¹H HR‐MAS spectroscopy for quantitative measurement of choline concentration in amniotic fluid as a marker of fetal lung maturity: Inter‐ and intraobserver reproducibility study

Abstract

Purpose To determine the intra- and interobserver reproducibility of human amniotic fluid metabolite concentration measurements (including potential markers of fetal lung maturity) detectable by MR spectroscopy. Materials and Methods 1H high-resolution magic angle spinning (HR-MAS) spectroscopy was performed at 11.7T on 23 third-trimester amniotic fluid samples. Samples were analyzed quantitatively using 3-(trimethylsilyl)propionic-2,2,3,3-d4 acid (TSP) as a reference. Four observers independently quantified eight metabolite regions (TSP, lactate doublet and quartet, alanine, citrate, creatinine, choline, and glucose) twice from anonymized, randomized spectra using a semiautomated software program. Results Excellent inter- and intraobserver reproducibility was found for all metabolites. Intraclass correlation as a measure of interobserver agreement for the four readers ranged from 0.654 to 0.995. A high correlation of 0.973 was seen for choline in particular, a major component of surfactant. Pearson correlation as a measure of intraobserver reproducibility ranged from 0.478 to 0.999. Conclusion Quantification of choline and other metabolite concentrations in amniotic fluid by high-resolution MR spectroscopy can be performed with high inter- and intraobserver reproducibility. Demonstration of reproducible metabolite concentration measurements is a critical first step in the search for biomarkers of fetal lung maturity.

Metabolomic profile of amniotic fluid to evaluate lung maturity: the diaphragmatic hernia lamb model

“…Metabolomics of human AF has been recently used to detect different fetal pathologies in pregnancy such as chromosomal disorders [ 18 – 20 ], renal dysfunction [ 10 , 21 ], metabolic disease [ 10 ], neural tube anomalies [ 10 , 22 – 24 ] and defects of intrauterine growth [ 25 – 28 ]. Recent advances in metabolomics [ 10 – 13 , 29 ] also introduce AF evaluation as a new approach to fetal pulmonary development studies.…”

“…Metabolomics is commonly used to measure the entire metabolomic profile in biological fluids, cells, tissues or organs and to elucidate the association between metabolic pathways and perturbations that arise as a result of disease or organ malformation [ 10 – 13 ].…”

Comprehensive multiphase NMR: a promising technology to study plants in their native state

“…Even simple NMR experiments can provide molecular insights into the physical disposition of the phases, allowing quantitative and qualitative comparisons of the gel and soluble components from different samples. [8][9][10][11] However, the exploration of the molecular dynamics underpinning complex multiphase processes (such as primary cell wall formation, lignification, or root proliferation) would ideally involve simultaneous interrogation of all molecular components of a plant, including the solid phase in addition to the liquid and gel phases. This would require NMR technology that can handle the full range of liquid, HR-MAS (gel), and solid-state NMR experiments.…”

Can Biofluids Metabolic Profiling Help to Improve Healthcare during Pregnancy?

“…This paper describes the use of metabonomics, mainly based on nuclear magnetic resonance (NMR) spectroscopy, as a holistic analytical strategy in the quest for new and earlier biomarkers of both fetal and maternal health. In this context, previous reports of NMR of amniotic fluid (AF) have addressed, at a preliminary level, fetal maturity [2,3], gestational age [4,5], and several disorders, for example, PE, fetal malformations (FM), GDM, PTD, and premature rupture of membranes (PROM) [2,[6][7][8]. Metabolite profiling of urine and blood has been, however, less developed, in spite of the great potential of these biofluids for less-invasive diagnosis methods.…”