Therapeutic effectiveness of minimal doses of rituximab in a patient with rheumatoid arthritis

We report the case of a man suffering from rheumatoid arthritis, resistant to common DMARDs and anti-TNF-alpha, who received an excellent response, in terms of effectiveness and depletion of CD20 positive B-lymphocytes, to minimal doses of anti-CD20 monoclonal antibody (rituximab). The dose used was only 100 mg, repeated after 2 weeks. Already after the first infusion of rituximab, a profound depletion of CD20 B-lymphocytes and an improvement of clinical symptoms were evident. The patient, after 4 months from the first two infusions, maintained an accentuated lymphocyte depletion and obtained a low disease activity, passing from an initial DAS28 of 6.3 to a DAS28 of 2.8. The possible practical implications of this observation are taken into consideration.