[Anti-rituximab antibodies in autoimmune diseases and hematologic malignancies: An update].

Rituximab, a chimeric monoclonal antibody targeting the CD20, is a key therapy for treating haematological malignancies and numerous autoimmune diseases. However, its use may be complicated by the occurrence of anti-drug antibodies (ADA), which reflect its immunogenicity. This immunogenicity varies depending on the clinical context: it remains rare in oncology, but is more common in autoimmune diseases. These ADAs may be neutralising or non-neutralising and may influence pharmacokinetics, B-cell depletion, clinical efficacy and the risk of hypersensitivity reactions. Their occurrence is influenced by multiple factors: drug characteristics, administration methods, treatment regimen, but also patient-specific parameters. To limit immunogenicity, several approaches are being studied, such as optimising treatment regimens, combining with immunosuppressants, or using alternative humanised or fully human antibodies. This review provides an updated summary of anti-rituximab antibodies and highlights the importance of a personalised monitoring strategy to optimise the management of patients treated with rituximab.