Activation of the alternative pathway of human complement by haemoglobin.
Haemoglobin solutions (concentration greater than 1.5 mg/ml), prepared from lysates of erythrocytes from a normal subject and from a patient with sickle cell anaemia, caused factor B and C3 cleavage and loss of haemolytic activity of factor B wehn incubated with fresh autologous serum. Under the same experimental conditions, preparations of erythrocyte stroma or of buffycoat lysates did not produce factor B and C3 cleavage. This reaction required Mg++ but not C1q or C4, indicating that the alternative complement pathway was activated.
D000755:Anemia, Sickle Cell / Q000276:immunology; D002118:Calcium / Q000097:blood; D003167:Complement Activation / Q000187:drug effects; D003176:Complement C3 / Q000378:metabolism; D011415:Complement Factor B / Q000378:metabolism; D003170:Complement Pathway, Alternative / Q000187:drug effects; D004533:Egtazic Acid / Q000494:pharmacology; D006454:Hemoglobins / Q000276:immunology*; D006461:Hemolysis; D006801:Humans; D007122:Immunoelectrophoresis; D008274:Magnesium / Q000097:blood
D003176:Complement C3; D006454:Hemoglobins; D004533:Egtazic Acid; D011415:Complement Factor B; D008274:Magnesium; D002118:Calcium