Enzyme linked immunosorbent assay (ELISA) as screening method for anti-paternal allo-antibodies in patients with recurrent pregnancy loss (RPL)

The optimal timing of immunotherapy may improve pregnancy outcome in women with unexplained recurrent pregnancy loss: A perspective follow-up study in northeastern China

PROBLEM

To determine whether patients with unexplained recurrent pregnancy loss (URPL) can benefit from pre-conception immunotherapy or on the early phase of the first trimester.

METHOD OF STUDY

The prospective follow-up study which involved pre-conception patients diagnosed with URPL following rigorous etiology screening in the medical center of recurrent pregnancy loss. In this study, pre-conception immunotherapy included lymphocyte immunotherapy (pre-LIT). Post-conception immunotherapy (post-IM) included LIT or intravenous immunoglobulin (IVIG). Patients were recommended to undergo post-IM immediately from human chorionic gonadotrophin (hCG) elevation. Autoimmune antibodies (AIA) and anti-paternal lymphocytotoxic antibodies (APLA) were tested before and after pre-LIT. Favorable outcome was defined as pregnancy over 14 weeks. Unfavorable outcomes included biochemical pregnancy loss (BPL) and pregnancy loss with clear implantation location (PLCIL).

RESULTS

In this study, URPL accounted for 12.9% of recurrent pregnancy loss (217/1682). Frequency of BPL was significantly lower in patients with post-IM than that without post-IM [2.8% vs 28.2%; adjusted relative risk (aRR), 0.06; 95% confidence interval (CI), 0.01-0.24]. There was a significant positive conversion in the AIA induced by pre-LIT (0.0% vs 31.0%). Frequency of PLCIL in patients with positive iatrogenic AIA conversion induced by pre-LIT was higher than that in patients without AIA conversion [30.4% vs 5.8%; aRR, 7.53; 95% CI, 1.31-43.34].

CONCLUSION

Pre-LIT of patients with URPL contributed to a positive iatrogenic AIA conversion, which was associated with an increased risk of PLCIL. Post-IM immediately initiated from the time of hCG elevation can reduce the incidence of BPL.

Comparison of Anti-HLA Antibody Production According to Gestational Periods in Pregnant Women

BACKGROUND

To evaluate paternal anti-HLA antibody profiles, sera samples were collected from pregnant women in different trimesters and the panel-reactive antibody (PRA) specificities were identified.

METHODS

From 2013 to 2015, serum samples were obtained from 41 pregnant women who had registered at the Izmir Tepecik Education and Research Hospital Gynecology Clinic. Anti-HLA antibodies were screened by using the panel reactive antibody screening and identification tests. Sera samples were obtained at the first, second, and third trimesters. The primary outcome was to determine the anti-HLA antibody production term during pregnancy; the secondary outcome was identification of anti-HLA antibodies.

RESULTS

None of the women had a sensitization history except during pregnancy. We observed that 54% of the women produced paternal antibodies, either class I or II. Class I PRA positivity of the women who had a first or second pregnancy was the same in all 3 trimesters, whereas class II positivity was increased in the third trimester. Class II and both class I and II positivity increased in the third trimester; class I positivity was decreased in the third trimester. PRA positivity could be affected by the history of pregnancy and could be raised, but no impact was observed from the history of abortion and miscarriage (odds ratios, 1.9, 0.4, and 0.5 [95% confidence intervals, 0.5-7.8, 0.1-2.0, and 0.3-0.7], respectively; P > .05). The most frequently detected antibodies were A2, B7, DR7, DR4, DR11, DR13, DQ2, and DQ8.

CONCLUSIONS

Anti-HLA antibodies against paternal HLA antigens were detected more in multiparous women than in primiparous women. Anti-HLA antibody detection ratios did not change until the third trimester and were followed by a specific increase in class II anti-HLA antibody production.

Clinical observation of lymphocyte active immunotherapy in 380 patients with unexplained recurrent spontaneous abortion

PURPOSE

This study aims to investigate the clinical curative effect of lymphocyte active immunotherapy (LAI) on unexplained recurrent spontaneous abortion (RSA).

METHODS

A total of 749 RSA patients who received medical service in our hospital from October 2009 to June 2013 were enrolled into this study. These patients were randomly divided into two groups: LAI group (treatment group) and routine progesterone for maintenance tocolysis group (control group). A comparative analysis on the pregnancy outcomes in these two groups was conducted.

RESULTS

Abortion rate was significantly lower in the LAI group than in the control group (P<0.05). Furthermore, pregnancy success rates were 89.7% and 32.2% in patients who received LAI and routine progesterone for maintenance tocolysis, respectively, and the difference was statistically significant (P<0.05).

CONCLUSION

Our analysis suggested that LAI can treat RSA effectively and has an excellent clinical effect. Furthermore, the detection of blocking antibodies showed a positive prediction on pregnancy outcome.

Detection of anti-HLA antibodies in maternal blood in the second trimester to identify patients at risk of antibody-mediated maternal anti-fetal rejection and spontaneous preterm delivery

PROBLEM

Maternal anti-fetal rejection is a mechanism of disease in spontaneous preterm labor. The objective of this study was to determine whether the presence of human leukocyte antigen (HLA) panel-reactive antibodies (PRA) during the second trimester increases the risk of spontaneous preterm delivery.

METHODS OF STUDY

This longitudinal case-control study included pregnant women with spontaneous preterm deliveries (n = 310) and control patients with normal term pregnancies (n = 620), matched for maternal age and gravidity. Maternal plasma samples obtained at 14-16, 16-20, 20-24, and 24-28 weeks of gestation were analyzed for HLA class I and class II PRA positivity using flow cytometry. The fetal HLA genotype and maternal HLA alloantibody epitope were determined for a subset of patients with positive HLA PRA.

RESULTS

(i) Patients with spontaneous preterm delivery were more likely to exhibit HLA class I (adjusted OR = 2.54, P < 0.0001) and class II (adjusted OR = 1.98, P = 0.002) PRA positivity than those delivering at term; (ii) HLA class I PRA positivity for patients with spontaneous preterm delivery between 28 and 34 weeks (adjusted OR = 2.88; P = 0.001) and after 34 weeks of gestation (adjusted OR = 2.53; P < 0.0001) was higher than for those delivering at term; (iii) HLA class II PRA positivity for patients with spontaneous preterm delivery after 34 weeks of gestation was higher than for those delivering at term (adjusted OR = 2.04; P = 0.002); (iv) multiparous women were at a higher risk for HLA class I PRA positivity than nulliparous women (adjusted OR = 0.097, P < 0.0001 for nulliparity); (v) nulliparous women had a higher rate of HLA class I PRA positivity with advancing gestational age (P = 0.001); and (vi) 78% of women whose fetuses were genotyped had alloantibodies specific against fetal HLA class I antigens.

CONCLUSION

Pregnant women with positive HLA class I or class II PRA during the second trimester are at an increased risk of spontaneous preterm delivery due to antibody-mediated maternal anti-fetal rejection.

Unexplained fetal death has a biological signature of maternal anti-fetal rejection: chronic chorioamnionitis and alloimmune anti-human leucocyte antigen antibodies

AIMS

Chronic chorioamnionitis is a histological manifestation of maternal anti-fetal cellular rejection. As failure of graft survival is the most catastrophic event in organ transplantation, we hypothesized that fetal death could be a consequence of maternal rejection. The aim of this study was to assess whether there is evidence of cellular and antibody-mediated rejection in fetal death.

METHODS AND RESULTS

Placental histology was reviewed for the presence of chronic chorioamnionitis in unexplained preterm fetal death (n=30) and preterm live birth (n=103). Amniotic fluid CXCL10 concentrations were measured with a specific immunoassay. Chronic chorioamnionitis was more frequent in fetal death than in live birth (60.0% versus 37.9%; P<0.05) and fetal death had a higher median amniotic fluid CXCL10 concentration than live birth (2.0 versus 1.8 ng/ml, P<0.05), after adjusting for gestational age at amniocentesis. Maternal anti-human leucocyte antigen class II panel-reactive seropositivity determined by flow cytometry was higher in fetal death compared to live birth (35.7% versus 10.9%; P<0.05).

CONCLUSIONS

Chronic chorioamnionitis is a common pathologic feature in unexplained preterm fetal death. This novel finding suggests that cellular and antibody-mediated anti-fetal rejection of the mother is associated with fetal death (graft failure) in human pregnancy.