New Approach for Inborn Errors of Metabolism Screening by NMR

At the 12th International Congress of Inborn Errors of Metabolism (www.iciem2013.com), Bruker announces another milestone in the cost-effective use of NMR (nuclear magnetic resonance) spectroscopy screening as a clinical research tool for metabolic screening and small molecule in vitro diagnostics (IVD) research and validation.

The novel Inborn Errors of Metabolism (IEM) screening assay was successfully demonstrated during a clinical study in Turkey, in which over 1,000 newborn babies were screened by NMR in an effort to establish a method for a non-invasive, efficient and reliable assessment of absolute and relative metabolite concentrations in newborns, allowing pediatricians to assess their health, and to detect a multitude of inborn metabolic errors simultaneously.

The comprehensive urine-screening program included 14 hospitals in Turkey, integrating both targeted and non-targeted screening techniques in a high-throughput method requiring only approximately 12 minutes of NMR measurement time per sample. The study has successfully demonstrated the ability to quantify simultaneously 45 metabolites occurring in 49 different types of inborn errors of metabolism in neonates at clinically relevant metabolite concentrations. Moreover, the novel IEM-by-NMR screen also provides additional metabolic information on other health conditions, such as maturity problems, jaundice or ketosis, from the same assay and without additional measurements or costs.

Initially started as a ZIM project (German Government Central Innovation Program SME), Bruker partnered on the development of this IEM screening method for Turkish newborns with INFAI GmbH in Cologne, Germany, which coordinated the screening program in Turkey with the assistance of Professor Selda Bülbül from Kirikkale University (www.kku.edu.tr). The IEM screening study has been utilizing the Bruker AVANCE™ IVDr, a novel high-throughput screening and IVD research NMR platform , which offers simultaneous non-targeted and targeted analysis.

In the IEM screening study in Turkey, the targeted method was optimized to deliver the automatic quantification of 65 relevant urinary metabolites, including 20 endogenous metabolites connected to general health state and 45 metabolites indicative for inborn errors of metabolism, allowing to screen for 49 IEMs on newborns, as several markers appear in more than one disease, but with different co-biomarkers. The metabolic screening of urine by NMR has significant benefits over other methods, being non-invasive, including straightforward sample collection and preparation without derivatization, requiring only 12 minutes for 1D and 2D NMR measurements without the need for chromatography, and offering unbiased NMR quantitation with high dynamic range and without the need for spiking expensive isotopic standards.

The emerging IEM-by-NMR screening method also has potential limitations, including intrinsically lower metabolite sensitivity compared to mass spectrometry or immunoassays, as NMR is generally not suitable for trace analysis and requires moderate to high metabolite concentrations for correct identification and quantification. IEM-by-NMR screening also is not designed to detect any genetic, proteomic or peptide biomarkers.

The majority of IEMs, however, can be quantified with NMR simultaneously and quickly, which promises to make IEM-by-NMR screening very cost-effective, as multiple conventional methods would be needed to get the same results. As stated earlier, NMR is not able to measure all possible types of inborn errors of metabolism, therefore other methods may be recommended in addition. Bruker has developed appropriate standard operating procedures (SOPs), a fast 1D and 2D NMR data acquisition strategy, proprietary and novel statistical tools and quantitation algorithms, as well as a large metabolite database which together have successfully overcome potential issues like the dependency of NMR chemical shifts on ionic matrix changes and composition, or NMR spectral overlap in many signal regions.

Moreover, in addition to the metabolic concentrations for the targeted 49 inborn errors of metabolism, the information-rich, multi-parameter, simultaneous IEM-by-NMR assessment also delivers a non-targeted general metabolic overview of normal health of newborns, including metabolic deviations from normality, and important outlier information, which may suggest pediatric follow-up or longitudinal NMR monitoring of certain newborns.

Dr. Sitke Aygen, President and CEO of INFAI GmbH, commented: “We are excited about the possibilities of newborn screening by NMR, offering the possibility to combine targeted and untargeted screening in one experiment. To exploit this new technology, INFAI started a project on newborn urine screening in cooperation with Bruker and 14 screening centers all over Turkey. The unmatched reproducibility of NMR, when working under strict SOPs, offers the unique chance in a multi-center approach to recognize a multitude of inborn errors within one experiment, and to obtain general information on newborn status and health. The new, standardized AVANCE IVDr 600 MHz NMR system provides an excellent basis for this work.”

The next steps for the clinical study partners are support for the clinical adoption, regulatory approval and reimbursement of IEM-by-NMR screening in Turkey, while Bruker is planning further method refinements to the algorithms and database to expand the targeted screening with clinical IEM studies in other European countries. Further clinical research directions include the gradual expansion of the number of targeted metabolites quantified, as well as clinical studies for the assessment of children and adults suffering from inborn or other metabolic errors.

Dr. Manfred Spraul, Bruker’s Director of Business Development for Applied & Clinical NMR, stated: “Using the AVANCE IVDr platform, we have built a NMR database of over 240 metabolites related to inborn errors of metabolism, which is supplemented by an even larger database of metabolites relevant for general health and phenotype assessment. Being able to identify and quantify 65 metabolites simultaneously in a single, 12 minute IEM-by-NMR screen, without chromatography or expensive isotopic standards, offers significant cost and throughput benefits. We are looking forward to validating this IEM-by-NMR approach in other European countries.”

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