Abstract
Background: A hypothesis suggests that chronic fatigue syndrome is associated with elevated circulating concentrations of cytokines, supported by the role of infections triggering the illness and the similarity with acute sickness behaviour, which is associated with elevated circulating cytokines. A preliminary study supported the roles of transforming growth factor beta and tumour necrosis factor alpha.
Method: We measured serum protein levels and mRNA of 11 cytokines at baseline, after commuting across London, and before and after exercise. After exercise, samples were taken immediately, 3 h and 2 days later. We studied 24 patients with CFS and 21 age- and sex-matched healthy but sedentary controls, following a preliminary study.
Results: There were significant differences between patients and controls in TGFβ protein levels both at baseline and all other measurement points. No other cytokine was abnormally distributed. Neither commuting nor exercise had a significant effect on TGFβ or any other cytokine concentrations. There were no significant differences in mRNA between groups at any time point.
Conclusion: This study replicates the results in both our preliminary study and a systematic review that circulating TGFβ was at a higher concentration at all times in patients with CFS compared to controls. In this study, mRNA for TGFβ was no different between patients and controls. This finding cannot be related to post-exertional exacerbation of symptoms, but needs further exploration. Studying cytokines in other body tissues, such as cerebrospinal fluid may provide different results.
Method: We measured serum protein levels and mRNA of 11 cytokines at baseline, after commuting across London, and before and after exercise. After exercise, samples were taken immediately, 3 h and 2 days later. We studied 24 patients with CFS and 21 age- and sex-matched healthy but sedentary controls, following a preliminary study.
Results: There were significant differences between patients and controls in TGFβ protein levels both at baseline and all other measurement points. No other cytokine was abnormally distributed. Neither commuting nor exercise had a significant effect on TGFβ or any other cytokine concentrations. There were no significant differences in mRNA between groups at any time point.
Conclusion: This study replicates the results in both our preliminary study and a systematic review that circulating TGFβ was at a higher concentration at all times in patients with CFS compared to controls. In this study, mRNA for TGFβ was no different between patients and controls. This finding cannot be related to post-exertional exacerbation of symptoms, but needs further exploration. Studying cytokines in other body tissues, such as cerebrospinal fluid may provide different results.
| Original language | English |
|---|---|
| Pages (from-to) | 631 |
| Journal | Journal of Psychosomatic Research |
| Volume | 78 |
| Issue number | 6 |
| Early online date | 2 May 2015 |
| DOIs | |
| Publication status | Published - Jun 2015 |