THE DISTRIBUTION OF ANTIBODIES TO STREPTOKINASE

To determine the distribution of antibodies to streptokinase that migh t be anticipated in patients requiring treatment with streptokinase, s pecific antistreptokinase antibody titres were determined in a group o f subjects from the general population and in a group of patients pres enting with acute myocardial infarction. Enzyme-linked immunosorbent a ssays were developed to measure specific anti-streptokinase IgG and su bclass IgG, in 95 subjects from the general population and in 160 pati ents presenting with acute myocardial infarction. Low titres of IgG(1) were found in both the general population (median = 5; range: 0-490) and in the myocardial infarction group (median = 7; range: 0-2000). A minority of subjects in both groups had high titres. The findings sugg est that low titres of antibody are widespread in the population. The minority of subjects in both groups who had high titres may explain th e infrequent type III immune reactions encountered with streptokinase.