Abstract

Background: Previous research has suggested that natural killer (NK) cell activity may be reduced in patients with chronic fatigue syndrome (CFS). Aim: To evaluate the effectiveness of a putative NK cell stimulant, BioBran MGN-3, in reducing fatigue in CFS patients. Design: Randomized, double-blind, placebo-controlled trial. Methods: We recruited 71 patients with CFS (according to the Centers for Disease Control 1994 criteria) attending an out-patient specialist CFS service. Participants were given oral BioBran MGN-3 for 8 weeks (2 g three times per day) or placebo equivalent. The primary outcome measure was the Chalder physical fatigue score. Self-reported fatigue measures, self-assessment of improvement, change in key symptoms, quality of life, anxiety and depression measures were also included. Results: Data were complete in 64/71 patients. Both groups showed marked improvement over the study duration, but without significant differences. Mean improvement in the Chalder fatigue score (physical scale) was 0.3 (95%CI –2.6 to 3.2) lower in the BioBran group. Discussion: The findings do not support a specific therapeutic effect for BioBran in CFS. The improvement showed by both groups over time highlights the importance of placebo controls when evaluating interventions in CFS.