Lymphocytes are white blood cells making up 20-40% of total WBCs. Found in circulation and concentrated in lymphoid organs. Most lymphocytes live 7-10 days, some live for years
Anti-HBs test determines immune status and disease progression in HBV patients. Anti-HBs can persist for years after acute infection resolves. Test results may be affected by recent blood transfusions or plasma treatments
Immune system prevents or limits infection through recognizing danger-associated molecular patterns (DAMPs). System distinguishes between healthy and unhealthy cells using pathogen-associated molecular patterns (PAMPs). Immune responses must be activated when needed to prevent infections. Unactivated responses can lead to allergic reactions and autoimmune diseases
Immune system defends body against foreign invaders like bacteria and viruses. System distinguishes between self and nonself using antigens. Normal response includes recognition, activation, attack, and control
Opsonins are extracellular proteins that tag substances for phagocytosis. They were discovered in 1904 by Wright and Douglas. At least 50 proteins act as opsonins for pathogens
Humoral immunity involves macromolecules in extracellular fluids. Antibodies are Y-shaped proteins synthesized by plasma cells. Five types of antibodies exist in mammals