Serum activin B concentration as predictive biomarker for ectopic pregnancy

Evaluation of novel biomarkers for early pregnancy outcome prediction†

OBJECTIVE

To assess performance and discriminatory capacity of commercially available enzyme-linked immunosorbent assays of biomarkers for predicting first trimester pregnancy outcome in a multi-center cohort.

DESIGN

In a case-control study at three academic centers of women with pain and bleeding in early pregnancy, enzyme-linked immunosorbent assays of biomarkers were screened for assay performance. Performance was assessed via functional sensitivity, assay reportable range, recovery/linearity, and intra-assay precision (%Coefficient of Variation). Top candidates were analyzed for discriminatory capacity for viability and location among 210 women with tubal ectopic pregnancy, viable intrauterine pregnancy, or miscarriage. Assay discrimination was assessed by visual plots, area under the curve with 95% confidence intervals, and measures of central tendency with two-sample t-tests.

RESULTS

Of 25 biomarkers evaluated, 22 demonstrated good or acceptable assay performance. Transgelin-2, oviductal glycoprotein, and integrin-linked kinase were rejected due to poor performance. The best biomarkers for discrimination of pregnancy location were pregnancy-specific beta-1-glycoprotein 9, pregnancy-specific beta-1-glycoprotein 1, insulin-like growth factor binding protein 1, kisspeptin (KISS1), pregnancy-specific beta-1-glycoprotein 3, and beta parvin (PARVB). The best biomarkers for discrimination of pregnancy viability were pregnancy-specific beta-1-glycoprotein 9, pregnancy-specific beta-1-glycoprotein 3, EH domain-containing protein 3, KISS1, WAP four-disulfide core domain protein 2 (HE4), quiescin sulfhydryl oxidase 2, and pregnancy-specific beta-1-glycoprotein 1.

CONCLUSION

Performance of commercially available enzyme-linked immunosorbent assays was acceptable for a panel of novel biomarkers to predict early pregnancy outcome. Of these, six and seven candidates demonstrated good discriminatory capacity of pregnancy location and viability, respectively, when validated in a distinct external population. Four markers demonstrated good discrimination for both location and viability.

Ectopic pregnancy: search for biomarker in salivary proteome

Ectopic pregnancy (EP) is associated with high maternal morbidity and mortality. Ultrasonography is the only dependable diagnostic tool for confirming an ectopic pregnancy. In view of inadequate early detection methods, women suffer from a high-life risk due to the severity of EP. Early detection of EP using pathological/molecular markers will possibly improve clinical diagnosis and patient management. Salivary proteins contain potential biomarkers for diagnosing and detecting various physiological and/or pathological conditions. Therefore, the present investigation was designed to explore the salivary proteome with special reference to EP. Gel-based protein separation was performed on saliva, followed by identification of proteins using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). Totally, 326 proteins were identified in the salivary samples, among which 101 were found to be specific for ruptured ectopic pregnancy (EPR). Reactome analysis revealed innate immune system, neutrophil degranulation, cell surface interactions at the vascular wall, and FCERI-mediated NF-kB activation as the major pathways to which the salivary proteins identified during EPR are associated. Glutathione-S-transferase omega-1 (GSTO1) is specific for EPR and has been reported as a candidate biomarker in the serum of EPR patients. Therefore, saliva would be a potential source of diagnostic non-invasive protein biomarker(s) for EP. Intensive investigation on the salivary proteins specific to EP can potentially lead to setting up of a panel of candidate biomarkers and developing a non-invasive protein-based diagnostic kit.

Miscarriage determination in first trimester based on alpha-fetoprotein extracted from sanitary pads

OBJECTIVE

To determine if high alpha-fetoprotein (AFP) level in vaginal blood collected on a sanitary pad can assist with detecting an active miscarriage.

DESIGN

A prospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

Five groups were evaluated: women with active miscarriage, pregnancy of unknown location, completed miscarriage or extrauterine pregnancy (EUP), ongoing pregnancy, and undergoing elective dilation and curettage (D&C).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

For each patient, AFP level in the vaginal blood collected on a sanitary pad was quantified.

RESULT(S)

The vaginal blood AFP median levels (and their ranges) were 3.7 IU/mL (0.5-739.2) and 4,542 IU/mL (15.6-100,000) in the active miscarriage (n = 16) and the elective D&C (n = 24) groups, respectively. Alpha-fetoprotein was detected in all elective D&C and active miscarriage cases except in 1 case. In the ongoing pregnancy group (n = 35), only 2 of 35 specimens showed detectable AFP levels. In the pregnancy of unknown location (n = 12) and the completed miscarriage or EUP (n = 10) groups, no AFP was detected. Receiver operating characteristic analysis demonstrated 93.7% sensitivity and 97.8% specificity for the detection of an active miscarriage (cutoff 0.61 IU/mL; area under the curve 0.96).

CONCLUSION(S)

Alpha-fetoprotein can be extracted from vaginal blood collected on sanitary pads. A high level of vaginal AFP can assist with the same-day detection of an active miscarriage. This novel test is useful in differentiating active miscarriages from ongoing pregnancies, completed miscarriages, and EUPs and, therefore, it reduces uncertainty, anxiety level, and number of repeat office visits.

Evaluation of maternal serum biomarkers in predicting outcome of successful expectant management of tubal ectopic pregnancies

OBJECTIVE

To assess the value of multiple serum biomarkers for the prediction of successful outcome of expectant management in women with tubal ectopic pregnancy (TEP).

STUDY DESIGN

Women with a conclusive ultrasound diagnosis of TEP had a blood test to measure β-human chorionic gonadotropin (β-hCG), progesterone, inhibin A, activin A and high sensitivity C-reactive protein (hsCRP) at the initial visit. Women presenting with pain, serum β-hCG ≥ 1500 IU, evidence of a live ectopic pregnancy or a significant haemoperitoneum were advised to have emergency surgery. Women eligible for expectant management were followed-up prospectively until serum β-hCG declined to non-pregnant level or surgical treatment was required.

RESULTS

A total of 93 women with a TEP were included in the final cohort. Emergency surgery was carried out in 42/93 (45 %) of women whilst 51/93 (55 %) were managed expectantly. Of the latter group, 42/51 (82 %) had successful expectant management and 9/51(18 %) required surgical procedure after a period of follow up. On multi-variable analysis, only higher values of serum β-hCG and progesterone at the initial visit were associated with a lower chance of successful expectant management of TEP. A one-unit increase in either variable on the log-scale was associated with an approximate 20-fold reduction in the odds of a successful outcome.

CONCLUSION(S)

Serum β-hCG and progesterone were significantly lower in women who had successful expectant management of TEP. Other biomarkers under consideration were not significantly different in women with successful and failed expectant management.

Same-day confirmation of intrauterine pregnancy failure in women with first- and early second-trimester bleeding

OBJECTIVE

To determine if alpha-fetoprotein (AFP) concentration in vaginal blood, in the setting of dissolved fetal tissue, is significantly higher than its concentration in the maternal serum.

DESIGN

A prospective cohort study.

SETTING

Medical center.

PATIENT(S)

Four groups of women were evaluated: 1) with missed/incomplete miscarriage with vaginal bleeding; 2) with threatened miscarriage; 3) with vaginal bleeding during cerclage placement; and 4) undergoing dilation and curettage (D&C).

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

In each patient, AFP concentration in the vaginal blood or in the liquid component of the evacuated products of conception (POC; D&C group) was compared with the AFP concentration in the maternal serum.

RESULT(S)

The median (range) concentration ratios of AFP in vaginal blood (or POC) to AFP in maternal serum were 24.5 (5.1-8,620) and 957 (4.6-24,216) for the missed/incomplete (n = 30) and the D&C (n = 22) groups, respectively, whereas they were only 1.2 (0.4-13.4) and 1.01 (0.7-1.5) for the threatened miscarriage (n = 15) and cerclage (n = 9) groups, respectively. Receiver operating characteristic (ROC) analysis demonstrated 100% sensitivity and 86.7% specificity for the detection of the passage of fetal tissue (ratio 4.3, area under the ROC curve 0.96).

CONCLUSION(S)

Higher concentrations of AFP in vaginal blood than in maternal serum may indicate the presence of dissolved fetal tissue (i.e., confirming a failed pregnancy).

Cytokines in relation to hCG are significantly altered in asymptomatic women with miscarriage - a pilot study

BACKGROUND

Spontaneous abortion is one of the most common complications in early pregnancy. A preventive test to identify women who will experience a miscarriage, even before first symptoms occur, is not established. Activation of maternal immunological tolerance seems to be essential for early fetal development and various cytokines have been described in different stages of pregnancy. Therefore, we aimed to investigate if chemokine levels at the time of pregnancy testing relative to human Choriogonadotropin (hCG) are altered in patients who will experience a miscarriage in this pregnancy.

METHODS

We obtained blood samples from 39 women. Dependent on the follow-up, patients with a positive pregnancy test were subsequently divided in two groups: ongoing pregnancy (n = 22) and miscarriage (n = 17) in this pregnancy. Immunological and endocrine profiling of maternal plasma at the time of pregnancy testing (5th week of gestation) was performed for each group at the time of pregnancy test using Multiplex and ELISA analysis.

RESULTS

hCG was significantly decreased in patients with abortion whereas levels of IL-1ra, MIP-1a and TNF-alpha were significantly increased. GCSF/ IL-1ra-ratio was 1.66-fold increased in patients with ongoing pregnancy. TGF-beta /MIP1a-ratio was significantly 3.45-times higher in patients with miscarriage. Comparing patients with ongoing pregnancy to patients experiencing a miscarriage, we could demonstrate significant alterations of the ratios MIP1a/hCG, IL-1ra/hCG, TNFalpha/hCG, MCP1/hCG, IL-6/hCG, TPO/hCG and TGF-beta1/hCG. The strongest effects were seen for the ratio MIP1a/hCG, IL-1ra/hCG and TNFalpha/hCG.

CONCLUSIONS

We have shown that cytokines in relation to hCG after 4 weeks of gestation are significantly altered in women with miscarriage, promising potential as a prognostic biomarker.

The potential value of activin B and fibronectin for the triage of pregnancies of unknown location and prediction of first trimester viability

Aim

We have assessed the potential predictive ability of the biomarkers activin B and fibronectin (FN1) alone and when added to established markers for triaging patients as being at low or high risk of ectopic pregnancy (EP). We also assessed their use as predictors of viability at 12 weeks gestation.

Methods

Exploratory secondary analysis of a prospective study including all women classified as a pregnancy of known location (PUL) based on transvaginal ultrasonography between January and December 2007 at the early pregnancy unit of St Georges' Hospital (London). We used multinomial logistic regression to assess the diagnostic potential of the biomarkers to triage PUL at high risk of complications (EP or persistent PUL), and standard binary logistic regression to predict first trimester viability at 12 weeks.

Results

For discriminating high-risk (n = 16) from low-risk PUL (n = 93), the area under the receiver operating characteristic curve (AUC) was 0.75 (95% confidence interval 0.60-0.85) for activin B and 0.55 (0.41-0.68) for FN1. Adding activin B to a multinomial logistic regression model incorporating β-hCG ratio and initial progesterone yielded odds ratios of 0.16 (0.05-0.55) for failing vs high-risk PUL and 0.29 (0.07-1.19) for intrauterine vs high-risk PUL and increased the model's AUC from 0.84 to 0.89. At a risk threshold of 5% for high-risk PUL, sensitivity increased from 84% to 87% and specificity from 48% to 64%. For discriminating viable (n = 28) from non-viable (n = 81) pregnancies at 12 weeks, both markers had an AUC of 0.54.

Conclusions

Our results suggested that activin B may be a promising marker to improve PUL triage in addition to established markers.

Serum periostin levels in early in pregnancy are significantly altered in women with miscarriage

BACKGROUND

Miscarriage is a common complication in pregnancy and there is still a lack of biomarkers usable in asymptomatic patients before the event occurs. Periostin (PER), whose levels rise particularly during injury or inflammation, has been shown to play an important local role in implantation and early embryonic development. As PER has been described as a biomarker in various medical conditions we intended to evaluate if changes in PER serum levels may help to identify women at risk for spontaneous abortion in the first trimester.

METHODS

Women between 18 and 42 years without confounding comorbidities who conceived by IVF/ICSI and ovarian hyperstimulation were analysed in the study after informed consent. Maternal serum samples from 41 patients were assessed at the time of pregnancy testing (PT) and the following first ultrasound checkup (US). Patients were subsequently divided in two groups: (1) patients with subsequent miscarriage in the first trimester (n = 18) and (2) patients with ongoing pregnancy (n = 23), allowing for statistical analysis and investigating the change of PER levels per individual. PER levels were measured using enzyme-linked immunosorbent assay. Statistical analysis was performed using the Fisher exact and Student's t test. p ≤ 0.05 was considered to be significant.

RESULTS

There was no significant difference concerning possible confounders between the two groups. We did not find any significant difference in PER levels at the time point of PT or US. By investigating the interindividual changes of PER between the two time points however, we observed that patients with a following miscarriage showed increasing levels of PER at the time point of PT compared to US in contrast to patients with an ongoing pregnancy who demonstrated a decrease in PER levels. These alterations were significant in the absolute as well as in the relative comparison.

CONCLUSION

The relative expression of PER between PT and US is significantly altered in asymptomatic women with subsequent miscarriage compared to women with ongoing pregnancy. Therefore systemic PER levels might represent a potential promising biomarker for the assessment of pregnancy outcome.

TRIAL REGISTRATION

Not applicable.