Antistreptolysin-o latex test. A simple screening method for the determination of antistreptolysin-o antibodies

Experiences with a rapid latex slide test to distinguish elevated fron normal antistreptolysin-O titers are reported. A series of 1000 randomly selected sera were tested in parallel with the ASO latex test and the classical antistreptolysin-O titration test. All sera with an ASO titer of more than 200 I.U. produced a positive agglutination with the ASO latex test. No false negative results were recorded. 6,2% of the sera with a positive ASO latex test exhibited less than 200 I.U. in the titration test. A further advantage of the ASO latex test, apart from its easy practicability, is that it is not inhibited by serum lipids like the hemolytic titration test. The dextransulphate precipitation method combined with the ASO titration showed no advantaged when compared with the ASO latex test combined with the ASO titration without dextransulphate. When patients in our series with ASO TITERS OF 500 AND MORE I.U. were considered in relation to their clinical diagnosis it as found that infections with beta-hemolytic streptococci would not be overlooked, when the ASO latex test is used as a screening procedure. The ASO latex test therefore all s a considerable reduction of personnel and working time. It is however, essential that industry should keep the quality of latex reagents strictly standardized.