Part II: Immunological Deficiency States

In the first lecture, the development of the organs, integrity from a congenital defect such as epidermocells, and proteins responsible for the immune lysis bullosa, or to an acquired disease like eczema response was discussed. Resistance to invasive or exfoliative dermatitis. In the eye, lack of tears or infection depends upon non-specific factors as well loss of the corneal reflux can lead to corneal ulceraas upon specific immune responses to the infecting tion and infection. Achlorhydria may diminish the organism. Poor resistance may be the result of resistance of the gastro-intestinal tract to enteric deficiencies in either non-specific or specific infection. In the respiratory tract, failure of the mechanisms, but the main concern of this lecture cough reflex, due to anaesthesia or to coma, and loss will be with deficiencies of specific immunological of ciliary action, such as occurs in certain viral mechanisms, which have only been recognized as infections, thermal and chemical injuries, or disease entities during the past 12 years. However, bronchiectasis, may pave the way for invasion of the in order to put these new disease entities in perspeclung. Obstruction of the air passages with viscid tive, we must first examine the various ways in which secretions, as in cystic fibrosis, recurrent asthma, or the body's defences against bacterial infection may bronchitis, or local obstruction by a foreign body, be impaired. frequently leads to pneumonia. Finally, the oedema From the clinical point of view, the physician produced by the viruses of influenza or the common seeing a child with the complaint of recurrent cold, by the allergic response, or in the nephrotic infections should first get a clear picture of whether syndrome, alters the respiratory tract so that these have been repetitive infections of the same pyogenic bacteria, when present, multiply rapidly anatomical area or a whole variety of severe infections and produce invasive infection. with different anatomical sites. The former type of history strongly suggests a local cause, the Failure of the clearing mechanism. This is latter a deficiency in the over-all capacity of the another important predisposing cause to infection. individual to resist infection. But, first of all, the Deficiency in production of the principal wandering physician must evaluate the mother's anxiety in phagocytic cell-the polymorphonuclear leucocyte order to determine whether, as so often happens in -usually is followed by infection, very frequently paediatrics, her expectations of good health for her due to staphylococci. This occurs very early in a child leave no place for the hundred or so infections, rare condition incompatible with life-congenital most of them mild and involving the respiratory aleukia (de Vaal and Seynhaeve, 1959; Gitlin, tract, which usually develop in the first decade of Vawter, and Craig, 1964)-but is a constant threat life and constitute the major manifestations of in patients with neutropenia, which may be congeniimmunological maturation of the child. tal, cyclic, or acquired as a result of bone-marrow failure in leukaemia, reticulo-endotheliosis (LettererImpairment of Non-specific Defences Siwe's disease), aplastic anaemia from radiation or Against Bacterial Infection chemical injury. Failure of the fixed tissue Failure of surface protection. This is a phagocytes of the reticulo-endothelial system may frequent predisposing cause to local infection by result in severe overwhelming septic infections. bacteria. In the case of the skin this may be due to Although there has been great dispute about trauma from burns or penetrating wounds, to loss of whether there is such an entity as a post-splenectomy syndrome (King and Shumacker, 1952; Gofstein and * The Sir Leonard Parson Lectures, delivered at the University of Gellis, 1956; Horan and Colebatch, 1962), there is Birmingham on March 22-23, 1965. no question but that following splenectomy,