1]. Since then, many cases have been published reporting patients with this devastating variant of the APS.

β2-glycoprotein I, lipopolysaccharide and endothelial TLR4: three players in the two hit theory for anti-phospholipid-mediated thrombosis

The thrombogenic effect of β2-glycoprotein I (β2GPI)-dependent anti-phospholipid antibodies (aPL) in animal models was found to be LPS dependent. Since β2GPI behaves as LPS scavenger, LPS/β2GPI complex was suggested to account for in vitro cell activation through LPS/TLR4 involvement being LPS the actual bridge ligand between β2GPI and TLR4 at least in monocytes/macrophages. However, no definite information is available on the interaction among β2GPI, LPS and endothelial TLR4 in spite of the main role of endothelial cells (EC) in clotting. To analyse at the endothelial level the need of LPS, we investigated the in vitro interaction of β2GPI with endothelial TLR4 and we assessed the role of LPS in such an interaction. To do this, we evaluated the direct binding and internalization of β2GPI by confocal microscopy in living TLR4-MD2 transfected CHO cells (CHO/TLR4-MD2) and β2GPI binding to CHO/TLR4-MD2 cells and human umbilical cord vein EC (HUVEC) by flow cytometry and cell-ELISA using anti-β2GPI monoclonal antibodies in the absence or presence of various concentrations of exogenous LPS. To further investigate the role of TLR4, we performed anti-β2GPI antibody binding and adhesion molecule up-regulation in TLR4-silenced HUVEC. Confocal microscopy studies show that β2GPI does interact with TLR4 at the cell membrane and is internalized in cytoplasmic granules in CHO/TLR4-MD2 cells. β2GPI binding to CHO/TLR4-MD2 cells and HUVEC is also confirmed by flow cytometry and cell-ELISA, respectively. The interaction between β2GPI and TLR4 is confirmed by the reduction of anti-β2GPI antibody binding and by the up-regulation of E-selectin or ICAM-1 by TLR4 silencing in HUVEC. β2GPI binding is not affected by LPS at concentrations comparable to those found in both β2GPI and antibody preparations. Only higher amount of LPS that can activate EC and up-regulate TLR4 expression are found to increase the binding. Our findings demonstrate that β2GPI interacts directly with TLR4 expressed on EC, and that such interaction may contribute to β2GPI-dependent aPL-mediated EC activation. At variance of monocytic cells, we also showed a threshold effect for the action of LPS, that is able to enhance anti-β2GPI antibody EC binding only at cell activating concentrations, shown to increase TLR4 expression. This in vitro model may explain why LPS behaves as a second hit increasing the expression of β2GPI in vascular tissues and triggering aPL-mediated thrombosis in experimental animals.

14th International Congress on Antiphospholipid Antibodies Task Force Report on Catastrophic Antiphospholipid Syndrome

The 'Task Force on Catastrophic Antiphospholipid Syndrome (CAPS)' was developed on the occasion of the 14th International Congress on Antiphospholipid Antibodies. The objectives of this Task Force were to assess the current knowledge on pathogenesis, clinical and laboratory features, diagnosis and classification, precipitating factors and treatment of this condition in order to address recommendations for future research. This article summarizes the studies analyzed by the Task Force, its recommendations and the future research agenda.

Eculizumab prevents recurrent antiphospholipid antibody syndrome and enables successful renal transplantation

Renal transplantation in patients with antiphospholipid antibodies has historically proven challenging due to increased risk for thrombosis and allograft failure. This is especially true for patients with antiphospholipid antibody syndrome (APS) and its rare subtype, the catastrophic antiphospholipid antibody syndrome (CAPS). Since a critical mechanism of thrombosis in APS/CAPS is one mediated by complement activation, we hypothesized that preemptive treatment with the terminal complement inhibitor, eculizumab, would reduce the extent of vascular injury and thrombosis, enabling renal transplantation for patients in whom it would otherwise be contraindicated. Three patients with APS, two with a history of CAPS, were treated with continuous systemic anticoagulation together with eculizumab prior to and following live donor renal transplantation. Two patients were also sensitized to human leukocyte antigens (HLA) and required plasmapheresis for reduction of donor-specific antibodies. After follow-up ranging from 4 months to 4 years, all patients have functioning renal allografts. No systemic thrombotic events or early graft losses were observed. While the appropriate duration of treatment remains to be determined, this case series suggests that complement inhibitors such as eculizumab may prove to be effective in preventing the recurrence of APS after renal transplantation.

Ferritin in the antiphospholipid syndrome and its catastrophic variant (cAPS)

BACKGROUND

Ferritin is an iron storage protein considered also as an acute phase reactant with high levels in various inflammatory conditions. Recently, a plausible role for ferritin in the pathogenesis of immune-mediated and especially autoimmune diseases has been suggested. However, the link between ferritin and the antiphospholipid syndrome (APS) has been rarely explored. Therefore, in the current study we evaluated ferritin levels and their correlation to clinical and serological manifestations in patients with APS. We further analyzed ferritin levels among patients with the catastrophic variant of APS (cAPS).

METHODS

Ferritin levels were determined in serum samples of 176 APS patients and 98 matched healthy controls according to age and sex (LIAISON, DiaSorin, Italy). APS samples were further analyzed for antiphospholipid (anti-cardiolipin, anti- beta-2-glycoprotein, lupus anticoagulant) and anti-infectious antibodies (CMV, EBV, rubella, toxoplasma, HBV) (LIAISON, DiaSorin, Italy). Clinical, serological and demographic manifestations were recorded. An additional analysis of ferritin levels among 14 patients with cAPS was performed.

RESULTS

Hyperferritinemia was present in 9% vs. 0% of APS patients and controls, respectively (p < 0.001). Among patients with APS, ferritin levels correlated with venous thrombosis, cardiac, neurological, and hematological manifestations and the presence of anti-CMV-IgM antibodies. Hyperferritinemia was present in 71% of cAPS patients, and ferritin levels among this subgroup were significantly higher compared with APS-non-cAPS patients (816 ± 847 ng/ml vs. 120 ± 230 ng/ml, p < 0.001).

CONCLUSIONS

Herein, we found that hyperferritinemia correlates with the presence of APS, its clinical manifestations and specifically with the catastrophic variant of this disease. Hyperferritinemia was also linked with anti-CMV antibodies among patients with APS. These associations allude to a pathogenic role of ferritin in the pathogenesis of APS, and the plausible role of ferritin as a marker of ensuing cAPS, although further studies are needed to elucidate these associations.

Vascular endothelial cell function in catastrophic antiphospholipid syndrome: a case report and review of the literature

Catastrophic antiphospholipid syndrome (CAPS) is a rare autoimmune condition, which has been associated with a high mortality rate. However, with current management that includes a combination of anticoagulation, glucocorticoid administration, and plasma exchange, mortality rate has declined. Despite survival improvement with new generation immunosuppressive agents, their mechanisms of action are poorly defined, and CAPS is still considered a high-risk complication in patients known with antiphospholipid antibody syndrome. Herein, we present a case of a 79-year-old male who presented with a myocardial infarct and renal failure secondary to CAPS following a splenectomy for immune thrombocytopenia. Regardless of rapid combination of first-line treatment and rituximab therapy, the patient developed lethal cardiogenic shock secondary to mitral valve papillary muscle necrosis. Discussion of the pathophysiology and avenues of future therapies in CAPS are reported.

Catastrophic antiphospholipid syndrome (CAPS)

Catastrophic antiphospholipid syndrome (CAPS) is a very severe variant of the classic APS, characterised by clinical evidence of multiple organ involvement developing over a very short period of time, histopathological evidence of multiple small vessel occlusions and laboratory confirmation of the presence of antiphospholipid antibodies (aPL), usually in high titre. Although patients with catastrophic APS represent less than 1% of all patients with APS, this is usually a life-threatening condition. In this article, we aimed to review the state-of-the art about current knowledge in pathogenesis, clinical manifestations, diagnosis and treatment strategies in CAPS.

Cytopenia and autoimmune diseases: a vicious cycle fueled by mTOR dysregulation in hematopoietic stem cells

A long-standing but poorly understood defect in autoimmune diseases is dysfunction of the hematopoietic cells. Leukopenia is often associated with systemic lupus erythematous (SLE) and other autoimmune diseases. In addition, homeostatic proliferation of T cells, which is a host response to T-cell lymphopenia, has been implicated as potential cause of rheumatoid arthritis (RA) in human and experimental models of autoimmune diabetes in the NOD mice and the BB rats. Conversely, successful treatments of aplastic anemia by immune suppression suggest that the hematologic abnormality may have a root in autoimmune diseases. Traditionally, the link between autoimmune diseases and defects in hematopoietic cells has been viewed from the prism of antibody-mediated hemolytic cytopenia. While autoimmune destruction may well be part of pathogenesis of defects in hematopoietic system, it is worth considering the hypothesis that either leukopenia or pancytopenia may also result directly from defective hematopoietic stem cells (HSC). We have recently tested this hypothesis in the autoimmune Scurfy mice which has mutation Foxp3, the master regulator of regulatory T cells. Our data demonstrated that due to hyperactivation of mTOR, the HSC in the Scurfy mice are extremely poor in hematopoiesis. Moreover, rapamycin, an mTOR inhibitor rescued HSC defects and prolonged survival of the Scurfy mice. Our data raised the intriguing possibility that targeting mTOR dysregulation in the HSC may help to break the vicious cycle between cytopenia and autoimmune diseases.

Severe abdominal pain as a presenting symptom of probable catastrophic antiphospholipid syndrome

Catastrophic antiphospholipid syndrome (APS) in pediatric medicine is rare. We report 3 adolescents who presented with acute onset of severe abdominal pain as the first manifestation of probable catastrophic APS. The 3 patients, 2 male patients and 1 female patient were 14 to 18 years old. One had been diagnosed with systemic lupus erythematosus in the past, but the other 2 had no previous relevant medical history. All presented with excruciating abdominal pain without additional symptoms. Physical examination was noncontributory. Laboratory results were remarkable for high inflammatory markers. Abdominal ultrasonography was normal, and abdominal computed tomography scan showed nonspecific findings of liver infiltration. Only computed tomography angiography revealed evidence of extensive multiorgan thrombosis. All patients had elevated titers of antiphospholipid antibodies. The patients were treated with full heparinization, high-dose steroids, and intravenous immunoglobulin with a resolution of symptoms. One patient was resistant to the treatment and was treated with rituximab. In conclusion, severe acute abdominal pain can be the first manifestation of a thromboembolic event owing to catastrophic APS even in previously healthy adolescents. Diagnosis requires a high index of suspicion with prompt evaluation and treatment to prevent severe morbidity and mortality.

Multiple thromboemboli associated to two occult tumors: a case mimicking catastrophic antiphospholipid syndrome

Thromboembolic events tend to arise during the natural lifetime of tumors. However, multiple thromboemboli mimicking catastrophic antiphospholipid syndrome is quite rare as a first manifestation of a tumor. Herein we describe the case of a 51-year old woman that presented with multiple thromboemboli affecting her brain, lung and kidneys. Despite bolus administration of corticosteroids, anticoagulant therapy and immunoglobulin infusion treatment, the patient died. She had suffered from two occult tumors, which could not be identified premortem: a lung adenocarcinoma and an intrahepatic cholangiocarcinoma. This case underscores the importance of determining the underlying etiology behind multiple thromboemboli. The most important prognostic factor is rapid initiation of treatment of the multiple thromboemboli, emphasizing treatment of their etiology.

Toll-like receptor 2 mediates the activation of human monocytes and endothelial cells by antiphospholipid antibodies

The presence of antiphospholipid antibodies (aPLAs) is associated with arterial or venous thrombosis and/or recurrent fetal loss. The proposed pathogenic mechanisms for aPLA effects include the inflammatory activation of monocytes and endothelial cells. Toll-like receptors (TLRs) are candidate signaling intermediates. The aim of this study was to investigate the relative contribution of TLR2 and TLR4 in cell activation by aPLAs. Of 32 patient-derived aPLAs, 19 induced an inflammatory activation of human monocytes and umbilical vein endothelial cells (HUVECs). In HUVECs, inflammatory responses to these aPLAs were increased by TNF pretreatment, which increases the expression of TLR2 but not TLR4. Anti-TLR2 but not anti-TLR4 antibodies reduced the aPLA-induced activation of monocytes and HUVECs. aPLAs activated TLR2-expressing human embryonic kidney 293 (HEK293) cells but not TLR4-expressing cells. Binding studies demonstrated an interaction between aPLAs and TLR2 but not TLR4. A role for CD14, a coreceptor for TLR2 and TLR4, can be inferred by observations that anti-CD14 antibodies reduced responses to aPLAs in monocytes, and that responses in HEK293 cells expressing TLR2 and CD14 were greater than in HEK293 cells expressing TLR2 alone. Our results demonstrate a role for TLR2 and CD14 in human endothelial cell and monocyte activation by aPLAs.

Mycobacterium tuberculosis, autoimmunity, and vitamin D

Mycobacterium tuberculosis (TB) is a major cause of morbidity and mortality worldwide. Current anti-TB chemotherapies, although effective, are associated with side effects and are limited in treating drug-resistant strands. Autoimmune diseases are a leading cause of morbidity and mortality, with a growing mass of evidence implicating infections (e.g., TB) as their triggers. The burden of TB might further increase by reactivation threats hovering over millions harboring latent infection, thus, calling for novel approaches for this dire ailment. In recent years, the non-calcemic physiological actions of vitamin D have drawn a great deal of attention. In this review, we will focus on the role of vitamin D in the innate immune defense against TB on the one hand and conversely on the immunomodulatory effects of vitamin D on autoimmunity. Taken together, the suggested dual role of vitamin D in treating TB infection and possibly preventing associated autoimmunity will constitute the basis of the current review.

Antiphospholipid syndrome: frequency, main causes and risk factors of mortality

The presence of antiphospholipid antibodies has been shown to be related to an increased risk of thrombotic events. In patients with definite antiphospholipid syndrome (APS), that is, those who have had thrombosis and at least two positive determinations of antiphospholipid antibodies, secondary thromboprophylaxis with long-term anticoagulation therapy results in a low rate of recurrent thrombotic events, ranging from 0.016 to 0.031 events per patient per year. Thrombotic complications are, however, the most common cause of death in APS. The mortality rate in a large European cohort of patients with APS during a 5-year study period was 5.3%, and up to 40% of the deaths in this cohort were attributed to severe thrombotic events such as myocardial infarction, stroke and pulmonary embolism. Catastrophic APS is an unusual form of the disease, being observed in less than 1% of reported cases of APS, which is associated with a much higher mortality rate than classical APS. The combined use of anticoagulation, corticosteroids, plasma exchange and intravenous immunoglobulin therapy could result in a dramatic reduction in mortality, by approximately 20%, in patients with catastrophic APS.

Catastrophic cerebral antiphospholipid syndrome presenting as cerebral infarction with haemorrhagic transformation after sudden withdrawal of warfarin in a patient with primary antiphospholipid syndrome

Catastrophic antiphospholipid syndrome (APS) is caused by thrombotic vascular occlusions that affect both small and large vessels, producing ischaemia in the affected organs. The "catastrophic" variant of the antiphospholipid syndrome (cAPS) develops over a short period of time. Although patients with cAPS represent <1% of all patients with APS, they are usually life threatening with a 50% mortality rate. A strong association with concomitant infection is thought to act as the main trigger of microthromboses in cAPS. Several theories have been proposed to explain these physiopathological features. Some of them suggest the possibility of molecular mimicry between components of infectious microorganisms and natural anticoagulants, which might be involved in the production of cross-reacting antiphospholipid antibodies. We present a case of catastrophic cerebral APS characterised by massive temporal lobe infarction and subsequent haemorrhagic transformation after sudden withdrawal of warfarin.

The implications of autoimmunity and pregnancy

There are multiple epidemiological studies that document the potential adverse affects of autoimmunity on nearly every aspect of reproduction, even in the absence of clinically manifest autoimmune disease. Two decades ago, it was suggested that women with autoimmune diseases avoid pregnancy due to inordinate risks to the mother and the child. In contrast, newer epidemiological data demonstrated that advances in the treatment of autoimmune diseases and the management of pregnant women with these diseases have similarly improved the prognosis for mother and child. In particular, if pregnancy is planned during periods of inactive or stable disease, the result often is giving birth to healthy full-term babies without increased risks of pregnancy complications. Nonetheless, pregnancies in most autoimmune diseases are still classified as high risk because of the potential for major complications. These complications include disease exacerbations during gestation and increased perinatal mortality and morbidity in most autoimmune diseases, whereas fetal mortality is characteristic of the anti-phospholipid syndrome (APS). In this review, we will discuss these topics, including issues of hormones, along with potential long-term effects of the microchimerism phenomenon. With respect to pregnancy and autoimmune diseases, epidemiological studies have attempted to address the following questions: 1) Is it safe for the mother to become pregnant or are there acute or chronic effects of pregnancy on the course of the disease? 2) Does the disease alter the course and/or the outcome of a pregnancy and thereby represent an inordinate risk for the fetus and infant? And do new therapeutic and management approaches improve the pregnancy outcomes in women with autoimmune diseases? 3) Does passage of maternal autoantibodies represent a risk to the child? 4) Do pregnancy, parity, or other factors influencing hormonal status explain the female predominance of many autoimmune diseases, and is the pregnancy effect related to microchimerism? Answering these questions has taken on additional importance in recent decades as women in western countries now frequently choose to delay pregnancies and have some or all of their pregnancies after disease onset. In this paper, we primarily focus on APS, systemic lupus erythematosus (SLE), multiple sclerosis (MS), rheumatoid arthritis (RA), and type 1 diabetes (T1D).

The geoepidemiology of the antiphospholipid antibody syndrome

Antiphospholipid antibodies (aPL) can be detected by functional (lupus anticoagulant) and/or by solid phase assays (anti-cardiolipin and anti-beta2 glycoprotein I). Although detectable in 1-5% of asymptomatic apparently healthy subjects, persistent aPL are significantly associated with recurrent arterial/venous thrombosis and with pregnancy morbidity. Such an association is the formal classification tool for the antiphospholipid syndrome (APS). The prevalence of the syndrome with no associated systemic connective tissue diseases (primary APS) in the general population is still a matter of debate since there are no sound epidemiological studies in the literature so far. aPL display higher prevalence in systemic lupus erythematosus and rheumatoid arthritis than in other systemic autoimmune diseases. However not all the aPL positive lupus patients display the clinical manifestations. Comparable findings may be found in the paediatric population, although anti-beta2 glycoprotein I antibodies are detected in healthy children more frequently than in adults. High prevalence of aPL has been also reported in clinical manifestations that are not formal APS classification criteria: heart valve disease, livedo reticular, nephropathy, neurological manifestations, and thrombocytopenia. Antiphospholipid antibodies can be associated with infectious processes, active vaccination, drug administration and malignancies. Their prevalence and titres are lower and the relationship with the APS clinical manifestations are less strong than in the previously mentioned conditions. Ethnicity was also reported to influence the prevalence of aPL.

Common infectious agents prevalence in antiphospholipid syndrome

Antiphospholipid syndrome is characterized by thrombosis and pregnancy loss. Infections are generally associated with autoimmune diseases, but in the setting of antiphospholipid syndrome this link has been suggested as having a pathogenic role. In this study, 98 patients with antiphospholipid syndrome were screened for antibodies directed to several infectious agents. The main finding in this study is the significantly higher prevalence of IgM antibodies to toxoplasma and rubella. This novel finding suggests that these infections might be associated with antiphospholipid syndrome. As autoimmune diseases and, in particular, antiphospholipid syndrome are associated with infections, mainly the catastrophic type of the syndrome, this finding implies that a current infection with these agents, i.e. toxoplasma and rubella, might either be related to the pathogenesis of antiphospholipid syndrome or alternatively to its manifestations. Lupus (2009) 18, 1149—1153.