Immunology of infusion reactions in the treatment of patients with acute lymphoblastic leukemia.

Infusion reactions are potentially dose-limiting adverse events associated with intravenous administration of several common agents used to treat patients with acute lymphoblastic leukemia. True clinical hypersensitivity reactions are antibody-mediated and can occur only after repeated exposure to an antigen. Conversely, anaphylactoid infusion reactions are nonantibody-mediated and often occur on the initial exposure to a drug. Cytokine-release syndrome comprises a subset of nonantibody-mediated infusion reactions associated with the use of monoclonal antibodies and immune therapies. Clinical symptoms of hypersensitivity reactions and nonantibody-mediated infusion reactions heavily overlap and can be difficult to distinguish in practice. Regardless of the underlying mechanism, any infusion reaction can negatively affect treatment efficacy and patient safety. These events require prompt response, and potentially, modification of subsequent therapy.