Effect of increased serum sulphydryl content on titre of rheumatoid factor.

The prolonged administration of the sulphydryl compound penicillamine to rheumatoid arthritis patients results in a fall in the titre of rheumatoid factor (Jaffe, 1963). The mechanism by which the drug produces this effect is unknown, though it does not appear to be by intravascular depolymerization of macroglobulins (Jaffe, 1964) or by immunosuppression by pyridoxine antagonism (Jaffe, 1965). It has been reported that the serum sulphydryl content is abnormally low in patients with rheumatoid arthritis, and that the deficiency in protein sulphydryl groups may be responsible for the formation of abnormal immunoglobulins including rheumatoid factor (Lorber, Pearson, Meredith, and Gantz-Mandell, 1964). The restoration of the depressed serum sulphydryl content by penicillamine was suggested as a possible mechanism to explain the fall in rheumatoid factor titre and clinical improvement observed following a course of treatment with this drug (Lorber, 1966). The purpose of this study was to test that hypothesis by correlating the changes in rheumatoid factor and the serum sulphydryl content induced by THREE sulphydryl compounds systemically administered to two patients with rheumatoid arthritis.