Anticardiolipin and Anti-β 2-Glycoprotein-I Antibodies in Hypertensive Disorders of Pregnancy

Abstract

Background This study was undertaken in order to determine the frequency of anticardiolipin (aCL) and anti-β 2-glycoprotein-I antibodies (anti-β 2GP-I) in patients with hypertensive disorders of pregnancy. Methods We studied aCL (IgG and IgM) and IgG anti-β 2GP-I by ELISA in the serum and IgG aCL and anti-β 2GP-I in the urine of 125 women with hypertensive disorders of pregnancy (cases) (75 had preeclampsia, 25 had eclampsia, and 25 had chronic hypertension). One hundred and twenty seven normal women were used as controls. Antibody positivity was defined as above the 90 th percentile of the controls. Results We found no differences in frequency of serum anti-β 2GP-I or serum and urinary aCL between cases and controls. In contrast, we found that frequency of IgG anti-β 2GP-I was higher in the urine of cases (26.1%) compared to controls (9.4%, p = 0.001). Strength of association was stronger for urinary anti-β 2-glycoprotein-I in women with preeclampsia (odds ratio [OR] = 4.3, 95% confidence limit [CI 95%] = 1.95–9.62, p <0.0001). Cases and the subgroup of preeclamptic patients also had higher titers of urinary IgG anti-β 2GP-I than control women ( p <0.0001). Conclusions Our work suggests that urine testing is necessary in order to ascertain whether antibodies to β 2GP-I are associated with preeclampsia.