What is immunotoxicity?

• A. Adverse effects on the nervous system
• B. Adverse effects on the endocrine system
• C. Adverse effects on the immune system
• D. Adverse effects on the liver

Answer: (C)

Immunotoxicity refers to adverse effects on the immune system caused by chemicals, drugs, or environmental agents. It covers disruption of normal immune function in several ways: suppression of immune responses (increased susceptibility to infections and reduced vaccine effectiveness), overactivation or misdirected activation leading to hypersensitivity and allergic reactions, and autoimmune or dysregulated immune processes where the body attacks its own tissues. Because the immune system involves many cells and organs, immunotoxic effects can show up as reduced lymphocyte proliferation, impaired antibody production, diminished natural killer cell activity, or changes in cytokine signaling, which toxicology tests may detect through specific immune assays.

Effects on the nervous system, liver, or endocrine system are separate types of toxicity—neurotoxicity, hepatotoxicity, and endocrinotoxicity—where the impact is on those specific organ systems rather than the immune system.