In examining 170 samples of blood sera of healthy and sick individuals it was shown that with the aid of a simple and express antilipoproteinase test it was possible not only to reveal, but also to determine the titre of specific antibodies to the lipoproteinases of various serological M-types (2, 4, 22/12, 22 and 49) of a hemolytic streptoccus, group A. The antibodies to the enzymes were frequently revealed in the sera of adults and older children. The results obtained were still inadequate for the epidemiological or clinico-immunological analysis, but pointed to the principal possibility of using the antilipoproteinase test for the mentioned purpose.
