Role of long-persisting human hepatitis E virus antibodies in protection.
The role of long-persisting HEV antibodies in humans was investigated. A well-characterized human volunteer anti-HEV (IgG) after 4 years of the recovery of the disease was passively immunized (200 mg kg-1 body wt) intramuscularly into three rhesus monkeys (nos 7, 8 and 9), while two monkeys (nos 5 and 6) were injected with normal immunoglobulin preparation (negative for anti-HEV IgG). At 16 h later all the animals were challenged intravenously with live HEV, as 10% stool extract prepared from the volunteer (positive for HEV by solid-phase immune electron microscopy). It was seen that transaminases (ALT/AST) were elevated in immunized monkeys on day 49 (no. 8), 60 (no. 7) and 86 (no. 9) after the virus challenge. On serological examination, all immunized (nos 7, 8 and 9) and one unimmunized (no. 6) monkeys were found positive for HEV IgM on day 10 post-challenge, while monkey no. 5 was negative. Further, all the animals from the immunized and unimmunized group seroconverted to HEV-IgG when tested on days 25 and 55 post-challenge. This has clearly shown that there is no protection. Therefore, these long-persisting HEV antibodies alone in humans, may not be protective in passive immunization.
Chauhan
A
A
Molecular Biology, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.
Dilawari
J B
JB
Sharma
R
R
Mukesh
M
M
Saroa
S R
SR
D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology* / Q000494:pharmacology; D001219:Aspartate Aminotransferases / Q000097:blood; D016751:Hepatitis E / Q000517:prevention & control*; D016752:Hepatitis E virus / Q000276:immunology*; D006801:Humans; D007116:Immunization, Passive; D007074:Immunoglobulin G / Q000276:immunology / Q000494:pharmacology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D008253:Macaca mulatta; D013997:Time Factors
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase