6 – Antibody deficiency

Publisher Summary This chapter describes antibody deficiency. Resistance to an infection depends upon many factors, including not only the balance between natural immunity and the virulence of the infecting organism but also the effectiveness of nonspecific defenses, such as the skin and mucosal surfaces, the expulsive action of bronchial cilia, the action of bactericidal substances such as lysozyme, and the maintenance of local pH conditions. Breakdown of local mechanical barriers, for example by severe burns, is invariably accompanied by impaired resistance to infection despite of intact immune responses. If microorganisms successfully evade these barriers, their elimination then requires cooperation between elements of the immune system. However, in some individuals, defective immunity predisposes them to persistent, recurrent, or unusual infections. Specific immunity is conventionally classified into humoral immunity and cell-mediated immunity. By definition, non-specific immune mechanisms lack immunological memory of the antigen, yet defects of these pathways, which include the phagocyte and complement systems, are also accompanied by severe infections.