[Comparison of value of four immunological methods (AST, ADNase B, AHy, ANADase) by A-streptococcal infections and their significance in the routine diagnostic (author's transl)].

In the sera of approximately 600 patients of all age groups, who were on clinical suspicion of an A-streptococcal infection, AST, ADNase B, AHy and ANADase were determined. The ANADase alone detects 90% of the acute A-streptococcal infections, the AHy and the ADNase B 80% and the ASO 50%. In skin infections superinfected by A-streptococci, the AHy is positive in 85%, the ANADase in 80%, the ADNase B in 75% and the AST in 40% of the cases. The most frequent A-streptococcal infection, Angina tonsillaris, is determined in the best manner possible through the combination ADNase B + ANADase + AHy. According to the statistical evaluation, the ADNase B and the ANADase are the most reliable tests. The age group of the 4 to 15 year-olds reaches for ASO, ADNase B and AHy a percentage of highly increased titers twice as high in comparison with the adult group. In no case does one test determine 100% of the collective; therefore, a combination of several antibody reactions is desirable for the diagnosis. Increased titers should be checked every four weeks, also normal titers with patients, who continue on the clinical suspicion of having an A-streptococcal infection, because their blood sample may have been taken before the immune reaction occurred.