A Study on Serum Titers of Anti-Streptococcal Polysaccharide (ASP) Among School Children
1985 Volume 59 Issue 9 Pages 883-891
Details
1985 Volume 59 Issue 9 Pages 883-891
Determination of ASO and other serum antibodies to extracellular antigens has been widely employed for the diagnosis of infection of hemolytic streptococcus.A new laboratory microtiter technique for determining antibodies to a bacterial somatic component (anti-streptococcal-polysaccharide (ASP)) has been developed.This technique permits an easy detection of antibodies to C polysaccharide that is a component of the cell wall of Group A hemolytic streptococcus.The present study was designed to evaluate diagnostic value of ASP determination.
Serum samples were obtained from 538 children aged between 6 and 15 years (patients in Osaka municipal children's hospital and elementary school children in Osaka City) from April, 1979 to January, 1983 and serum ASP, ASO and ASK titers were determined.
The mean ASP level was 1: 64 for the age group between 6 and 9 years, 1: 43, between 10 and 12 years, and 1: 50, between 13 and 15 years, and the cutoff value between a normal and an abnormal level would be between 1: 32 and 1: 64.The coefficents of correlation was 0.214 between ASP and ASO, 0.103 between ASP and ASK, and 0.705 between ASO and ASK, which indicated that ASO and ASK had the most correlative, value.
Clinical isolates were obtained from a throat of 109 elementary school children in Osaka City six times over the period of one year and the relationship between Group A hemolytic streptococcus and titers of these antibodies was studied.The proportion of cases with elevated titers increased in all antibodies as the incidence of positive bacterial cultures increased.Of 50 patients from whom Group A hemolytic streptococcus isolated at least once, 23 (46.0%) showed elevations in ASO and ASK titers but only 18 (36.0%) had elevation in ASP titer.Among 28 children with normal ASO titer of below 1: 240 despite a positive bacterial culture, the numbers of cases with elevated ASP and ASK levels were 10 (38.5%) and 7 (25.0%), respectively.The determination of ASP was slightly more beneficial for the diagnosis of infections with Group A hemolytic streptococcus.
