This is the first publication within IBD-RESPONSE umbrella. A multi-disciplinary project undertaken by the wider team and led by Dr James Alexander and Dr Nicola Wyatt. This research investigates the important consideration of the impact of short- and long-term storage of whole blood and isolated plasma, ahead of analysing metabolite profiles from patients recruited to CD-metaRESPONSE, a nested study within IBD-RESPONSE. For more information about this, please click here.
As CD-metaRESPONSE aims to recruit 300 patients from >15 centres across the UK, it is important to understand the impact of any differing sample handling and storage conditions on the metabolome data generated from samples. This may in theory occur during sample collection at hospitals, transfer of samples from sites to the central lab, and during long-term storage of isolated plasma at either -20oC or -80 oC. It is critical that these differences are considered to ensure high quality, robust and appropriately interpreted data.
The team conducted this research with whole blood from 5 adult participants and investigated the impact of 10 different conditions that may occur during initial processing, transport, and longer-term storage of CD-metaRESPONSE samples. Conditions include differing storage times of whole blood at 4oC, and long-term storage temperatures of subsequently isolated plasma samples (see diagram of conditions below).
Following the storage of blood and plasma, metabolites profiles were analysed by two methods: LCMS (liquid chromatography-mass spectrometry) and NMR (nuclear magnetic resonance).
LCMS analysis found that storage times of blood and plasma did not impact the metabolite profiles of the 5 participants, and any differences seen in the profiles were due to the inter-individual differences between participants. Interestingly, NMR analysis showed that one metabolite, lactic acid, was raised following 24 and 72 hours of storage of whole blood. Removal of lactic acid in future data sets may therefore be necessary to remove the impact of long-term storage of whole blood at 4 oC.
These important findings will be applicable to our CD-metaRESPONSE cohort, to ensure optimum sample collection, storage, and subsequent data analysis. Read the full research article here.