Systemic toxicity of non-cell corynebacterium parvum (CP) in monkeys.

AIM: Non-cell corynebacterium parvum product (NCPP) is a new preparation of corynebacterium parvum (CP), an immunomodulator that displays anticancer activities. It is prepared by nanotechnology and is intended to minimize the side effects of CP. The aim of the present study was to evaluate the immunogenicity and systemic toxicity of NCPP compared with CP in animals. METHODS: 30 monkeys were randomly divided into 5 groups and given CP (3 mg/monkey), three doses of NCPP (9, 3, 1 mg/monkey) and 0.9% normal saline (NS, 4 ml/monkey) individually by intramuscular injection twice a week for 13 weeks. The immunogenicity and systemic toxicity of NCPP and CP were compared. RESULTS: NCCP and CP caused histopathological changes in the liver, spleen and kidney, but pathologic changes in NCCP-treated groups were slighter than that in the CP group. Only 9 mg/monkey of NCPP caused the similar damage as the CP in intensity. Deposition of immune complexes in the glomerular basement membrane was observed only in the CP group. ELISA detection showed that the anti-CP antibody was at a high level, while the anti-NCPP antibody was at low level and disappeared during the recovery period. CONCLUSION: Our study has led to the view that NCPP is safer than CP.