1. Any substance elaborated by a living agent and capable of causing lysis of red blood cells and liberation of their hemoglobin. SYN: erythrocytolysin, erythrolysin. 2. A sensitizing (complement-fixing) antibody that combines with red blood cells of the antigenic type that stimulated formation of the h., a fixing complement with the antibody-cell union resulting in lysis of the cells.
- α h. α′ hemolysis.
- β h. β hemolysis.
- bacterial h. any hemolytic agent elaborated by various species of bacteria, or by certain strains within a species.
- heterophil h. a sensitizing antibody that can combine with red blood cells of various species (in addition to those used as the antigen in stimulating the formation of the h.), resulting in hemolysis when the proper amount of complement is present.
- immune h. a sensitizing, complement-fixing, hemolytic antibody formed in an animal as the result of parenteral administration of red blood cells or whole blood from another species; immune h. may also be formed in human beings who are transfused with human blood that is antigenic in the recipient, e.g., the formation of anti-Rh antibody in an Rh-negative person who is treated with Rh-positive red blood cells.
- natural h. h. occurring in the plasma of an animal of one species, e.g., a dog, which fixes complement with the red blood cells of some other species, e.g., a rabbit, thereby causing hemolysis of the cells of the rabbit, although the dog was not previously exposed to antigenic stimulation with such cells.
- specific h. a sensitizing, complement-fixing, hemolytic antibody that reacts totally or completely with red blood cells of the antigenic type used to stimulate the formation of the h..
- warm-cold h. h. which combines with red blood cells at temperatures below 20°C and are eluted at warmer temperatures, e.g., 30–37°C. See Donath-Landsteiner cold autoantibody, hemagglutinating cold autoantibody.
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he·mo·ly·sin or chiefly Brit hae·mo·ly·sin .hē-mə-'līs-ən, hi-'mäl-ə-sən n a substance that causes the dissolution of red blood cells called also hemotoxin compare HEMORRHAGIN
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he·mol·y·sin (he-molґə-sin) [hemo- + lysin] a substance that causes hemolysis; called also erythrocytolysin and erythrolysin.Medical dictionary. 2011.