Association of HLA antigens, toxic reactions and therapeutic response to auranofin and aurothioglucose in patients with rheumatoid arthritis.

To investigate the possible relation between HLA antigens and either favourable clinical response or toxic reaction to two different gold compounds, aurothioglucose and auranofin, a new orally absorbable gold compound, we studied 50 patients with rheumatoid arthritis prospectively. Of the 25 aurothioglucose-treated patients, response to treatment could not be evaluated in four patients because of early toxicity. Nine patients showed an excellent response, while 12 were moderate or non-responders. Four of the 9 excellent responders were HLA-DR3 positive, but none of the 12 moderate or non-responders possessed this antigen (P less than 0.025). In accordance with previous reports HLA-DR3 was found more frequently in patients developing toxicity on aurothioglucose than in those who did not (RR = 5.6). No association was found between HLA antigens and favourable clinical response in 25 auranofin-treated patients. Two of them showed a severe adverse reaction, neither of them being DR3-positive. HLA-DR3 positivity is associated not only with drug toxicity, but also with excellent respondership to aurothioglucose treatment.