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Studies on serological cross-reaction in sequential flavivirus infections
1Department of Virology, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
Microbiology and Immunology
|January 1, 1994
Summary
Sequential flavivirus infections, including dengue (DEN) and Japanese encephalitis (JE), often show cross-reacting antibodies. This study found significant cross-reactivity between DEN, JE, and yellow fever (YF) viruses in patients with prior flavivirus exposure.
Area of Science:
- Virology
- Immunology
- Infectious Diseases
Background:
- Flaviviruses, such as dengue (DEN), Japanese encephalitis (JE), and yellow fever (YF), can cause significant human disease.
- Pre-existing antibodies from a prior flavivirus infection can complicate the diagnosis of subsequent flavivirus infections.
- Cross-reactivity among flaviviruses is a known phenomenon, but its extent and implications in sequential infections require further investigation.
Purpose of the Study:
- To investigate the presence and significance of cross-reacting antibodies to DEN, JE, and YF viruses in patients with sequential flavivirus infections.
- To differentiate between specific and cross-reactive antibody responses using neutralization tests and antibody class analysis.
- To understand the impact of pre-existing flavivirus antibodies on immune responses during secondary flavivirus infections.
Main Methods:
- Analysis of acute- and convalescent-phase sera from patients diagnosed with dengue hemorrhagic fever (DHF) and Japanese encephalitis (JE).
- Use of neutralization (N) tests to assess antibody titers against DEN, JE, and YF viruses.
- Sucrose gradient centrifugation and fractionation of sera to analyze IgM and IgG antibody classes in cross-reactive cases.
Main Results:
- In DHF patients, 38.5% showed a rise in DEN antibodies, and another 38.5% showed significant rises in both DEN and JE antibodies.
- In JE patients, 61.5% showed a rise in JE antibodies, and 15.4% showed significant rises in both DEN and JE antibodies.
- IgM antibodies were specific for JE, while IgG antibodies demonstrated cross-reactivity in JE patients; both IgM and IgG antibodies to YF virus were elevated in JE cases with pre-existing YF antibodies.
Conclusions:
- Cross-reactivity among flaviviruses from different subgroups is frequently observed, even with neutralization tests, particularly in sequential infections.
- The study highlights the complexity of diagnosing flavivirus infections when pre-existing antibodies are present.
- Understanding antibody class-specific responses (IgM vs. IgG) is crucial for interpreting serological results in flavivirus infections.