The Correlation between a Semi-quantitative ASO(Antistreptolysin O) Assay by Rantz-Randall and a Quantitative ASO Assay by Nephelometry |
Sung-Keun Park, Seok-Hee Ahn, Jung-Woo Lee, Byoung-Soo Cho, Sung-Ho Cha, Yong-Mook Choi |
Department of Pediatrics, College of Medicine, KyungHee University, Seoul, Korea |
ASO(Antistreptolysin O)검사에 있어 반정량법의 Rantz-Randall법과 정량법의 Nephelometry법 간의 상관 관계 |
박성근, 안석희, 이정우, 조병수, 차성호, 최용묵 |
경희대학교 의과대학 소아과학교실 |
|
|
Abstract |
Purpose : Accurate diagnosis and prompt treatment of infection with Streptococcus
pyogenes (group A streptococci) is required as it may cause many complications, and
chronic serious sequelae, acute rheumatic fever and acute glomerulonephritis. Recently,
the assay methods of ASO concentration tend to be changed into quantitatively from
semi-quantitative or qualitative methods in this country. We would like to know
relationships and degree of concurrences between two methods.
Methods : Total eighty-three elementary school children, aged from 7 to 8, were
involved for this study. They had been examined throat swab culture with conventional
methods and letting down the blood for measuring ASO titer simultaneously. We
examined ASO titer by both Rantz-Randall method and Nephelometry.
Results : The correlation between a semi-quantitative ASO assay by Rantz-Randall
(X) and a quantitative ASO assay by Nephelometry(Y) was Y=1.69X+76.7(r=0.81). Compared
to the Nephelometry test, Rantz-Randall test showed a sensitivity of 72.7% and
specificity of 100%. Accordingly, the concordance rate of two methods was 89.2%.
Conclusions : There seems to be high correlation and concordance rate between
Rantz-Randall and Nephelometry. It needs to be changed methods for ASO titer
measurement from semi-quantitative to quantitative methods for reducing possible
laboratory error and for reliable standardization. Altogether, interpretation of ASO titer
should be on the ASO value of different geographic areas, in different seasons, and year
by year. |
Key Words:
Antistreptolysin O, Group A streptococcus |
|