The IgG and IgM isotypes of anti-annexin A5 antibodies: relevance for primary antiphospholipid syndrome

Preconception anti-annexin A5 antibodies are associated with subsequent live birth in women with recurrent miscarriage: A retrospective study from China

PROBLEM

To evaluate the correlation between the antiannexin A5 antibodies (aAnxA5) multiples of median (MOM) and subsequent pregnancy outcomes in women with recurrent miscarriage (RM).

METHODS

Totally, 310 RM women were included in this study and grouped into tertiles according to their MOM of preconception aAnxA5 circulating levels determined by ELISA. The effect of aAnxA5 on the pregnancy outcomes was performed using multiple logistic regression. The outcomes included early miscarriage (before 10 weeks of gestation), late miscarriage (between 10 and 24 weeks), ongoing pregnancy (beyond 10 weeks), and live birth (after 24 weeks) characterized by pregnancy with fetal heartbeat.

RESULTS

For each unit increase in aAnxA5 MOM, the odds of live birth after 24 weeks and ongoing pregnancy were reduced by 40.2% (OR = .598; 95%CI 0.406-0.882, P = .010) and 38.1% (OR = .619; 95%CI 0.424-0.904, P = .013), respectively, after adjusting for demographic and clinical characteristics. The rise in aAnxA5 MOM was associated with an increased risk of early miscarriage (OR = 1.616; 95%CI 1.106-2.361, P = .013) and miscarriage (early + late miscarriage) (OR = 1.671; 95%CI 1.134-2.464, P = .010). Further subgroup analyses showed a decreased risk of live birth rates after 24 weeks of gestation in the two subgroups: maternal age ≥35 years (OR = .131; 95%CI 0.026-0.652), and previous pregnancy loss ≥ 3 (OR = .381; 95%CI 0.173-0.837).

CONCLUSIONS

Higher preconception aAnxA5 MOM levels in women with RM may be linked with a decreased risk of live birth after 24 weeks and an increased risk of early miscarriage, especially in individuals aged ≥35 years or with previous pregnancy losses ≥3.

Preconception Non-criteria Antiphospholipid Antibodies and Risk of Subsequent Early Pregnancy Loss: a Retrospective Study

The aim of this study was to investigate the subsequent early pregnancy outcomes in women positive for non-criteria antiphospholipid antibodies (NC-aPLs) before pregnancy. A total of 273 patients who had experienced sporadic or recurrent pregnancy loss and had been screened for 13 NC-aPLs at preconception were recruited in this study from September 2019 to February 2022. Serum levels of NC-aPLs were measured by ELISA using specific kits. The primary outcome was early pregnancy loss, and the secondary outcomes were biochemical pregnancy, clinically confirmed pregnancy loss, and ongoing pregnancy. Among these subjects, 56 patients had one previous pregnancy loss, and 217 had recurrent pregnancy loss (RPL). The NC-aPLs (+) and NC-aPLs (-) groups had similar rates of early pregnancy loss (EPL) after adjustment, regardless of the number of positive NC-aPLs (aOR = 1.054, 95% CI 0.602-1.846). Other outcomes were comparable in both groups, including the rates of biochemical pregnancy (aOR = 1.344, 95% CI 0.427-4.236), clinically confirmed pregnancy loss (aOR = 0.744, 95% CI 0.236-2.344), and ongoing pregnancy (aOR = 0.949, 95% CI 0.542-1.660). Based on sensitivity analysis, the NC-aPLs (+) were not associated with adverse early pregnancy outcomes in women with RPL. Furthermore, the difference in gestational weeks of pregnancy loss between the two groups was also insignificant. This study found no evidence linking preconception NC-aPL positivity to early pregnancy outcomes but offers a reference for future research to clarify NC-aPLs' potential clinical impact.

The Effect of COVID-19 Severity, Associated Serum Autoantibodies and Time Interval after the Disease on the Outcomes of Fresh Oocyte ART Cycles in Non-Vaccinated Patients

It is assumed that SARS-CoV-2- and COVID-19-associated autoimmune processes may affect the outcomes of assisted reproductive technology (ART) cycles. This observational prospective study included 240 infertile patients: 105 patients had no history of COVID-19 (group 1) and 135 patients had experienced COVID-19 (group 2) in a mild (n = 85) or moderate (n = 50) form less than 12 months prior to oocyte retrieval. Using ELISAs, the profiles of their serum autoantibodies were determined, including antiphospholipid antibodies and antibodies to nuclear and thyroid antigens. The parameters of oogenesis and embryogenesis, as well as the pregnancy and childbirth rates, did not differ between groups 1 and 2, and also between the subgroups with different severities of COVID-19. However, when oocyte retrieval was performed less than 180 days after COVID-19, a higher proportion of poor-quality blastocysts was obtained (p = 0.006). A high risk of early miscarriage was found in the patients with moderate COVID-19. In group 2, IgG antibodies to annexin V, phosphatidylethanolamine (PE), and TSHr were detected more often than in group 1 (p = 0.035; p = 0.028; and p = 0.033, respectively), and a weak inverse correlation was revealed between anti-PE IgG and the number of oocytes and zygotes obtained. The results of the study suggest a possible adverse effect of COVID-19 and its associated autoantibodies on the outcomes of fresh oocyte ART cycles and early pregnancy, which depends on the severity of COVID-19 and the time interval after the disease.

The Weight of IgA Anti-β2glycoprotein I in the Antiphospholipid Syndrome Pathogenesis: Closing the Gap of Seronegative Antiphospholipid Syndrome

The specific value of IgA Anti-β2glycoprotein I antibodies (aB2GP1) in the diagnosis and management of antiphospholipid syndrome (APS) is still controversial and a matter of active debate. The relevance of the IgA aB2GP1 isotype in the pathophysiology of APS has been increasingly studied in the last years. There is well know that subjects with multiple positive APS tests are at increased risk of thrombosis and/or miscarriage. However, these antibodies are not included in the 2006 APS classification criteria. Since 2010 the task force of the Galveston International Congress on APS recommends testing IgA aB2GP1 isotype in patients with APS clinical criteria in the absence of criteria antibodies. In this review, we summarize the molecular and clinical “state of the art” of the IgA aB2GP in the context of APS. We also discuss some of the characteristics that may help to evaluate the real value of the IgA aB2GP1 determination in basic research and clinical practice. The scientific community should be aware of the importance of clarifying the role of IgA aB2GP1 in the APS diagnosis.

Non-criteria Antiphospholipid Antibodies: a narrative review

SUMMARY The 2006 Revised Sapporo Classification Criteria for Definite Antiphospholipid Syndrome included as laboratory criteria the tests for antiphospholipid antibodies whose accuracy was regarded as satisfactory according to the evidence available at that time. In practice, however, the sensitivity and specificity of these “criteria” of antiphospholipid antibodies are sometimes insufficient for identifying or ruling out antiphospholipid syndrome. It has been studied whether the accuracy of the laboratory diagnosis of the syndrome could be improved by testing for non-criteria antiphospholipid antibodies. In this work, we review evidence on the clinical associations and diagnostic value of the most commonly studied non-criteria antibodies, namely: antiphosphatidylethanolamine, anti-annexin A5, anti-prothrombin, anti-phosphatidylserine/prothrombin complex, IgA anticardiolipin, and IgG anti-domain I of the β2 glycoprotein antibodies.

Reduced Annexin A3 in schizophrenia

The cellular and molecular mechanisms underlying onset and development of schizophrenia have not yet been completely elucidated, but the association of disturbed neuroplasticity and inflammation has gained particular relevance recently. These mechanisms are linked to annexins functions. ANXA3, particularly, is associated to inflammation and membrane metabolism cascades. The aim was to determine the ANXA3 levels in first-onset drug-naïve psychotic patients. We investigated by western blot the protein expression of annexin A3 in platelets of first-onset, drug-naïve psychotic patients (diagnoses according to DSM-IV: 28 schizophrenia, 27 bipolar disorder) as compared to 30 age- and gender-matched healthy controls. Annexin A3 level was lower in schizophrenia patients as compared to healthy controls (p < 0.001) and to bipolar patients (p < 0.001). Twenty out of 28 schizophrenic patients had undetectable annexin A3 levels, as compared to none from the bipolar and none from the control subjects. ANXA3 was reduced in drug-naïve patients with schizophrenia. ANXA3 affects neuroplasticity, inflammation and apoptosis, as well as it modulates membrane phospholipid metabolism. All these processes have been discussed in regard to the biology of schizophrenia. In face of these data, we feel that further studies with larger samples are warranted to investigate the possible role of reduced ANXA3 as a possible risk marker for schizophrenia.

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.

Antiphospholipid syndrome – an update

Abstract. Antiphospholipid syndrome (APS) is an autoantibody-mediated acquired thrombophilia. It is characterized by the presence of antiphospholipid antibodies (APL) that are directed against phospholipid-binding plasma proteins, such as beta-2-glycoprotein I (b2GPI). Its main manifestations are recurrent vascular thromboses (so-called “thrombotic APS”) and pregnancy complications (“obstetric APS”). According to the current consensus criteria, a persistently positive functional lupus anticoagulant (LA) assay and/or the presence of anti-b2GPI and/or anti-cardiolipin antibodies, together with clinical symptoms, is mandatory for the diagnosis of APS. Other clinical features, such as thrombocytopenia, Coombs-positive haemolytic anaemia, heart valve disease, renal microangiopathy and neurologic disorders are also common in APL-positive patients. APS can be associated with other autoimmune disorders, such as systemic lupus erythematosus. In rare cases, catastrophic APS (CAPS) occurs, with the development of excessive thrombosis at multiple sites, usually affecting small vessels and leading to multi-organ dysfunction and organ failure. Treatment usually comprises antithrombotic therapy using antiplatelet and anticoagulant agents. However, there is no consensus concerning the intensity or duration of therapy. Despite apparently adequate anticoagulation, the risk of recurrent thrombosis remains high. For patients with CAPS, a combined therapeutic approach that includes anticoagulation, glucocorticoids, plasma exchange and/or intravenous immunoglobulin seems to be the best treatment option.

Keywords: Antiphospholipid syndrome, lupus anticoagulants, anti-cardiolipin, anti-beta-2-glycoprotein I, vascular thrombosis, pregnancy complication

Insights into the diagnosis and pathogenesis of the antiphospholipid syndrome

The Antiphospholipid syndrome (APS), formerly known as Anticardiolipin or Hughes syndrome, is a systemic autoimmune disorder characterized by obstetrical complications and thrombotic events affecting almost every organ-system in patients persistently testing positive for antiphospholipid antibodies (aPL). The contribution of the extra-criteria aPL to the pathogenesis of APS have exceeded the expectations of a simple, direct pathologic 'hit' leading to thrombogenesis or obstetrical complications, and more pathologic pathways are being linked directly or indirectly to aPL. The value of extra-criteria aPL is on the rise, and these antibodies are nowadays evaluated as markers for risk assessment in the diagnostic approach to APS. A diagnosis of APS should be considered in pediatric patients with suggestive clinical and laboratory picture. Management of APS remains mostly based on anticoagulation, while other drugs are being tested for efficacy and side effects. Low-dose aspirin may have a role in the management of thrombotic and obstetric APS. Due to the high variability in disease severity and complication recurrence outcomes, new tools are being developed and validated to assess the damage index and quality of life of APS patients.

Anti-annexin A5 antibodies and 25-hydroxy-cholecalciferol in female patients with primary antiphospholipid syndrome

Vascular antiphospholipid syndrome (VAPS) and obstetric (OAPS) are different entities because some patients only develop thrombosis (without recurrent pregnancy losses) and vice versa. Only two articles have reported that low 25-hydroxy-cholecalciferol (vitamin D3, VD3) levels were not correlated with the presence of conventional antiphospholipid antibodies (aPL Abs: anticardiolipin (aCL), anti-beta2glycoprotein I (aβ2gpI), and lupus anticoagulant (LA)), but no article analyzed the association of VD3 and anti-annexin A5 (aanxA5) Abs. The aim of our study was to investigate the association between VD3, multiple positivity of conventional aPL and aanxA5 Abs levels only in female OAPS vs. VAPS. Our study included 62 consecutive female PAPS patients. Concentrations of Abs were measured by ELISA, while VD3 levels were determined by immunochemiluminescence. Only 10/62 (16.13%) had sufficient (≥ 30 ng/ml) VD3 levels, while 48/62 (77.42%) and 4/62 (6.45%) had insufficiency and VD3 deficiency, respectively. Statistically significant VD3 deficiency was noticed in VAPS (vs. OAPS, P = 0.013). A negative correlation between VD3 levels and the age of patients was noticed (r = - 0.493, P = 0.032) only in VAPS subgroup. Multiple positivity of aPL and aanxA5 Abs was not associated with VD3 deficiency. Newly emerging aPL Abs, such as aanxA5 Abs, or their combinations with classical aPL Abs are not associated with VD3 deficiency in neither OAPS nor VAPS patients. Due to its immunomodulatory roles in B-Ly homeostasis, supplementation with VD3 should be considered in APS, at least in subgroup with severe form of the disease, i.e., VAPS.

Clinical Risk Assessment in the Antiphospholipid Syndrome: Current Landscape and Emerging Biomarkers

PURPOSE OF REVIEW

Laboratory criteria for the classification of antiphospholipid syndrome include the detection of a lupus anticoagulant and/or anticardiolipin and anti-β2-glycoprotein I antibodies. However, the majority of patients who test positive in these assays do not have thrombosis. Current risk-stratification tools are largely limited to the antiphospholipid antibody profile and traditional thrombotic risk factors.

RECENT FINDINGS

Novel biomarkers that correlate with disease activity and potentially provide insight into future clinical events include domain 1 specific anti-β₂GPI antibodies, antibodies to other phospholipids or phospholipid/protein antigens (such as anti-PS/PT), and functional/biological assays such as thrombin generation, complement activation, levels of circulating microparticles, and annexin A5 resistance. Clinical risk scores may also have value in predicting clinical events. Biomarkers that predict thrombosis risk in patients with antiphospholipid antibodies have been long sought, and several biomarkers have been proposed. Ultimately, integration of biomarkers with established assays and clinical characteristics may offer the best chance of identifying patients at highest risk of APS-related complications.

Diagnosing antiphospholipid syndrome: 'extra-criteria' manifestations and technical advances

First described in the early 1980s, antiphospholipid syndrome (APS) is a unique form of acquired autoimmune thrombophilia in which patients present with clinical features of recurrent thrombosis and pregnancy morbidity and persistently test positive for the presence of antiphospholipid antibodies (aPL). At least one clinical (vascular thrombosis or pregnancy morbidity) and one lab-based (positive test result for lupus anticoagulant, anticardiolipin antibodies and/or anti-β2-glycoprotein 1 antibodies) criterion have to be met for a patient to be classified as having APS. However, the clinical spectrum of APS encompasses additional manifestations that can affect many organs and cannot be explained exclusively by patients being in a prothrombotic state; clinical manifestations not listed in the classification criteria (known as extra-criteria manifestations) include neurologic manifestations (chorea, myelitis and migraine), haematologic manifestations (thrombocytopenia and haemolytic anaemia), livedo reticularis, nephropathy and valvular heart disease. Increasingly, research interest has focused on the development of novel assays that might be more specific for APS than the current aPL tests. This Review focuses on the current classification criteria for APS, presenting the role of extra-criteria manifestations and lab-based tests. Diagnostic approaches to difficult cases, including so-called seronegative APS, are also discussed.

Diagnosis and management of the antiphospholipid syndrome

Antiphospholipid syndrome (APS) is characterized by thrombosis and/or pregnancy complications in the presence of persistent antiphospholipid antibodies (APLA). Laboratory diagnosis of APLA depends upon the detection of a lupus anticoagulant, which prolongs phospholipid-dependent anticoagulation tests, and/or anticardiolipin (aCL) and anti-β2-glycoprotein-1 (β2GPI) antibodies. APLA are primarily directed toward phospholipid binding proteins. Pathophysiologic mechanisms underlying thrombosis and pregnancy loss in APS include APLA induced cellular activation, inhibition of natural anticoagulant and fibrinolytic systems, and complement activation, among others. There is a high rate of recurrent thrombosis in APS, especially in triple positive patients (patients with lupus anticoagulant, aCL and anti-β2GPI antibodies), and indefinite anticoagulation with a vitamin K antagonist is the standard of care for thrombotic APS. There is currently insufficient evidence to recommend the routine use of direct oral anticoagulants (DOAC) in thrombotic APS. Aspirin with low molecular weight or unfractionated heparin may reduce the incidence of pregnancy loss in obstetric APS. Recent insights into the pathogenesis of APS have led to the identification of new potential therapeutic interventions, including anti-inflammatory and immunomodulatory therapies. Additional research is needed to better understand the effects of APLA on activation of signaling pathways in vascular cells, to identify more predictive biomarkers that define patients at greatest risk for a first or recurrent APLA-related clinical event, and to determine the safety and efficacy of DOACs and novel anti-inflammatory and immune-modulatory therapies for refractory APS.

TNF-alpha and annexin A2: inflammation in thrombotic primary antiphospholipid syndrome

Antiphospholipid syndrome (APS) is characterized by thromboses and/or pregnancy losses. Laboratory criterion for the diagnosis of APS is the presence of antiphospholipid antibodies (anticardiolipin, anti-beta2-glycoprotein I (aβ2gpI) and lupus anticoagulant). On the one hand, the latest classification criteria for the diagnosis of APS emphasized that thrombotic manifestations of the syndrome should be without any signs of an inflammatory process, while on the other hand, some recent reports have suggested that APS is a "pro-inflammatory state." This article is focused on the importance of TNF-alpha and annexin A2 (anxA2) for patients with vascular (thrombotic) manifestations of the primary APS. The classic antithrombotic and antiplatelet therapy does not protect APS patients from the development of recurrent thrombosis. Therefore, an urgent need for the introduction of new therapeutic approaches in the treatment of APS patients is obvious. This review provides a rationale for the necessity for the use of immunomodulatory medications that could interfere with β2gpI binding to its receptor(s), such as anxA2, and/or inhibit TNF-alpha activity.