Humoraalseid

Humoraalseid is a term used to describe the soluble, fluid-phase components of the immune system that mediate humoral immunity. In contemporary immunology, this arm of immunity refers primarily to antibodies produced by B lymphocytes and the various factors present in body fluids that help defend against pathogens, as opposed to cellular immunity which relies on T cells and other immune cells.

The main components of humoraalseid are antibodies, or immunoglobulins, and the complement system. Antibodies are proteins produced by plasma cells derived from B cells. They recognize specific antigens on pathogens or toxins, neutralize them, block cellular entry, promote agglutination, and mark targets for destruction by other immune mechanisms. The complement system consists of a cascade of plasma proteins that become activated in the presence of antibodies or pathogens, leading to opsonization, inflammation, and the direct lysis of some microbes through the membrane attack complex.

In addition to antibodies and complement, other soluble mediators in serum and body fluids contribute to humoraalseid defense. These include antimicrobial proteins, acute-phase proteins, and various opsonins that enhance phagocytosis. While antibodies are the defining feature of adaptive humoral immunity, humoraalseid also encompass innate soluble factors that operate in the extracellular environment.

Clinical relevance includes disorders of humoral immunity, such as antibody deficiencies and autoimmune antibody production, and therapies that exploit humoraalseid, including vaccinations, intravenous immunoglobulin, and monoclonal antibodies. Humoraalseid interact closely with cellular immunity to provide comprehensive protection against infections.