Studies of Streptococcal Fibrinolysis. Iii. A Quantitative Method for the Estimation of Serum Antifibrinolysin 1

Abstract

The plasma clots of patients convalescent from hemolytic streptococcal infections have frequently been found resistant to dissolution by fibrinolysin (1, 2). The resistance of such clots is generally regarded as a specific response to streptococcal infection; consequently, tests for clot resistance have been widely employed as a diagnosic aid in the study of streptococcal disease. In general, the results of such antifibrinolysin tests have indicated that the development of antifibrinolytic properties in the plasma is correlated with infection due to the ,8-hemolytic streptococcus (3, 4). In some instances, however, the results have appeared to be non-specific (5, 6).As a result of recent studies of streptococcal fibrinolysis and its inhibition (7 to 9) it has been possible to understand more fully the qualitative and quantitative factors which participate in the antifibrinolytic reaction. It was found that the resistance of plasma clots could be attributed to each of the following three factors: (a) the presence in the plasma of specific antibody,

Studies of Streptococcal Fibrinolysis. I. The Dissimilarity of Serum Protease and Trypsin as Indicated by the Separate Specificities of Their Kinases, Fibrinolysin and Enterokinase 1

“…Units of trypsin activity were defined in terms of the reciprocal of the highest dilution of the reaction mixture which completely lysed the standard fibrin clot in 12 hours at 37°C. 7 The titer of antifibrinolysin in the serum was 625, as determined by the method described in a succeeding paper (31). * Units of trypsin is defined in terms of the reciprocal of the highest dilution of the reaction mixture which lysed completely a standard fibrin clot in 12 hours at 370 C.…”

Studies of Streptococcal Fibrinolysis. Iv. Clinical Application of a Quantitative Antifibrinolysin Test 1

“…A preliminary report of these investigations presented elsewhere (5) demonstrated that the increase in antifibrinolysin titer during convalescence was dependent on the strain of group A streptococcus responsible for the infection. Endemic infections caused by type 3 streptococci resulted in few antifibrinolytic responses (10 per cent), whereas 62 per cent of infections due to type 19 showed an increase in antifibrinolysin.…”

“…These antibody titers are recorded in Table II (10,5). In order to identify streptococcal infections accurately, each subject admitted to the hospital was examined daily, multiple cultures of the throat were taken, and acute-phase and usually several convalescent-phase blood specimens were obtained.…”

“…By control of the various participating factors, an antifibrinolysin test which is quantitative in nature has been devised (4) (5). The definition of the unit of measure (5) should result in more uniformity in reporting data concerning antifibrinolysin.…”

“…By control of the various participating factors, an antifibrinolysin test which is quantitative in nature has been devised (4) (5). The definition of the unit of measure (5) should result in more uniformity in reporting data concerning antifibrinolysin. Furthermore, the substitution of a clot formed from fibrinogen and thrombin for fresh plasma makes the test readily adaptable to the study of sera in a routine manner.…”