A prospective study of antibodies to beta2-glycoprotein I and prothrombin, and risk of thrombosis

The impact of antiphospholipid antibodies/antiphospholipid syndrome on systemic lupus erythematosus

aPLs are a major determinant of the increased cardiovascular risk in patients with SLE. They adversely affect clinical manifestations, damage accrual and prognosis. Apart from the antibodies included in the 2006 revised classification criteria for APS, other non-classical aPLs might help in identifying SLE patients at increased risk of thrombotic events. The best studied are IgA anti-β2-glycoprotein I, anti-domain I β2-glycoprotein I and aPS-PT. Major organ involvement includes kidney and neuropsychiatric systems. aPL/APS severely impacts pregnancy outcomes. Due to increased thrombotic risk, these patients require aggressive cardiovascular risk factor control. Primary prophylaxis is based on low-dose aspirin in high-risk patients. Warfarin is the gold-standard drug for secondary prophylaxis.

Pregnancy in antiphospholipid syndrome: what should a rheumatologist know?

This review focuses on the management of reproductive issues in women who have antiphospholipid syndrome (APS) or are carriers of antiphospholipid antibodies (aPL). The importance of aPL detection during preconception counselling relies on their pathogenic potential for placental insufficiency and related obstetric complications. The risk of adverse pregnancy outcomes can be minimized by individualized risk stratification and tailored treatment aimed at preventing placental insufficiency. Combination therapy of low-dose acetylsalicylic acid and heparin is the mainstay of prophylaxis during pregnancy; immunomodulation, especially with hydroxychloroquine, should be considered in refractory cases. Supplementary ultrasound surveillance is useful to detect fetal growth restriction and correctly tailor the time of delivery. The individual aPL profile must be considered in the stratification of thrombotic risk, such as during assisted reproduction techniques requiring hormonal ovarian stimulation or during the follow-up after pregnancy in order to prevent the first vascular event.

Anti-Phosphatidylserine, Anti-Prothrombin, and Anti-Annexin V Autoantibodies in Antiphospholipid Syndrome: A Real-Life Study

The antiphospholipid antibodies (aPL) increase the risk of developing thrombotic events and may coexist with a variety of autoimmune diseases. They can be detected chronically or temporarily in patients with infectious diseases, during drug therapy, or in cases of cancer. A thrombotic event with aPL detection is known as antiphospholipid syndrome (APS) and the diagnostic criteria include the presence of lupus anticoagulant (LA), anticardiolipin (aCL) and β2-glycoprotein-1(aβ2GPI) antibodies. Other autoantigens recognized in APS are phosphatidylserine (aPS), prothrombin (aPT) and Annexin-5 (aA5). This real life study aimed to explore the connections between laboratory criteria and the prevalence of "non-criteria aPL" in APS. This study followed 300 patients with thrombosis and employed two phospholipid sensitivity assays for LA detection, chemiluminescence assays for aCL and aβ2GPI and enzyme-linked immunoassays for aPS, aPT and aA5. A significant association was found between aPS and aCL (r = 0.76) as well as aβ2GPI (r = 0.77), while the association with LA was less significant (r = 0.33). The results of the aPT and aA5 test did not correlate with criteria-antiphospholipid antibodies (r < 0.30). Since the risk of thrombotic complications increases with the intensity and the number of positive autoantibodies, measuring aPT and aA5 autoantibodies may be useful, particularly in aCL/aβ2GPI-negative patients or in cases of isolated LA positivity.

Lupus, antiphospholipid syndrome, and stroke: An attempt to crossmatch

Cerebrovascular accidents (CVAs) or strokes are part of the common thrombotic manifestations of Systemic Lupus Erythematosus (SLEs) and Antiphospholipid syndrome (APS). Such neurological thrombotic events tend to occur in patients with SLE at a higher frequency when Antiphospholipid antibodies (aPLs) are present, and tend to involve the large cerebral vessels. The mechanism of stroke in SLE can be driven by complement deposition and neuroinflammation involving the blood-brain barrier although the traditional cardiovascular risk factors remain major contributing factors. Primary prevention with antiplatelet therapy and disease activity controlling agent is the basis of the management. Anticoagulation via warfarin had been a tool for secondary prevention, especially in stroke recurrence, although the debate continues regarding the target international normalized ratio (INR). The presence of either of the three criteria antiphospholipid antibodies (aPLs) and certain non-criteria aPL can be an independent risk factor for stroke. The exact mechanism for the involvement of the large cerebral arteries, especially in lupus anticoagulant (LAC) positive cases, is still to be deciphered. The data on the role of non-criteria aPL remain very limited and heterogenous, but IgA antibodies against β2GPI and the D4/5 subunit as well as aPS/PT IgG might have a contribution. Anticoagulation with warfarin has been recommended although the optimal dosing or the utility of combination with antiplatelet agents is still unknown. Minimal data is available for direct oral anticoagulants (DOACs).

Clinical and therapeutic value of the adjusted Global Antiphospholipid Syndrome Score in primary obstetric antiphospholipid syndrome

OBJECTIVES

(1) To assess the clinical utility of the adjusted global antiphospholipid syndrome score (aGAPSS) to predict new obstetric events during follow-up in primary obstetric antiphospholipid syndrome (POAPS) patients under standard-of-care treatment (SC) based on the use of low-dose aspirin (LDA) + heparin and (2) to study the risk of a first thrombotic event and to evaluate whether stratification according to this score could help to identify POAPS patients who would benefit from long-term thromboprophylaxis.

METHODS

This is a retrospective, multicentre study. 169 women with POAPS were evaluated for the presence of a new obstetric event and/or a first thrombotic event during follow-up [time period: 2008-2020, median: 7 years (6-12 years)]. The outcomes of 107 pregnancies from these POAPS patients with SC were studied to evaluate relapses. Simple and multivariable logistic regression analyses were performed.

RESULTS

Regarding obstetric morbidity, only triple positivity for antiphospholipid antibodies (aPLs) [OR = 8.462 (95% CI: 2.732-26.210); p < 0.0001] was found to be a strong risk factor independently associated with treatment failure. On the other hand, triple positivity for aPLs [OR=10.44 (95% CI: 2.161-50.469), p = 0.004] and an aGAPSS ≥7 [OR = 1.621 (95% CI: 1.198-2.193), p = 0.002] were independent risk factors associated with a first thrombotic event. LDA was marginally associated with a decrease in the risk of thrombosis only in patients with aGAPSS ≥ 7 (p = 0.048).

CONCLUSION

aGAPSS appears to be useful in predicting the occurrence of a first thrombotic event in POAPS patients, and these stratification of patients could be helpful in selecting patients who would benefit from thromboprophylaxis with LDA.

A systematic review of the association between anti-β-2 glycoprotein I antibodies and APS manifestations

Anti-β-2 glycoprotein I antibodies (anti-B2GPI) are often cited as the major pathogenically relevant antibody in antiphospholipid syndrome (APS), but it is unclear if there is clinical evidence to support this theory. We performed a systematic review to determine if immunoglobulin G anti-B2GPI positivity was independently associated with thrombotic and/or obstetric manifestations of APS. We searched MEDLINE, EMBASE, The Cochrane Library, and clinicaltrials.gov electronic databases through April 2020 for prospective studies that met prespecified design criteria. Of 4758 articles identified through computer-assisted search, 4 studies examining obstetric outcomes and 2 studies examining thrombotic outcomes were included for qualitative assessment. The presence of anti-B2GPI had only a weak independent association with thrombosis and was, at best, inconsistently associated with obstetric complications. A quantitative assessment could not be performed because of study heterogeneity. The overall quality of the evidence was very low. Although anti-B2GPI are commonly thought to mediate APS manifestations, clinical evidence is lacking with very low-quality data to support a weak association with thrombosis.

Risk Factors for the Development of the Disease in Antiphospholipid Antibodies Carriers: A Long-term Follow-up Study

The natural history of antiphospholipid antibodies (aPL) carriers is not well-established. The objectives of the present study were (a) to study the probability of developing clinical criteria of antiphospholipid syndrome (APS), (b) to identify potential risk factors for developing thrombosis and/or obstetric complications, (c) to study the association between the antibody profile and development of APS, and (d) to determine the efficacy of primary prophylaxis. We retrospectively analyzed 138 subjects with positive aPL who did not fulfill clinical criteria for APS. The mean follow-up time was 138 ± 63.0 months. Thirteen patients (9.4%) developed thrombosis after an average period of 73.0 ± 48.0 months. Independent risk factors for thrombosis were smoking, hypertension, thrombocytopenia, and triple aPL positivity. Low-dose acetyl salicylic acid did not prevent thrombotic events. A total of 28 obstetric complications were detected in 92 pregnancies. During the follow-up, only two women developed obstetric APS. Prophylactic treatment in pregnant women was associated with a better outcome in the prevention of early abortions. The thrombosis rate in patients with positive aPL who do not meet diagnostic criteria for APS is 0.82/100 patients-year. Smoking, hypertension, thrombocytopenia, and the aPL profile are independent risk factors for the development of thrombosis in aPL carriers. Although the incidence of obstetric complications in this population is high (31.6%), only a few of them meet APS criteria. In these women, prophylactic treatment might be effective in preventing early abortions.

Associations with thrombosis are stronger for antiphosphatidylserine/prothrombin antibodies than for the Sydney criteria antiphospholipid antibody tests in SLE

Objectives

Antiphosphatidylserine/prothrombin complex antibodies (aPS/PT) are risk factors for thrombosis, yet further validation of their clinical relevance in different ethnic groups is required. We investigated the performance of aPS/PT of IgA/G/M isotypes among Sudanese and Swedish systemic lupus erythematosus (SLE) patients.

Methods

Consecutive SLE patients/matched controls from Sudan (n = 91/102) and Sweden (n = 332/163) were included. All patients fulfilled the 1982 ACR SLE classification criteria. IgA/G/M of aPS/PT, anti-cardiolipin and anti-β₂glycoprotein I (anti-β₂GPI) were tested in both cohorts, and lupus anticoagulant (LA) also in the Swedish cohort. Clinical antiphospholipid syndrome-related events and atherosclerosis, measured as carotid plaques were assessed for associations. Univariate and multivariate analyses adjusting for cardiovascular risk factors were performed.

Results

Sudanese SLE patients had higher levels of IgM aPS/PT, but using national cut-offs, the frequency of positivity was similar to Swedish patients for all isotypes. Among Swedish patients, all isotypes of aPS/PT associated with venous thromboembolism (VTE), while only IgA aPS/PT associated with arterial thrombosis (AT). aPS/PT antibodies associated strongly with LA and they were, independently, the best predictor for VTE. Double positivity for aPS/PT and anti-β₂GPI associated with higher VTE risk than the conventional triple positivity. Carotid plaques did not associate with any antiphospholipid antibody.

Conclusions

IgA aPS/PT associated with AT, and the association of IgG/M aPS/PT with VTE outperforms LA and criteria antiphospholipid antibodies in Swedish SLE patients. Furthermore, double positivity for aPS/PT and anti-β₂GPI performed better than conventional triple positivity. Future studies need to address if aPS/PT can replace LA, as this would simplify clinical procedures.

Antiphospholipid syndrome in pediatric patients

PURPOSE OF REVIEW

The purpose of this review is to summarize the diagnosis and management of the antiphospholipid syndrome (APS) in children.

RECENT FINDINGS

APS is a rare, acquired autoimmune systemic disease that can result in significant morbidity in children related to vascular thrombosis. The diagnosis and management of APS in children can be challenging due to a lack of validated diagnostic criteria and the rarity of the disease. In addition, many healthy children have transient circulating antiphospholipid antibodies without thrombotic complications. Nevertheless, epidemiological studies suggest that APS represents a greater relative proportion of thrombotic disease in children than it does in adults. Management of pediatric APS is largely inferred from adult data despite unique characteristics of pediatric APS. The current recommendations include long-term anticoagulation, which can be problematic in young, active individuals. There is little data on potential benefits of nonantithrombotic therapy in the management of pediatric APS.

SUMMARY

Data on pediatric APS are limited, but evidence suggests that using current available diagnostic testing is valuable and, until further evidence is available, treating thrombotic complications with heparins or warfarin should be standard of care.

Profiles of criteria and non-criteria anti-phospholipid autoantibodies are associated with clinical phenotypes of the antiphospholipid syndrome

Background

Specific anti-phospholipids antibodies (aPLs) are used as classification criteria of the antiphospholipid syndrome (APS). These aPLs, although essential for diagnosis, do not predict disease phenotypes, which may require specific therapies. Non-criteria aPLs are rarely evaluated and their role is yet to be defined. In the current study, we aimed to examine the association between criteria and non-criteria aPLs and APS phenotypes.

Methods

Serum samples from 188 subjects, 130 APS patients and 58 controls were analyzed for the presence of 20 aPLs (IgG and IgM isotypes to cardiolipin (CL), beta2-glycoprotein1 (β2GP1), phosphatidic acid (P-acid), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylinositol (PI), phosphatidylserine (PS), annexin-5 (AN) and prothrombin (PT) using a line immunoassay (GA Generic Assays, Germany). Sero-positivity to the different aPLs/aPLs profiles was correlated to APS phenotypes (i.e. arterial thrombosis, CNS manifestations, venous thrombosis, relapsing disease, obstetric morbidity).

Results

In this cohort, arterial thrombosis was associated with accumulative number of ≥ 7/20 aPLs evaluated (OR 4.1; CI 95% 1.9–96, p = 0.001) as well as the sole presence of aPT (IgG) (OR 2.3;CI 95% 1.1–5.1, p = 0.03). CNS manifestations were linked with a profile of 4 aPLs (IgG): aPT, aPG, aPI and aAN (OR 2.6;CI 95% 1.1–6.3, p = 0.03). Symptom-free period of ≥ 3 years was linked with lower number of aPLs and the presence of aPI (IgG) (OR 3.0;CI 95% 1.08–8.1, p < 0.05) or aAN (IgG) (OR 3.4;CI 95% 1.08–10.9, p < 0.05). APS related pregnancy morbidity correlated with a profile of 2 aPLs (IgG): aCL and aPS (OR 2.9; CI 95% 1.3–6.5, p < 0.05) or the sole presence of aAN (IgG) (OR 2.8; CI 95% 1.02–8, p = 0.05).

Conclusion

In this study, we observed an association between specific criteria/non-criteria aPLs or aPLs profiles and clinical phenotypes of APS. Our data suggest that examination of a wider variety of aPLs may allow better characterization of APS.

Obstetric antiphospholipid syndrome is not associated with an increased risk of subclinical atherosclerosis

Objectives

The persistent positivity of aPLs, either isolated or associated with thrombotic and/or obstetric events (APS), has been associated with the increase of intima-media thickness (IMT) and carotid plaques. Despite the fact that aPLs can promote both thrombotic and obstetric complications, some pathogenic differences have been documented between the two entities. This study aimed to evaluate whether the atherosclerotic risk differs between subjects with obstetric and thrombotic APS.

Methods

A total of 167 APS women (36 obstetric and 131 thrombotic) were compared with 250 aPLs negative controls. IMT of the common carotid artery (CCA) and of the bulb and the prevalence of carotid plaques were assessed.

Results

CCA- and bulb-IMT were significantly higher in women with thrombotic APS, while being similar between the obstetric APS and the controls [CCA-IMT: mean (s.d.) 0.97 (0.49), 0.78 (0.22) and 0.81 (0.12) mm for the thrombotic, obstetric and control groups, respectively, P &lt; 0.001 between thrombotic and controls, P = 0.002 between thrombotic and obstetric; bulb-IMT: mean (s.d.) 1.38 (0.79), 0.96 (0.27) and 0.96 (0.51) mm for the thrombotic, obstetric and control groups, P &lt; 0.001]. Women with thrombotic APS had significantly increased risk of presenting carotid plaques. This risk was significantly lower in obstetric APS.

Conclusion

Unlike thrombotic APS, obstetric APS is not associated with an increase of markers of subclinical atherosclerosis. If confirmed on wider populations, these results could suggest different pathogenetic role of aPLs in promoting atherosclerosis in vascular and obstetric APS, and raise questions on the risk–benefit profile of thromboprophylaxis in obstetric APS outside pregnancy periods.

Global antiphospholipid syndrome score and anti-ß2-glycoprotein I domain I for thrombotic risk stratification in antiphospholipid syndrome: A four-year prospective study

Objective

This study aimed to assess prospectively the role of anti-ß2-glycoprotein I domain I antibody (aß2GPI-DI) and the Global Antiphospholipid Syndrome Score (GAPSS) in identifying antiphospholipid syndrome (APS) patients at higher risk of a new event.

Methods

Thrombotic APS patients were followed from May 2013 to July 2017. At baseline, we measured lupus anticoagulant, IgG/IgM anticardiolipin, anti-ß2-glycoprotein I, antiphosphatidylserine-prothrombin (aPS/PT) and IgG aß2GPI-DI, and calculated GAPSS for each patient.

Results

A total of 44 patients (age 43 ± 10 years, 89% female, 73% primary APS) were followed for 39 months (range 9–46 months). Four new thromboses occurred, two of them after vitamin K antagonist interruption. Recurrent patients presented higher GAPSS (median 20) and were triple and aß2GPI-DI positive; non-recurrent patients had lower GAPSS (median 10.5, range 0–20) and lower ratio of triple (33%) and aß2GPI-DI positivities (38%). aß2GPI-DI was associated with higher GAPSS (median 19 vs. 7, p < 0.001; Pearson correlation 0.82, p < 0.001) and had a greater proportion of triple (83% vs. 4%, p < 0.001) and aPS/PT positivity (94% vs. 50%, p = 0.002).

Conclusion

Our data show a significant correlation between a validated risk score such as GAPSS and the novel antiphospholipid antibody aß2GPI-DI. Future studies are needed. However, one could speculate a role of aß2GPI-DI as a risk-stratifying tool for thrombotic events in APS.

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.

What is the appropriate anticoagulation strategy for thrombotic antiphospholipid syndrome?

Antiphospholipid syndrome (APS) is an autoimmune prothrombotic disorder mediated by a heterogeneous group of autoantibodies collectively known as antiphospholipid antibodies (aPL). They include lupus anticoagulant (LA), IgG and IgM anticardiolipin antibodies (aCL) and anti-β2-glycoprotein I (anti-β2GPI) antibodies. It has been shown that those patients with all three aPL (triple positive) are at highest risk of both a first thrombotic event and of a recurrence, despite anticoagulation. In response to publication of a meta-analysis and a randomised controlled trial assessing the safety and efficacy of rivaroxaban versus warfarin in triple-positive APS with venous and/or arterial thrombosis, the Medicines and Healthcare Products Regulatory Agency (MHRA) and European Medicines Agency (EMA) issued recommendations that direct-acting oral anticoagulant (DOACs) should not be used for secondary prevention of thrombosis in all APS patients (although they did draw specific attention to the high risk of triple-positive patients). As there is less evidence for patients with single- or dual-positive patients with APS, this may be an over-interpretation of the data. In this review, we explore the available evidence on safety and efficacy of DOACs in thrombotic APS, the problem of detecting LA while on DOAC, and provide some practical guidance for managing this problem.

Seronegative antiphospholipid syndrome: refining the value of "non-criteria" antibodies for diagnosis and clinical management

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by arterial and venous thrombotic manifestations and/or pregnancy-related complications in patients with persistently high antiphospholipid antibodies (aPL), the most common being represented by anticardiolipin antibodies (aCL), anti-beta 2 glycoprotein-I (aβ2GPI), and lupus anticoagulant (LAC). A growing number of studies have showed that, in some cases, patients may present with clinical features of APS but with temporary positive or persistently negative titers of aPL. For these patients, the definition of seronegative APS (SN-APS) has been proposed. Nevertheless, the negativity to classic aPL criteria does not imply that other antibodies may be present or involved in the onset of thrombosis. The diagnosis of SN-APS is usually made by exclusion, but its recognition is important to adopt the most appropriate anti-thrombotic strategy to reduce the rate of recurrences. This research is in continuous development as the clinical relevance of these antibodies is far from being completely clarified. The most studied antibodies are those against phosphatidylethanolamine, phosphatidic acid, phosphatidylserine, phosphatidylinositol, vimentin/cardiolipin complex, and annexin A5. Moreover, the assays to measure the levels of these antibodies have not yet been standardized. In this review, we will summarize the evidence on the most studied non-criteria aPL, their potential clinical relevance, and the antithrombotic therapeutic strategies available in the setting of APS and SN-APS.

Immune Complexes of Beta-2-Glycoprotein I and IgA Antiphospholipid Antibodies Identify Patients With Elevated Risk of Thrombosis and Early Mortality After Heart Transplantation

Background: The presence of anti-Beta 2 glycoprotein antibodies (aB2GP1) of IgA isotype is common in patients with functional impairment of the organs in which B2GP1 is elaborated. Pretransplant IgA aB2GP1 has been associated with increased risk of thrombosis in kidney and heart transplanted patients and has also been related with early mortality after heart transplantation. Circulating immune complexes between IgA and B2GP1 (B2A-CIC) have been described in the blood of patients positive for IgA aB2GP1 with thrombotic clinical symptoms. In kidney transplanted patients, B2A-CIC is a biomarker that predicts which patients IgA aB2GP1 positive are at risk of thrombosis events following kidney transplantation and may lead to early prophylactic treatment. The prevalence of B2A-CIC and its relation with outcomes after heart transplantation is not known.

Methods: Follow-up study based on 151 consecutive patients who received a heart transplant. Autoantibodies and B2A-CIC were quantified in pre-transplant serum samples. Three groups of patients were followed-up for 2 years: Group-1, positive for IgA aB2GP1 and B2A-CIC (N = 19). Group-2, only positive for IgA aB2GP1 (N = 28). Group-0 (control group): IgA aB2GP1 negative (N = 104).

Results: Kaplan-Meir survival analysis showed that mortality in B2A-CIC positive was higher than group-0 at 3 months (HR:5.08; 95%CI: 1.36–19.01) and at 2 years (HR:3.82; 95%CI: 1.54–12.66). No significant differences were observed between group-2 and group-0. Multivariate analysis identified B2A-CIC as the most important independent risk factor for early mortality (OR = 6.12; 95% CI: 1.93–19.4). Post-transplant incidence of thrombosis was significantly higher in B2A-CIC positive patients than in the control group (OR: 6.42; 95%CI: 2.1–19.63). Multivariate analysis identified the presence of B2A-CIC (OR: 6.13; 95%CI: 2.1–19.63) and the pre-transplant habit of smoking actively (OR: 4.18; 95%CI: 1.35–12.94) as independent risk factor for thrombosis. The proportion of patients who had thrombotic events or died in the first trimester was significantly higher in group-1 (73.7%) than in group-0 (16.3%; p < 0.001) and in group-2 (39.3%; p = 0.02). Multivariate analysis identified B2A-CIC as the main independent risk factor for early outcomes (mortality or thrombosis) in the first 3 months after heart transplant (OR = 11.42, 95% CI: 1.69–9.68).

Conclusion: B2A-CIC are a predictor of early mortality and thrombosis after heart transplant.

EULAR recommendations for the management of antiphospholipid syndrome in adults

The objective was to develop evidence-based recommendations for the management of antiphospholipid syndrome (APS) in adults. Based on evidence from a systematic literature review and expert opinion, overarching principles and recommendations were formulated and voted. High-risk antiphospholipid antibody (aPL) profile is associated with greater risk for thrombotic and obstetric APS. Risk modification includes screening for and management of cardiovascular and venous thrombosis risk factors, patient education about treatment adherence, and lifestyle counselling. Low-dose aspirin (LDA) is recommended for asymptomatic aPL carriers, patients with systemic lupus erythematosus without prior thrombotic or obstetric APS, and non-pregnant women with a history of obstetric APS only, all with high-risk aPL profiles. Patients with APS and first unprovoked venous thrombosis should receive long-term treatment with vitamin K antagonists (VKA) with a target international normalised ratio (INR) of 2-3. In patients with APS with first arterial thrombosis, treatment with VKA with INR 2-3 or INR 3-4 is recommended, considering the individual's bleeding/thrombosis risk. Rivaroxaban should not be used in patients with APS with triple aPL positivity. For patients with recurrent arterial or venous thrombosis despite adequate treatment, addition of LDA, increase of INR target to 3-4 or switch to low molecular weight heparin may be considered. In women with prior obstetric APS, combination treatment with LDA and prophylactic dosage heparin during pregnancy is recommended. In patients with recurrent pregnancy complications, increase of heparin to therapeutic dose, addition of hydroxychloroquine or addition of low-dose prednisolone in the first trimester may be considered. These recommendations aim to guide treatment in adults with APS. High-quality evidence is limited, indicating a need for more research.

Management of thrombotic and obstetric antiphospholipid syndrome: a systematic literature review informing the EULAR recommendations for the management of antiphospholipid syndrome in adults

Objective

To perform a systematic literature review (SLR) informing the European Lmmendations for the management of antiphospholipid syndrome (APS) in adults.

Methods

A SLR through January 2018 was performed. Research questions were constructed using the Patient, Intervention, Comparator, Outcome (PICO) format. We included data from articles that reported on each relevant intervention. Summary effect estimates were calculated for direct comparison studies that matched the PICO question exactly, and for studies with the relevant intervention and comparator. When meta-analyses were available, we used these estimates.

Results

From 7534 retrieved articles (+15 from hand searches), 188 articles were included in the review. In individuals with high-risk antiphospholipid antibody (aPL) profile without prior thrombotic or obstetric APS, two meta-analyses showed a protective effect of low-dose aspirin (LDA) against thrombosis. Two randomised controlled trials (RCTs) and three cohort studies showed no additional benefit of treatment with vitamin K antagonists at target international normalised ratio (INR) 3–4 versus INR 2–3 in patients with venous thrombosis. In patients with arterial thrombosis, two RCTs and two cohort studies showed no difference in risk of recurrent thrombosis between the two target INR groups. One open-label trial showed higher rates of thrombosis recurrences in triple aPL-positive patients treated with rivaroxaban than those treated with warfarin. RCTs and cohort studies showed that combination treatment with LDA and heparin was more effective than LDA alone in several types of obstetric APS. SLR results were limited by the indirect evidence and the heterogeneity of patient groups for some treatments, and only a few high-quality RCTs.

Conclusion

Well-designed studies of homogeneous APS patient populations are needed.

Utility of current thrombophilia screening in young patients with stroke and TIA

Introduction

Approximately 40% of strokes in young adults are cryptogenic. The diagnostic yield of thrombophilia screening remains controversial. We aimed to determine utility of current thrombophilia testing for young patients with stroke and transient ischaemic attack (TIA).

Methods

We present a retrospective review of all patients with stroke and TIA ≤60 years presenting to University College London Hospital stroke unit and daily TIA clinic from 1 January 2015 to 1 August 2016. Consecutive clinical records and thrombophilia tests, including factor V Leiden (FVL), prothrombin G20210A mutation (PGM), antiphospholipid antibody (APA), and protein S, C and antithrombin (AT) levels, were reviewed.

Results

The mean age of 628 patients with stroke and TIA was 49.1 years (SD 9.2). Thrombophilia testing was performed in 360 (57%) patients, including 171 with stroke and 189 with TIA. Positive tests were found in 50 (14%) patients, of whom 24 patients were <50 years. Positive results were found in 36 (10%) with acute ischaemic stroke, 4 (1%) with haemorrhagic stroke and 10 (3%) with TIA. Thirteen patients (4%) had homozygous/heterozygous FVL or PGM, and 27 (7.5%) had positive APA (anticardiolipin antibody, anti-β2 glycoprotein antibody or lupus anticoagulant). Of 27 (7.5%) patients with protein C, S or AT deficiency, 10 (2.8%) had primary deficiency, presumed hereditary with other secondary causes excluded. 9% of patients with protein C, S or AT and 27% with APA were followed by confirmatory testing.

Conclusion

Thrombophilia testing was positive in only 14% of cases overall. Thrombophilia mutations and protein C, S or AT abnormalities were found rarely and were very uncommon in patients with TIA. Follow-up of abnormal results was generally poor for all groups, which further limited the impact of the thrombophilia testing policy.

Phospholipid inhibitors

The antiphospholipid syndrome (APS) is defined by the association of arterial and/or venous thrombosis and/or pregnancy complications with the presence of at least one among the main antiphospholipid antibodies (aPL) (i. e., Lupus anticoagulants, LA, IgG and/ or IgM anticardiolipin antibodies, aCL, IgG and/or IgM antiβ2-glycoprotein I antibodies, aβ2-GPI). Several clinical studies have consistently reported that LA is a stronger risk factor for both arterial and venous thrombosis compared to aCL and aβ2-GPI. In particular, LA activity dependent on the first domain of β2-GPI and triple aPL positivity are associated with the risk of thrombosis and obstetrical complications.

Asymptomatic aPL-positive subjects do not require primary thromboprophylaxis. Venous thromboembolism is the most common initial clinical manifestation of APS. To prevent its recurrence indefinite anticoagulation is recommended. Long duration treatment with warfarin or aspirin is used after a first cerebral arterial thrombosis. Low molecular weight heparin (LMWH) with or without aspirin is recommended to reduce the rate of obstetrical complications of APS pregnant women.

Complement activation in patients with isolated antiphospholipid antibodies or primary antiphospholipid syndrome

The antiphospholipid syndrome (APS) is the association of thrombosis and recurrent pregnancy loss and/or pregnancy morbidity with persistent antiphospholipid antibodies (aPL). Increased complement activation has been implicated in the pathogenesis of APS in animal models. It was our objective to evaluate complement activation in patients with aPL or primary antiphospholipid syndrome (PAPS). We measured complement activation products, fragments Bb and C3a–desArg by ELISA in 186 aPL/PAPS patients and 30 healthy controls. All patients with aPL had significantly increased levels of complement activation products. Fragment Bb levels (mean, 95% CI); (thrombotic APS 0.54 units/ml, 0.31–0.83, obstetric APS 0.60 units/ml,0.39–1.02, isolated aPL 0.48 units/ml, 0.29–0.85, overall 0.39 units/ml, 0.33–0.47) and C3a–desArg levels (mean, 95% CI): (thrombotic APS 261 ng/ml, 219–311, obstetric APS 308 ng/ml, 243–391, isolated aPL 258 ng/ml, 193–337, overall 225 ng/ml, 202–251) were significantly higher compared to controls (fragment Bb 0.06 units/ml, 0.03–0.11, C3a–desArg 69 ng/ml, 50–92). There were correlations between Fragment Bb and C3a–desArg levels in all patients with aPL. Receiver operator characteristic (ROC) analysis showed increased fragment Bb and C3a–desArg levels had strong associations with the presence of persistent lupus anticoagulant (area under ROC: Bb 0.89, and C3a–desArg 0.90), dual and triple aPL positivity (Bb 0.71–0.82, C3a–desArg 0.71–0.80) but not with high titre anti-cardiolipin antibodies (Bb 0.62, C3a–desArg 0.65), or anti β2-glycoprotein 1 antibodies (Bb 0.66, C3a–desArg 0.67). Complement activation is present in all patient groups within this large cohort of patients aPL. This suggests it may have a major role in the pathogenesis of APS and merits further study.

Subsequent Thrombotic Outcomes in Patients with Ischemic Stroke with Antiphospholipid Antibody Positivity

PURPOSE

International consensus criteria for antiphospholipid syndrome (APS) require persistently positive antiphospholipid antibodies (aPL) and medium or high titers in association with clinical manifestations. However, the clinical relevance of persistence and titers of aPL in patients with stroke has not been identified. We aimed to investigate the risk of subsequent thrombotic events in patients with ischemic stroke with aPL positivity in terms of aPL status.

MATERIALS AND METHODS

We reviewed the medical records of 99 patients with ischemic stroke with at least one or more aPL-positivity (i.e., positivity for aCL, anti-β2-glycoprotein-1, and/or lupus anticoagulants). The patients were divided into two groups: "definite APS" who fulfilled the laboratory criteria and "indefinite APS" who fell short of the criteria. We compared the risk of subsequent thrombotic events between the two groups. Cox proportional hazards model and Kaplan-Meier survival curves were used for the analyses.

RESULTS

Of the 99 patients, 46 (46%) were classified as having definite APS and 53 (54%) as having indefinite APS. The mean follow-up was 51.6 months. Overall event numbers were 14 (30.4%) in definite APS and 16 (30.2%) in indefinite APS. Increased subsequent thrombotic events (hazard ratio 1.039; 95% confidence interval 0.449-2.404; p=0.930) and decreased time to thrombotic events (log-rank p=0.321) were not associated with aPL status.

CONCLUSION

There was no increased risk of subsequent thrombotic events in ischemic stroke patients with definite APS, compared with those with indefinite APS.

Hydroxychloroquine in the primary thrombosis prophylaxis of antiphospholipid antibody positive patients without systemic autoimmune disease

Objective The objective of this study was to determine the efficacy of hydroxychloroquine (HCQ) in the primary thrombosis prevention of antiphospholipid antibody (aPL)-positive patients with no other systemic autoimmune diseases. Methods Under the auspices of Antiphospholipid Syndrome Alliance for Clinical Trials and International Networking, a multicenter, international, randomized controlled trial (RCT) was initiated, in which persistently aPL-positive but thrombosis-free patients without systemic autoimmune diseases were randomized to receive HCQ or no treatment in addition to their standard regimen. The primary objective was the efficacy of HCQ in preventing the first thrombosis. The secondary objectives were the thrombosis incidence rate, and the effects of HCQ on aPL profile and mortality rate. Patients were risk-stratified based on antiplatelet agent use. The goal was to follow patients every 6 months for 5 years. Results We recruited 20 persistently aPL-positive patients (female: 19, mean age: 46.6 ± 9.9 years, and baseline antiplatelet medication: 14); 9/20 were randomized to HCQ. During the mean follow-up of 1.7 years, no patients developed thrombosis or a serious adverse event. The study was terminated early due to the low recruitment rate, exacerbated by the prolonged manufacturing shortage and significant price increase of HCQ in the United States. Conclusion Given that a small number of patients with a relatively short follow-up were enrolled in our RCT, and no patients developed thrombosis, we cannot accurately assess the effectiveness of HCQ for primary thrombosis prevention in persistently aPL-positive patients with no other systemic autoimmune diseases. Our experience suggests that conducting an international RCT, especially without pharmaceutical support, is an extremely challenging undertaking.

Incidence of thromboembolic events in asymptomatic carriers of IgA anti ß2 glycoprotein-I antibodies

BACKGROUND

The antiphospholipid syndrome (APS) is defined by simultaneous presence of vascular clinical events and antiphospholipid antibodies (aPL). The aPL considered as diagnostics are lupus anticoagulant and antibodies anticardiolipin (aCL) and anti-ß2 glycoprotein-I (aB2GP1). During recent years, IgA aB2GP1 antibodies have been associated with thrombotic events both in patients positive, and mainly negative for other aPL, however its value as a pro-thrombotic risk-factor in asymptomatic patients has not been well defined.

OBJECTIVE

To test the role of IgA anti B2GP1 as a risk factor for the development of APS-events (thrombosis or pregnancy morbidity) in asymptomatic population with a 5-year follow-up.

METHODS

244 patients isolated positive for anti-beta2-glycoprotein I IgA (Group-1 study) and 221 negative patients (Group-2 control) were studied. All the patients were negative for IgG and IgM aCL.

RESULTS

During the follow-up, 45 patients (9.7%) had APS-events, 38 positive for IgA-aB2GP1 and 7 negative (15.6% vs 3.2%, p<0.001). The incidence rate of APS-events was 3.1% per year in IgA-aB2GP1 positive patients and 0.6% per year in the control group. Arterial thrombosis were the most frequent APS-events (N = 25, 55%) and were mainly observed in Group-1 patients (21 vs 4, p = 0.001). Multivariate analysis were shown as independent risk-factors for the development of APS-events, age, sex (men) and presence of IgA-aB2GP1 (odds ratio 5.25, 95% CI 2.24 to 12.32).

CONCLUSION

The presence of IgA-aB2GP1 in people with no history of APS-events is the main independent risk factor for the development of these types of events, mainly arterial thrombosis.

Anticoagulation withdrawal in antiphospholipid syndrome: a retrospective matched-control study

Background/Purpose

Long-term anticoagulation is the standard treatment for thrombotic antiphospholipid syndrome (APS). However, in daily practice, the question of withdrawing anticoagulation may arise, without any evidence-based recommendations. This study aimed to assess outcomes in APS patients after anticoagulation withdrawal.

Methods

Thrombotic APS patients followed in our centre, whose anticoagulation was withdrawn after APS diagnosis, were retrospectively selected, and were match-controlled with patients under anticoagulation, based on sex, age, APS clinical phenotype and disease duration.

Results

Thirty cases with anticoagulation withdrawal were included. Median follow-up was 51 months (12–124). The risk of thrombotic relapse was higher in cases compared to controls (7.3% versus 1.5% patient-year ( p = 0.01); hazard ratio 4.8; 95% confidence interval (1.4–16.7)). Male gender, anti-β2GP1 and triple positivity at inclusion were predictive factors for thrombotic relapse. Conversely, aspirin prescription was a protective factor against relapses. Persistence of LA, anti-β2GP1 and triple positivity over time were associated with a higher risk of thrombosis and aPL disappearance with a lower risk.

Conclusion

In our study, anticoagulation withdrawal was associated with an increased risk of thrombotic relapse. Our findings emphasize the influence of anti-β2GP1 and triple positivity persistence over time on the risk of relapse and the benefit of aspirin prescription when anticoagulation has been withdrawn.

Diagnosis and treatment of antiphospholipid syndrome in childhood: A review

The antiphospholipid syndrome (APS) is a multisystem autoimmune disease characterized by recurrent fetal loss and thromboembolic events associated with the presence of elevated titres of antiphospholipid antibodies (aPL). The purpose of this review is to summarize what is currently known about the diagnosis and treatment of pediatric APS, to highlight key differences between APS presenting in adults versus children throughout, and to identify areas where future research is needed.

Prevention of thrombosis in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an acquired autoimmune condition characterized by thrombotic events, pregnancy morbidity, and laboratory evidence of antiphospholipid antibodies (aPL). Management of these patients includes the prevention of a first thrombotic episode in at-risk patients (primary prevention) and preventing recurrent thrombotic complications in patients with a history of thrombosis (secondary prevention). Assessment of thrombotic risk in these patients, balanced against estimated bleeding risks associated with antithrombotic therapy could assist clinicians in determining whether antithrombotic therapy is warranted. Thrombotic risk can be assessed by evaluating a patient's aPL profile and additional thrombotic risk factors. Although antithrombotic options for secondary prevention of venous thromboembolism (VTE) have been evaluated in clinical trials, studies in primary prevention of asymptomatic aPL-positive patients are needed. Primary prevention with aspirin may be considered in asymptomatic patients who have a high-risk aPL profile, particularly if additional risk factors are present. Secondary prevention with long-term anticoagulation is recommended based on estimated risks of VTE recurrence, although routine evaluation of thrombotic risk can assist in determining whether ongoing anticoagulation is warranted. Studies that stratify thrombotic risk in aPL-positive patients, and patients with APS evaluating antithrombotic and non-antithrombotic therapies will be useful in optimizing the management of these patients.

The antiphospholipid syndrome in patients with systemic lupus erythematosus

The antiphospholipid syndrome (APS) is an autoimmune disease characterized by the occurrence of venous and/or arterial thrombosis and pregnancy morbidity in the presence of pathogenic autoantibodies known as antiphospholipid antibodies (aPL). APS may be associated with other diseases, mainly systemic lupus erythematosus (SLE). The presence or absence of SLE might modify the clinical or serological expression of APS. Apart from the classical manifestations, APS patients with associated SLE more frequently display a clinical profile with arthralgias, arthritis, autoimmune hemolytic anemia, livedo reticularis, epilepsy, glomerular thrombosis, and myocardial infarction. The management of patients with SLE and APS/aPL should include an accurate stratification of vascular risk factors. Low dose aspirin and hydroxychloroquine should be considered as primary prophylaxis. In high risk situations, such as surgery, prolonged immobilization, and puerperium, the prophylaxis should be potentiated with low molecular weight heparin. The challenge of treating patients with a previous vascular event (secondary prophylaxis) is the choice of treatment (anti-platelet agents, anticoagulation with vitamin K antagonists or combined therapy) and its duration, based on individual risk stratification and the site of vascular presentation. The role of novel anticoagulants in APS patients is still to be clearly defined. Novel approaches are needed since the prognosis of SLE patients with APS/aPL is still worse than that of SLE patients with negative aPL. The goal for the future is to improve the outcome of these patients by means of early recognition and optimal preventative treatment.

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.

IgG/IgM antiphospholipid antibodies present in the classification criteria for the antiphospholipid syndrome: a critical review of their association with thrombosis

Essentials The clinical value of IgM antibodies in thrombotic antiphospholipid syndrome (APS) is debated. By review of literature, we reconsidered the clinical value of IgM antibodies in thrombotic APS. More significant correlations with thrombosis were found for the IgG compared to IgM isotype. Unavailability of paired IgG/IgM results hampers evaluating the added value of IgM positivity. Click to hear Dr de Groot's perspective on antiphospholipid syndrome

SUMMARY

Background Despite the update of the classification criteria for the antiphospholipid syndrome (APS), difficulties persist in the identification of patients at risk for thrombosis. Current guidelines include assays detecting IgG/IgM anti-β2 -glycoprotein I and anti-cardiolipin antibodies, although the relevance of IgM antibodies has been debated. Objectives Through a review of the literature from 2001 to 2014, we aimed to formally establish the thrombotic risk stratification potential of IgM as compared with IgG anti-phospholipid antibodies (aPLs). Patients/methods One thousand two hundred and twenty-eight articles were selected by a computer-assisted search of the literature. Of the 177 studies that met our inclusion criteria, the clinical value of IgG/IgM aPLs was established through analysis of odds ratios for thrombosis or percentage of positives in the thrombotic population. Results/conclusions We clearly found more significant correlations with thrombosis for the IgG than for the IgM isotype. Nonetheless, in a minority of studies, significant associations with thrombosis were found for IgM but not IgG antibodies. The unavailability of paired results of IgG and IgM for each separate patient hampers evaluation of the added value of isolated IgM positivity. To fully take advantage of results obtained by future studies, we strongly encourage scientists to provide all studied information per patient. We planned a large multicenter study to investigate clinical associations of isolated/combined positivity for criteria/non-criteria aPLs. Importantly, because of the presence of non-pathogenic aPLs, quantitative assays are characterized by a high false-positivity rate. Optimization of functional assays, such as thrombin generation measuring the whole scheme of coagulation, may help to reduce APS-related morbidity and mortality.

Persistent triple antiphospholipid antibody positivity as a strong risk factor of first thrombosis, in a long-term follow-up study of patients without history of thrombosis or obstetrical morbidity

Introduction The long-term risk of first thrombosis and benefit of prophylaxis in antiphospholipid antibody (aPL) carriers without history of thrombosis or obstetrical morbidity is poorly known. This study aimed to evaluate the long-term rate and risk factors associated with a first thrombosis in those patients. Patients and methods After a prior study ended in December 2005 and was already published, we extended the follow-up period of our cohort of aPL carriers. Results Ninety-eight of the 103 patients of the previous study were included. The annual first thrombosis rate was 2.3% per patient-year during a median of 13 years (6-17). None of the baseline characteristics was predictive of risk of first thrombosis, but persistent aPL over time were associated with an increased risk. The stronger association was found in triple aPL-positive carriers: OR 3.38 (95% CI: 1.24-9.22). Of note, conversely to our previous findings, no benefit of aspirin prophylaxis was observed. Conclusion The risk of first thrombosis in aPL carriers without history of thrombosis or obstetrical morbidity was significant, persisted linearly over time and was associated with persistent aPL. This risk was especially increased in triple aPL-positive carriers, in whom a close follow-up seems to be necessary. Nevertheless, the benefit of aspirin prophylaxis remained unclear.

[Lupus anticoagulant: two cases report and literature review]

OBJECTIVE

To deepen the understanding of clinical manifestations and treatment of patients with positive lupus anticoagulant (LAC).

METHODS

The clinical data of 2 patients were analyzed and related literature were reviewed.

RESULTS

Case 1, a 31-year-old female, diagnosed as lupus anticoagulant positive, secondary to undifferentiated connective tissue disease, was presented with menorrhagia and thrombocytopenia. Anti-nuclear antibody (ANA) was positive 1:1000 (homogeneous type) with anti-double stranded DNA positive, and dRVVT LA1/LA2 was 3.4. Coagulation function was alleviated after treatment with glucocorticoid and total glucosides of paeony. Case 2, a 59-year-old female was presented with gingival bleeding, hematuria with the level of F II:C 13%. dRVVT LA1/LA2 was 2.0. Anti-nuclear antibody (ANA) was positive 1:1000 (type of cytoplasmic granule), anti-double stranded DNA was positive. The patient was diagnosed as hypoprothrombinemia-lupus anticoagulant syndrome (LAHS) and acquired coagulation factor deficiency. The signs of hemorrhage were alleviated after treatment with methylprednisolone 40 mg/day and cyclophosphamide, while the level of F II:C was below normal.

CONCLUSION

Symptoms of patients with positive LAC are variable. The diagnosis relies on history of disease and laboratory test. Currently, there is no standardized treatment. Cases of LAHS should be thoroughly investigated for any known causes and related disorder.

The IgM isotype of anti-annexin A5 antibodies and multiple positivity of conventional antiphospholipid antibodies: increasing the number of clinical manifestations of primary antiphospholipid syndrome

We evaluated the importance of anti-annexin A5 antibodies (aanxA5 Abs) for clinical (thrombosis and/or recurrent pregnancy loss) and serologic (presence of antiphospholipid antibodies: lupus anticoagulant (LA), anticardiolipin (aCL), and anti-β2 glycoprotein I (aβ2GPI) antibodies) features of patients with primary antiphospholipid syndrome (PAPS). Our study included 70 patients with PAPS according to the international consensus criteria for APS. The mean age of the analyzed patients was 45.97 ± 12.72. The disease duration above 5 years was present in 31/70 of patients. Concentrations of analyzed antibodies were measured by ELISA. Cutoff values were set in accordance to the manufacturers' recommendations. History of recurrent pregnancy loss was associated with double positivity for aanxA5 IgM and LA (χ (2) = 4.000, P = 0.046) and triple positivity for aanxA5 IgM + LA + aβ2GPI IgM (χ (2) = 4.168, P = 0.041). Venous thromboses were associated with triple positivity for aanxA5 IgM + aCLIgG + aβ2GPI IgM (χ (2) = 3.965, P = 0.046). The IgG isotype of aanxA5 Abs was in positive correlation with aCL Abs of the IgG (r = 0.310, P = 0.009) and IgM (r = 0.254, P = 0.034) isotype. The presence of the clinical manifestations of PAPS is increasing with the number of positive conventional aPL and the IgM aanxA5 Abs tests. This new combination of Abs is beneficial even when the number of patients with positivity for aanxA5 Abs is low. This is important in further detection of patients prone to recurrence of thrombotic episodes.

The challenges of lupus anticoagulants

The term "lupus anticoagulant" (LA) refers to a heterogeneous group of immunoglobulins behaving as acquired in vitro inhibitors of coagulation. These antibodies, namely anti-β2GPI and anti-prothrombin antibodies, induce the in vitro elongation of clotting time interfering with phospholipid-dependent coagulation cofactors. Positive LA is associated with thrombosis and pregnancy complications, providing one of the three laboratory criteria for the classification of the anti-phospholipid syndrome. LA is the strongest predictor of clinical events, especially when associated with other anti-phospholipid antibodies. Much more controversial is the risk conveyed by isolated and weak LA. LA detection is technically laborious, envisaging screening, mixing and confirming tests. Hopefully critical issues in LA detection, such as the interference of anticoagulants, will be overcome, in the next future.

Influence of the serum levels of immunoglobulins on clinical outcomes in medical intensive-care patients

INTRODUCTION

Endogenous immunoglobulins (Igs) are of fundamental importance in the host defense after microbial infections. However, the therapeutic administration of intravenous IgG (IVIgG) has not yet been shown to improve clinical outcomes in patients suffering from sepsis, and in the case of IgM-containing preparations (IVIgGMA) the positive evidence is only weak. Recently published studies implicate that Ig levels on admission could have an impact on the patient's response to IVIg treatment and on outcomes of critically ill patients.

METHODS

In this noninterventional study, the serum levels of IgG, IgM, and IgA were determined in 340 medical patients on ICU admission, and clinical outcomes were prospectively recorded (ICU mortality, need for renal replacement therapy (RRT), need for mechanical ventilation, substitution of coagulation factors, and amount of red cell transfusions). Patients were prospectively grouped according to their main reason for ICU admission (sepsis, respiratory failure, cardiovascular diseases, acute renal failure, postoperative condition, state after cardiopulmonal resuscitation, gastrointestinal diseases, and others).

RESULTS AND DISCUSSION

There was no correlation between the Ig levels on admission and ICU mortality neither in the total cohort of medical ICU patients nor in any prespecified subgroup. However, in a logistic regression model that was adjusted for APACHE II score on admission, an increase in serum IgG was associated with a reduced need for mechanical ventilation in patients suffering from cardiovascular disease. On the other hand, in patients suffering from sepsis, an increased level of IgM was linked to an increased administration of coagulation factors.

CONCLUSION

Our data do not support the hypothesis that serum levels of immunoglobulins are linked to mortality in medical ICU patients.

Antiphospholipid Antibodies and Recurrent Thrombotic Events: Persistence and Portfolio

BACKGROUND

There are very limited prospective data on the significance of persistent antiphospholipid antibodies (aPL) and recurrent thrombo-occlusive events (TOEs). We investigated the prognostic value of (1) 2 newer aPL assays, (2) an aPL portfolio and (3) persistent aPL positivity following stroke.

METHODS

A total of 1,770 subjects from the APASS-WARSS study underwent further aPL testing for antibodies to phosphatidylserine (aPS) and anti-β2-glycoprotein-I (anti-β2GPI) from stored sera. Follow-up aPL status was also tested in a subset of subjects. Primary analysis was based on time to any TOE (ischemic stroke, myocardial infarction, transient ischemic attack, deep vein thrombosis, pulmonary embolism or systemic arterial occlusion)/death at 2 years. Cox proportional hazard analyses assessed whether aPL independently related to outcome.

RESULTS

Persistent anti-β2GPI decreased the time to TOE/death after adjustment for potential confounders (hazards ratio (HR) 2.86, 95% CI 1.21-6.76, p = 0.017). When persistent anti-β2GPI was combined with another persistently positive aPL, time to TOE/death was also reduced (HR 3.79, 95% CI 1.18-12.14, p = 0.025). Neither persistent anticardiolipin antibodies nor persistent aPS alone nor a single positive anti-β2GPI nor aPS was associated with decreased time to TOE/death. No single positive aPL, portfolio of baseline aPL or any persistent aPL increased the rate of TOE/death.

CONCLUSIONS

Rates of TOE/death were not influenced by aPL results at baseline or follow-up. Persistent anti-β2GPI alone, and with persistent second aPL, was independently associated with decreased time to TOE/death. Persistent aPL, an aPL portfolio and newer aPL in ischemic stroke patients are not helpful in predicting an increased rate of recurrent TOEs.

Increased Performances of the Biological Diagnosis of the Antiphospholipid Syndrome by the Use of a Multiplex Assay

Antiphospholipid syndrome (APS) is characterized by development of venous and/or arterial thrombosis and pregnancy morbidity. Biological criteria are the persistent presence of lupus anticoagulant (LA) and/or anti-cardiolipin (aCL) and/or anti-B2GP1 autoantibodies' positivity. The assays' performances are of crucial importance. We evaluated a multiplex assay allowing simultaneous detection of IgG anti-cardiolipin, anti-B2GP1, and anti-factor II. 300 samples were tested. Patients were categorized according to clinical scores of APS from 0 to 3 based on presence or not of arterial or venous thrombosis, fetal loss, and autoimmunity. We used a multiplex assay for APS for simultaneous detection of aCL, anti-B2GP1, and factor II and compared its performances to ELISA assays. Presence of LA was also assessed. We performed a correlation study of the tested assays and compared their clinical efficacy by ROC curve analysis. We obtained significantly higher performances with the multiplex assay than ELISA with higher area under the curve (AUC). The disease rate increased with the number of positive markers from 9% for 1 marker to 100% for 4 markers positive for patients with high risk scores. The multiplex APS assay exhibited higher performances particularly in case of primary APS and is useful for rapid diagnosis of APS.

"New" antigenic targets and methodological approaches for refining laboratory diagnosis of antiphospholipid syndrome

Antiphospholipid antibodies (aPLs) are a heterogeneous group of antibodies directed against phospholipids or protein/phospholipid complexes. Currently, aPLs are assessed using either "solid-phase" assays that identify anticardiolipin antibodies and anti-β2-glycoprotein I antibodies or "liquid-phase" assay that identifies lupus anticoagulant. However, in the last few years, "new" antigenic targets and methodological approaches have been employed for refining laboratory diagnosis of antiphospholipid syndrome (APS). In this review the potential diagnostic value of antibodies to domains of β2-GPI, prothrombin/phosphatidylserine, vimentin/cardiolipin, protein S, protein C, annexin A2, annexin A5, and phospholipid antigens is discussed. Moreover, new technical approaches, including chemiluminescence, multiline dot assay, and thin layer chromatography (TLC) immunostaining, which utilize different supports for detection of aPL, have been developed. A special focus has been dedicated on "seronegative" APS, that is, those patients with a clinical profile suggestive of APS (thromboses, recurrent miscarriages, or foetal loss), who are persistently negative for the routinely used aPL. Recent findings suggest that, in sera from patients with SN-APS, antibodies may be detected using "new" antigenic targets (mainly vimentin/cardiolipin) or methodological approaches different from traditional techniques (TLC immunostaining). Thus, APS represents a mosaic, in which antibodies against different antigenic targets may be detected thanks to the continuously evolving new technologies.

New tests to detect antiphospholipid antibodies: antiprothrombin (aPT) and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies

Antiprothrombin antibodies have been proposed as potential new biomarkers for thrombosis and/or pregnancy morbidity in the setting of the antiphospholipid syndrome (APS). Antiprothrombin antibodies are commonly detected by ELISA, using prothrombin coated onto irradiated plates (aPT), or prothrombin in complex with phosphatidylserine (aPS/PT), as antigen. Although these antibodies can co-exist in the same patient, aPT and aPS/PT seem to belong to different populations of autoantibodies. Early research explored the role of antibodies to prothrombin as potential antigenic targets for the lupus anticoagulant (LA). To date their clinical significance is being investigated and their potential role in identifying patients at higher risk of developing thrombotic events or pregnancy morbidity is being probed.

Multiple antiphospholipid antibodies positivity and antiphospholipid syndrome criteria re-evaluation

The antiphospholipid syndrome (APS) is characterized by the presence of aPL and thrombosis and/or pregnancy morbidity. The last APS laboratory classification criteria include the presence of at least one of the antiphospholipid antibodies (aPL) [lupus anticoagulant (LA), anticardiolipin (aCL) and/or anti-β2 glycoprotein I antibodies (aβ2GPI)] and introduced the concept of subclassification of APS patients into two different categories of aPL assay positivity (combination or single aPL). Several studies have recently shown that the risk for thrombosis increases with each additional aPL detected. We found that the presence of IgG antibodies to β2GPI and/or prothrombin increased thrombotic risk in patients with LA and/or aCLin a prospective study. Various studies have recently demonstrated that patients with triple positivity (LA, aCL and aβ2GPI) are at the highest risk for venous and arterial thrombosis and for obstetric complications. In retrospective but also in prospective studies the rate of thrombotic recurrence was high in subjects with triple positivity even while on anticoagulant therapy. In addition, the occurrence of a first thrombotic event in asymptomatic carriers of triple positivity was higher than in those with single aPL positivity. The inclusion of the detection of antibodies against domain I of β2GPI and/or antibodies to prothrombin would probably help to further identify more clinically relevant aPL. Based on the last findings, there are some proposals to consider only patients with triple positivity as definite APS (thrombotic and obstetric).

Persistent antiphospholipid antibody (aPL) in asymptomatic carriers as a risk factor for future thrombotic events: a nationwide prospective study

Objectives

The long-term prognosis of individuals fulfilling the laboratory criteria, but not clinical criteria, of antiphospholipid syndrome (APS) has not been widely investigated. The primary aim of this study was to evaluate the incidence of first thrombotic event (deep venous thrombosis (DVT), pulmonary embolism (PE), myocardial infarction (MI), stroke or transient ischaemic attack (TIA) in a nationwide antiphospholipid antibody (aPL) carrier cohort.

Design

We conducted a prospective nationwide cohort study.

Setting

The aPL profile of participants was recorded from the laboratory database. Information was collected about thrombotic and pregnancy complications, subsequent medical history, other risk factors for thrombosis, use of prophylactic antithrombotic medication and general health.

Participants

Participants included adult asymptomatic aPL carriers recognized in Finland during 1971–2009.

Main outcome measure

The main outcome measure was incidence of first thrombotic event.

Results

A total of 119 (89% female) aPL carriers were followed for mean (SD) of 9.1 (7.5) years (range 3–41 years). Sixty-one per cent of the study participants had autoimmune disease, most often systemic lupus erythematosus (SLE). Thirty-six of 119 (30%) were either double or triple positive, 56% single lupus anticoagulant (LA) positive, and 8% and 5% single anticardiolipin antibodies (aCL) and anti-β2glycoprotein I antibodies (aβ2GPI) positive, respectively. Nine (7.6%) study patients experienced a first thrombotic event (five DVT, one PE, two MI, one TIA) mean (SD) 7.2 (8.3) years (range 1–26 years) after aPL detection (annual incidence rate 0.8%). All individuals who developed thrombotic complications had autoimmune disease. Annual rate of first thrombotic event in carriers of single positivity (0.65%) was equal to the known risk of thrombosis in the healthy Caucasian population, whereas the rate was two times higher in carriers of double or triple positivity (1.27%). Sixteen of 79 (20%) women experienced pregnancy complications.

Conclusions

Double or triple positivity for aPL is a risk factor for future thrombotic events, especially in individuals with an underlying autoimmune disease, whereas single positivity does not seem to carry an elevated risk of thrombosis.