Prophylactic immunotherapy in newborn rat endotoxicosis.

Area of Science:

• Neonatal immunology
• Microbiology
• Immunotherapy

Background:

• Gram-negative bacterial sepsis and septic shock pose significant risks to newborns, with high incidence and mortality rates.
• Current therapeutic strategies for neonatal endotoxemia are limited, necessitating novel approaches.

Purpose of the Study:

• To investigate the efficacy of prophylactic immunotherapy in preventing and treating newborn endotoxemia.
• To determine if antiserum against lipopolysaccharide (LPS) from Salmonella enteritidis can protect newborn rats from gram-negative endotoxicosis.

Main Methods:

• Lipopolysaccharide (LPS)-tolerant rats were generated using serial Salmonella enteritidis LPS injections; their sera were used as antiserum for immunotherapy.
• Antiserum was administered to newborn rats simultaneously with or prophylactically to pregnant rats before endotoxin challenge.
• Mortality rates, hypoglycemia, and lactacidemia were assessed in response to LPS from S. enteritidis, S. typhosa, and Escherichia coli.

Main Results:

• Antiserum cotreatment significantly reduced mortality in 0-day-old rats challenged with LPS from S. enteritidis, S. typhosa, and E. coli.
• Prophylactic administration of antiserum to pregnant rats also decreased mortality in their offspring, indicating transplacental transfer of protective antibodies.
• The protective effect was attributed to antibodies recognizing a common antigen in LPS.

Conclusions:

• Prophylactic and simultaneous immunotherapy with antiserum is beneficial in treating newborn rat endotoxemia.
• Transplacental transfer of antibodies provides protection against gram-negative bacterial infections in neonates.
• This study highlights the potential of immunotherapy as a preventive measure against neonatal sepsis.