Antiphosphatidylserine antibodies and reproductive failure

Antiphospholipid and antioangiogenic activity in females with recurrent miscarriage and antiphospholipid syndrome

Background Antiphospholipid syndrome is an autoimmune disease characterized by thrombosis, fetal losses and thrombocytopenia associated to antiphospholipid antibodies. They are directed to phospholipids, such as cardiolipins (anticardiolipin) and lupus anticoagulant or to complexes formed by phospholipids and protein cofactors, such as β2 glycoprotein 1 (a-β2GP1) and annexin V (a-annexin V). These auto-antibodies may be considered as a family of antibodies involved in thrombotic events and antiphospholipid activity. On the other hand, some proangiogenic factors are involved in the normal development of placental vasculature, such as the vascular endothelial growth factor. Overexpression of vascular endothelial growth factor receptor in its soluble form (sVEGFR-1) has been associated to a higher antiangiogenic activity. Our aim was to analyse the association between anticardiolipin, lupus anticoagulant, a-β2GP1, a-annexin V and sVEGFR-1 with recurrent miscarriage before week 10 of gestation in females with antiphospholipid syndrome. Methods We studied 24 females (primary or secondary antiphospholipid syndrome), who were divided into two groups: females with recurrent miscarriage before week 10 of gestation (M; n = 12) and females with no history of fetal loss (NM; n = 12). Anticardiolipin, a-β2GP1, a-annexin V and sVEGF-R1 concentrations were assessed by ELISA, while lupus anticoagulant was assessed by screening and confirmatory tests. Results A significant association was observed between the number of positive biomarkers and the belonging group ( P < 0.05). Besides, a positive result for lupus anticoagulant and a-β2GP1 was found to be significantly associated to the M group ( P < 0.05). Conclusions Lupus anticoagulant and a-β2GP1 may be implicated in pregnancies complicated by recurrent miscarriage in females with antiphospholipid syndrome.

Autoantibodies associated with reproductive failure

Autoimmune factors are involved in some of the cases of reproductive failure. These factors entail several autoantibodies, especially in patients having systemic lupus erythematosus (SLE) or the antiphospholipid syndrome (APS). These autoantibodies include mainly antibodies directed to phospholipid such as cardiolipin, phosphatidylserine, phosphatidylethanolamine or phospholipids binding glycoproteins such as b2glycoprotein-I, annexin V, prothrombin and protein-Z. There are also some other autoantibodies directed to laminin-I, thromboplastin, mitochondrial antibodies of the M5 type, corpus luteum, prolactin, poly (ADP-ribose), thyroglobulin and more, which were also found in SLE or APS patients with reproductive failure. Moreover, the presence of additional autoantibodies directed to actin, enolase, cubilin and others, needs further investigation to support a firm association to reproductive failure in women. Future studies are likely to help to determine and expand the number of autoantibodies screened in these patients, as well as by the use of proteomics technology, to determine peptides resembling the epitope specificities associated with the specific clinical manifestations.

Human IgG Antinuclear Antibodies Induce Pregnancy Loss in Mice by Increasing Immune Complex Deposition in Placental Tissue: In Vivo Study

PROBLEM

A threefold higher prevalence of antinuclear antibodies (ANA) has been reported in patients with recurrent pregnancy loss (RPL). Nevertheless, the role of ANA in reproductive failure is still unclear. The aim of this study was to investigate the role of ANA during early pregnancy in vivo.

METHOD OF STUDY

We used pregnant mice treated with immunoglobulin G (IgG) obtained from normal healthy subjects (NHS); ANA(+) sera of patients with RPL; and ANA(+) sera from women with uncomplicated pregnancies (HW). Placental immunohistochemical/immunofluorescence staining was performed to detect complement and immune complex deposition. ELISA was performed to evaluate complement levels.

RESULTS

ANA(+) IgG from RPL women significantly increased embryo resorption rate, reduced C3, and increased C3a serum levels compared to NHS IgG or ANA(+) -HW IgG. Increased C3 deposition and increased immune complex staining in placental tissues from mice treated with ANA(+) -RPL IgG fraction compared to NHS- and ANA(+) -HW-IgG-treated mice were found.

CONCLUSION

ANA(+) IgG injection in mice is able to induce fetal resorption and complement activation. The presence on placental tissues of immune complexes and complement fragments suggests the complement activation as a possible mechanism of placental damage.

Profile of autoantibodies against phosphorylcholine and cross-reactivity to oxidation-specific neoantigens in selective IgA deficiency with or without autoimmune diseases

Immunoglobulin A deficiency (IgAD) is considered the most common form of primary immunodeficiency. The majority of IgA-deficient individuals are considered asymptomatic, even though IgAD has been associated with an increased frequency of recurrent infections, allergy, and autoimmune diseases. In this study we evaluate the Natural autoantibodies (NatAbs) reactivity to phosphorylcholine (PC) and to some pro-inflammatory molecules in IgAD with or without autoimmune disorders. We observed that in the absence of IgA there is an enhancement of IgG subclasses functioning as NatAbs against PC. Immunoglobulin G (IgG) against lipopolysaccharide, C-reactive protein, and IgA was found in IgAD, regardless of the autoimmune manifestations. Nonetheless, IgAD patients with autoimmune disease showed significantly higher IgG reactivity against pro-inflammatory molecules, such as cardiolipin, oxidized low-density lipoproteins, and phosphatidylserine, with positive correlation between them. In conclusion, the IgG NatAbs against PC may represent a compensatory defense mechanism against infections and control excess of inflammation, explaining the asymptomatic status in the IgA deficiency.

Anti-beta(2)-glycoprotein-I and anti-phosphatidylserine antibodies in women with spontaneous pregnancy loss

OBJECTIVE

To evaluate the role of anti-beta(2)-glycoprotein-I (anti-beta(2)GPI-ab) and anti-phosphatidylserine (aPS-ab) antibodies as a risk factor in both recurrent miscarriage (RM) and unexplained fetal losses (UFL).

DESIGN

Retrospective, cohort study.

SETTING

Vall d'Hebron University Hospital, Barcelona, Spain.

PATIENT(S)

122 pregnant women divided in two groups: study group of 54 women with RM and/or UFL and control group of 68 pregnant without RM history.

INTERVENTION(S)

Analysis of lupus anticoagulant, anticardiolipin antibodies, and anti-beta(2)GP1 and aPS antibodies.

MAIN OUTCOME MEASURE(S)

Comparison of aPL antibody between groups.

RESULT(S)

The prevalence of aPL positive results was 8 out of 54 (14.8%) in the study group and 3 out of 68 (4.41%) in the controls. In the RM subgroup, the prevalence was 3 out of 25 (12%) versus 3 out of 68 (4.4%), and 7 out of 34 (20.6%) versus 3 out of 68 (4.4%) in UFL subgroup. As a whole, the prevalence of anti-beta(2)GP1-ab in the RM/UFL group showed a difference compared with controls but not aPS-ab. In the RM women, anti-beta(2)GP1-ab was positive in 3 out of 25 (12%) versus 1 out of 68 (1.5%) in controls and in 4 out of 34 versus 0 out of 68 cases in women with UFL. In the RM subgroup, aPS-ab was positive in 1 out of 25 (4%) versus 2 out of 68 (2.9%) in control group and in 3 out of 34 versus 2 out of 68 cases in women with UFL.

CONCLUSION(S)

Our results suggest that anti-beta(2)GP1-ab but not aPS-ab is related to RM/UFL and should be considered as a pregnancy-loss risk factor.