Ledenmatsweefsels

Ledenmatsweefsels are components of the lymphatic system that house immune cells and support the initiation of adaptive immune responses. They consist of lymphocytes, antigen-presenting cells such as dendritic cells and macrophages, and a supporting reticular framework that organizes cells into functional units. Lymphoid tissue is found in primary lymphoid organs, where lymphocytes develop, and in secondary lymphoid organs, where immune responses are activated.

Primary lymphoid tissues include the bone marrow and the thymus, where B cells and T cells complete their maturation. Secondary lymphoid tissues include lymph nodes, the spleen, tonsils, and mucosa-associated lymphoid tissue (MALT) such as Peyer's patches. These organs exhibit specialized architecture, including germinal centers within lymphoid follicles and distinct T cell zones, which facilitate the encounter with antigens, lymphocyte activation, and clonal expansion.

Functions of ledenmatsweefsels include filtering lymph and blood for antigens, presenting peptides to lymphocytes, and initiating and regulating adaptive immune responses. B cells can differentiate into antibody-secreting plasma cells, while T cells differentiate into various effector and memory subsets. The spleen’s white pulp surveys blood-borne antigens, and MALT protects mucosal surfaces against ingested or inhaled pathogens.

Clinical relevance: changes in lymphoid tissues are common in infections, autoimmune disorders, and cancers. Lymphadenopathy can signal infection or malignancy, and lymphoid neoplasms such as lymphomas originate in these tissues. Understanding their structure and function supports diagnosis, vaccination strategies, and cancer therapies.