Prophylactic effect of human immunoglobulin against pneumococcal post-splenectomy sepsis in the rat

Failure to clear the blood of pneumococci after splenectomy may be corrected by active immunization, but some patients show poor antibody response to pneumococcal vaccination. Long-term antibiotic prophylaxis against post-splenectomy sepsis carries the risk of development of bacterial resistance and low patient compliance. In the present study, using a rat model for post-splenectomy sepsis, human immunoglobulin was given 24 h before challenging the animals with 10(3) Streptococcus pneumoniae. Immunoglobulin at a dosage of 300 mg/kg body weight was protective. Reducing the immunoglobulin dose to 75 mg/kg did not alter the mortality rate but significantly prolonged the survival time. The results indicate that the new immunoglobulin preparations for intravenous use might provide an effective means of reducing the risk of post-splenectomy sepsis, even in the most susceptible patients.