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Antibody response to bacteriophage hyaluronidase in acute glomerulonephritis after group A streptococcal infection
Abstract:
In a test of the hypothesis that lysogeny of group A streptococci by a temperate bacteriophage might confer nephritogenicity, 283 sera from 69 patients were examined for IgG and IgM antibodies to M 49 streptococcal bacteriophage hyaluronidase. The IgG and IgM response to bacteriophage hyaluronidase was greatest in M 49 streptococci-infected individuals with nephritis, but M 49 streptococci-infected subjects without nephritis also had a greater immune response than did subjects infected with serotypes other than M 49. Although antibody to bacterial hyaluronidase was detected in all Streptococcus-infected groups, antibody to M 49 streptococcal bacteriophage hyaluronidase usually was found in only M 49 streptococci-infected patients. Although the greatest IgG and IgM antibody response to bacteriophage hyaluronidase can be demonstrated in individuals with glomerulonephritis, the antibody response does not indicate a direct relation of lysogeny and nephritis because subjects with and without nephritis after M 49 streptococcal infection all had a significant rise in antibody titer.
Insights
Group A streptococci lysogeny by bacteriophage may influence nephritis. Researchers studied antibodies to M 49 streptococcal bacteriophage hyaluronidase in patients with and without nephritis, finding a link but not direct causation.
Area of Science:
- Microbiology
- Immunology
- Nephrology
Background:
- Lysogeny, the integration of a bacteriophage genome into a host bacterium's genome, is hypothesized to contribute to bacterial pathogenicity.
- Group A Streptococcus (GAS) infections are linked to post-infectious glomerulonephritis (PIGN).
- Specific M serotypes of GAS, like M 49, are associated with nephritis.
Purpose of the Study:
- To investigate the hypothesis that lysogeny of group A streptococci by a temperate bacteriophage confers nephritogenicity.
- To examine the immune response to M 49 streptococcal bacteriophage hyaluronidase in patients with and without nephritis.
Main Methods:
- Sera from 69 patients (283 samples) were analyzed for IgG and IgM antibodies.
- Antibodies were specifically targeted against M 49 streptococcal bacteriophage hyaluronidase.
- Comparison of antibody titers between patients with nephritis, patients without nephritis, and those infected with non-M 49 GAS serotypes.
Main Results:
- A greater IgG and IgM antibody response to bacteriophage hyaluronidase was observed in M 49 streptococci-infected individuals with nephritis.
- M 49 streptococci-infected subjects without nephritis also showed a higher immune response compared to subjects with other GAS serotypes.
- Antibody to M 49 streptococcal bacteriophage hyaluronidase was predominantly found in M 49 streptococci-infected patients, unlike antibodies to bacterial hyaluronidase.
Conclusions:
- While the greatest antibody response to bacteriophage hyaluronidase was in glomerulonephritis patients, this does not confirm a direct causal link between lysogeny and nephritis.
- Both nephritis and non-nephritis patients with M 49 streptococcal infection exhibited a significant rise in antibody titer, suggesting a complex relationship.