The Antifibrinolysin Test in Normal and Toxemic Pregnancy *

This study was undertaken as the result of a discussion of the relationship of toxemia of pregnancy to acute nephritis. It was thought that if hemolytic streptococcal infection played any such part in toxemia as it has been shown to play in many instances of acute nephritis, this might perhaps be detected by use of the antifibrinolysin test. It was first shown by Tillett and Garner4 in 1933 that individuals who had had a hemolytic streptococcal infection developed in most instances a reaction which enabled their clotted plasma to resist the fibrinolytic activity of the streptococcus. This reaction could be demonstrated by the incubation of a mixture of oxalated plasma diluted with saline, calcium chloride, and a broth culture of a potent streptococcus. In the susceptible individual, the resultant clot would be lysed within an hour; in the individual who had had a hemolytic streptococcal infection, lysis might not occur in 24 hours or longer. Sulbsequen-t observers1' 2 demonstrated that the test was not entirely specific, and others found that this power of resistance might persist for months following infection and might appear following subclinical infection,2 3 but in general it is agreed that a positive reaction as a rule represents the result of exposure to hemolytic streptococci. Although the test is usually read semiquantitatively, it has been shown2 that the major distinction is between positive and negative, and that degrees of reactivity may vary without apparent reason. Therefore, although our tests were read in the usual manner, from 1+ (lysis in 1 to 3 hours) to 4+ (no lysis in 24 hours), the results are grouped for reporting solely as positive or negative. Two major series of tests were done: a control series consisting of tests on 421 pregnant women as they were consecutively registered in the prenatal clinic of the New Haven Hospital from October 1942 to May 1943, and a series consisting of tests on women admitted