title: Morphology of delayed-type hypersensitivity reactions in man.
abstract: The new morphologic findings reviewed here substantially alter prevalent conceptions of delayed hypersensitivity as a simple cutaneous infiltration of lymphocytes and macrophages. By assigning an integral role of basophils, mast cells, the microvasculature, and the clotting system, the findings have far-reaching implications for an understanding of these clinically important reactions. Morphologic observations, of course, represent only a first step, a foundation on which subsequent immunologic, physiologic, and biochemical experiments can build. Much further work will be required to interrelate these new findings and to integrate them with older observations into a coherent sequence of events which can explain the pathogenesis of cell-mediated reactions. A preliminary attempt in this direction, based on present, rather incomplete information, is presented in Figure 8 as a basis for further investigation.
mesh_terms: D000707:Anaphylaxis / Q000503:physiopathology; D001491:Basophils / Q000276:immunology / Q000473:pathology; D001777:Blood Coagulation; D003594:Cytoplasmic Granules / Q000473:pathology; D004487:Edema / Q000473:pathology; D005260:Female; D005337:Fibrin / Q000502:physiology; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology / Q000473:pathology*; D008297:Male; D008407:Mast Cells / Q000473:pathology; D008938:Mitosis; D008954:Models, Biological; D012867:Skin / Q000098:blood supply
chemical_list: D005337:Fibrin