Distribution of gold in blood during chrysotherapy

Measurement of 'free' gold in patients receiving disodium aurothiomalate and the association of high free to total gold levels with toxicity

Serum from patients with rheumatoid arthritis (RA) receiving disodium aurothiomalate was analysed for total gold by atomic absorption spectrometry and for unbound (free) gold by the same method after ultrafiltration by an inert membrane. It was shown that it is possible to obtain reliable free gold concentrations by this method. Good correlations were shown between total and 'free' gold and between total and protein bound gold (PBG) for 54 patients with RA who were stabilised on gold therapy. Significant correlation was also shown between the same parameters for a second group of 15 patients starting gold therapy who were bled at weekly intervals for nine weeks immediately before medication. A single correlation with regression for all patients studied again showed good correlation between total and free gold and between total and PBG. Of the 189 paired values plotted, 182 fell within 2SD of the regression lines for the two plots. Of the seven patients with results outside 2SD of the regression line, six presented with side effects during the study.

Gold in erythrocytes, whole blood, and plasma during long-term chrysotherapy

The concentrations of gold in erythrocytes, whole blood, cell-rich plasma, and cell-free plasma were investigated in 17 patients with rheumatoid arthritis undergoing long-term chrysotherapy. Gold estimations were performed with a graphite tube atomic absorption spectrophotometer. Significant quantities of gold were found in isolated erythrocytes of 12 patients. There was no correlation between erythrocyte gold and therapeutic response, plasma gold, and gold in whole blood. Nor did gold in whole blood or plasma show any correlation with therapeutic responses and toxic reaction. However, all patients (3) with toxic reactions had a significantly higher gold concentration in the erythrocytes than the patients without toxic reactions. This result indicates that erythrocyte gold estimations could provide a useful warning of impeding toxic reactions.