Antiphospholipid antibodies and fetal compromise

Complementemia in pregnancies with antiphospholipid syndrome

Prognosis of pregnancies in women with antiphospholipid syndrome has dramatically improved over the past two decades using conventional treatment with low molecular weight heparin and low-dose aspirin. However, despite this regimen, 10-15% of antiphospholipid syndrome patients experience pregnancy losses. Several studies have been performed in order to identify risk factors predictive of complications. Thrombosis has been generally accepted as the key pathogenetic mechanism underlying pregnancy morbidity. However, the thrombogenic state alone is not able to explain all the different mechanisms leading to pregnancy failure. In fact, emerging evidence shows that complement pathway could play an important role in mediating clinical events in antiphospholipid syndrome. However, the exact mechanism through which complement mediates antiphospholipid syndrome complications remains unknown. Low complement levels (C3 and C4) are associated with poor pregnancy outcome in women with antiphospholipid syndrome in different studies. Hypocomplementemia could be indicated as an early predictor of adverse pregnancy outcome, available at the beginning of pregnancy for starting, if necessary, additional treatment to conventional therapy. However, future studies need to better understand the impact of low complement level on antiphospholipid syndrome pregnancy outcome.

Umbilical arterial Doppler ultrasonography predicts late pregnancy outcomes in patients with lupus nephritis: a multicenter study from southern China

OBJECTIVES

To investigate the fetal adverse pregnancy outcomes (APOs) and the predictive value of umbilical arterial Doppler ultrasonography in the third trimester in pregnant women with lupus nephritis (LN).

METHODS

A retrospective cohort study enrolling 203 LN patients from 2007 to 2017 was performed. Ultrasonic parameters were recorded.

RESULTS

Fetal APOs occurred in 103 patients (103/203, 50.7%). Sixty-six pregnancies (66/203, 32.5%) ended with preterm births. The incidence rate of intrauterine growth restriction (IUGR) was 18.2% (37/203). Fetal distress was noted in 23 pregnancies (23/203, 11.3%). All the Doppler parameters elevated in patients with IUGR, fetal distress, and composite conditions. Resistance index (RI) indicated the highest risk of IUGR and composite APOs. The cutoff values were 0.66 and 0.67, respectively. Sensitivities were 51.4% and 33.7%, and specificities were 87.4% and 92.1%. Peak velocity of the umbilical arteries at end-systole (Vmax, abbreviated as S) to that at end-diastole (Vmin, abbreviated as D) (S/D) ratio was also a best predictor for IUGR, with the optimal cutoff value of 2.88. Sensitivity and specificity were comparable with RI. Pulsatility index (PI) over 0.84 was an ideal indicator for fetal distress with an optimal combination of sensitivity (89.5%) and specificity (51.6%).

CONCLUSIONS

Fetal complications were frequent in patients with LN. Umbilical arterial Doppler ultrasonography was a useful measure to predict late IUGR, fetal distress, and the composite APOs.

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.

Pregnancy and autoimmune connective tissue diseases

Autoimmune connective tissue diseases predominantly affect women and often occur during the reproductive years. Thus, specialized issues in pregnancy planning and management are commonly encountered in this patient population. This chapter provides a current overview of pregnancy as a risk factor for onset of autoimmune disease, considerations related to the course of pregnancy in several autoimmune connective tissue diseases, and disease management and medication issues before pregnancy, during pregnancy, and in the postpartum period. A major theme that has emerged across these inflammatory diseases is that active maternal disease during pregnancy is associated with adverse pregnancy outcomes, and that maternal and fetal health can be optimized when conception is planned during times of inactive disease and through maintaining treatment regimens compatible with pregnancy.

Top 10 clinical research developments in antiphospholipid syndrome

Persistently positive antiphospholipid antibodies (aPL) with thrombosis and/or pregnancy morbidity are a characteristic of antiphospholipid syndrome (APS). Although many challenges and controversies exist regarding APS diagnosis and management, there has been significant progress in APS clinical research in parallel with increased understanding of the pathogenesis. The purpose of this review is to discuss the "top ten" recent clinical developments in APS, including the magnitude of the problem, standardization of aPL tests, predictors of clinical events, diagnostic algorithms, new clinical research collaboration, and potential future treatments, e.g., new anticoagulants and immunosuppressive agents.

Prediction of adverse pregnancy outcome by the presence of lupus anticoagulant, but not anticardiolipin antibody, in patients with antiphospholipid antibodies

OBJECTIVE

To investigate which serologic and clinical findings predict adverse pregnancy outcome in patients with antiphospholipid antibody (aPL) and to test the hypothesis that a pattern of clinical and serologic variables can identify women at highest risk of adverse pregnancy outcome.

METHODS

Women enrolled in a multicenter prospective observational study of risk factors for adverse pregnancy outcome in patients with aPL (lupus anticoagulant [LAC], anticardiolipin antibody [aCL], and/or antibody to β2-glycoprotein I [anti-β2 GPI]) and/or systemic lupus erythematosus (SLE) were recruited for the present prospective study. Demographic, clinical, serologic, and treatment data were recorded at the time of the first study visit. The relationship between individual and combined variables and adverse pregnancy outcome was assessed by bivariate and multivariate analysis.

RESULTS

Between 2003 and 2011 we enrolled 144 pregnant patients, of whom 28 had adverse pregnancy outcome. Thirty-nine percent of the patients with LAC had adverse pregnancy outcome, compared to 3% of those who did not have LAC (P<0.0001). Among women with IgG aCL at a level of ≥40 units/ml, only 8% of those who were LAC negative had adverse pregnancy outcome, compared to 43% of those who were LAC positive (P=0.002). IgM aCL, IgG anti-β2 GPI, and IgM anti-β2 GPI did not predict adverse pregnancy outcome. In bivariate analysis, adverse pregnancy outcome occurred in 52% of patients with and 13% of patients without prior thrombosis (P=0.00005), and in 23% with SLE versus 17% without SLE (not significant); SLE was a predictor in multivariate analysis. Prior pregnancy loss did not predict adverse pregnancy outcome. Simultaneous positivity for aCL, anti-β2 GPI, and LAC did not predict adverse pregnancy outcome better than did positivity for LAC alone.

CONCLUSION

LAC is the primary predictor of adverse pregnancy outcome after 12 weeks' gestation in aPL-associated pregnancies. Anticardiolipin antibody and anti-β2 GPI, if LAC is not also present, do not predict adverse pregnancy outcome.

Follow-up of babies born to mothers with antiphospholipid syndrome: Preliminary data from the European neonatal registry

In this review preliminary data on the follow-up of 141 babies born to mothers with antiphospholipid syndrome are reported. In spite of maternal treatment, the rate of both preterm delivery and low birth weight were 16 and 17%, respectively. At birth, no clinical evidence of perinatal thrombosis was observed. Placental transfer of antiphospholipid antibodies occurred in 20, 25 and 43% of cases for lupus anticoagulant, anticardiolipin and anti-β2-glycoprotein I antibodies, respectively. At 24 months of follow-up, four children showed behaviour abnormalities suggesting the possible need for long-term neurological evaluation in this clinical setting.

A possible mechanism of autoimmune-mediated infertility in women with endometriosis

PROBLEM

Endometriosis has been proposed to be an autoimmune disease because of the presence of a variety of autoantibodies specific for endometrial or ovarian antigens. The object of the present study is to characterize binding specificity of anti-laminin-111 autoantibodies in infertile patients with endometriosis and to investigate whether these autoantibodies affect the in vitro embryo development.

METHOD OF STUDY

An ELISA analysis using overlapping synthesized peptides that covered the entire G domain of laminin-α1 chain was performed in infertile patients with endometriosis (n = 45). Mouse blastocysts were cultured in media containing the purified IgG from one antibody-positive serum on laminin-111-coated dishes.

RESULTS

Anti-laminin-111 autoantibodies were directed to several particular biologically functional peptide sequences in laminin-α 1 chain G domain. The tested IgG significantly inhibited the extent of in vitro trophoblast outgrowth.

CONCLUSION

Anti-laminin-111 autoantibodies may have major pathogenic roles on early reproductive failure including endometriosis-associated infertility.

Antiphospholipid antibodies and pregnancy outcomes in women heterozygous for factor V Leiden

Antiphospholipid antibodies are associated with a spectrum of pregnancy complications, including preeclampsia and small for gestational age (SGA) fetuses. We sought to assess anticardiolipin and anti-beta2-glycoprotein I (anti-beta2-GPI) IgG and IgM antibody prevalence and the relationship of these antibodies to pregnancy complications in women with the Factor V Leiden (FVL) mutation. The study comprised a secondary analysis of a multicenter, prospective observational study of FVL prevalence among 5188 asymptomatic pregnant women. A subset of 362 women (117 FVL heterozygotes, 245 matched controls) had serum collected at the time of the original study and underwent serum analysis for anticardiolipin and anti-beta2-GPI IgG and IgM as a part of this analysis. The primary outcome was preeclampsia and/or SGA (<10%). The overall prevalence of anticardiolipin and anti-beta2-GPI IgG and IgM antibodies was low and did not vary with FVL status. Forty-seven women (13.0%) developed preeclampsia and/or SGA. There were no differences in primary outcome rates between women with and without aPL antibodies, regardless of FVL mutation status. Among FVL carriers, the presence of antiphospholipid antibodies does not appear to contribute to adverse pregnancy outcome.

The enigmas of the lupus anticoagulant: mechanisms, diagnosis, and management

Lupus anticoagulant (LA) is a laboratory abnormality associated with the antiphospholipid syndrome. It is a paradoxical phenomenon in which one or more in vitro diagnostic clotting tests are prolonged and thus seem due to an anticoagulant, whereas the antiphospholipid syndrome is manifest clinically as inappropriate or excessive thrombosis. LA should be suspected when thrombosis, recurrent fetal loss, or a prolonged phospholipid (PL)-dependent clotting test is present without other identifiable causes. Despite the heterogeneity of LA antibodies, a consensus has evolved to identify the LA. Four conditions must be met for this laboratory diagnosis: 1) prolongation of a PL-based clotting test, 2) confirmation of an inhibitor-like pattern in the clotting test, 3) confirmation of PL dependence in coagulation tests, and 4) exclusion of a specific factor inhibitor. Even with an extensive armamentarium for LA diagnosis and treatment, it is still a formidable task.

Uterine Artery Velocity Waveforms as Predictors of Pregnancy Outcome in Patients with Antiphospholipid Syndrome: A Review

In pregnant women, antiphospholipid syndrome (APS) is associated with an increased risk for preeclampsia, fetal intrauterine growth restriction, and other complications related to uteroplacental insufficiency. In normal pregnancy, impedance to flow in the uterine arteries decreases with gestation, as the likely consequence of the physiologic change of spiral arteries into low-resistance vessels. The presence of antiphospholipid antibodies can impair this vascular adaptation, resulting in a reduced placental perfusion. Doppler investigation provides a noninvasive method for the study of uteroplacental blood flow. Several studies were performed to detect the predictive role of uterine artery Doppler velocimetry in relation to pregnancy outcome in APS patients. In some studies, a high resistance index in the uterine arteries strongly predicted the subsequent development of obstetric complications. In other studies, persistent bilateral uterine artery notches identified the risk of preeclampsia and fetal intrauterine growth restriction. To date, the uterine artery Doppler velocimetry resulted to be a useful tool for identifying APS pregnancies at risk for adverse pregnancy outcome. These findings might have important implications for the management of these patients.

Current concepts on the pathogenesis of the antiphospholipid syndrome

The antiphospholipid syndrome (APS) is an important cause of acquired thrombophilia. It is characterized by the core clinical manifestations of thrombosis, either venous or arterial, and in women it can also be associated with recurrent fetal loss. The detection of persistently elevated levels of antiphospholipid antibodies (aPL Abs) is a requisite laboratory feature for the diagnosis to be made. The dominant antigenic targets in APS are beta 2-glycoprotein I (β2-GPI) and prothrombin. There is an accumulating body of experimental evidence that suggests that specific subgroups of aPL Abs may directly contribute to disease pathogenesis. This review critically examines the experimental evidence underlying the various propositions made to explain how these antibodies may predispose to disease in humans. Furthermore, it also examines the evidence relating to the immunologic mechanisms that may contribute to the breakage of peripheral tolerance in this disorder. Delineating the strengths and limitations of the experimental evidence accumulated thus far will hopefully stimulate further experimentation toward achieving the ultimate goal of precisely defining the dominant pathogenic mechanisms operational in APS. This may pave the way for the development of improved therapies.