Current role of rituximab in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by periods of flares and remission, resulting in organ damage over time caused by persistent disease activity and treatment-related complications. Conventional therapies are not ideal in terms of efficacy and safety. Novel biological therapies are being developed to enhance therapeutic efficacy, minimize disease exacerbation and reduce toxicities. As dysregulation of B cells is the hallmark of SLE, B-cell targeted therapies are the focus of recent clinical research. Rituximab, a chimeric anti-CD20 monoclonal antibody, has been used with success in recalcitrant lupus manifestations. However, randomized controlled trials have failed to reveal its benefit in renal and non-renal SLE when combined with conventional immunosuppressive protocols. Although heterogeneity of SLE manifestations, pitfalls in study design and the limitations of the assessment tools for various clinical end points may have contributed to the discouraging results, rituximab remains an option in patients who are refractory or intolerant to conventional therapies. Recently, a regimen consisting of rituximab and mycophenolate mofetil without oral corticosteroids was reported to be effective in lupus nephritis. While the efficacy of this regimen has to be confirmed, future controlled trials should focus on the efficacy of rituximab in refractory lupus manifestations and its synergistic effect with other immunosuppressive agents such as cyclophosphamide. In short-term randomized controlled trials, a non-significant increase in serious adverse events was observed in SLE patients treated with rituximab. Long-term safety data of rituximab in SLE, in particular the incidence of hypogammaglobulinemia and serious/opportunistic infections, have to be continuously surveyed.