The Determination of Streptococcal Antiproteinase Titers in Sera of Patients with Rheumatic Fever and Streptococcal Infection

[摘要] Procedures have been described for the measurement by complement fixation and adsorption-hemagglutination of antibodies to streptococcal proteinase, which had been partially purified from concentrates of supernates of steady-state cultures of hemolytic streptococci. Antiproteinase titers of a number of sera as obtained by each of these two procedures were compared with titers of these sera obtained by neutralization of enzymatic activity of the proteinase (inhibition of milk-clotting). The ratios of titers by either of the other procedures to that obtained by milk clotting inhibition fell in a fairly narrow range, those by adsorption hemagglutination being 16–32 times as high as the neutralization titers.In 101 sera of presumably normal children streptococcal antiproteinase titers by hemagglutination showed a wide distribution, 39% of these being below 12, with the remainder distributed up to 384. Children convalescing from miscellaneous viral infections showed approximately similar distributions, except for the occurrence of some higher titers, up to 1536.Sera were obtained from 100 patients with an acute streptococcal infection, at the onset and in the convalescent stage. In ½ of these pairs of sera, the antiproteinase titers were not found to be different in the two stages of the disease. Increases in titer of 1 or 1 ½ powers of 2 were found in 19%, the remainder showing greater increases in titer in the course of the infection.Patients with acute rheumatic fever showed streptococcal antiproteinase titers in the range of 16-8192, with a geometric mean of 420. In comparison, the convalescents from scarlet fever showed a range of 12-2000 with a geometric mean titer of 42, and patients with rheumatic fever in the inactive state showed a range of <12-512, with a geometric mean of 66.

[学科分类] 生物科学（综合）