Failure of gamma-interferon to decrease mortality from group B streptococcal sepsis in neonatal rats.
Newborns possess an altered immune response to infection with impaired leukocyte chemotaxis and deficient production of gamma-interferon (IFN-gamma). IFN-gamma enhances neonatal leukocyte activation and movement. We proposed that IFN-gamma in conjunction with penicillin compared to penicillin therapy without IFN-gamma would increase survival from group B streptococcal sepsis in a neonatal rat model. Newborn rats were infected with 10(5) cfu of group B streptococci at 48-72 h of age and randomized to receive either serum albumin (controls), rat recombinant IFN-gamma, albumin and penicillin, or IFN-gamma and penicillin. Survival 120 h postinfection revealed: controls 5% (1/21); IFN-gamma 4% (1/24); penicillin 23% (5/22); and IFN-gamma plus penicillin 10% (2/21). Survival analysis with a lognormal parametric regression model revealed only the penicillin group to have improved survival compared to controls. Contrasting the penicillin group with the IFN-gamma plus penicillin group did not reveal a statistically significant difference by the Wald chi2 statistic (p = 0.25).
Department of Pediatrics, Fitzsimons Army Medical Center, Aurora, Colo., USA. rwittler@ix.netcom.com
R R
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Wittler
R W
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Harris
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Paine
D000818:Animals; D000831:Animals, Newborn; D016470:Bacteremia / Q000401:mortality / Q000628:therapy*; D007371:Interferon-gamma / Q000008:administration & dosage / Q000627:therapeutic use*; D010406:Penicillins / Q000008:administration & dosage / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins; D013290:Streptococcal Infections / Q000401:mortality* / Q000628:therapy*; D013292:Streptococcus agalactiae; D015996:Survival Rate
D010406:Penicillins; D011994:Recombinant Proteins; D007371:Interferon-gamma