Immunology

Innate and adaptive immune cells coordinate antigen recognition, lymphocyte activation, antibody production, and immunoglobulin effector functions.

Antibody binding, lattice formation, and complement activation make immune reactions measurable and let functional defects be localized.

Laboratory patterns in autoimmune disease, hypersensitivity, monoclonal gammopathy, and immunodeficiency help identify the affected immune mechanism.

HLA typing, antibody assessment, donor crossmatching, and chimerism testing measure immune recognition in transplantation. Tumor antigens and immune escape explain immune recognition of cancer.

Viral antibody, antigen, and nucleic-acid patterns distinguish immune status, recent infection, current infection, and reactivation across major serologic targets.

The CDC and APHL three-step algorithm combines antigen, antibody, and nucleic-acid results to diagnose HIV, and CD4 counts and viral loads track disease stage and treatment response.

Nontreponemal and treponemal algorithms, Lyme two-tier testing, and tuberculin and interferon-gamma methods measure antibody and cell-mediated responses, interpreted by disease stage, confirmatory testing, and timing limits.

Precipitation, agglutination, labeled immunoassay, immunofluorescence, and multiplex methods produce the result patterns and interferences that serologic interpretation depends on.