Study of Seroprevalence of Antimycoplasma Antibody in Healthy Children and its Diagnostic Value

Purpose : To evaluate the diagnostic reliability of the single serum titers of the specific serum antibody determiantion method, we compared antimycoplasma antibody titers of 177 healthy children with 353 children who had respiratory symptoms indicative of Mycoplasma pneumoniae infection. Methods : We used Serodia-Myco II particle agglutination test and the titers of ≥1:40 were regarded as positive. Results : Age distribution of 177 healthy children was between 4-17 years and among these children there were 105 males and 75 females. Age distribution of 353 children with respiratory symptoms was between 2-17 years and consisted of 187 males and 166 female children. The results of antimycoplasma antibody titers of healthy 177 children were 95 cases(53.7%) of negative AMA, 30 cases(16.9%) of 1:40, 27 cases(15.3%) of 1:80, 19 cases(10.7%) of 1:160, 6 cases(3.4%) of 1:320 and there were no cases of ≥1:640. The results of antimycoplasma antibody titers of 353 children with respiratory symptoms were 195 cases(55.2%) of negative antimycoplasma antibody 19 cases(5.4%) of 1:40, 28 cases(7.9%) of 1:80, 30 cases(8.5%) of 1:160, 33 cases(9.3%) of 1:320, and there were a total of 48 cases(13.6%) that were ≥1:640. In healthy children the antimycoplasma antibody titers above 1:40 were 14% at 4 years of age, 7% at 5 years, 40% at 6 years and leveled out until 16 years of age. Conclusion : Antimycoplasma antibody titer distribution in healthy children ranged from negative to 1:320, therefore, if the single serum sample titer is ≤1:320, for a definitive diagnosis it is necessary to compare antibody levels after 2-3 weeks. (J Korean Pediatr Soc 1998;41:489-497)