Abstract: CFSUM1 and CFSUM2 In Urine From Patients
With Chronic Fatigue Syndrome (...)
Abstract: CFSUM1 and CFSUM2 in urine from patients with chronic
fatigue syndrome are methodological artefacts.
8 August 2005
Clin Chim Acta. 2005 Aug 8; [Epub ahead of print]
Chalmers RA, Jones MG, Goodwin CS, Amjad S.
St George's Hospital Medical School, Cranmer Terrace, London SW17
McGregor et al. reported increased levels of an unidentified urinary
compound (CFSUM1) in patients with chronic fatigue syndrome (CFS),
with reduced excretion of another unidentified compound (CFSUM2),
and suggested the possibility of chemical or metabolic 'markers'
for CFS. The identity of CFSUM1 as reported was erroneous and the
identities of these compounds have remained unknown until now. Urine
samples were obtained from 30 patients with ME/CFS, 30 age- and
sex-matched healthy controls, 20 control patients with depression
and 22 control patients with rheumatoid arthritis. Samples were
prepared using the published methods of McGregor et al. to produce
heptafluorobutyryl-isobutyl derivatives of urinary metabolites.
Alternative preparations utilised isopropyl, n-butyl and trifluoroacetyl
derivatives. These were separated and identified using gas chromatography-mass
spectrometry. CFSUM2 was identified as being partially derivatised
[isobutyl ester-mono-heptafluorobutyryl (HFB)] serine. CFSUM1 was
identified as partially derivatised pyroglutamic acid, being the
isobutyl ester without formation of a HFB derivative. Both CFSUM1
and CFSUM2 are artefacts of the sample preparation procedure and
previously reported quantitative abnormalities of CFSUM1 and CFSUM2
in urine from patients with ME/CFS are also artefactual. Pyroglutamic
acid may be of primarily dietary origin. The methods used cannot
provide reliable qualitative or quantitative data on urinary metabolites.
No clinical or biochemical significance can be drawn between these
compounds in ME/CFS or any other clinical conditions.
Source: PMID: 16095585 [PubMed - as supplied by
Category: CFSUM1 and CFSUM2 in urine from patients
with chronic fatigue syndrome are methodological artefacts, Chalmers
, Jones , Goodwin , Amjad
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