Clin Sci (Lond). 2003 Sep 23 [Epub ahead of print]. Khan F, Kennedy G, Spence VA, Newton DJ, Belch JJ.
We investigated whether the peripheral cholinergic abnormalities we previously reported in patients with chronic fatigue syndrome (CFS) are also present in those with Gulf War syndrome (GWS) and agricultural workers exposed to organophosphate pesticides, where cholinesterase inhibition is specifically implicated.
We also looked at whether these abnormalities might be due to a reduction in the activity of cholinesterase expressed on the vascular endothelium. We used laser Doppler imaging to measure the forearm skin blood flow responses to iontophoresis of acetylcholine and of methacholine (which is resistant to breakdown by cholinesterase) in patients with CFS, GWS, and those with a history of ill health after definite organophosphate exposure, as well as in matched, healthy controls.
The response to acetylcholine was significantly higher in patients with CFS than in controls (P = 0.029, repeated-measures analysis of variance), but was normal in those with GWS and those exposed to organophosphates. The methacholine response was higher than the acetylcholine response in all patient groups except for CFS, where there was no difference between the responses.
Although there are many clinical similarities between these three illnesses, our results indicate peripheral cholinergic abnormalities in the vascular endothelium of only patients with CFS, suggesting that this syndrome has a different aetiology, which might involve inhibition of vascular cholinesterase.
PMID: 14503920 [PubMed – as supplied by publisher]