The structural and functional characteristics of viscerales lymph nodes in the human of old age

The problem of age-related involution of the structures of the immune system is now becoming more and more urgent. The aim of this study is the structural and functional characteristics of the visceral lymph nodes of an elderly person. Using immune morphological methods, the structure and cellular composition of the subcarinal and mesenteric lymph nodes of an elderly person were studied. A pronounced development of fibrous connective tissue is shown, which leads to fragmentation of the parenchyma of the nodes and a reduction in the area of the cortex. In the cortex, small lymphoid nodules and a narrow para-cortical zone are revealed. In lymphoid nodules, the absence of light centers with dividing and poorly differentiated lymphocytes and a high concentration of mature CD20 B-lymphocytes are noted. In the para-cortical zone, CD4 T-helpers are not detected. In all structural components of the lymph node, Ki67-positive cells are absent, which indicates the extinction of lymphocyte-poietic function, which is due to the replacement of the reticular tissue of the microenvironment with fibrous connective tissue and the absence of CD4 T-lymphocytes, which regulate the reactions of cellular and humoral immunity. Destruction of the reticular stroma in the sinus system, which is a biological filter, leads to impaired lymph purification function.