Abstract
Two pairs of sibs with definite rheumatoid arthritis responded in a remarkably similar way to parenteral gold therapy, in terms of both toxicity and efficacy. Both pairs proved to be HLA identical. One of the pairs possessed the HLA antigens B8 and DR3, which have been associated with both drug toxicity and excellent clinical response. The other pair did not possess either of these antigens, suggesting that the reaction to gold therapy in patients with rheumatoid arthritis may be determined by other HLA or genetic factors coded for by chromosome 6, or both.