CFS Twin Study: Phase 1 Abstracts Cellular immunity in monozygotic twins discordant for chronic fatigue syndrome. Journal: J Infect Dis 2002 Mar 15;185(6):828-32 Books, LinkOut Authors: Sabath DE, Barcy S, Koelle DM, Zeh J, Ashton S, Buchwald D. Affiliations: Departments of Laboratory Medicine, Medicine, and the Chronic Fatigue Syndrome Cooperative Research Center, University of Washington, Seattle, Washington 98195-7110, USA. mailto:dsabath@u.washington.edu NLM Citation: PMID: 11920301 Studies elsewhere have suggested that immune dysfunction may be common in patients with chronic fatigue syndrome (CFS). The objective of this study was to assess the nature and extent of abnormalities in lymphocyte cell surface markers and NK cell activity in patients with CFS while controlling for genetic factors. A co-twin control study of immune system parameters was conducted for 22 pairs of monozygotic twins discordant for CFS and 9 healthy pairs of twins. The CFS twins had greater numbers of CD62L(+) T cells in several T cell subsets, although these differences did not achieve statistical significance. Significantly greater variability was noted in twins discordant for CFS than in the concordant healthy twins for 20 of 48 variables examined. The monozygotic co-twin control design is of unique value because of its ability to control for genetic influences on CFS; however, additional studies will be required to further assess immune dysregulation in this illness. Chronic fatigue and chronic fatigue syndrome: a co-twin control study of functional status. Journal: Qual Life Res 2002 Aug;11(5):463-71 Authors: Herrell R, Goldberg J, Hartman S, Belcourt M, Schmaling K, Buchwald D. Affiliation: Division of Epidemiology-Biostatistics, University of Illinois at Chicago, USA. NLM Citation: PMID: 12113393 Chronic fatigue syndrome (CFS) and the symptom of chronic fatigue may be accompanied by substantial functional disability. A volunteer sample of twins discordant for fatigue was identified from throughout the US. Fatigued twins were classified using three increasingly stringent definitions: (1) > or = 6 months of fatigue (119 pairs); (2) CFS-like illness based on self-report of the Centers for Disease Control and Prevention CFS research definition criteria (74 pairs); and (3) CFS assessed by clinical examination (22 pairs). Twins with chronic fatigue were compared with their unaffected co-twins on the eight standard scales and two physical and mental component summary scales from the medical outcomes study short-form health survey (SF-36). Substantial impairment was observed for fatigued twins across all levels of fatigue, while scores in the healthy twins were similar to US population values. Mean scores among fatigued twins on the physical and mental component summary scales were below 97 and 77%, respectively, of the US population scores. Diminished functional status was found across increasingly stringent classifications of fatigue and was associated with a dramatic decrement in physical functioning. The symptom of fatigue has a pronounced impact on functional status, especially in the domain of physical functioning. Co-Cure Web Site: http://www.co-cure.org/