RESUMO
BACKGROUND: Antistreptolysin O (ASO) has been widely used to diagnose Streptococcus Pyogenes infections and their sequelae, rheumatic fever and acute glomerulonephritis. Butt in some cases there is no elevation of ASO that it is necessary to add one or more tests detecting immune response to S. pyogenes.. The authors analyzed the distribution of antideoxyibonuclease (ADNase) B and antistreptolysin O (ASO) among the children of an elementary school in Seoul and calculated their upper limit of normal (ULN) value. METHODS: ADNase B concentrations were determined by nephelometry (Behring Nephelometer 100 Analyzer, Germany) on 236 sera of healthy elementary school children in Seoul. Throat cultures were taken at the same time to compare ADNase B lovels between S. pyogenes carriers and non-carriers. RESULTS: The distribution of ADNase B concentrations among school children ranged from 77 (detection limit) to 1616 IU/ml and the ULN was estimated to be 362 IU/mL. The carriers of S. pyogenes clad significantly higher ADNase B levels (mean 392 IU/ml) than carriers of non-group A beta-hemolytic streptococci (BHS, 236 IU/ml) oY non-carriers of BHS (234 IU/ml). The relationship between ADNase B (Y) and ASO (X) levels was Y=0.4X+173 (r2=0.209). CONCLUSIONS: The distribution of ADNase B levels showed no close correlation with that of ASO, and ADNase B test was considered to have additive value to ASO test for detecting S. pyogenes infection.