Morphological anomalies associated with immunodeficiencies in the lymph nodes of aging mice.

Immunodeficiencies can emerge in aging normal animals. We wondered whether the morphological taking place in nodes of normal but aging animals comprise anomalies associated with immunodeficiencies. We analyzed the nodes of various anatomical sites in 20 normal mice, aged 12 or 24 months. The same morphological anomalies described recently in nodes of young athymic animals and reflecting immunodeficiencies were found to develop in present mice, though varying in extent with age, individuals, anatomical site of a node, and compartments of a given node. Some anomalies reflect deficiencies of cellular immune responses; others reflect deficiencies of humoral immune responses. Practicality restricts the variety of antigens which can be tested to recognize the possible emergence of immunodeficiencies in an aging animal. A morphological analysis of its nodes can thus indicate if immunodeficiencies occur with respect to a fraction of the challenging antigens.