RT Journal Article SR Electronic T1 Exercise Capacity and Immune Function in Male and Female Patients with Chronic Fatigue Syndrome (CFS) JF In Vivo JO In Vivo FD International Institute of Anticancer Research SP 387 OP 390 VO 19 IS 2 A1 CHRISTOPHER R. SNELL A1 J. MARK VANNESS A1 DAVID R. STRAYER A1 STACI R. STEVENS YR 2005 UL http://iv.iiarjournals.org/content/19/2/387.abstract AB Hyperactivition of an unwanted cellular cascade by the immune-related protein RNase L has been linked to reduced exercise capacity in persons with chronic fatigue syndrome (CFS). This investigation compares exercise capacities of CFS patients with deregulation of the RNase L pathway and CFS patients with normal regulation, while controlling for potentially confounding gender effects. Thirty-five male and seventy-one female CFS patients performed graded exercise tests to voluntary exhaustion. Measures of peak VO2, peak heart rate, body mass index, perceived exertion, and respiratory quotient were entered into a two-way factorial analysis with gender and immune status as independent variables. A significant multivariate main effect was found for immune status (p<0.01), with no gender effect or interaction. Follow-up analyses identified VO2 peak as contributing most to the difference. These results implicate abnormal immune activity in the pathology of exercise intolerance in CFS and are consistent with a channelopathy involving oxidative stress and nitric oxide-related toxicity.