Longterm clinical and immunological effects of anti-CD20 treatment in patients with refractory systemic lupus erythematosus.

OBJECTIVE

To retrospectively evaluate longterm clinical and immunological effects of anti-CD20 treatment in patients with systemic lupus erythematosus (SLE) with active nephritis or autoantibody-mediated cytopenias refractory to conventional immunosuppressive treatment.

METHODS

Anti-CD20 treatment (rituximab) was added to the ongoing immunosuppressive treatment in 31 SLE patients with active nephritis (n = 17), thrombocytopenia (n = 10), and hemolytic anemia (n = 4) refractory to conventional therapy. Disease activity was evaluated by the SLE Disease Activity Index. The median followup time after anti-CD20 treatment was 22 months (range 1-61 mo).

RESULTS

Complete B cell depletion was obtained in all patients. In 11 of the 17 lupus nephritis patients complete or partial responses were achieved after 6-12 months. Eight of these patients increased their glomerular filtration rate (GFR) by > 25%. The responders were characterized by having shorter nephritis duration, a baseline GFR > 30 ml/min, and detectable circulating CD19+ B lymphocytes before B cell depletion. Anti-CD20 treatment was highly effective in patients with autoimmune thrombocytopenia, inducing a significant increase of platelet counts after 1 month (p < 0.01). Five of 10 patients achieved complete normalization of their platelet counts within 6 months. The anti-CD20 treatment was followed by a significant reduction of autoantibodies against dsDNA and platelets, in nephritic and in thrombocytopenic patients, respectively.

CONCLUSION

Addition of anti-CD20 treatment to conventional immunosuppressive therapy may be a beneficial strategy in refractory lupus nephritis and autoimmune cytopenias, possibly by reducing the levels of pathogenic autoantibodies.