Lipid Metabolism Affects Fetal Fraction and Screen Failures in Non-invasive Prenatal Testing

Serum IL-18R1 and its effect on immune cell infiltration in asthma

OBJECTIVE

Asthma is a common chronic respiratory disease, affecting 5-10% of the global population. Despite its widespread impact, underdiagnosis remains a significant concern. This study aimed to explore the diagnostic potential of interleukin 18 receptor 1 (IL-18R1) and its relationship to immune cell infiltration in asthma.

METHODS

We retrospectively collected clinical and laboratory data of all participants. The expression of serum IL-18R1 in patients with asthma and healthy controls was quantified using enzyme linked immunosorbent assay (ELISA). The associations of IL-18R1 with clinical laboratory indicators and the diagnostic efficacy of IL-18R1 for asthma were assessed. Bioinformatic analysis was used to explore the biological function of IL-18R1 in asthma.

RESULTS

Peripheral blood white blood cells (WBC), neutrophils (NE), eosinophils (EO) and serum IL-18R1 were significantly elevated in patients with asthma compared to heathy controls. Patients with high IL-18R1 also had increased blood lymphocytes. The expression of IL-18R1 was associated with diverse immune cell infiltration and inflammatory pathways. Mendelian randomization (MR) analysis revealed a positive relationship between IL-18R1 and asthma. The area under the receiver operating characteristic (ROC) curve of the combination of IL-18R1 with WBC was 0.884, with a sensitivity and specificity of 84.8% and 81.8%.

CONCLUSION

Elevated expression of IL-18R1 is linked to the infiltration of various immune cells and the activation of inflammatory pathways. The combination of IL-18R1 and WBC may be a biomarker with high diagnostic accuracy for asthma.

TNFSF12 is associated with breast cancer prognosis and immune cell infiltration

BACKGROUND

Breast cancer (BRCA) is one of the most common cancers in women and is the leading cause of cancer-related deaths in women. TNFSF12, originally a member of the TNF superfamily, is considered a key molecule that is associated with poor prognosis of many cancers. However, its role in progression of BRCA remains unclear.

METHODS

In this study, the expression profile and clinical information of TNFSF12 across various cancers were obtained from The Cancer Genome Atlas (TCGA) database. Differences in TNFSF12 expression levels between carcinoma and paraneoplastic cancers were compared, and its association with prognosis was examined. Functional enrichment analysis was conducted to explore the potential signaling pathways and biological functions linked with TNFSF12. Moreover, the correlation between TNFSF12 and immune cell infiltration, response to immune checkpoint inhibitors (ICIs), and response to chemotherapy were evaluated. TNFSF12 level in BRCA and normal serum was detected by ELISA.

RESULTS

TNFSF12 was lowly expressed in BRCA and is significantly associated with PAM50. TNFSF12 low expression correlates with poor overall survival, particularly among HER2-positive patients. Patients with high level of TNFSF12 expression are usually accompanied with elevated levels of various immune cells, including CD8 T cells, cytotoxic cells, DCs, eosinophils, iDCs, mast cells, neutrophils, NK CD56bright cells, NK cells, pDC, T cells, Tem, and TFH Th17 cells, and exhibit sensitivity to immune checkpoint inhibitors. Functional enrichment analysis indicates significant activation of KRAS signaling, TNFA signaling via NFKB, and epithelial-mesenchymal transition (EMT) in the high TNFSF12 expression group, while MTORC1 signaling, MYC, G2M checkpoint, and E2F targets are inhibited. Furthermore, patients in the low expression group demonstrate higher sensitivity to paclitaxel and rapamycin, whereas those in the high expression group show increased sensitivity to erlotinib and foretinib. ELISA analysis also confirmed a significant decrease of TNFSF12 protein levels in BRCA patients.

CONCLUSION

This study presents a comprehensive analysis of the close correlation between TNFSF12 and prognosis, immune response, as well as the effectiveness of chemotherapeutic agents in BRCA patients.

cfDNA from maternal plasma for noninvasive screening of fetal exomes

In recent years, a shift in prenatal screening methods has been observed, moving away from traditional approaches such as ultrasound and maternal serologic markers towards the utilization of noninvasive prenatal testing (NIPT) based on cfDNA extracted from peripheral blood. This cutting-edge technology has established itself as the primary screening method, attributed to its superior detection rate and reduced false-positive rate. Although NIPT predominantly focuses on screening for chromosomal abnormalities, it currently does not encompass the identification of single-gene disorders. Considering that single-gene disorders contribute significantly to birth defects, accounting for 7.5% to 12% of cases, it becomes imperative to integrate screening for single-gene disorders into the birth defect prevention and control system. This study aims to provide a succinct overview of the recent advancements in NIPT specifically tailored for monogenic disorders.

Maternal and Fetal Factors Affecting Cell-Free Fetal DNA (cffDNA) Fraction: A Systematic Review

Background

Cell-free fetal DNA (cffDNA) is a novel screening method for fetal aneuploidy that facilitated non-invasive prenatal testing (NIPT) through analysis of cffDNA in maternal plasma. However, despite increased sensitivity, it has a number of limitations that may complicate of its results interpretation. Therefore, elucidating factors affecting fetal fraction, as a critical limitation, guides its clinical application.

Methods

In this report, systematic search was carried out through PubMed, Web of Science, and Scopus databases until February 11, 2022 by using keywords consist of "noninvasive prenatal screening", "NIPT", "noninvasive prenatal", "cell free DNA" and "fetal fraction". The articles were screened for eligibility criteria before data extraction.

Results

A total of 39 eligible studies, most published between 2010 and 2020, were included. Based on the results of studies, a negative correlation between maternal age and BMI/body weight with fetal fraction was found. Furthermore, LDL, cholesterol, triglyceride level, metformin, heparin and enoxaparin therapy, hemoglobin-related hemoglobinopathies, and physical activity showed to have negative associations. Interestingly, it seems the ethnicity of patients from South and East Asia has a correlation with fetal fraction compared to Caucasians. Positive correlation was observed between gestational age, free β-hCG, PAPP-A, living in high altitude, and twin pregnancy.

Conclusion

Considering each factor, there was significant inconsistency and controversy regarding their impact on outcomes. Indeed, multiple factors can influence the accuracy of NIPS results, and it is worth noting that the impact of these factors may vary depending on the individual's ethnic background. Therefore, it is important to recognize that NIPS remains a screening test, and comprehensive pre- and post-NIPS counseling should be conducted as part of standard clinical practice.

What helps define outcomes in persistent uninterpretable non-invasive prenatal testing: Maternal factors, fetal fraction or quality scores?

OBJECTIVES

To assess maternal characteristics and comorbidities in patients with persistent uninterpretable non-invasive prenatal testing (NIPT) and to evaluate the association with adverse pregnancy outcome in a general risk population.

METHODS

A retrospective cohort study (July 2017-December 2020) was conducted of patients with persistent uninterpretable NIPT samples. Maternal characteristics and pregnancy outcomes were compared with the general Belgian obstetric population.

RESULTS

Of the 148 patients with persistent uninterpretable NIPT, 37 cases were due to a low fetal fraction (LFF) and 111 due to a low quality score (LQS). Both groups (LFF, LQS) showed more obesity (60.6%, 42.4%), multiple pregnancies (18.9%, 4.5%) and more obstetrical complications. In the LQS group, a high rate of maternal auto-immune disorders (30.6%) was seen and hypertensive complications (17.6%), preterm birth (17.6%) and neonatal intensive care unit (NICU) admission (22%) were significantly increased. In the LFF group hypertensive complications (21.6%), gestational diabetes (20.6%), preterm birth (27%), SGA (25.6%), major congenital malformations (11.4%), c-section rate (51.4%) and NICU admission (34.9%) were significantly increased. Chromosomal abnormalities were not increased in both groups.

CONCLUSIONS

Patients with persistent uninterpretable NIPT have significantly more maternal obesity, comorbidities and adverse pregnancy outcome than the general population and should receive high-risk pregnancy care. Distinguishing between LFF and LQS optimizes counseling because maternal characteristics and pregnancy outcome differ between these groups.

White blood cell count affects fetal fraction and test failure rates in noninvasive prenatal screening

Objective

To investigate the effects of white blood cell (WBC) count on fetal fraction (FF), which is an essential quality control for obtaining reliable results, and on the rate of screen failures in noninvasive prenatal screening (NIPS).

Methods

Noninvasive prenatal screening, serum lipid and liver enzyme level measurements, and WBC count were performed for 4,281 pregnancies with male fetuses. After adjusting for confounders, including the maternal characteristics and alanine aminotransferase (ALT) levels, the effect of WBC count on FF and test failure rate was measured by linear and logistic regression analyses.

Results

Fetal fraction was negatively associated with BMI, ALT, IVF conceptions, and WBC count and positively correlated with gestational age in the multivariate linear regression model. Moreover, WBC count was the most important factor affecting FF after BMI according to the standardization coefficient analysis. In the 4,281 pregnancy samples with male fetuses, FF decreased with WBC count from 11.45% at ≤8 to 9.02% at >12, and FF markedly decreased to 7.40% in pregnancies with a higher WBC count (>12) and higher BMI (≥25 kg/m²). Meanwhile, the test failure rates were significantly higher in the WBC count > 12 group (4.29%) than in the WBC count ≤ 8 group (0.89%). Notably, when the BMI of pregnancies with a WBC count of >12 was >25, the rate reached 7.53%. Subsequently, multivariate logistic regression analysis further confirmed that an increased BMI and WBC count were independently and significantly associated with the test failure rates.

Conclusion

An increased WBC count was associated with lower FF and higher test failure rates, suggesting that these important factors should be carefully considered during genetic counseling in pregnant women who decide to undergo blood collection or resampling.

The Effect of Elevated Alanine Transaminase on Non-invasive Prenatal Screening Failures

Objective

To determine the effects of alanine transaminase (ALT) levels on the screening failure rates or “no calls” due to low fetal fraction (FF) to obtain a result in non-invasive prenatal screening (NIPS).

Methods

NIPS by sequencing and liver enzyme measurements were performed in 7,910 pregnancies at 12–26 weeks of gestation. Univariate and multivariable regression models were used to evaluate the significant predictors of screening failure rates among maternal characteristics and relevant laboratory parameters.

Results

Of the 7,910 pregnancies that met the inclusion criteria, 134 (1.69%) had “no calls.” Multiple logistic regression analysis demonstrated that increased body mass index, ALT, prealbumin, albumin levels, and in vitro fertilization (IVF) conception rates were independently associated with screening failures. The test failure rate was higher (4.34 vs. 1.41%; P < 0.001) in IVF pregnancies relative to those with spontaneous conceptions. Meanwhile, the screening failure rates increased with increasing ALT levels from 1.05% at ≤10 U/L to 3.73% at >40 U/L. In particular, IVF pregnancies with an ALT level of >40 U/L had a higher test failure rate (9.52%). Compared with that for an ALT level of ≤10 U/L, the adjusted odds ratio of “no calls” for ALT levels of 10–20, 21–40, and >40 U/L was 1.204 [95% confidence interval (CI), 0.709–2.045], 1.529 (95% CI, 0.865–2.702), and 2.764 (95% CI, 1.500–5.093) (Ptrend < 0.001), respectively.

Conclusions

Increased ALT and IVF conceptions were associated with a higher screening failure rates in NIPS. Therefore, a feasible strategy to adjust these factors to reduce the probability of “no calls” due to low FF would be of great clinical significance.