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.
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.
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.
- ANTINUCLEAR ANTIBODY
- RECURRENT PREGNANCY LOSS