Autoantibodies to contact proteins in patients with recurrent pregnancy losses

Depressed Kallikrein Generation in Women With Preeclampsia: A Matched Cross-Sectional Study

Objective

The pathophysiology of preeclampsia is not fully understood. Disturbances in the contact system are associated with preeclampsia. Few studies have investigated the association between preeclampsia and alterations in the contact system in plasma. This study aims to elucidate whether this basic biological system is affected in preeclampsia using new methods focusing on the dynamic interactions and total capacity of the contact system in blood.

Design

Cross-sectional study matching women with preeclampsia and controls without preeclampsia regarding age, pregestational body mass index, and gestational age at onset of the disease.

Setting

Two Danish University hospitals.

Sample

A cohort of 117 women with preeclampsia and 117 controls.

Methods

The turnover and capacity of the contact system were determined with new methods. Paired t-test, Wilcoxon signed-pairs signed rank test, Mann-Whitney or Chi²-test were applied, as appropriate.

Main Outcome Measurements

Kallikrein generation (peak kallikrein concentration and endogenous kallikrein potential), coagulation factor XII, prekallikrein, H-kininogen, cleaved H-kininogen, and complement C1 esterase inhibitor.

Results

The endogenous kallikrein potential, peak kallikrein concentration, prekallikrein and cleaved H-kininogen were significantly lower in women with preeclampsia compared to the controls, p ≤ 0.005, whereas the concentration of coagulation factor XII, H-kininogen and complement C1 esterase inhibitor was not significantly different, p > 0.05.

Conclusion

This study demonstrates significant reduction in kallikrein generating capacity, prekallikrein and cleaved H-kininogen indicating that the contact system is affected in preeclampsia suggesting a link to the pathophysiology of the disease.

Antiphospholipid antibodies may impair factor XIIa-dependent activation of fibrinolysis in pregnancy: in vitro evidence with human endothelial cells in culture and monoclonal anticardiolipin antibodies

OBJECTIVE

The purpose of this study was to analyze the in vitro activation of the contact complex with the use of human umbilical vein endothelial cells (HUVEC) in culture and monoclonal anticardiolipin antibodies (MaCL).

STUDY DESIGN

Cultured HUVECs were incubated with pooled plasma from third-trimester pregnant women with the addition (20 mg/mL) of MaCL with anti-beta-2 glycoprotein I activity that was obtained from patients with antiphospholipid syndrome (APS), MaCL from an individual without APS, or from a control patient with immunoglobulin M without aCL activity. Supernatants were evaluated. Activated factors XII and VII, prothrombin-fragment 1 + 2, urokinase-type plasminogen activator (UPA), and differentiating 2 chain UPA were determined.

RESULTS

In the cultured HUVEC supernatants, the addition of MaCL increased activated factor VII and prothrombin-fragment 1 + 2, did not modify UPA, and decreased activated factor XII and differentiating 2 chain UPA, in comparison with samples with control immunoglobulin M added. The MaCL without APS activity did not change any parameter that was evaluated.

CONCLUSION

MaCL with anti-beta-2 activity that was obtained from patients with APS may interfere in the activation of the contact complex during pregnancy.

Autoantibody to tumor antigen, alpha 2-HS glycoprotein: a novel biomarker of breast cancer screening and diagnosis

We sought to identify a new serum biomarker for breast cancer screening and diagnosis using stepwise proteomic analysis of sera from breast cancer patients to detect the presence of autoantibodies that react with urinary protein. Two-dimensional immunoblotting was done for screening autoimmunogenic tumor antigens in the urine of breast cancer patients. Reactive spots were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Among urinary proteins separated by two-dimensional electrophoresis, 13 spots showed strong reactivity with pooled sera from breast cancer patients or control sera. By mass spectrometry, we identified alpha 2-HS glycoprotein (AHSG) as a tumor antigen. Peripheral blood was obtained from 81 women diagnosed with breast cancer before surgery and 73 female donors without evidence of any malignancy for the individual analysis. In one-dimensional Western blot analysis, AHSG autoantibody was detected in 64 of 81 breast cancer patients (79.1%) and in 7 of 73 controls (9.6%). The sensitivity of this test in breast cancer patients was 79.0%. Our results suggest that AHSG and anti-AHSG autoantibody may be useful serum biomarkers for breast cancer screening and diagnosis.

Impaired factor XIIa-dependent activation of fibrinolysis in treated antiphospholipid syndrome gestations developing late-pregnancy complications

OBJECTIVE

The objective of the study was to investigate the potential role of impaired factor XII-dependent activation of fibrinolysis in treated antiphospholipid syndrome gestations developing late-pregnancy complications.

STUDY DESIGN

This was a prospective study in a third-level teaching hospital, including 75 patients: 25 pregnant patients having the antiphospholipid syndrome and carrying their pregnancies until 26 weeks' gestation or later (group 1); 25 pregnant patients having normal term pregnancies and delivery and no previous miscarriage (group 2); and 25 pregnant patients being diagnosed as having severe pre-eclampsia and/or intrauterine growth restriction but testing negative for antiphospholipid antibodies (group 3). Hemostatic evaluation was carried out from patients in groups 1 and 2 between 6 and 10 weeks, between 18 and 22 weeks, and between 28 and 32 weeks' gestation. Patients in group 3 were sampled between 28 and 32 weeks. An additional blood sample was obtained 4 to 6 months after delivery (baseline). The Mann-Whitney U test, the Friedman test, and the chi2 test were used.

RESULTS

Patients in group 1 were characterized by increased factor VIIa levels, increased prothrombin fragment 1+2 levels, reduced factor XIIa levels, diminished functional urokinase-type plasminogen activator levels, and decreased levels of plasmin/alpha-2-plasmin inhibitor complexes. These abnormalities were more evident in patients in group 1 developing pre-eclampsia and/or intrauterine growth restriction.

CONCLUSIONS

Impaired factor XIIa-dependent activation of fibrinolysis seems to be a key mechanism related to late-pregnancy complications in patients with the antiphospholipid syndrome.

New fetoproteins, as presumptive antigenic inducers of abortions and congenital anomalies. Temporal forking of immunological abortions. A working hypothesis

In a previous experimental study soluble alloantigens and soluble foreign (not recognized by the dam's immune system) transitory antigens in chick embryo have been detected. When a chick embryo extract was injected in hens and their eggs were incubated, the death or a delay in chick embryo development or congenital anomalies were observed. Based on the foregoing, the following working hypothesis is established: any fetoprotein not coming into contact with the fetal immune system during the central clonal selection period becomes a foreign antigen. If it is a female fetus that becomes pregnant at adult age, then passage to the maternal circulation or to the decidua of the same foreign fetoprotein from her fetus is a candidate to induce a humoral or cell-mediated response. If specific IgG or toxic factors of the different cells activated by cell-mediated immunity in the mother access the inductive antigen (e.g., an enzyme) in the conceptus, there functions may be cancelled or the antigen-carrier cell may undergo lysis. This will result in damage to tissues leading to abortion or to a viable but morphologically or functionally abnormal offspring. This can occurs with some of soluble foreign transitory antigens existents. The soluble alloantigens are foreign for the mother because are coded by paternal genes and act of similar way.