Benefit from B-Lymphocyte Depletion Using the Anti-CD20 Antibody Rituximab in Chronic Fatigue Syndrome
Øystein Fluge, Olav Mella, Ove Bruland et al. · PLoS ONE · 2011 · DOI
Quick Summary
In this pilot RCT, 30 ME/CFS patients received rituximab (a B-cell depleting antibody used in cancer and autoimmune disease) or placebo. Two-thirds of the rituximab group showed clinical improvement, with delayed response patterns consistent with autoimmune disease mechanisms. The placebo group had minimal response.
Why It Matters
This was the first RCT to suggest an immune (autoimmune) mechanism in ME/CFS with a therapeutic signal. The delayed response to B-cell depletion suggested ME/CFS might involve pathological antibodies. It triggered a large Phase III trial.
What This Study Does Not Prove
The Phase III rituximab trial (Fluge et al. 2019) was negative, failing to replicate these results. This pilot study, while historically important, should be interpreted in light of the negative phase III outcome.
Topics
Tags
Metadata
- DOI
- 10.1371/journal.pone.0026358
- Sample size
- 30 patients
- Control group
- Yes
- Review status
- Editor reviewed
- Evidence level
- Single-study or moderate support from human research
- Last updated
- 7 April 2026