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  1. Beth Dibnah1,
  2. Emmanuella Traianos1,
  3. Jessica Tarn1,
  4. Dennis Lendrem1,
  5. Wan Fai Ng1,2,
  6. on behalf of United Kingdom Primary Sjögren’s Syndrome Registry
  1. 1Newcastle University, Institute of Cellular Medicine, Newcastle, United Kingdom
  2. 2NIHR Newcastle Biomedical Research Centre, Newcastle, United Kingdom


Background: Chronic fatigue syndrome (CFS) is estimated to affect up to 5% of people in Europe and is more common in women than men. It is characterised by unexplained fatigue, post-exertional malaise and a range of other symptoms. Recent studies indicate potential immune dysfunction in CFS, specifically regarding cytokines and the adaptive behavioural response.

Objectives: This study aims to investigate serum transforming growth factor-beta (TGF-β) and the expression of the TGF-β Receptor 1 (TGFBR1) and TGF-β Receptor 2 (TGFBR2) genes, in relation to the fatigue associated with CFS.

Methods: Serum active and total TGF-β concentrations were measured in 117 CFS patients and 40 HCs using a TGF-β responsive luciferase bioassay. Expression levels of TGFBR1 and TGFBR2 were analysed using quantitative PCR. Fatigue was measured using the fatigue impact scale (FIS)1. FIS was categorised into three groups; ‘mild’ (0-80), ‘moderate’ (81-120) and ‘severe’ (121-160). Linear and ordinal regressions were performed on the continuous FIS and FIS categories respectively.

Results: Serum TGF-β concentrations in the CFS group did not differ significantly compared with the HC group (p=0.58). TGF-β concentrations showed no correlation with disease duration but there was a trend towards decreased TGF-β with increasing symptom duration. There were no significant differences between the levels of TGFBR1 and TGFBR2 in any of the fatigue groups, or between HCs. Active TGF-β concentrations were significantly elevated in the ‘severe’ FIS group compared to the ‘mild’ FIS group (p=0.04). Active/total TGF-β levels were significantly higher in the ‘severe’ FIS group than the ‘mild’ and ‘moderate’ FIS groups (p=0.02, p=0.03 respectively).

Conclusion: These data suggest no differences in serum concentrations of TGF-β or expression of TGFBR1 and TGFBR2, between the HC and CFS groups. It also suggests no differences in expression levels of TGFBR1/2 between any of the CFS fatigue groups. However, active/total TGF-β levels were increased in more severely fatigued patients based on FIS. This finding could be due to higher levels of circulating TGF-β, or increased amounts of TGF-β activation. Further work is necessary to confirm this finding in a larger cohort of CFS patients, and to explore how this increase in TGF-β relates to fatigue.

References [1] Fisk JD, Ritvo PG, Ross L, Haase DA, Marrie TJ, Schlech WF. Measuring the functional impact of fatigue: initial validation of the fatigue impact scale. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 1994;18Suppl 1:S79-83.

Disclosure of Interests: None declared

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