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Infection of group A streptococcus and antibody response to extracellular antigens
Insights
Diagnosing streptococcal infections in children can be improved by measuring both anti-streptolysin O (ASO) and antideoxyribonuclease B (ADNase B) antibody titers. Elevated levels of both antibodies indicate infection and are associated with acute rheumatic fever.
Area of Science:
- Pediatric infectious diseases
- Immunology of streptococcal infections
- Diagnostic marker development
Background:
- Group A streptococci (GAS) pharyngeal infections are common in children.
- Assessing the immune response to GAS is crucial for diagnosis.
- Existing diagnostic methods may require enhancement for accuracy.
Purpose of the Study:
- To investigate the relationship between GAS pharyngeal infection and specific antibody responses.
- To evaluate the diagnostic utility of anti-streptolysin O (ASO) and antideoxyribonuclease B (ADNase B) titers.
- To explore antibody profiles in children with acute rheumatic fever.
Main Methods:
- Detection of Group A streptococci in throat swabs from children.
- Measurement of serum anti-streptolysin O (ASO) and antideoxyribonuclease B (ADNase B) antibody titers.
- Comparison of antibody titers between infected and non-infected children, and those with acute rheumatic fever.
Main Results:
- Group A streptococci were identified in 9.4% of children studied.
- 55% of infected children showed a significant rise in ASO titers.
- Elevated ADNase B titers were significantly higher in GAS-positive children with high ASO titers.
- Patients with acute rheumatic fever exhibited elevated ASO and ADNase B titers.
Conclusions:
- Combined measurement of ASO and ADNase B titers may improve the diagnosis of streptococcal infections.
- These antibody titers are valuable indicators in pediatric GAS infections and acute rheumatic fever.
- Further application of combined ASO and ADNase B testing is recommended for clinical diagnosis.
Abstract:
A study demonstrating the relationship between pharyngeal infection of group A streptococci and the antibody response was performed. Group A streptococci were recovered from 44 (9.4%) of 466 children, of which 41 strains were typable by T-protein. Fifty-five percent of 41 children from whom group A streptococci were recovered showed a significant rise in anti-streptolysin O (ASO) titers in sera. In children from whom group A streptococci were recovered and with elevated ASO titers, titers of antideoxyribonuclease B (ADNase B) were significantly higher than those who were negative for group A streptococci and also showed elevated or normal titers for ASO. Patients with acute rheumatic fever demonstrated elevated titers of both ASO and ADNase B. These findings suggest that a combination of ASO and ADNase B titers should be applied to diagnose the streptococcal infections. Antinicotinamideadenine dinucleotidase showed a low level of titers in children who had group A streptococci in their throat and exhibited elevated titers in streptococcal antibodies, and also in patients with acute rheumatic fever.