Limfoides

Limfoides is a term used in histology and immunology to denote tissues, organs, and cells associated with the lymphoid system. In many Iberian and Latin-derived scientific contexts, limfoide corresponds to the English lymphoid. The term derives from lymph, the fluid involved in immune responses, and the -oid suffix meaning “resembling” or “forming part of.” Limfoides is commonly used to describe lymphoid tissue and lymphoid-related cell lineages, rather than the myeloid lineage.

The lymphoid system is a component of the immune system that concentrates in lymphoid tissues and generates adaptive immunity. It includes primary lymphoid organs, such as bone marrow and the thymus, where lymphocytes develop, and secondary lymphoid organs, such as lymph nodes, the spleen, and mucosa-associated lymphoid tissue (MALT), where immune responses are organized. Lymphoid tissue is distributed in diffuse form as well as organized into lymphoid follicles within these organs.

Lymphoid cells arise from hematopoietic stem cells and differentiate into T cells, B cells, and natural killer (NK) cells. T cells mature in the thymus, B cells mature in the bone marrow, and NK cells arise from lymphoid progenitors. Lymphoid tissue also contains specialized compartments that support antigen encounter, lymphocyte activation, and the clonal expansion of immune cells during responses.

Pathologies affecting limfoides include benign lymphoid hyperplasia and malignant lymphoid neoplasms, such as Hodgkin and non-Hodgkin lymphomas, and lymphoid leukemias. Immune deficiencies and autoimmune conditions can also involve lymphoid components. Understanding limfoid tissues helps describe immune function and disease, in contrast to myeloid tissues that arise from a different hematopoietic lineage.