Clinical chemistry最新文献

Background: Newborn screening (NBS) is a foundational public health program designed to identify severe but treatable conditions in presymptomatic newborns. Since Robert Guthrie introduced the phenylketonuria test in the 1960s, NBS has evolved from single-condition assays to multiplex platforms, enabling early diagnosis, intervention, and long-term follow-up. Understanding the historical, technological, and organizational aspects of NBS is critical to addressing the challenges posed by the integration of genomic technologies.

Content: Tandem mass spectrometry forms the backbone of current NBS, allowing cost-effective detection of multiple metabolites and expanding the scope of screening. NBS requires coordinated efforts among primary care providers, specialized teams, and state public health programs. Although the federal Recommended Uniform Screening Panel currently includes 64 conditions, adoption and implementation vary across states. Advances in genomic technologies, particularly next-generation sequencing (NGS), offer the potential to further expand NBS, complementing rather than replacing traditional functional screening. Integrating NGS raises challenges, including selection of disorders, management of variants of uncertain significance, presymptomatic diagnoses, and ethical and privacy considerations. Evidence is still needed to define the clinical utility, cost-effectiveness, and long-term outcomes of population-wide genomic screening.

Summary: NBS has transformed over the past 6 decades from single-condition testing to complex, multi-disorder programs. While genomic technologies promise further expansion, careful evaluation of clinical, ethical, and practical considerations is essential to ensure that NBS continues to provide timely, equitable, and beneficial care to all newborns.

Background: Prenatal cell-free DNA (cfDNA) screening has transformed the prenatal aneuploidy testing landscape testing since its clinical introduction in 2011. Leveraging placentally derived cfDNA fragments as fetal indicators in maternal plasma, cfDNA screening enables highly sensitive aneuploidy detection, most notably for trisomies 21, 18, and 13. With its superior performance compared to traditional screening approaches, cfDNA screening has been rapidly adopted into routine obstetric care worldwide.

Content: This review provides an overview of central laboratory foundations of prenatal cfDNA screening based on our in-house developed test experience and includes preanalytical, analytical, and postanalytical considerations. Key topics include specimen handling, quality management practices, an overview of assay platforms, and bioinformatic processing. We explore test performance characteristics such as sensitivity, specificity, and positive predictive value (PPV), as well as factors influencing test accuracy. We discuss critical topics such as interpreting discordant results, the significance of low fetal fraction, and the challenges of confined placental mosaicism and maternal health conditions, including malignancy. Additionally, we consider cfDNA screening expansion to genome-wide analysis with associated interpretive complexities.

Summary: Prenatal cfDNA screening has quickly become a cornerstone of modern prenatal care. Accurate test performance requires rigorous assay validation, quality assurance, and clear interdisciplinary communication. Understanding laboratory methods and limitations underlying tests is essential for accurate interpretation and appropriate clinical integration. This review highlights the rapid evolution of testing and its profound impact on prenatal screening. As adoption expands and clinical guidelines evolve, the laboratory role in ensuring analytical quality and accurate result interpretation is critical.

Background: Accurate quantification of neonatal bilirubin remains a perennial challenge. To monitor analytical performance of total bilirubin measurements across hospitals in the Netherlands, a dedicated neonatal external quality assessment (EQA) program is in place.

Methods: We retrospectively analyzed Dutch EQA data from 2013 until 2025. Each year, the 81 participating laboratories received 24 pooled adult blood serum samples spiked with unconjugated bilirubin (range 100-400 µmol/L or 5.85-23.40 mg/dL). Bias from the target value determined by the reference measurement procedure (RMP) and the coefficient of variation (CV) were established for both unfactored and factored measurements.

Results: In total, 25 983 bilirubin measurements were analyzed. Three analytical principles were used on 12 platforms from 6 manufacturers. Diazo-based methods exhibited the lowest median bias (+0.4% in 2024), alongside spectrophotometric methods (-3.8% in 2024). Vanadate-based methods showed a bias of +19.5% in 2024 that was reduced to +3.0% for factored measurements. Substantial differences in bias were observed among manufacturers and platforms, with some exhibiting concentration dependency. Comparable patterns were seen for CVs, which generally remained below 5%.

Conclusion: EQA results demonstrated temporal variability in bias across all analytical principles, manufacturers, and platforms used for neonatal bilirubin assays. Bias was found to vary with bilirubin concentration. Standardization of neonatal bilirubin assays is urgently needed to ensure more reliable and accurate measurements across different systems. Meanwhile, EQA programs are important in monitoring future assay adjustments to ensure appropriate and consistent management of neonatal hyperbilirubinemia.

Background: Childhood cancer, though rare, remains the leading cause of disease-related death among children in the United States. The overall incidence has been rising for the past several decades, and the factors underlying the increasing rates are unclear. This unexplained increase underscores the critical need for high-quality, well-powered epidemiologic research to elucidate causes and the natural history of childhood cancers.

Content: Newborn screening (NBS) utilizes dried blood spots collected soon after birth to identify serious, treatable conditions and enable timely intervention, testing over 98% of infants born in the United States annually. Some NBS programs allow for the retention and release of residual dried blood spots (rDBS) for research. rDBS enable population-based assessment of both endogenous and exogenous factors, including genetic, epigenetic, metabolic, immune characteristics, and environmental exposures during the perinatal period. This resource can overcome challenges of recall bias, exposure misclassification, and the impracticality of prospective cohort studies for rare cancers. Investigators have successfully used rDBS in epidemiologic studies, substantially advancing knowledge of several types of childhood cancers. Despite variability in storage and analyte stability, rDBS remain an invaluable resource to promote child health and constitute the only widely available prediagnostic biospecimen source for studies of childhood cancers.

Summary: rDBS from NBS programs represent a population-based, widely collected, prediagnostic biospecimen to investigate genetic, epigenetic, metabolic, and immune pathways underlying childhood cancer. Despite variability in storage policies, rDBS offer an unparalleled resource to advance etiologic understanding. Their integration into research could transform knowledge of childhood cancer causes and inform strategies for prevention and surveillance.

Background: Angiogenic biomarkers aid in short-term prediction of preeclampsia (PE) but are often limited by false-positive results. N-terminal pro-B-type natriuretic peptide (NT-proBNP), which is elevated in PE due to cardiovascular dysfunction, may enhance diagnostic precision. This study evaluated whether adding NT-proBNP to the soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio improves prediction of PE and associated complications within 1 week.

Methods: We performed a prospective multicenter case-control study in pregnancies with suspected PE between 24 + 0 and 41 + 0 weeks. Three models evaluated the addition of NT-proBNP (cutoff ≥116 pg/mL) to the sFlt-1/PlGF ratio using thresholds <38, ≥85, and 38 to 84. All models were assessed for early-onset, preterm, term, and overall PE prediction using receiver operating curve analysis, predictive metrics, and Kaplan-Meier survival curves.

Results: A total of 316 women (424 serum samples) were included. PE occurred in 23.4% of cases, including 8.5% early-onset PE. NT-proBNP levels were significantly elevated in PE cases. The addition of NT-proBNP improved early-onset PE prediction, particularly in intermediate-risk cases (sFlt-1/PlGF 38-84), achieving an area under the curve (AUC) of 0.949 and a negative predictive value (NPV) of 99.5%, outperforming sFlt-1/PlGF alone. Survival analysis revealed a shorter median time to delivery when both biomarkers were elevated (1.3 vs 4.0 weeks; P < 0.001). For term PE, NT-proBNP increased positive predictive value when combined with sFlt-1/PlGF ≥ 38. In complicated PE, the combined model improved specificity (77.4%) and AUC (0.770), with an NPV of 91.1%.

Conclusions: NT-proBNP enhances the short-term predictive performance of the sFlt-1/PlGF ratio, particularly in intermediate-risk cases. This multimarker approach may refine risk stratification and support timely clinical intervention in pregnancies at risk of PE.

Background: Birth defects registries seek to identify all cases of major birth defects occurring in a population that are identified in the first year of life, while other public health programs collect data on special needs, developmental disabilities, and early intervention services. Because newborn screening programs are population-based, despite that many of the conditions screened for are also birth defects, these conditions are not typically included in birth defects registries.

Content: This paper explores opportunities for integration of data from laboratory screening and diagnosis with birth defects registries and other public health programs to improve surveillance and better characterize phenotypic variation in infants born with metabolic disorders.

Summary: Utilizing laboratory data from newborn screening and genetic testing can improve birth defects surveillance and other public health programs.

Background: Rupture of membranes is defined as the leaking of amniotic fluid caused by the breaking of fetal amniotic membranes. Rupture of membranes is a major contributor to neonatal morbidity and mortality because it often occurs at preterm gestational ages leading to preterm birth. It also poses significant risk to maternal and fetal well-being due to the risk of infection, bleeding, cord prolapse, and placental abruption. Diagnosis can be challenging in up to 10% of cases. High diagnostic accuracy is required as it can have a profound impact on the recommendations for management and lead to iatrogenic preterm birth, especially at early gestational ages.

Content: Greater than 90% of rupture of membrane diagnoses can be made with physical examination, nitrazine testing, and microscopic fern testing. The gold standard for diagnosis is visualizing clear, amniotic fluid egressing from the external cervical os or with an amniocentesis dye test. The amniocentesis dye test is invasive and is associated with obstetric and fetal risks. Therefore, in cases equivocal for rupture of membrane diagnosis by physical examination, additional commercial immunoassays have been developed to detect protein markers that have a high concentration in amniotic fluid.

Summary: Rupture of membrane diagnosis should begin with conventional tests of physical examination, nitrazine paper testing, and microscopic ferning evaluation. Commercial immunoassays should be utilized in equivocal cases to assist in the diagnosis of membrane rupture when the diagnosis is unclear.

Background: Congenital cytomegalovirus (cCMV) infection is a leading cause of sensorineural hearing loss in children. Recent evidence that high-dose valacyclovir reduces vertical transmission following primary maternal infection has renewed the urgency for screening. We investigated the utility of quantifying cell-free CMV DNA from noninvasive prenatal screening (NIPS) data to identify pregnancies at risk for primary CMV infection and cCMV.

Methods: In this retrospective study, we analyzed NIPS data from 22 333 unselected pregnancies at 12 weeks gestation. CMV-aligned reads were quantified from low-pass whole-genome sequencing data and validated against quantitative PCR (qPCR) for viral load, maternal serology for infection status and systematic newborn screening for cCMV.

Results: CMV read counts demonstrated good correlation with qPCR-measured viral loads (rs = 0.76; 95%CI: 0.68-0.81). Presence of ≥1 CMV read count (2.1% of pregnancies) was highly predictive of cCMV [likelihood ratio (LR) = 21.1; 95% confidence interval (CI): 14.9-30.1]. CMV read counts showed good diagnostic accuracy for primary infection [area under the receiver operator characteristic curve (AUROC) = 0.77; 95% CI: 0.72-0.82] and for cCMV (AUROC = 0.82; 95% CI: 0.76-0.86). A threshold of ≥4 read counts identified a subgroup with significantly elevated risk for primary infection (LR = 7.8; 95% CI: 4.3-14.2) and cCMV (LR = 6.0; 95% CI: 3.3-10.8), achieving positive predictive value for cCMV of 51.7%.

Conclusion: Quantification of CMV DNA during NIPS is an accurate and sensitive method for CMV viral load. This approach effectively stratifies risk for both primary maternal infection and cCMV, enabling identification of pregnancies that may benefit from antiviral therapy.