Analytic review: disorders of phagocyte function.

R ECENT CLINICAL AND LABORATORY INVESTIGATIONS have led to the description of a group of syndromes related to impaired bactericidal functions of neutrophils and monocytes.13 Although the pathophysiology of this group of disorders is unknown, detailed immunologic, biochemical and morphologic studies have elucidated some clues to the basic defects leading to impairment of phagocyte function. The complex biology of the polymorphonuclear neutrophil and the mononuclear phagocyte ( blood monocyte and tissue macrophage ) will be considered in relation to phagocytosis and bactericidal capacity. The role of extracellular factors in host defense including properidin, interferon, complement, plasma factors and kinins will not be considered in detail; these subjects have been extensively reviewed by others47 and will be mentioned only in relation to possible pathophysiologic significance in phagocyte dysfunction. The cellular mechanisms of host resistance to viral infection, which are for the most part unknown in man, are not discussed in this review. Although it may be premature to make such a comparison, it seems apparent that the diseases of the phagocyte, in some respects similar to the erythrocyte, will involve membrane abnormalities, genetically determined and acquired enzyme deficiencies, alterations in cytoplasmic proteins ( specifically proteins with antibacterial activity ) ,defects secondary to immunologic factors involved in the opsonization of organisms, and abnormalities related to various humoral mediators. Thus far, three types of clinical syndromes have been described: ( 1 ) A defect involving neutrophil chemotaxis8; (2 ) defects in the ingestion phase of phagocytosis, involving plasma opsonizing ability9”0; and ( 3 ) defective intracellular killing of bacteria by both neutrophils and monocytes.’3 The third type has been shown to have several distinct genetic and clinical forms”3’ 11-14