immunemediated

Immune-mediated is a clinical term used to describe diseases in which the immune system contributes to tissue injury or dysfunction. The phrase covers a spectrum of mechanisms, including autoimmunity, immune complex–mediated injury, and T-cell– or antibody-driven inflammation. It is distinct from injuries caused solely by nonimmune factors and from primary infections or physical damage.

Mechanisms underlying immune-mediated conditions are diverse. They can involve autoantibodies that target self-antigens, immune complex deposition that activates complement and recruits inflammatory cells, antibody-dependent cellular cytotoxicity, and direct T-cell–mediated cytotoxicity. Genetic susceptibility, environmental triggers, infections, and other factors can influence the onset and course of immune-mediated disease.

Common examples span several categories. Autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis are often described as immune-mediated. Hematologic disorders like immune-mediated hemolytic anemia and immune thrombocytopenia involve antibody- or immune complex–driven destruction of blood cells. Neurologic, renal, and dermatologic conditions may also be immune-mediated, including Guillain-Barré syndrome, certain glomerulonephritides, and inflammatory skin diseases.

Diagnosis typically integrates clinical presentation with laboratory and sometimes histopathologic evidence. Serologic tests for autoantibodies, measurements of complement levels, assessments for immune complex activity, and tissue biopsy demonstrating immune cell infiltration or deposits can support the diagnosis. Imaging and functional studies may be used to assess organ involvement.

Management aims to attenuate harmful immune responses and control symptoms. Treatments include corticosteroids and other immunosuppressants, disease-modifying therapies, intravenous immunoglobulin, plasmapheresis, and targeted biologic agents such as monoclonal antibodies. Supportive care addresses organ dysfunction and complications. The term “immune-mediated” emphasizes the immune system’s role, even when the precise mechanism is not fully established.