HM Medical Clinic

Slide

The role of NMIs in providing reference measurements for the clinical sector - an LGC perspective Dr Ruth Hearn
Biomedical Analysis & Metrology Laboratories Workshop
Rabat, Morocco
19 – 20 November 2012

• Introduction to LGC • LGC, the National Measurement Institute • Scientific capabilities • Isotope dilution methods • Reference material certification • Examples of reference measurements for the clinical – Metals in serum CRM – Reference measurements for TDM

LGC today
Home of the UK's designated National Measurement
Institute and the UK Government Chemist
Measurement research Regulatory services Reference measurement services Standards development Training and consultancy Scientific programme management Reference Materials at LGC
• Worldwide distributor of reference materials from numerous producers • In-house RM production facilities: – The NMI facility at Teddington, UK – Two laboratories in the US: • New Hampshire – oil based and aqueous standards • Denver – metal CRMs – Gemany – pharmaceutical standards – India – pharmaceutical standards LGC locations
Edinburgh
N. IRELAND
St Petersburg
UK
Wakefield
Tamworth
Bromsgrove
Hoddesdon
Twickenham
Teddington
Luckenwalde
POLAND Lomianki
NETHERLANDS Wesel
Shanghai
GERMANY REPUBLIC
Molsheim
Szentendre
Cluj-Napoca
Manchester
Istanbul
USA
Lexington
Barcelona
UAE
SOUTH AMERICA
Ahmadabad
Sao Paulo
Hyderabad
Bangalore
SOUTH AFRICA
LGC's national roles
National Measurement
Government Chemist
Institute (NMI)
Referee Analyst (4 Acts of Delivers world-class measurement science: a leading Adviser to government and NMI for chemistry & bioanalysis industry on regulations & Provides traceable and accurate scientific input standards of measurement for "Using sound analytical use in industry, academia and science in support of policy and regulation" Active involvement in CCQM, RMO, ISOREMCO, etc Range of capabilities listed on CMC1 and JCTLM2 databases 1 http://kcdb.bipm.org/AppendixC 2 http://www.bipm.org/jctlm Scientific Capabilities:
Inorganic
• High accuracy quantitative analysis by ICP-MS • Speciation analysis (quantitative & identification) by LC- ICP-MS, GC-ICP-MS and ion trap LC-MS • Nano-particle analysis using field flow fractionation FFF- • Solid sampling and imaging using laser ablation ICPMS • Isotope ratio determination by multi-collector ICP-MS Scientific Capabilities:
Organic
• High accuracy quantitative analysis by LC-MS/MS • High mass accuracy identification using ion traps and time of flight instruments • Specialist separation techniques including nano LC, multidimensional GC, ion mobility • Imaging capability using MALDI-TOF-TOF and DESI • Quantitative and structural analysis of proteins and • High accuracy purity assessment using a range of classical techniques and qNMR Scientific Capabilities:
Biological
• Next generation sequencing: – High accuracy sequencing and differentiation of microbial • Foods analysis – High accuracy quantification of GMOs - NRL status – Detection of food fraud and food adulteration • MiRNA analysis: – High accuracy mi RNA quant – Development of prototype reference materials • Cell analysis: – High accuracy cellular imaging and metrology – Nanotoxicology and toxicology Isotope Dilution Mass
Spectrometry
• The sample is spiked with a solution of an isotopic analogue of the analyte of interest (= sample blend) • A calibration standard is spiked with the same solution as the sample (= calibration blend) • Sample blends and calibration blends are prepared such – the isotope ratios in the blends are the same – the intensities of the peaks in the blends are the sa Exact Matching Double IDMS
Advantages of IDMS
• the spike material is the ideal internal standard as it behaves in exactly the same way as the analyte • once equilibrated, any losses due to the sample preparation do not affect the result • the effects of mass bias and linearity are eliminated since they affect both calibration and sample blends • accurate quantification of the isotopic analogue is not • potential for high accuracy and low & well-defined Limitations of IDMS
• an iterative process as the analyte concentration must be determined before exact matching can occur • equilibration between the analyte and the isotopic analogue must occur before extraction. For organic extractions, extensive equilibrium studies must be performed • traceability is through the calibration standard (hence the emphasis on purity determination) • there must be no significant conversion of compounds during extraction →Time-consuming and expensive. CRM Production within the NMI
Accredited to ISO-Guide 34 Pure RM production for >20 years • Matrix materials • Single substance organic – Melting point – Enthalpy of fusion – Elemental content European Reference Materials
(ERM)
A joint collaboration of three major European reference materials
producers (IRMM, BAM & LGC)
Peer-review of CRMs by the European Reference Materials
technical committee ensures highest quality and reliability
Full transparency of the certification principles and the evaluation
report provides valuable insight to help analysts get the maximum
benefit from the use of the material.
Clearly defined and stated traceability of the certified values
ensures applicability of the materials to the respective analytical
problem.
Internationally recognised values underpinned through the
participation of the producing institutes in the key comparisons
organised by the BIPM
Characterisation Approaches
• Single Primary (Definitive) Method – Utilises NMI capabilities eg isotope dilution mass spec • Consensus certification – Multiple laboratory study – Typically benefits from robust estimates • Two or More Independent Methods – Requires detailed uncertainty information for methods – Particular problems with ‘between-method' effects Approaches to Stability
Assurance
Prior information – Use Published and/or Readily Available Information – Use of Data from Related • materials, packaging and New Stability studies – Accelerated testing – Long-term testing • Isochronous testing Determine a value for ults = the equivalence of the mathematical relationships between the results of different measurement procedures for a RM and for representative samples from healthy and diseased individuals • Particularly relevant for clinical CRMs where method used for certification (eg IDMS) may be very different from routine methods (eg assay) • Important component of CRM certification All materials distributed through LGC Standards All stored in controlled conditions mostly in the UK Additional world-wide warehousing is imminent Customer Support
Expertise / knowledge available for lifetime of material All enquiries are collated and stored Trace metals in biological CRMs
The analysis of trace metals in biological matrices such as serum or urine is performed routinely These can be performed as part of clinical studies; as indicators or disease or organ function or as indictors of artificial joint corrosion ERM-DA120a1 has been certified for content of Cu, Se & Zn and will soon be additionally certified for Ca, Fe, K, Mg and selenomethionine We are also planning to certify a blood CRM for Co & Cr content in response to a recent MHRA directive2 that recommends blood level monitoring for metal-on-metal hip-replacement patients and additional remedial action if Co & Cr levels are observed at > 7 Therapeutic drug monitoring of
immunosuppressants
Immunosuppressants such as tacrolimus, sirolimus and ciclosporin ar e primarily used to prevent rejection of organ transplants Potent compounds with very severe side-effects Patients monitored monthly to check levels in blood in therapeutic range: e.g. tacrolimus therapeutic range is typically 3 – 15 ng/mL A variety of techniques are used in clinical laboratories including immunoassay and mass spectrometry There are no reliable standards and clinicians cannot compare data obtained from different laboratories LGC have released a CRM of
tacrolimus in whole blood using an
isotope dilution method and provided
reference measurements to 2 assay
kit producers.
Other clinically relevant CRMs
A range of high purity organic compounds to be used for calibration purposes, eg digoxin, theophylline, etc A range of ethanol solutions used for blood alcohol and breath analyser calibration ERM-DA200 & 201 Digoxin in serum ERM-DA250 to 253 Creatinine & Electrolytes in serum • ERM-DA345 & 346 Testosterone in serum LGC is active in provision of high accuracy measurement services and certified reference materials We are keen to receive feedback from RM users about what materials are required Thank you for your attention

Source: http://www.miraproject.eu/workgroups-area/workgroup.wp7/workgroup-documents-library/workshop-on-networking-on-life-sciences-health-laboratories-in-the-mediterranean-region-1/The%20role%20of%20NMIs%20in%20providing%20reference%20measurements%20for%20the%20clinical%20sector%20-%20An%20LGC%20perspective%20-%20Ruth%20Hearn.pdf