Background Autoimmune thrombocytopenia is a common manifestation of systemic lupus erythematosus (SLE) which may accompany bleeding risk and complications. B cell depleting therapy has been tried experimentally in SLE related thrombocytopenia refractory to standard treatment including corticosteroids, intravenous immunoglobulin, cyclophosphamide, and mycophenolate mofetil.
Objectives Here, we evaluated the efficacy of rituximab in SLE patients with severe thrombocytopenia refractory to conventional treatment.
Methods In our retrospective study, rituximab was administered in 5 patients with severe thrombocytopenia (platelet count <50 x109/l) refractory to traditional treatments. Patients received i.v. rituximab at a dose of 500mg every week for 4 doses or 1000mg every 2 weeks for two doses. Peripheral CD 19+ B cell counts were evaluated before and after rituximab infusion.
Results Among five patients with refractory thrombocytopenia, 2/5 (40%) patients achieved complete responses (CR, platelet count >100 x109/l) at week 4 after rituximab infusion. The CR rate increased to 3/5 patients at week 12, and 5/5 at week 24. Overall response (OR, platelet count >50 x109/l) was achieved in 4/5 and 5/5 at week 4 and 12 respectively. Baseline B cell count was 158±133 x106/l (range 3-348 x106/l) and complete depletion (<5 x106/l) was achieved in all 5 patients at week 4. Although 4 patients maintained normal platelet counts through 28 (range 11-48) months follow up period, one patient had relapsed 2 years after the last rituximab infusion with increasing B cell counts. However, good response was observed after reinfusion with rituximab.
Conclusions Our study showed that rituximab therapy induces a rapid and sustained remission in severe and refractory autoimmune thrombocytopenia in SLE patients.
Pinto LF, Velasquez CJ, Prieto C et al. Rituximab induces a rapid and sustained remission in Colombian patients with severe and refractory systemic lupus erythematosus. Lupus 2011;20:1219-26.
Lee JW, Kim HA, Sung JM et al. Successful treatment of refractory immune thrombocytopenia with anti-CD20 antibody in a patient with systemic lupus erythematosus. Lupus 2010;19:227-8.
Disclosure of Interest None declared