[Does parenteral gold inhibit roentgen progression of chronic polyarthritis?]

Abstract

The retardation of radiological progression is one of the most important characteristics of a disease-modifying effect of an antirheumatic drug. For the following overview 10 trials were identified dealing with x-ray progression under treatment with parenteral gold. Nine of these trials were randomised parallel studies, one was a retrospective long-term observational study, all had a control group, in five this control group was treated with placebo, in two trials parenteral gold was compared with another DMARD (auranofin and methotrexate, respectively), in two trials different doses of gold were compared and in two trials the radiological progression during the first 6 months was compared with the following treatment period (in one of these trials gold was compared with methotrexate as well). The duration of treatment and follow-up was up to 1 year in two trials, up to 2 years in six, and over 2 years in only two studies. There is a great number of limitations in these studies: for instance, there was a large number of withdrawals who were not followed, x-rays were available for evaluation only in a relatively small proportion of treated patients in five studies, in six studies the disease duration was over 2 years at baseline, which limits the evaluability of x-ray progression for technical reasons. In one study juxta articular osteoporosis and joint swelling were evaluated; but these parameters are very difficult to evaluate in a multicenter study because of the different quality of the films. In spite of all limitations and reservations with the studies reviewed the published results indicate a reduction of radiological progression with parenteral gold treatment of rheumatoid arthritis patients: in the placebo-controlled studies outcome in the gold group was significantly better than in the placebo group. The study of the Empire Rheumatism Council failed to show a significant difference compared to the control group after 30 months, but the patients had been treated sufficiently only for 5 months. The study of Cats indicated a better outcome in the group of patients with a high gold dose, which is confirmed by the retrospective analysis of Luukkainen. In a comparison between 113 patients treated with parenteral gold and 119 patients treated with auranofin for 1 year Larsen found a significantly smaller progression in the patients treated with parenteral gold. In a patient population of 73 and 53 the difference between methotrexate and parenteral gold was too small to be detectable, but the progression curve was significantly flattened after the first 6 months, indicating a treatment effect. In a macroradiographic study the erosion surface area increased during the first 6 months of gold treatment, it did not change during the second 6 months, and decreased during the third 6 months together with healing of erosions. In conclusion, the studies reviewed in this paper indicate a disease-modifying potency of parenteral gold treatment, especially when the treatment is started early and sufficiently dosed.