CFS/ME is a disease of unknown cause with no confirmatory tests. It is therefore diagnosed on the basis of its symptoms, which include physical and mental fatigue which may be of overwhelming severity. There is no curative treatment so it is is managed symptomatically.
One theory is that it is an autoimmune diseases (one in which the body reacts against its own tissues). There have been reports of improvement when patients were receiving chemotherapy for lymhoma or cancer. Also, elderlly patients with ME/CFS have an increased incidence of B cell lymphoma. For these reasons it seemed feasible to try treating ME/CFS with rituximab, a medication that is used to treat certain autoimmune diseases and some cancers.
Unfotunately, a 12-month trial in 151 patients in Norway has not shown a positive effect. Overall respone rates were 35.1% for placebo and 26.0% for rituximab. Twenty patients (26.0%) in the rituximab group and 14 (18.9%) in the placebo group had serious adverse events. Few patient in either group showed major improvements and 10% got worse.
Limitations of the trial: the patients were self-referred and outcome measurements were based on self=reported symptoms over two years, so there was possible recall bias.
This is a disappointing result. But at least it’s good that serious research is being done in this baffling and often devastating disease. Up to now there hasn’t been very much, and the quality of what has been done has been rather uneven.
Source: Ann Intern Med doi:10/7326/M18-1451