Venous thromboembolism in the antiphospholipid syndrome: management guidelines for secondary prophylaxis

Recommendations of the Spanish Rheumatology Society for Primary Antiphospholipid Syndrome. Part I: Diagnosis, Evaluation and Treatment

OBJECTIVE

The difficulty in diagnosis and the spectrum of clinical manifestations that can determine the choice of treatment for primary antiphospholipid syndrome (APS) has fostered the development of recommendations by the Spanish Society of Rheumatology (SER), based on the best possible evidence. These recommendations can serve as a reference for rheumatologists and other specialists involved in the management of APS.

METHODS

A panel of four rheumatologists, a gynaecologist and a haematologist with expertise in APS was created, previously selected by the SER through an open call or based on professional merits. The stages of the work were: identification of the key areas for drafting the document, analysis and synthesis of the scientific evidence (using the Scottish Intercollegiate Guidelines Network [SIGN] levels of evidence) and formulation of recommendations based on this evidence and formal assessment or reasoned judgement techniques (consensus techniques).

RESULTS

46 recommendations were drawn up, addressing five main areas: diagnosis and evaluation, measurement of primary thromboprophylaxis, treatment for APS or secondary thromboprophylaxis, treatment for obstetric APS and special situations. These recommendations also include the role of novel oral anticoagulants, the problem of recurrences or the key risk factors identified in these subjects. This document reflects the first 21, referring to the areas of: diagnosis, evaluation and treatment of primary APS. The document provides a table of recommendations and treatment algorithms.

CONCLUSIONS

An update of the SER recommendations on APS is presented. This document corresponds to partI, related to diagnosis, evaluation and treatment. These recommendations are considered tools for decision-making for clinicians, taking into consideration both the decision of the physician experienced in APS and the patient. A partII has also been prepared, which addresses aspects related to obstetric SAF and special situations.

Antiphospholipid syndrome: state of the art on clinical practice guidelines

Antiphospholipid syndrome (APS) is a rare disease characterised by venous and/or arterial thrombosis, pregnancy complications and the presence of specific autoantibodies called antiphospholipid antibodies. This review aims to identify existing clinical practice guidelines (CPG) as part of the ERN ReCONNET project, aimed at evaluating existing CPGs or recommendations in rare and complex diseases. Seventeen papers providing important data were identified; however, the literature search highlighted the scarceness of reliable clinical data to develop CPGs. With no formal clinical guidelines in place, diagnosis and treatment of APS is largely based on consensus and expert opinion. Patients' unmet need refers to the understanding of the disease and its clinical picture and implications, the need of education for patients, family members and healthcare providers, as well as to the development of monitoring pathways involving multiple healthcare providers.

Analysis of risk factors for the development of thrombotic complications in antiphospholipid antibody positive lupus patients

The objective of this study was to characterize risk factors for thrombotic events in lupus patients. A total of 272 lupus patients were followed up for five years during which the presence of aPL antibodies [anticardiolipin (aCL), anti-beta2-glycoprotein I (aβ2GPI) and lupus anticoagulant (LAC)] were determined, and all thrombotic incidents and antithrombotic therapy-related data were collected. At baseline, three groups were constituted, an aPL–group with 107 aPL negative patients, an aPL+ group with 81 aPL positive patients without clinical thrombosis and a secondary antiphospholipid syndrome (APS) group with 84 aPL+ patients who met the Sapporo criteria. LAC was more common in the APS than the aPL+ group (32.1% versus 9.9%, P < 0.001). The prevalence of clinical thrombotic events was significantly higher when all three types of aPL were present compared to only aCL positive cases. During follow up, aPL appeared in 7.5% of the aPL - group, and 2.8% of this group had thrombotic complications. In the aPL + group, thrombotic events reoccurred in 1.9% of those receiving antithrombotic prophylaxis and 6.9% of those without primary prophylaxis. Despite anticoagulant therapy, thrombotic events reoccurred in 8.3% of the APS group. These findings indicate that LAC, constant and cumulative presence of aPL and previous thrombosis are positive predictors for the development of thrombotic complication in lupus patients.

Idiopathic Intracranial Hypertension: Associations with Thrombophilia and Hypofibrinolysis in Men

The existence of an association between idiopathic intracranial hypertension (IIH) and coagulation disorders in men was assessed prospectively. Microthrombi, associated with thrombophilia-hypofibrinolysis, occlude arachnoid sinus villi, thus reducing resorption of cerebrospinal fluid, leading to IIH. Ten consecutively referred men with IIH, nine whites, one African American, median age 36 years, were 2 to 1 matched by age and race by healthy male controls. Polymerase chain reaction assays were done for four thrombophilic and one hypofibrinolytic gene mutations: G1691A factor V Leiden, G20210A prothrombin, C677T MTHFR, platelet glycoprotein IIb/IIIa (PL A1/A2), and 4G/5G polymorphism of the plasminogen activator inhibitor (PAI-1) gene promoter. Coagulation measures in plasma included dilute Russel’s viper venom time (dRVVT), activated partial thromboplastin time (aPTT), the lupus anticoagulant, factor VIII, factor XI, plasminogen activator inhibitor activity (PAI-Fx), protein C antigenic, protein S total (antigenic), protein S free (antigenic), antithrombin III (functional), and resistance to activated protein C (RAPC). Tests performed on serum included anticardiolipin antibodies, homocysteine, and Lp(a). The body mass index was 40 kg/m2 or greater (extremely obese) in two men, 30 to 40 kg/m2(obese) in three, and was 25 to 30 kg/m2 in five (overweight). Cases differed from controls for inherited 4G4G homozygosity of the PAI-1 gene, four of 10 (40%) vs. one of 20 (5%), Fisher’s p [pf]= .031, and for high levels (>21.1 U/mL) of the hypofibrinolytic PAI-1 gene product, PAI-Fx, 5 of 10 (50%) vs. one of 18 (6%), pf = .013. Thrombophilic factor VIII was high (≥ 150%) in three of 10 (30%) cases vs. zero of 16 (0%) controls, pf=. 046. The thrombophilic lupus anticoagulant was present in two of 10 (20%) cases vs. zero of 32 (0%) controls, pf = .052. Heritable hypofibrinolysis and heritable and acquired thrombophilia appear, speculatively, to be treatable etiologies of IIH in men. Understanding contributions of hypofibrinolysis and thrombophilia to the development of IIH should facilitate development of novel new approaches to treat this often-disabling neurologic disorder.

Immunomodulatory effects of therapeutic plasma exchange on monocytes in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by thrombosis and recurrent fetal loss, with the persistent presence of antiphospholipid antibodies (aPLs). aPLs exert their pathogenic effect via the overproduction of tissue factor and activation of complement and several cell types, including endothelial cells, platelets and notably monocytes. As a result, a hypercoagulable state develops leading to APS-associated obstetric complications and fetal loss. Despite being far from optimal, treatment of APS usually includes heparin and low dose aspirin. Recently, plasma exchange (PE) therapy was successfully used in patients with APS with obstetric complications who did not respond to the standard treatment. Therefore, the present study investigated the mechanism underlying PE action, and aimed to determine whether PE affects the functional activity of APS monocytes by examining the expression of 11 mRNA transcripts encoding cytokines, signaling molecules and transcription factors. Monocytes were collected prior to and following the PE treatment from women with APS who experienced recurrent pregnancy losses, as well as from healthy volunteers. Compared with control cells, APS monocytes showed deregulated expression of interleukin (IL)-1β, IL-6, IL-23, chemokine (C-C motif) ligand 2 (CCL2), C-X-C motif chemokine 10 (CXCL10), toll-like receptor 2, and signal transducer and activator of transcription 3. PE treatment resulted in increased IL-1β, IL-6, IL-23, CCL2, P2X7 and tumor necrosis factor-α mRNA transcripts in APS monocytes, restoring the mRNA expression levels to within normal ranges. Furthermore, PE therapy counterbalanced the expression levels of CCL2 and CXCL10, the levels of which are indicative of T helper cell 1/2 balance. The results of the present study indicate that the altered transcriptional profile in APS monocytes was restored by the immunomodulatory effect of plasmapheresis.

Acute physical exercise is safe in patients with primary antiphospholipid syndrome with exclusive venous thrombosis and under oral anticoagulation with warfarin

The purpose of present study was to evaluate the effects of maximal acute physical exercise on prothrombin time/international normalized ratio (PT/INR) in patients with primary antiphospholipid syndrome (PAPS) under oral anticoagulation with warfarin and the safety of acute exercise in regard to thrombosis and bleeding risk. Eighteen physically inactive women with PAPS (Sydney criteria) with exclusive venous events and without thrombocytopenia were included. All patients were under stable warfarin therapy (PT/INR target: 2.0-3.0). Eighteen age-matched healthy sedentary women without thrombosis/bleeding disorders were selected as controls. All subjects performed a maximal exercise test, and capillary blood samples were obtained pre-, post- and at 1-h post-exercise (recovery time) for PT/INR analysis using a portable CoaguCheck. PAPS patients and controls had similar mean age (31.50 ± 8.06 vs. 29.61 ± 7.05 years, p = 0.46) and body mass index (24.16 ± 3.67 vs. 24.66 ± 2.71 kg/m(2), p = 0.65). PAPS had a mild but significant increase in PT/INR value at 1-h post-exercise (recovery) compared with pre- (2.33 ± 0.34 vs. 2.26 ± 0.29, p = 0.001) and post-exercise (2.33 ± 0.34 vs. 2.26 ± 0.32, p = 0.001) that was observed in 61.11 % of these patients. None of the subjects had thrombotic or bleeding complications related to the acute exercise. Acute exercise in patients with PAPS with exclusive venous thrombosis was safe with a minor increase in PT/INR. This is an important step to introduce regular exercise training as a therapeutic tool in the management of these patients.

Influence of antiphospholipid antibody levels and type on thrombotic manifestations: results from the Serbian National Cohort Study

Repeated thromboses are the most frequent clinical manifestation of antiphospholipid syndrome (APS) in the presence of antiphospholipid antibodies (aPL). The objective of this study was to observe the prevalence and localization of thrombosis, and to investigate the importance of aPL type and level for thrombosis-related events in patients diagnosed with APS. These are the first results of patients enrolled in Serbian National Cohort Study which comprises 256 patients: 162 with primary antiphospholipid syndrome (PAPS) and 94 with APS associated with systemic lupus erythematosus (SLE). aPL analysis included detection of aCL (IgG/IgM), β(2)GPI, and lupus anticoagulant. Thrombosis was diagnosed in 119 (46.5%) patients, with higher prevalence in PAPS compared with SLE patients (51.2% and 38.3%, respectively, p = 0.045). There was similar prevalence of arterial thrombosis in PAPS and SLE groups (34.6% and 34%, respectively, p = 0.932) although venous thrombosis was more frequent in PAPS (25.9% and 8.5%, respectively, p = 0.001). Thrombosis was observed in 92 (55.8%) patients who had more than one type of antibody (category I), in 13 (41.9%) patients with category IIa, in 19 (46.3%) patients with category IIb, and in 73 (44.2%) patients with category IIc (p = 0.10). The patients with thrombosis were older than those without thrombosis (49.8 and 39.8 years, respectively, p = 0.001). Overall, older age was a risk factor for thrombosis. The prevalence of venous thrombosis was higher in the PAPS group, but with lower frequency than in literature data. Any aPL type and level is a risk factor for thrombosis.

Controversies in the antiphospholipid syndrome: can we ever stop warfarin?

Patients with antiphospholipid syndrome are at increased risk for recurrent arterial and venous thrombosis and therefore benefit from long term warfarin therapy. The optimal duration of warfarin therapy after a first venous thromboembolic event is however a matter of some controversy and many questions remain unanswered. After reviewing and analysing the available evidence, we discuss some common scenarios in everyday clinical practice where treatment decisions are difficult.

[The management of thrombosis in the antiphospholipid antibody syndrome: insights from recent clinical trials and remaining unsolved issues]

The antithrombotic therapy of the antiphospholipid syndrome (APS) has long been based on an empirical strategy. In the absence of appropriate randomised controlled trials, data of retrospective cohort studies were used to establish these strategies. Here we report the results of recent clinical trials, what they add to patient management and the issues that remain unsolved. SECONDARY PROPHYLAXIS OF THROMBOTIC EVENTS: While there is a consensus for prolonged vitamin K antagonist anticoagulation after a first event, two recent randomised clinical trials have compared various intensities of anticoagulation. Both studies have shown that high intensities of warfarin were not superior to conventional intensities. Patients included in these studies had mainly venous thromboembolic events. There has been no study comparing different antithrombotic strategies for arterial thrombosis associated with APS. The WARSS/APASS study, in particular has not been conducted in patients with definite APS and should not be applied to these patients. For now, vitamin K antagonist anticoagulants should remain the treatment of choice in these patients. PRIMARY PROPHYLAXIS OF THROMBOTIC EVENTS: Because of the high incidence of thrombotic events in asymptomatic patients with antiphospholipid antibodies, especially in systemic lupus erythematosus, a clinical trial compared aspirin and placebo in this setting. This study did not demonstrate any benefit of aspirin. We conclude that recent clinical trials indicate the optimal antithrombotic strategy in APS with venous thromboembolism. However, the best options for patients with arterial thrombosis and for primary prophylaxis remain to be established by further studies.

A systematic review of secondary thromboprophylaxis in patients with antiphospholipid antibodies

OBJECTIVE

To systematically review the efficacy and safety data of different therapeutic approaches in patients with antiphospholipid antibodies (aPL) and thrombosis.

METHODS

The Medline database and references from selected reports and review articles were used. Randomized controlled trials, prospective and retrospective cohort studies, and subgroup analysis (n > 15) that focused on the secondary thromboprophylaxis in patients with aPL were selected.

RESULTS

Sixteen studies were selected. Patients with venous events and a single test for aPL showed a low recurrence rate while receiving oral anticoagulation at a target international normalized ratio (INR) of 2.0-3.0. Patients with stroke and a single positive aPL test had no increased risk compared with those without aPL. Recurrence rates in patients with definite antiphospholipid syndrome (APS) and previous venous thromboembolism were lower than in patients with arterial and/or recurrent events, both with and without therapy. Only 3.8% of recurrent events occurred at an actual INR >3.0. Mortality due to recurrent thrombosis was higher than mortality due to bleeding (18 patients versus 1 patient reported).

CONCLUSION

For patients with definite APS, we recommend prolonged warfarin therapy at a target INR of 2.0-3.0 in APS patients with first venous events and >3.0 for those with recurrent and/or arterial events. For patients with venous thromboembolism or stroke and a single positive aPL test, we recommend further testing to determine if they have a persisting antibody. If they do not, the same therapy as for the general population should be used (warfarin at a target INR of 2.0-3.0 and low-dose aspirin, respectively).

Performance of Platelin LS and dilute Russell's viper venom for the screening of lupus anticoagulant in patients with venous thromboembolism

Lupus anticoagulant is associated with thrombosis and pregnancy morbidity, and its detection is of major clinical importance. The nature and concentration of phospholipids strongly influence the sensitivity of activated partial thromboplastin time (aPTT) reagents to lupus anticoagulant. We investigated the ability of Platelin LS, an aPTT reagent, to screen lupus anticoagulant among 94 patients with venous thromboembolism by comparing its performance with the dilute Russell viper venom time (dRVVT). Twenty-four patients had an abnormal aPTT and dRVVT, whereas 37 only had a prolonged dRVVT. In users of oral anticoagulants (n = 56), the dRVVT prolonged more frequently than the aPTT (98.2 vs 39.3%, P < 0.0001). After the mixing study, seven patients maintained abnormal aPTT and dRVVT ratios, five of whom had prolonged mixture with both tests. The agreement in the mixing study between aPTT and dRVVT was substantial (kappa = 0.78, 95% confidence interval = 0.48-1.00). Except for one patient, the aPTT screened all cases that demonstrated phospholipid dependency of their inhibitor during the confirmatory procedure with the dRVVT. In conclusion, the aPTT using Platelin LS was highly associated with the presence of lupus anticoagulant detected by the dRVVT among patients with venous thromboembolism, and could be reliably employed as a screening assay for lupus anticoagulant.

Five-year follow-up by transesophageal echocardiographic studies in primary antiphospholipid syndrome

This prospective study describes valvular abnormalities assessed by transesophageal echocardiography (TEE) in patients with primary antiphospholipid syndrome (APLS) over a 5-year follow-up. Of the 56 patients with APLS evaluated at baseline, 47 (84%) had repeat TEE examinations, including 3 patients who died before the end of the follow-up. The first TEE study showed cardiac involvement (thickening or vegetations and embolic sources) in 34 subjects (61%), with mitral valve thickening, the most common abnormality, present in 30 patients (54%). Embolic sources were found in 14 patients (25%; 9 severe spontaneous echocardiographic contrast, 5 Libman-Sacks endocarditis), associated with mitral valve thickening or stenosis in 10 patients. Over the 5-year follow-up, cardiac involvement was unchanged in 30 subjects (64%). New cardiac abnormalities were observed in 17 patients (36%), 15 (88%) with high immunoglobulin-G (IgG) anticardiolipin antibody (aCL) titers and 2 (12%) with low IgG aCL titers. In conclusion, this study showed that mitral valve thickening and embolic sources are frequently observed in patients with APLS. Anticoagulant and/or antiplatelet treatment was ineffective in terms of valvular lesion regression. New appearances of cardiac involvement are significantly related to high IgG aCL titers.

The systemic nature of the antiphospholipid syndrome

Antiphospholipid syndrome (APS, Hughes' syndrome) is a systemic autoimmune disorder characterized by arterial and/or venous thrombosis and recurrent foetal loss, accompanied by mild to moderate thrombocytopaenia and elevated titres of antiphospholipid antibodies (aPLs): lupus anticoagulant (LAC) and/or anticardiolipin (aCL) antibodies. APS was defined originally in 1983 in systemic lupus erythematosus (SLE) patients, but later it was found that APS can be primary or secondary to other autoimmune diseases or malignancy. During the past 20 years many organs have been reported to be involved in this syndrome and the clinical manifestations are seen in every medical field. Moreover, many aPLs have been found in APS besides aCLs and LACs, which bind to the autoantigen beta-2-glycoprotein I (beta2GPI). Treatment for APS, based on antiplatelet and anticoagulation drugs, is dependent on various parameters, including whether SLE is also present, classical vs non-classical manifestations of the diseases, women with APS based on pregnancy morbidity, the presence of elevated aCL antibody titres in the absence of clinical manifestations, and catastrophic APS.

Recurrent life-threatening thromboembolism and catastrophic antiphospholipid syndrome in a patient despite sufficient oral anticoagulation

We report on a 32-year old female patient with primary antiphospholipid syndrome (PAPS) and several thromboembolic events despite stable doses of oral anticoagulation, good patient compliance and maintained INR values of >3. Over the preceding 3 years the patient had presented a wide spectrum of manifestations of APS, including recurrent venous and arterial thromboses, cardiac, gynecological (HELLP syndrome), neurological involvements, livedo reticularis, a mild thrombocytopenia and the most feared manifestation of the catastrophic antiphospholipid syndrome (CAPS). Life-threatening bilateral subdural bleeding occurred while she was anticoagulated. The clinical features appeared to be refractory to oral anticoagulation with phenprocoumon. They were life threatening on each occasion and she developed repetitive episodes of organ damage with cardiac insufficiency (NYHA III), pulmonary hypertension and other residual defects. Even during heparinization recurrent thromboembolism supervened as well as livedo reticularis of the extremities. Lupus anticoagulants (LAC), anticardiolipin (aCL) antibodies and anti-β₂-glycoprotein-1 (β₂GPI) titers were all markedly elevated. This case report shows that recurrent episodes of thrombosis can occur despite seemingly adequate anticoagulation in patients with CAPS.

How much warfarin is enough in APS related thrombosis?

Warfarin is the best available, most effective treatment for the secondary prevention of recurrent thrombosis in antiphospholipid syndrome (APS) patients. However, warfarin is cumbersome for both patients and physicians because of risk for bleeding and the need for frequent monitoring. Much detail regarding optimal management of APS patients still lacks an evidence-based approach. Asymptomatic patients should not receive warfarin. An optimal treatment for patients with livedo, cardiac valve disease, leg ulcers or microangiopathic nephropathy is unknown; it is likely that warfarin is ineffective for these manifestations of the APS. In low risk patients who have not previously failed warfarin, moderate intensity anticoagulation (target international normalized ratio [INR] 2.5) is as effective as, and safer than, high intensity anticoagulation (INR 3.5), at least for patients with venous thrombosis. Current recommendations, based on the opinion rather than on documentation, state that warfarin should be prescribed for the APS patient's life; studies that challenge this conclusion for carefully defined low risk patients whose thromboses occurred with trigger events will be welcome, as will be studies examining alternatives to warfarin, including antiplatelet drugs.

Therapeutic Potential of Toleragens in the Management of Antiphospholipid Syndrome

Autoantibodies to beta2-glycoprotein I (beta2GPI) are believed to be the primary cause of coagulation abnormalities in patients with antiphospholipid syndrome (APS). Clinical features include a range of life-threatening thrombotic events and microangiopathies affecting multiple organ systems. Current standard of care relies on long-term, high-intensity anticoagulation and is associated with a high risk for serious bleeding events. The relation between autoantibodies and the pathophysiology of APS is not clearly understood, but numerous in vitro studies have characterized the effects of antiphospholipid autoantibodies on various components of the coagulation cascade, including tissue factor and the protein C pathway. The fine specificity of autoantibodies to beta2GPI is a subject of considerable debate; however, a body of evidence may offer resolution by integrating concepts of antibody affinity and assay sensitivity with carefully designed molecular studies. An investigational new therapy for APS is based on the approach that pathogenic antibodies may be reduced via depletion of circulating autoantibodies and induction of immune tolerance at the B-cell level. Preliminary results from a phase I/II clinical trial with LJP 1082, a B-cell toleragen, indicate the drug was well tolerated and may warrant further development for reduction of thrombotic events in patients with APS.