Related Experiment Video
Updated: May 3, 2026
Measuring Influenza Neuraminidase Inhibition Antibody Titers by Enzyme-linked Lectin Assay
Published on: September 6, 2016
How to use antistreptolysin O titre
1Department of Paediatric Rheumatology, Bristol Royal Hospital for Children, Bristol, UK.
Abstract:
Group A streptococcus (GAS) is the cause of a wide range of acute suppurative and, following a latent period, non-suppurative diseases such as rheumatic fever and poststreptococcal glomerulonephritis. Diagnosis of the latter group requires evidence of preceding GAS infection. The bacteria produce a range of extracellular antigens, including streptolysin O, which induce an antibody response in the host. A rise in antistreptolysin O titre (ASOT) is indicative of preceding GAS infection. In clinical practice, often only a single ASOT measurement is available and its timing in relation to a possible GAS infection is unknown. Interpretation of the result in this context is liable to misdiagnosis. In order to optimise diagnosis of preceding GAS infection, at least two sequential ASOT measurements, together with simultaneous assay for anti-DNase B, a second antistreptococcal antibody, is recommended.
Insights
Diagnosing Group A Streptococcus infections is challenging with single antibody tests. Sequential antistreptolysin O titre (ASOT) and anti-DNase B measurements improve diagnostic accuracy for past GAS infections.
Area of Science:
- Microbiology
- Immunology
- Infectious Diseases
Background:
- Group A Streptococcus (GAS) causes acute and non-suppurative diseases like rheumatic fever.
- Diagnosing post-streptococcal conditions requires evidence of prior GAS infection.
- GAS produces extracellular antigens, including streptolysin O, triggering antibody responses.
Purpose of the Study:
- To address challenges in diagnosing preceding GAS infections.
- To improve the interpretation of antistreptolysin O titre (ASOT) results.
- To recommend an optimized diagnostic strategy for GAS infections.
Main Methods:
- Analysis of antibody responses to GAS extracellular antigens.
- Evaluation of single versus sequential ASOT measurements.
- Inclusion of anti-DNase B antibody assays in diagnostic protocols.
Main Results:
- Single ASOT measurements are often insufficient and prone to misdiagnosis.
- The timing of a single ASOT test relative to infection is frequently unknown.
- Sequential ASOT testing combined with anti-DNase B offers enhanced diagnostic utility.
Conclusions:
- Optimizing GAS infection diagnosis requires more than one antibody test.
- Sequential ASOT measurements are recommended for accurate diagnosis.
- Simultaneous anti-DNase B assay provides a valuable second marker for GAS infection.
