Anti-β2 glycoprotein I antibodies and pregnancy outcome in antiphospholipid syndrome

Serum antiphospholipid antibody status may not be associated with the pregnancy outcomes of patients undergoing in vitro fertilization

BACKGROUND

Antiphospholipid syndrome (APS) is an autoimmune disease that is associated with recurrent pregnancy loss. It is still controversial whether the presence of antiphospholipid antibodies (aPL) in the serum of patients with in vitro fertilization-embryo transfer (IVF-ET) has a negative effect on the outcomes. In view of the discrepancies, a meta-analysis of the published data was performed to explore the relationship of aPL and IVF-ET outcomes.

METHODS

We searched for all published articles indexed in PubMed, Web of Science, and Cochrane Library, which were retrieved up to April, 2021. A total of 921 studies were yielded, of which 6 finally met the inclusion criteria. We carried out the meta-analysis by pooling results of these studies with Review Manager 5.3 software. The effect index was measured with 95% confidence intervals (CIs) of the relative risks (RRs).

RESULTS

Six eligible studies were included in this meta-analysis, involving 3214 patients. Our results showed that positive aPL was not associated with decreased clinical pregnancy rate (RR 0.97; 95% CI 0.91-1.04). There was no correlation between positive aPL and increased miscarriage risk (RR 1.22; 95% CI 0.94-1.58). Only 5 of the 6 studies referred to live birth rate, but still no association was found between them (RR 0.95; 95% CI 0.81-1.11).

CONCLUSIONS

The results showed that the presence of positive aPL neither decreased clinical pregnancy rate and live birth rate, nor increased miscarriage rate in women undergoing IVF, which is differed from the opinion of clinical practice. More prospective studies with high quality and larger sample size are needed to evaluate the relationship between positive aPL and outcomes of IVF-ET.

Obstetric anti-phospholipid syndrome: from pathogenesis to treatment

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by clinical manifestations such as thrombosis and obstetric complications with documented persistence of antiphospholipid antibodies (aPLs). Recent studies have revealed that the cause of aPL-related obstetric complications is dysfunction of placental trophoblasts and inflammation of the maternal-fetal interface induced by aPLs, not thrombosis. Although aPLs are associated with recurrence of serious complications during pregnancy, appropriate combination therapy with heparin and low-dose aspirin can improve the course of 70-80% of subsequent pregnancies. Preconception counseling and patient-tailored treatment are fundamental to improving maternal and fetal outcomes. Non-anticoagulant treatments such as hydroxychloroquine and statins are being developed for cases refractory to conventional treatment. Risk factors for thrombosis after pregnancy complications were identified based on the analysis of large databases of obstetric APS.

Pregnancy outcome predictors in antiphospholipid syndrome: A systematic review and meta-analysis

OBJECTIVE

To identify and assess the magnitude of effect of pregnancy outcome predictors in women with antiphospholipid syndrome (APS) by means of systematic review and meta-analysis.

METHODS

PubMed and Embase were searched (13th June 2020) for studies reporting on pre-pregnancy risk factors of pregnancy outcomes in APS patients. Literature screening and data extraction were conducted by two reviewers independently, in a blinded standardized manner. Pooled univariate odds ratios (OR) were computed using a random effects model. Heterogeneity was assessed by I²%.

RESULTS

The search yielded 3013 unique results; 27 records were included in this meta-analysis. Previous thrombosis was associated with a decreased live birth risk (OR 0.60, p < 0.01, I² = 40%), increased neonatal mortality (OR 15.19, p < 0.01, I² = 0%), an increased risk of antenatal or postpartum thrombosis (OR 6.26, p < 0.01, I² = 0%) and an increased risk of delivering a small for gestational age neonate (SGA) (OR 2.60, p = 0.01, I² = 0%). Patients with an APS laboratory category I (double or triple positivity) profile had a decreased live birth risk (OR 0.66, p < 0.01, I² = 0%), an increased risk of SGA (OR 1.86, p = 0.01, I² = 43%) and preterm birth (OR 1.35, p < 0.01, I² = 49%). Triple positivity was associated with a decreased live birth risk (OR 0.33, p < 0.01, I² = 68%), an increased risk of preeclampsia (OR 2.43, p = 0.02, I² = 35%) and SGA (OR 2.47, p = 0.04, I² = 61%). Patients with lupus anticoagulant positivity had an increased risk of preeclampsia (OR 2.10, p = 0.02, I² = 48%), SGA (OR 1.78, p < 0.01, I² = 0%) and preterm birth (OR 3.56, p = 0.01, I² = 48%). Risk of bias assessment suggested considerable bias on study participation and statistical methods.

CONCLUSIONS

The results of this meta-analysis identified previous thrombosis, laboratory category I, triple positivity and lupus anticoagulant positivity as the most important predictors of adverse pregnancy outcomes. This up-to-date knowledge, can be used in preconception counseling and tailoring of obstetric care.

Anti-phospholipid antibodies and reproductive failures

Anti-phospholipid syndrome (APS) recapitulates the link between autoimmunity and pregnancy failure: Acquired anti-phospholipid antibodies (aPL) play a pathogenic role in pregnancy complications. The diagnosis of obstetric APS can easily be pursued when women present with laboratory and clinical features fulfilling the international classification criteria. Standard therapeutic approach to obstetric APS consists in the association of anti-platelet agents and anticoagulants. Most patients achieve a live birth thanks to conventional treatment; however, approximately 20% fail to respond and are managed with additional therapeutic tools added on the top of conventional treatment. Surely, a refinement of risk stratification tools would allow early identification of high-risk pregnancies that warrant tailored treatment. In real life, obstetricians and rheumatologists face complex diagnostic scenarios including women with pregnancy morbidities other than those mentioned in classification criteria such as one or two early losses and premature birth after 34 weeks due to preeclampsia or placental insufficiency, women with low-titer aPL not fulfilling criteria laboratory requirements, women with positive non-criteria aPL, asymptomatic aPL carriers, and infertile women found to be aPL-positive. This review focuses on some of the several unanswered questions related to diagnostic, prognostic, and therapeutic aspects in obstetric 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.

Antiphospholipid syndrome: An update on risk factors for pregnancy outcome

BACKGROUND

The optimal treatment of women with primary antiphospholipid syndrome (APS) is still debated. About 20-30% of women with APS remain unable to give birth to healthy neonates despite conventional treatment, consisting of prophylactic-dose heparin and low-dose aspirin. These cases are defined "refractory obstetric APS". The early identification of risk factors associated with poor pregnancy outcome could be the optimal strategy to establish criteria for additional therapies, such as hydroxychloroquine, steroids, intravenous immunoglobulin, and plasma exchange.

PURPOSE

The aim of the present study was to review current literature about risk factors for poor pregnancy outcome.

SEARCH METHODS

The PubMed database was used to search for peer-reviewed original and review articles concerning risk factors for pregnancy outcome in APS from 1st January 1990 to 15th January 2018.

OUTCOMES

History of pregnancy morbidity and/or thrombosis, the association with SLE and/or other autoimmune diseases are well known history-based predictive factors for obstetrical complications, such as miscarriage, maternal venous thromboembolism, intrauterine foetal demise, preeclampsia, and neonatal death. Moreover, laboratory findings associated with poor pregnancy outcome are:triple antiphospholipid antibodies aPL positivity, double aPL positivity, single aPL positivity, false-positive IgM for CMV, and hypocomplementemia. Triple positivity is confirmed as the most significant risk factor by a large body of evidence. Furthermore, the abnormal uterine arteries Doppler velocimetry results are confirmed to be strongly associated with poor pregnancy outcomes in APS. The good performance of the uterine arteries velocimetry, as a negative predictive factor, was reported by different studies. On the contrary, in case of abnormal uterine arteries results, the relevance of a careful surveillance is highlighted for the high risk of maternal-foetal complications. Nevertheless, this tool is a late indicator to suggest any additional treatments.

CONCLUSIONS

In order to prevent obstetrical complications and establish the optimal combination therapy, the knowledge at preconception or at the beginning of pregnancy of risk factors associated with poor pregnancy outcome could be a crucial step for management and treatment of APS. In addition, in the preconception assessment a regimen with low-dose aspirin, folic acid, and vitamin D supplementation should be offered, and a treatment strategy has to be established (conventional vs additional therapy). In fact, additional treatment has to be tailored for each patient.

Antiphospholipid antibody profile based obstetric outcomes of primary antiphospholipid syndrome: the PREGNANTS study

BACKGROUND

Antiphospholipid syndrome is an autoimmune, hypercoagulable state that is caused by antiphospholipid antibodies. Anticardiolipin antibodies, anti-β2 glycoprotein-I, and lupus anticoagulant are the main autoantibodies found in antiphospholipid syndrome. Despite the amassed body of clinical knowledge, the risk of obstetric complications that are associated with specific antibody profile has not been well-established.

OBJECTIVE

The purpose of this study was to assess the risk of obstetric complications in women with primary antiphospholipid syndrome that is associated with specific antibody profile.

STUDY DESIGN

The Pregnancy In Women With Antiphospholipid Syndrome study is a multicenter, retrospective, cohort study. Diagnosis and classification of antiphospholipid syndrome were based on the 2006 International revised criteria. All women included in the study had at least 1 clinical criteria for antiphospholipid syndrome, were positive for at least 1 antiphospholipid antibody (anticardiolipin antibodies, anti-β2 glycoprotein-I, and/or lupus anticoagulant), and were treated with low-dose aspirin and prophylactic low molecular weight heparin from the first trimester. Only singleton pregnancies with primary antiphospholipid syndrome were included. The primary outcome was live birth, defined as any delivery of a live infant after 22 weeks gestation. The secondary outcomes were preeclampsia with and without severe features, intrauterine growth restriction, and stillbirth. We planned to assess the outcomes that are associated with the various antibody profile (test result for lupus anticoagulant, anticardiolipin antibodies, and anti-β2 glycoprotein-I).

RESULTS

There were 750 singleton pregnancies with primary antiphospholipid syndrome in the study cohort: 54 (7.2%) were positive for lupus anticoagulant only; 458 (61.0%) were positive for anticardiolipin antibodies only; 128 (17.1%) were positive for anti-β2 glycoprotein-I only; 90 (12.0%) were double positive and lupus anticoagulant negative, and 20 (2.7%) were triple positive. The incidence of live birth in each of these categories was 79.6%, 56.3%, 47.7%, 43.3%, and 30.0%, respectively. Compared with women with only 1 antibody positive test results, women with multiple antibody positive results had a significantly lower live birth rate (40.9% vs 56.6%; adjusted odds ratio, 0.71; 95% confidence interval, 0.51-0.90). Also, they were at increased risk of preeclampsia without (54.5% vs 34.8%; adjusted odds ratio, 1.56; 95% confidence interval, 1.22-1.95) and with severe features (22.7% vs 13.8%, adjusted odds ratio, 1.66; 95% confidence interval, 1.19-2.49), of intrauterine growth restriction (53.6% vs 40.8%; adjusted odds ratio, 2.31; 95% confidence interval, 1.17-2.61) and of stillbirth (36.4% vs 21.7%; adjusted odds ratio, 2.67; 95% confidence interval, 1.22-2.94). In women with only 1 positive test result, women with anti-β2 glycoprotein-I positivity present alone had a significantly lower live birth rate (47.7% vs 56.3% vs 79.6%; P<.01) and a significantly higher incidence of preeclampsia without (47.7% vs 34.1% vs 11.1%; P<.01) and with severe features (17.2% vs 14.4% vs 0%; P=.02), intrauterine growth restriction (48.4% vs 40.1% vs 25.9%; P<.01), and stillbirth (29.7% vs 21.2% vs 7.4%; P<.01) compared with women with anticardiolipin antibodies and with women with lupus anticoagulant present alone, respectively. In the group of women with >1 antibody positivity, triple-positive women had a lower live birth rate (30% vs 43.3%; adjusted odds ratio,0.69; 95% confidence interval, 0.22-0.91) and a higher incidence of intrauterine growth restriction (70.0% vs 50.0%; adjusted odds ratio,2.40; 95% confidence interval, 1.15-2.99) compared with double positive and lupus anticoagulant negative women.

CONCLUSION

In singleton pregnancies with primary antiphospholipid syndrome, anticardiolipin antibody is the most common sole antiphospholipid antibody present, but anti-β2 glycoprotein-I is the one associated with the lowest live birth rate and highest incidence of preeclampsia, intrauterine growth restriction, and stillbirth, compared with the presence of anticardiolipin antibodies or lupus anticoagulant alone. Women with primary antiphospholipid syndrome have an increased risk of obstetric complications and lower live birth rate when <1 antiphospholipid antibody is present. Despite therapy with low-dose aspirin and prophylactic low molecular weight heparin, the chance of a liveborn neonate is only 30% for triple-positive women.