The effect of longterm treatment with auranofin and gold sodium thiomalate on immune function in the dog.

Although gold compounds are recognized as effective immunomodulatory agents in the treatment of rheumatoid arthritis (RA), their mechanism of action is controversial. We examined the effect of longterm treatment with 0.6-3.6 mg/kg auranofin (AF) per os q24h, or intramuscular injections of 0.5-2.0 mg/kg gold sodium thiomalate (GSTM) q3d, on 13 variables of immune function in normal dogs. None of the changes in these variables previously attributed to treatment with AF or GSTM could be demonstrated after 6-7 years' dosing. As gold compounds are effective in treating spontaneous RA in dogs, these proposed actions may not be responsible for the remittive effects of chrysotherapy in this disease.