Should low-dose mycophenolate mofetil be used to prolong the response after rituximab therapy in patients with immune thrombocytopenic purpura? A case report.

Rituximab and mycophenolate mofetil are used in the treatment of resistant immune thrombocytopenic purpura (ITP). Both therapeutic approaches can induce responses in subsets of patients, but these responses are usually of limited duration and often lasting for less than one year. Mycophenolate mofetil 250 mg twice daily was insufficient to induce a prolonged response. In this article, we describe a patient with severe chronic ITP that was treated with rituximab. The platelet count started to decrease 5 months after rituximab therapy, low dose therapy with mycophenolate mofetil 250 mg twice daily was then started and peripheral blood platelet counts then stabilized between 70 and 100 x 10(9)/l. Mycophenolate mofetil could later be reduced to 250 mg once daily, and the patient has now had stable platelet counts for more than 4 years. Thus, the previous mycophenolate mofetil treatment that was insufficient to induce a prolonged response could maintain a prolonged response after rituximab therapy. This observation suggests that mycophenolate mofetil can be used to prolong responses after rituximab therapy for ITP.