immunotoxicology

Immunotoxicology is a branch of toxicology that studies adverse effects of chemicals, drugs, and other xenobiotics on the immune system. It covers immune suppression, hypersensitivity, autoimmunity, allergy, and impaired immune surveillance that can increase infection risk, affect vaccine responses, or promote tumor development. The field integrates data from in vitro and in vivo experiments to understand mechanisms and risk across immune organs, cells, and mediators.

Common endpoints include changes in lymphoid organ weight and cellularity, lymphocyte proliferative responses, antibody production, cytokine and chemokine profiles, natural killer cell activity, and markers of allergic or autoimmune reactions. Assays span animal models, human cell cultures, and immunophenotyping, contributing to hazard identification and dose–response assessment.

Mechanisms are diverse and include direct cytotoxic effects on the bone marrow or thymus, oxidative stress, disruption of signaling pathways, endocrine disruption, and modulation of inflammatory responses. Exposures of interest encompass pharmaceuticals, pesticides, metals, solvents, plastics, and environmental pollutants, as well as nanomaterials and complex mixtures.

In risk assessment and regulation, immunotoxicology informs hazard identification, dose–response relationships, and considerations of vulnerable populations. Regulatory guidelines and testing methods are used to evaluate immunotoxic potential and to guide safety standards for exposed populations.

Vulnerable groups include pregnant individuals, infants, the elderly, and immunocompromised persons. Emerging topics include immunotoxic effects of nanomaterials and immunomodulatory therapies, as well as interactions with infectious and autoimmune diseases.