Comparison of antibody titres to streptococcal extracellular antigens.

Antibody titres were measured against extracellular products of group A beta haemolytic streptococci. Comparison of the titres obtained with antistreptolysin O (ASO), streptozyme, antideoxyribonuclease-B (ADN-B), antinicotinamide adenine dinucleotidase (ANAD), antihyaluronidase (ASH), and antistreptokinase (ASK), in 412 human serum specimens with different categories were tested. The results obtained were as follows: the streptozyme test was in good correlation with ASO, and can detect more specimens with elevated antibody titres than any other single test, but was not as good as the combination of any other tests like ASO and ADN-B. For determination of streptococcal infection, it is necessary to test for more than one antibody. Streptozyme test is valuable screening in combination with ASO, for those laboratories depending on ASO alone.