Comment on: Immune responsiveness in chronic fatigue syndrome. [Postgrad Med J. 1991]
Sir, The paper by Milton and colleagues (1) challenges the hypothesis that patients with postviral fatigue syndrome (myalgic encephalomyelitis) have a persisting viral infection along with consequent immune dysregulation. The protocol employed in the study suggests that their conclusions may not be valid.
Firstly, the 31 patients were selected from a group attending a ‘muscle clinic’ who complained of ‘unexplained chronic fatigue’. Of these only 15 had a clear history of a precipitating viral illness – a key diagnostic feature of postviral fatigue syndrome. Secondly, although other research groups have also demonstrated that raised levels of Coxsackie B virus IgG and IgM antibodies are not diagnostic of the syndrome, (2) these findings cannot be used to exclude the possibility of persisting viral infection within either muscle or the central nervous system.
As far as muscle is concerned, Gow and colleagues( 3) have recently detected enteroviral RNA sequences in muscle biopsies of 53% of patients with a well-defined postviral fatigue syndrome compared to 15% in a control group, and Archard et al. (4) have shown that this persisting enterovirus is poorly replicating.
Demonstrating the presence of persisting virus within the central nervous system is obviously far more difficult without autopsy material. However, Daugherty et al. (5) in America have published the results of MRI scans and cognitive function tests on 20 patients (with age and sex matched healthy controls) showing abnormalities consistent with an organic brain syndrome similar to that seen in patients who are positive for human immunodeficiency virus.
You can read the rest of this letter here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2399327/pdf/postmedj00061-0069a.pdf
Source: Shepherd C. Immune responsiveness in chronic fatigue syndrome. Postgrad Med J. 1992 Jan;68(795):66-7. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2399327/