title: Asymptomatic infection by Streptococcus pyogenes in schoolchildren and diagnostic usefulness of antideoxyribonuclease B.
abstract: This study is designed to evaluate the immune status of schoolchildren with respect to Streptococcus pyogenes, and to ascertain the usefulness of antideoxyribonuclease B (ADNase B). Antistreptolysin O (ASO) and ADNase B concentrations were measured quantitatively in 266 serum samples from healthy elementary school children in Seoul. Simultaneously, throat cultures were taken in order to isolate S. pyogenes and other beta-hemolytic streptococci (BHS). The upper limits of the normal (ULN) concentration of ASO and ADNase B were 326 IU/mL, and 362 IU/mL, respectively. The correlation between ADNase B (y) and ASO (x) was y = 0.4x+173 (r = 0.46). Mean ADNase B level (392 IU/mL) was significantly higher in children with S. pyogenes than in those with non-group A BHS (236 IU/mL) or no BHS (234 IU/ mL). Some schoolchildren were proven, via ASO and ADNase B tests, to be harboring asymptomatic S. pyogenes infections. The high ULN of ASO and ADNase B in schoolchildren should be carefully considered, in order to interpret the data collected from the patients. We could add the ADNase B test to our set of diagnostic tools, which would allow us to more accurately detect and diagnose streptococcal infections, as ADNase B was more specifically related to the results of throat cultures, and there was little correlation between ASO and ADNase B.
authors.affiliation: Department of Laboratory Medicine, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Sunjoo
authors.initials: S
authors.lastname: Kim
authors.forename: Nam Yong
authors.initials: NY
authors.lastname: Lee
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D001426:Bacterial Proteins / Q000276:immunology; D002648:Child; D003851:Deoxyribonucleases / Q000276:immunology*; D005260:Female; D006801:Humans; D007723:Korea; D008297:Male; D012698:Serologic Tests; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000276:immunology*; D013297:Streptococcus pyogenes / Q000201:enzymology / Q000276:immunology*; D013301:Streptolysins / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D013301:Streptolysins; C025964:streptolysin O; D003851:Deoxyribonucleases; C020069:deoxyribonuclease B