Advances in Immunopathology: Autoimmunity, Immune Dysregulation, and Tissue Injury

This chapter presents a thorough review of the immunopathological mechanisms underlying autoimmune and immune-mediated diseases, with an emphasis on how disruptions in central and peripheral tolerance, cytokine signaling networks, and lymphocyte activation pathways culminate in tissue injury and organ-specific disease. It covers recent advances in the pathological classification and mechanistic understanding of conditions such as systemic lupus erythematosus, inflammatory bowel disease, and immune-mediated hepatitis, incorporating insights from single-cell immunophenotyping and next-generation flow cytometry. The chapter also addresses the expanding role of the pathologist in guiding biologic therapy selection through immunohistochemical and molecular profiling.