Granulopoietic increase by BCG in mice.

Repeated doses of the non-specific immunostimulant BCG were injected intraperitoneally, followed by serial measurement of serum colony stimulating factor (CSF), and CFU-C number and percent synthesizing DNA. Following primary challenge with BCG, CSF remained at low levels until day 7, rose to a peak by day 10, and remained elevated through 14 days. Secondary challenge resulted in a bi-phasic CSF response with a small peak on day 1 and a larger one by day 7. Following secondary challenge, the percent of CFU-C in 'S' phase doubled in 24 hours; CFU-C significantly increased in number by 48 hours. The studies suggest that the marrow toxicity of cycle active cytotoxic drugs might be altered by non-specific immunostimulants such as BCG.