Primary Immunodeficiency Syndromes and Their Manifestations in Lymph Nodes

Abstract

Originally, the term “immunity” designated a state in which the organism is resistant against commonly disease-inducing infectious agents. This notion was later expanded to include the preservation of “self” by elimination or at least containment of “nonself”, the latter encompassing all sorts of exogenous (“foreign”) materials as well as altered “self” cells/molecules. In the pathogenesis of infectious disease (for review, see Mims 1987), to be successful the attacking microbes must cross outer and/or inner body surfaces and survive in a normally hostile microenvironment, in which various types of host defense mechanism become active. So-called nonspecific immunity, the phylogenetically older principle, relies mainly on phagocytosis and intracellular killing of microorganisms (for references, see Van Der Valk and Herman 1987), especially by granulocytes (Elsbach and Weiss 1985) and monocytes/macrophages (Lowrie et al. 1985). Activation of complement. (reviewed by Williams et al. 1988) and the cooperative action of other microbicidal, microbistatic, and/or cytolytic substances (e.g., certain cytokines) are usually important in this process, which corresponds to an acute inflammatory reaction (for references, see Gallin et al. 1988). The most efficient defense mechanisms, however, are phylogenetically younger and show a marked antigen-directed response. This represents the basis of “specific immunity” which depends on the production of sensitized T lymphocytes [“cell-mediated (specific) immunity”] and/or of antibodies by plasma cells, the differentiated end cells of the B lymphocyte lineage [“humoral (specific) immunity”].