B-lymphocyte Depletion Using Rituximab in Chronic Fatigue Syndrome/ Myalgic Encephalopathy (CFS/ME). A Randomized Phase-III Study.

Inclusion Criteria: * Patients with Chronic Fatigue Syndrome/ Myalgic Encephalopathy (CFS/ME) according to Canadian diagnostic criteria (Carruthers, 2003) * Duration of CFS/ME disease 2-15 years. For patients with mild CFS/ME duration of disease must be 5-15 years. * Mild, Mild/Moderate, Moderate, Moderate/Severe and Severe CFS/ME may be included * Signed informed consent Exclusion Criteria: * Patients with fatigue, who do not comply with Canadian diagnostic criteria (2003) * Duration of CFS/ME \< 2 years or \>15 years * Patients with very severe CFS/ME * Pregnancy or lactation. * Previous malignant disease (except basal cell carcinoma in skin or uterine cervical dysplasia) * Previous treatment with B-lymphocyte depleting therapeutic monoclonal antibodies, such as rituximab * Previous long-term systemic immunosuppressive treatment, including drugs such as cyclosporine, azathioprine, mycophenolate mofetil, but except steroid treatment e.g. for obstructive lung disease or for other autoimmune diseases such as ulcerative colitis * Severe endogenous depression * Lack of ability to adhere to protocol * Known multi-allergy with clinically assessed risk from rituximab infusion * Reduced kidney function (serum creatinine \> 1,5x upper normal level) * Reduced liver function (serum bilirubin or transaminases \> 1,5x upper normal level) * Known HIV positivity, previous hepatitis B or hepatitis C * Evidence of ongoing, active and clinically relevant infection * Known immunodeficiency …