Treatment in thrombotic antiphospholipid syndrome: a review.

Antiphospholipid syndrome an autoimmune disease characterized by thrombosis and/or pregnancy morbidity alongside the presence of antiphospholipid antibodies (aPL). This review evaluates primary and secondary thromboprophylaxis in patients with aPL and thrombotic events. In primary thromboprophylaxis a risk-stratified approach is needed based on aPL, comorbidity with other autoimmune conditions and cardiovascular vascular risk factors. In primary thromboprophylaxis, the efficacy of low-dose aspirin is debatable and requires better-designed controlled studies. So far warfarin has not been shown to improve venous and/or arterial thrombosis incidence in aPL carriers and instead increased safety concerns. The benefit of hydroxychloroquine is inconclusive despite promising data, requiring large, controlled trials. For secondary thromboprophylaxis warfarin seems to be the best option with potential in renal transplant recipients and better efficacy at high intensity, although maintenance of target international normalized ratio needs careful monitoring. Aspirin has not shown to be beneficial, and data on rivaroxaban are limited and contradictory. Despite all data being informative, there are limitations that need to be addressed with robust clinical trials.

Can we withdraw anticoagulation in patients with antiphospholipid syndrome after seroconvertion?

The current mainstay of treatment in patients with thrombotic antiphospholipid syndrome (APS) is long-term anticoagulation, mainly with Vitamin K antagonist agents. Some recently available studies have created new ground for discussion about the possible discontinuation of anticoagulation therapy in patients with a history of thrombotic APS in whom antiphospholipid antibodies (aPL) are not detected any longer (i.e. aPL seroconversion). We report the main points discussed at the last CORA Meeting regarding the issue whether or not anticoagulation can be stopped after aPL seroconversion. In particular, we systematically reviewed the available evidence investigating the clinical outcome of APS patients with aPL seroconversion in whom anticoagulation was stopped when compared to those in whom therapy was continued regardless the aPL profile. Furthermore, the molecular basis for the aPL pathogenicity, the available evidence of non-criteria aPL and their association with thrombosis are addressed. To date, available evidence is still limited to support the indication to stop oral anticoagulation therapy in patients with a previous diagnosis of thrombotic APS who subsequently developed a negative aPL profile. The identification of the whole risk profile for cardiovascular manifestations and possibly of a second level aPL testing in selected patients with aPL might support the eventual clinical decision but further investigation is warranted.

Evaluation of phosphatidylserine-dependent antiprothrombin antibody testing for the diagnosis of antiphospholipid syndrome: results of an international multicentre study.

Objective A task force of scientists at the International Congress on Antiphospholipid Antibodies recognized that phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT) might contribute to a better identification of antiphospholipid syndrome (APS). Accordingly, initial and replication retrospective, cross-sectional multicentre studies were conducted to ascertain the value of aPS/PT for APS diagnosis. Methods In the initial study (eight centres, seven countries), clinical/laboratory data were retrospectively collected. Serum/plasma samples were tested for IgG aPS/PT at Inova Diagnostics (Inova) using two ELISA kits. A replication study (five centres, five countries) was carried out afterwards. Results In the initial study ( n = 247), a moderate agreement between the IgG aPS/PT Inova and MBL ELISA kits was observed ( k = 0.598). IgG aPS/PT were more prevalent in APS patients (51%) than in those without (9%), OR 10.8, 95% CI (4.0-29.3), p < 0.0001. Sensitivity, specificity, positive (LR+) and negative (LR-) likelihood ratio of IgG aPS/PT for APS diagnosis were 51%, 91%, 5.9 and 0.5, respectively. In the replication study ( n = 214), a moderate/substantial agreement between the IgG aPS/PT results obtained with both ELISA kits was observed ( k = 0.630). IgG aPS/PT were more prevalent in APS patients (47%) than in those without (12%), OR 6.4, 95% CI (2.6-16), p < 0.0001. Sensitivity, specificity, LR + and LR- for APS diagnosis were 47%, 88%, 3.9 and 0.6, respectively. Conclusions IgG aPS/PT detection is an easily performed laboratory parameter that might contribute to a better and more complete identification of patients with APS.

Autoantibodies to domain 1 of beta 2 glycoprotein I determined using a novel chemiluminescence immunoassay demonstrate association with thrombosis in patients with antiphospholipid syndrome.

INTRODUCTION: Antibodies to the domain 1 of beta 2 glycoprotein I (ß2GPI-D1) have been suggested as a risk marker for thrombosis in patients with the antiphospholipid syndrome (APS). This cross-sectional study aimed to analyze the clinical utility of a novel chemiluminescence assay for the detection of anti-ß2GPI-D1 antibodies. PATIENTS AND METHODS: Sera collected from patients with primary or secondary APS (n = 106; 72 with and 34 without history of thrombosis) and controls (n = 272) were tested for anti-ß2GPI-D1 IgG by chemiluminescence assay (QUANTA Flash) and by two anti-ß2GPI IgG assays (QUANTA Lite and QUANTA Flash ß2GPI IgG). RESULTS: Anti-ß2GPI-D1 IgG titers were significantly higher in patients with thrombosis (P = 0.0032) than those without. At the cut-off of 20 units, which yielded a 99.5% specificity, 24 of 72 (34.9%) patients with thrombosis and four of 34 (11.8%) without thrombosis were anti-ß2GPI-D1 IgG positive (odds ratio, OR = 4.0). By further optimizing the cut-off specifically for correlation with thrombosis, 20.8% of the patients with thrombosis and 2.9% of the patients without thrombosis were positive (OR = 8.7). The ORs were significantly lower for antibodies to the full-length ß2GPI by either the chemiluminescence assay or ELISA. Using the anti-ß2GPI chemiluminescence assay, the OR was 2.3 (recommended cut-off of 20 CU) or 4.1 (optimal cut-off 164.6 CU). Using the anti-ß2GPI ELISA, the OR was 2.7 (recommended cut-off of 20 units) or 3.7 (optimal cut-off 7.6 units). CONCLUSION: These data indicate that anti-ß2GPI-D1 IgG are present more frequently and in higher titers in APS patients with thrombotic complications than in those without.The novel ß2GPI-D1 chemiluminescence assay appears to be superior to full-length ß2GPI assays for the risk assessment of thrombotic events in APS patients.

Morbidity and mortality in the antiphospholipid syndrome during a 10-year period: a multicentre prospective study of 1000 patients.

OBJECTIVES: To assess the prevalence of the main causes of morbi-mortality in the antiphospholipid syndrome (APS) during a 10-year-follow-up period and to compare the frequency of early manifestations with those that appeared later. METHODS: In 1999, we started an observational study of 1000 APS patients from 13 European countries. All had medical histories documented when entered into the study and were followed prospectively during the ensuing 10 years. RESULTS: 53.1% of the patients had primary APS, 36.2% had APS associated with systemic lupus erythematosus and 10.7% APS associated with other diseases. Thrombotic events appeared in 166 (16.6%) patients during the first 5-year period and in 115 (14.4%) during the second 5-year period. The most common events were strokes, transient ischaemic attacks, deep vein thromboses and pulmonary embolism. 127 (15.5%) women became pregnant (188 pregnancies) and 72.9% of pregnancies succeeded in having one or more live births. The most common obstetric complication was early pregnancy loss (16.5% of the pregnancies). Intrauterine growth restriction (26.3% of the total live births) and prematurity (48.2%) were the most frequent fetal morbidities. 93 (9.3%) patients died and the most frequent causes of death were severe thrombosis (36.5%) and infections (26.9%). Nine (0.9%) cases of catastrophic APS occurred and 5 (55.6%) of them died. The survival probability at 10 years was 90.7%. CONCLUSIONS: Patients with APS still develop significant morbidity and mortality despite current treatment. It is imperative to increase the efforts in determining optimal prognostic markers and therapeutic measures to prevent these complications.

Thrombotic risk assessment in APS: the Global APS Score (GAPSS).

Recently, we developed a risk score for antiphospholipid syndrome (APS) (Global APS Score or GAPSS). This score derived from the combination of independent risk factors for thrombosis and pregnancy loss, taking into account the antiphospholipid antibodies (aPL) profile (criteria and non-criteria aPL), the conventional cardiovascular risk factors, and the autoimmune antibodies profile. We demonstrate that risk profile in APS can be successfully assessed, suggesting that GAPSS can be a potential quantitative marker of APS-related clinical manifestations.

Antibodies to phosphatidylserine/prothrombin complex and the antiphospholipid syndrome.

Antibodies to prothrombin can be detected by ELISA using prothrombin coated onto irradiated plates (aPT) or the phosphatidylserine/prothrombin complex as antigen (aPS/PT) and they have been both related with the clinical manifestation of APS. Current evidence supports the concept that they belong to distinct populations of autoantibodies. Nevertheless, they can both be detected simultaneously in one patient. This mini-review will focus on data available on aPS/PT antibodies and their clinical utility in the diagnosis of APS.

Clinical accuracy for diagnosis of antiphospholipid syndrome in systemic lupus erythematosus: evaluation of 23 possible combinations of antiphospholipid antibody specificities.

OBJECTIVES: To evaluate the clinical accuracy of antiphospholipid antibody (aPL) specificities both individually and/or in combination, in a wide cohort of systemic lupus erythematosus (SLE) patients in an attempt to identify a panel of tests that may provide the best accuracy for diagnosing antiphospholipid syndrome (APS). PATIENTS AND METHODS: This study included 230 patients (218 women, mean age 42.7 ± 11.9 years, mean disease duration 12.2 ± 8.7 years), all fulfilling the 1982 criteria for SLE. All patients were tested for lupus anticoagulant (LA), anti-cardiolipin (aCL), anti-ß(2) glycoprotein I (anti-ß2GPI), solid phase anti-prothrombin (aPT), anti-phosphatidylserine/prothrombin (aPS/PT), and anti-phosphatidylethanolamine (aPE) antibodies. Sensitivity, specificity and predictive values were calculated. The diagnostic accuracy for each combination of tests was assessed by ROC and their area under the curve analysis as well as by the Youden's index (YI). RESULTS: Testing for six aPL derived 23 possible combinations of results. Among them, LA + anti-ß(2)GPI + aPS/PT had the best diagnostic accuracy for APS as a whole and individually for both thrombosis and pregnancy loss (AUC 0.712, OR 3.73 [95% CI 1.82-5.38], P = 0.0001, YI = 0.32 and AUC 0.709, OR 3.75 [95% CI 2.13-6.62], P = 0.0001, YI = 0.37 and AUC 0.677, OR 4.82 [95% CI 2.17-10.72], P = 0.0007, YI = 0.38, respectively) and the best specificity when compared with all the other obtainable combination of tests. Triple positivity for LA + anti-ß(2)GPI + aPS/PT was more strongly associated with clinical events (thrombosis and/or PL) when compared with double or single positivity (OR 23.2 [95% CI 2.57-46.2] vs. OR 7.3 [95% CI 2.21-25.97], OR 5.7 [95% CI 2.12-17.01] or OR 3.11 [95% CI 1.56-7.8] for single positivity for LA, aPS/PT and anti-ß(2)GPI, respectively). CONCLUSIONS: Combining LA, anti-ß(2)GPI and aPS/PT improves the diagnostic power and helps in stratifying the risk for each patient, according to their aPL profile.

The clinical value of testing for antibodies to phosphatidylethanolamine (aPE) in patients with systemic lupus erythematosus (SLE).

UNLABELLED: The value of testing for aPE in venous thrombosis and fetal death is in constant debate. We evaluated if testing for aPE has a diagnostic value in patients with SLE. PATIENTS AND METHODS: We included 224 patients. aPE were tested by an in-house ELISA using FCS. RESULTS: aPE were found in 41% of the patients. IgG and IgM aPE were more frequently found along with other aPL than in those negative for aPL (p=0.003 and p=0.01). IgG aPE were more frequently found in patients with definite APS than in those without (p=0.003). aPE were more frequent in patients with thrombosis than in those without, particularly the IgG isotype (p=0.03). When subdividing between venous and arterial thrombosis, only an association between IgG aPE with venous thrombosis was retained (p=0.01). Titres of IgG aPE were significantly higher in patients with arterial or those with venous thrombosis, when compared to the patients without thrombosis (p=0.004 and p=0.001). Titres of IgM aPE were higher in patients with arterial thrombosis when compared to those without (p=0.014). No associations were found between the presence of aPE and/or pregnancy morbidity. The presence of aPE did not correlate with that of any other aPL. After multivariate analysis all clinical associations failed to retain significance. CONCLUSIONS: aPE are frequently seen in SLE and do not correlate with other routinely tested aPL. Although more prevalent, aPE is not an independent risk factor for thrombosis or pregnancy morbidity in patients with SLE.

Antibodies to prothrombin.

Research on antiphospholipid antibodies (aPL) and the thrombotic manifestations associated with these antibodies has grown since the description of anticardiolipin antibodies (aCL) by Harris and colleagues in the early 1980s. Antiprothrombin (aPT) antibodies are commonly detected by ELISA, using irradiated plates (aPT) or prothrombin in complex with phosphatidylserine (aPS/PT). Although aPT and/or aPS/PT are associated with antiphospholipid syndrome (APS) -related clinical features and these antibodies correlate with each other, aPT and aPS/PT belong to different populations of autoantibodies even though they can both be present in the same patient. Early studies suggested that these antibodies might be the antigenic target of lupus anticoagulant (LA) and their correlation and clinical significance is being investigated.

'Non-criteria' aPL tests: report of a task force and preconference workshop at the 13th International Congress on Antiphospholipid Antibodies, Galveston, TX, USA, April 2010.

Abstract: Current classification criteria for definite APS recommend the use of one or more of three positive standardized laboratory assays, including anticardiolipin antibodies (aCL), lupus anticoagulant (LA), and antibodies directed to ß(2)glycoprotein I (anti-ß(2)GPI) to detect antiphospholipid antibodies (aPL) in the presence of at least one of the two major clinical manifestations (i.e., thrombosis or pregnancy morbidity) of the syndrome. Several other autoantibodies shown to be directed to phospholipids and/or their complexes with phospholipids and/or to proteins of the coagulation cascade, as well as a mechanistic test for resistance to annexin A5 anticoagulant activity, have been proposed to be relevant to APS. A task force of worldwide scientists in the field discussed and analyzed critical questions related to 'non-criteria' aPL tests in an evidence-based manner during the 13th International Congress on Antiphospholipid Antibodies (APLA 2010, 13-16 April 2010, Galveston, Texas, USA). This report summarizes the findings, conclusions, and recommendations of this task force.

Morbidity and mortality in the antiphospholipid syndrome during a 5-year period: a multicentre prospective study of 1000 patients.

OBJECTIVES: To identify the main causes of morbidity and mortality in patients with antiphospholipid syndrome (APS) during a 5-year period and to determine clinical and immunological parameters with prognostic significance. METHODS: The clinical and immunological features of a cohort of 1000 patients with APS from 13 European countries who had been followed up from 1999 to 2004 were analysed. RESULTS: 200 (20%) patients developed APS-related manifestations during the 5-year study period. Recurrent thrombotic events appeared in 166 (16.6%) patients and the most common were strokes (2.4% of the total cohort), transient ischaemic attacks (2.3%), deep vein thromboses (2.1%) and pulmonary embolism (2.1%). When the thrombotic events occurred, 90 patients were receiving oral anticoagulants and 49 were using aspirin. 31/420 (7.4%) patients receiving oral anticoagulants presented with haemorrhage. 3/121 (2.5%) women with only obstetric APS manifestations at the start of the study developed a new thrombotic event. A total of 77 women (9.4% of the female patients) had one or more pregnancies and 63 (81.8% of pregnant patients) had one or more live births. The most common fetal complications were early pregnancy loss (17.1% of pregnancies) and premature birth (35% of live births). 53 (5.3% of the total cohort) patients died. The most common causes of death were bacterial infection (21% of deaths), myocardial infarction (19%) and stroke (13%). No clinical or immunological predictor of thrombotic events, pregnancy morbidity or mortality was detected. CONCLUSION: Patients with APS still develop significant morbidity and mortality despite current treatment (oral anticoagulants or antiaggregants, or both).

Migraine and antiphospholipid antibodies: no association found in migraine-discordant monozygotic twins.

Migraine headache (with and without aura) is common in the general population and is known to be influenced by genetic factors with heritability estimates between 34-57%. Antiphospholipid syndrome (APS) is a hypercoagulable state characterized by clinical features including venous and arterial thromboses, pregnancy loss and migraine, and by association with antiphospholipid antibodies (aPL). Numerous small studies have investigated whether aPL are associated with migraine in the general population--with contradictory results. In this study, the question was addressed by studying the prevalence of aPL in members of monozygotic (MZ) twin pairs differing in their migraine status. Such twins provide a unique natural experiment, matched as they are for age, sex and genetic factors, and allow the role of environmental factors, such as aPL, to be determined. Despite 95% power to detect a difference of 0.59 IgG units per litre in anticardiolipin antibody IgG titres, no difference in prevalence of aPL could be detected in migraine-discordant MZ twins.

Laboratory diagnosis and management challenges in the antiphospholipid syndrome.

The antiphospholipid syndrome (APS) is characterized by recurrent arterial and/or venous thrombosis and pregnancy morbidity manifested by early or late losses. Laboratory diagnosis ofAPS relies on the demonstration of a positive test for antiphospholipid antibodies (aPL). In clinical practice, the gold standard tests are those that detect anticardiolipin antibodies (aCL) and/or the lupus anticoagulant (LA). Although other specificities for aPL have been described their clinical utility and standardization has still to be established. Persistence of aPL positive tests must be demonstrated, and other causes and underlying factors considered. Although it is universally recognized that the routine screening tests (aCL and/or LA) might miss some cases, careful differential diagnosis and repeat testing are mandatory before the diagnosis of 'seronegative APS' can be made. Correct identification of patients with APS is important, because prophylactic anticoagulant therapy can prevent thrombosis from recurring, and treatment of affected women during pregnancy can improve fetal and maternal outcome.

Antiferritin antibodies discovered by phage display expression cloning are associated with radiographic damage in rheumatoid arthritis.

OBJECTIVE: Several autoantibodies have been described in individuals with rheumatoid arthritis (RA), leading to interest in the use of such antibodies as diagnostic or prognostic markers in RA as well as in their relevance to disease pathology. The objective of this study was to use a phage display expression cloning system to identify novel autoantibody targets in RA. METHODS: We used immunoscreening of a phage-displayed complementary DNA (cDNA) library to isolate a cDNA clone encoding the ferritin heavy chain polypeptide. Antiferritin antibody levels in patients with early and established RA, healthy controls, and disease controls were measured by enzyme-linked immunosorbent assay. Antibody-positive and antibody-negative individuals were compared with respect to disease severity as measured by the modified Larsen score, demographic variables, rheumatoid factor status, and carriage of HLA-DRB1 shared epitope alleles. RESULTS: Antiferritin antibodies were present in 60 (16%) of 366 patients with established RA, 23 (19%) of 118 patients with early RA, 2 (2.7%) of 73 healthy blood donors, 2 (2.1%) of 94 individuals with osteoarthritis, and 2 (2.1%) of 97 patients with systemic lupus erythematosus (P < 0.01, RA patients versus healthy and disease controls). Antiferritin antibodies were more common in men than in women (28.4% versus 12.2%; P < 0.001), and antiferritin levels were associated with the severity of joint damage (P = 0.01). CONCLUSION: Antiferritin antibodies are observed in a subset of patients with RA, are present early in the disease course, and are associated with the severity of radiographic damage. Further studies are required to explore their potential as diagnostic and prognostic markers in RA.

Antiphospholipid antibody tests: spreading the net.

OBJECTIVE: To examine the hypothesis that testing for new antiphospholipid antibody specificities may help to identify the antiphospholipid syndrome (APS) in patients with systemic lupus erythematosus (SLE) with thrombosis who are repeatedly negative for anticardiolipin antibodies (aCL) and/or lupus anticoagulant (LA). METHODS: Three groups of patients with SLE were studied: (a) SLE/APS (n = 56): 51 female, mean (SD) age 46 (11) years, fulfilling 1999 Sapporo criteria for the APS; (b) SLE/thrombosis (n = 56): 53 female, age 42.6 (12) years, all with a history of thrombosis and persistently negative for aCL and/or LA; (c) SLE only (n = 56): 53 female, age 40 (11) years, without a history of thrombotic events. aCL and LA were retested in all samples. All patients were tested for anti-beta(2)-glycoprotein I (anti-beta(2)GPI) and antiprothrombin antibodies (aPT) by coating prothrombin on irradiated plates or using phosphatidylserine-prothrombin complex as the antigen (aPS-PT). RESULTS: Anti-beta(2)GPI were only present in patients from the SLE/APS group, all of whom were also positive for aCL. aPT and aPS-PT were also more commonly found in SLE/APS than in SLE/thrombosis or SLE only groups (54% v 5%, p<0.0001 or v 16%, p<0.0001 for aPT and 63% v 2%, p<0.0001 or v 11%, p<0.0001 for aPS-PT, respectively). No differences were found between SLE/thrombosis and SLE only groups (p = 1.5 for beta(2)GPI, p = 0.1 for aPT, and p = 0.1 for aPS-PT). CONCLUSION: Testing for aPT in patients with SLE with thrombosis, but persistently negative for aCL and LA, may be helpful in some selected cases. Anti-beta(2)GPI are not present in patients who are negative for aCL.

Anti-C1q antibodies in nephritis: correlation between titres and renal disease activity and positive predictive value in systemic lupus erythematosus.

OBJECTIVE: To investigate antibodies to complement 1q (anti-C1q) and investigate the correlation between anti-C1q titres and renal disease in systemic lupus erythematosus (SLE). METHODS: 151 SLE patients were studied. In patients with biopsy proven lupus nephritis (n = 77), activity of renal disease was categorised according to the BILAG renal score. Sera were tested for anti-C1q by enzyme immunoassay. Serum samples were randomly selected from 83 SLE patients who had no history of renal disease, and the positive and negative predictive value of the antibodies was studied. RESULTS: Patients with active lupus nephritis (BILAG A or B) had a higher prevalence of anti-C1q than those with no renal disease (74% v 32%; relative risk (RR) = 2.3 (95% confidence interval, 1.6 to 3.3)) (p<0.0001). There was no significant difference in anti-C1q prevalence between SLE without nephritis and SLE with non-active nephritis (BILAG C or D) (32% v 53%, p = 0.06) or between active and non-active nephritis (74% v 53%, p = 0.06). Patients with nephritis had higher anti-C1q levels than those without nephritis (36.0 U/ml (range 4.9 to 401.0) v 7.3 U/ml (4.9 to 401.0)) (p<0.001). Anti-C1q were found in 33 of 83 patients (39%) without history of renal disease. Nine of the 33 patients with anti-C1q developed lupus nephritis. The median renal disease-free interval was nine months. One patient with positive anti-C1q was diagnosed as having hypocomplementaemic urticarial vasculitis syndrome during follow up. CONCLUSIONS: Anti-C1q in SLE are associated with renal involvement. Monitoring anti-C1q and their titres in SLE patients could be important for predicting renal flares.

Association of HLA-DM polymorphism with the production of antiphospholipid antibodies.

OBJECTIVE: To investigate whether variation in the HLA-DM gene is important in producing a group of pathogenic autoantibodies-antiphospholipid antibodies (aPL)-on the basis that HLA class II restricted antigen presentation is involved in the production of aPL. METHODS: HLA-DMA and DMB polymorphisms were genotyped by polymerase chain reaction combined with restriction enzyme digestion in 51 white patients with primary antiphospholipid syndrome (APS), 82 with systemic lupus erythematosus (SLE) (42 with APS and 40 without APS), and 109 healthy white controls. The association with the aPL profile was examined. RESULTS: The distribution of DMA alleles in APS patients and in patients with APS associated with SLE was significantly different from that in controls by 4x2 chi(2) test with 3 degrees of freedom (p = 0.035 and 0.011, respectively), but it was not different between SLE patients without APS and controls. The allelic distribution of DMA was also different between patients with IgG class anticardiolipin antibody or those with lupus anticoagulant (LA) and controls (p = 0.012 and 0.007, respectively) and between patients with and without LA among SLE patients (p = 0.035). All these differences included the increase in DMA*0102 in the former groups. CONCLUSIONS: The results suggest that HLA-DMA*0102 or its linked gene(s) form one of the genetic risks for the production of aPL.