Anti-GalNAcβ: A novel anti-glycan autoantibody associated with pregnancy loss in women with antiphospholipid syndrome and in a mouse experimental model

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.

Detection of novel auto-antigens in patients with recurrent miscarriage: description of an approach and preliminary findings

Aim

To develop and test a protocol for isolation of potential auto-antigens from chorionic tissue that may be linked to recurrent miscarriage (RM).

Methods

The strategy included: 1) isolation of IgGs tightly bound to chorionic tissue of RM patients by protein G chromatography; 2) construction of affinity columns using the chorionic antibodies for isolation of auto-antigens; 3) enrichment of auto-antigens from detergent extracted solution of chorionic proteins by affinity chromatography; 4) separation by dodecyl sulfate-electrophoresis followed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry identification.

Results

Five potential auto-antigens were detected: neutral alpha-glucosidase AB, endoplasmin, transitional endoplasmic reticulum ATPase, putative endoplasmin-like protein, and cytoplasmic actin 2.

Conclusions

We developed a strategy for identification of auto-antigens in the chorionic tissue of women with RM, which could be of diagnostic and prognostic value.

Maternal autoimmunity and adverse pregnancy outcomes

Some of the most dangerous and costly complications of human pregnancy, including premature labor and preeclampsia/eclampsia, have remained unexplained. While not noted by the authors of a recently published study of three distinct groups of patients with thyroid disease, their data may offer new insights into the interplay between thyroid autoimmune disease, indeed possibly autoimmunity in general, and human pregnancy. This editorial discusses a report of 223,512 pregnancies (2002-2008) from a retrospective U.S. cohort, the Consortium of Safe Labor, reported by Männistö et al. from the Epidemiology Branch, Division of Epidemiology, Statistics and Prevention Research, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Rockville, Maryland in the July 2013 issue of The Journal of Clinical Endocrinology and Metabolism. Reading between the lines of this publication offers potential insights into the etiologies of preeclampsia/eclampsia and of term as well as premature labor. Moreover, this study, unintentionally, may also offer insights into currently still only poorly understood immune dysfunction that links autoimmunity with adverse pregnancy outcomes.