Gold Therapy in Rheumatoid Arthritis

Correlation between osteochondral changes depicted by magnetic resonance imaging and disease progression

PURPOSE

To determine the consequences of the chronic use of systemic corticosteroids in children with juvenile rheumatoid arthritis by means of evaluating osteochondral effects depicted by magnetic resonance imaging.

PATIENTS AND METHODS

We reviewed clinical and magnetic resonance imaging findings in 69 children (72 knees) with juvenile rheumatoid arthritis. Two groups were studied. Group I: 34 (49.3%) children had previous or current use of systemic corticotherapy (22 girls; 12 boys; mean age: 11.3 years; mean disease duration: 5.9 years; mean corticotherapy duration: 2.9 years; mean cumulative dose of previous corticosteroids: 5000 mg); Group II: 35 (50.7%) children had no previous use of corticosteroids (27 girls; 8 boys; mean age: 11.7 years; mean disease duration: 5.3 years). The groups were compared statistically.

RESULTS

In the group that had received corticotherapy (Group I), osteochondral abnormalities were significantly correlated to long-standing disease (>3.5 years; p<0.001). This correlation was not found in the group that had no previous history of corticotherapy (Group II). No correlations were established between median dose of corticosteroids and magnetic resonance imaging findings.

CONCLUSION

It is important to further investigate the long-term intra-articular effects of systemic corticotherapy to ensure that the side effects of the aggressive therapy will not be more harmful for the joints than the symptoms suffered over the natural course of the disease.

Injectable gold for rheumatoid arthritis

OBJECTIVES

To estimate the short-term benefit and risk of side-effects of injectable gold for rheumatoid arthritis.

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Group trials register, and Medline, up to July 1997, using the search strategy developed by the Cochrane Collaboration (Dickersin 1994). The search was complemented with bibliography searching of the reference list of the trials retrieved from the electronic search. Key experts in the area were contacted for further published and unpublished articles.

SELECTION CRITERIA

Randomized clinical trials (RCT) comparing injectable gold against placebo in patients with rheumatoid arthritis were included.

DATA COLLECTION AND ANALYSIS

Methodological quality of the RCTs was asessed by two reviewers (MS, BS) (kappa=1.0). Rheumatoid arthritis outcome measures were extracted by two reviewers from the publications for the 6 month endpoint. Sufficient data was obtained to conduct a pooled analysis of the number of swollen joints, physician global assessment, patient global assessment and erythrocyte sedimentation rate (ESR). Results were analyzed as standardized weighted mean differences for swollen joints and global assessments and weighted mean differences for ESR. Toxicity was evaluated with pooled odds ratios for withdrawals. Heterogeneity was estimated using a chi-square test. Fixed effects models were used throughout.

MAIN RESULTS

Four trials and 415 patients were included. A statistically significant benefit was observed for injectable gold when compared to placebo. The standardized weighted difference (effect size) between gold and placebo for the number of swollen joints was -0.5, translating into a percentage change of 30% in favour of gold adjusted for placebo. Statistically significant differences were also observed for ESR and patient and physician assessments. Twenty two percent of the treated patients withdrew from toxicity compared to 4% of controls (OR=3.9 - 95%Cl: 2.1 - 7.2).

REVIEWER'S CONCLUSIONS

Although its use can be limited by the incidence of serious toxicity, injectable gold has an important clinically and statistically significant benefit in the short term treatment of patients with rheumatoid arthritis.

Rheumatoid arthritis: pathogenesis and early recognition

Rheumatoid arthritis (RA) is a chronic, destructive disease characterized by joint pain and swelling, which progresses in a substantial percentage of patients to invasion of bone and cartilage. If not successfully treated, progressive joint destruction results in loss of function, disability, and increased mortality. The time from onset of symptoms to joint destruction is frequently measured in months rather than years. Unfortunately, the time from disease onset to diagnosis and initiation of effective therapy is often prolonged, allowing development of irreversible joint destruction. In order to apply current knowledge to reduce the disability and death associated with progressive RA, the clinician must understand the pathophysiologic stages of the disease as reflected in symptoms, radiography, and biochemical markers. Prognostic factors relevant to RA severity, including factors relevant to RA severity, including serum markers and genetic traits, must also be known so that appropriate therapeutic strategies can be planned. Although current therapy cannot reliably alter the long-term outcome of RA, new approaches are promising. Patients at high risk or who fail to respond to conservative therapy are candidates for earlier, more aggressive strategies using single or possibly combination antirheumatic therapy.

Inhibition of hydrolytic enzymes by gold compounds. I. beta-Glucuronidase and acid phosphatase by sodium tetrachloroaurate (III) and potassium tetrabromoaurate (III)

Purified bovine liver beta-glucuronidase (beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32) and wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) were inhibited with freshly dissolved and 24 h aquated tetrahaloaurate (III) compounds. Rate and equilibrium inhibition constants were measured. From this data two acid phosphatases species were observed. Equilibrium inhibition constants ranged from 1 to 12.5 microM for the various gold compounds toward both enzymes. The first order rate constants ranged between 0.005 and 0.04 min.-1 for most reactions with the exception of the fast reacting acid phosphatase which had values as high as 2.6 and 2.8 min.-1. It is observed that the beta-glucuronidase is rapidly inhibited during the equilibrium phase before the more slower reaction covalent bond formation takes place. The acid phosphatases form the covalent bonds more rapidly, especially the faster reacting species suggesting a unique difference in the active site geometry to that of the more slowly reacting species. The tightly bonded gold (III)-enzyme complex is probably the reason for its toxicity and non-anti-inflammatory use as a drug.

A double-blind study on the effect of discontinuation of gold therapy in patients with rheumatoid arthritis

To assess the benefit of further gold treatment of rheumatoid arthritis (RA) patients who had already received more than 6 g of this metal, 24 such patients were included in a double-blind trial. Besides this "gold group" comprising 11 patients who received gold (Auromyose) in the same dosage schedule as before the study, the trial included a "placebo group" comprising 13 patients who received gold in a suspension diluted 1/100. In either group clinical, laboratory, and radiological data did not differ after 6 and 24 months in relation to the results at entry except for the serum gold concentrations, which were lower in the placebo group. We conclude that discontinuation of the treatment in RA patients who have received more than 6 g gold is not harmful to the patients for at least two years after withdrawal.

Gold compounds in rheumatic diseases--1

Gold complexes diminish synovitis and improve therapeutic outcome in rheumatoid arthritis, psoriatic arthritis, some forms of juvenile chronic arthritis, and palindromic rheumatism. The decision to treat a patient with a gold compound should not be undertaken lightly. It should be understood by the patient that the commitment to therapy is potentially long-term, that major benefit is not assured, and that there is, approximately, a 50% probability of an adverse reaction which may terminate treatment. Nevertheless, most adverse effects are mild and transient and the probability of good control, even remission, in an otherwise threatening disease, is sufficiently high to justify a therapeutic trial in the majority of patients. Those patients whose rheumatoid arthritis appears to respond to gold may be encouraged to continue long-term therapy with maintenance doses, in view of the evidence of sustained efficacy in most patients and of the declining risk of adverse reactions after the first 12 months.

Does drug therapy slow radiographic deterioration in rheumatoid arthritis?

Many clinicians believe that slow-acting therapeutic agents, such as fold, penicillamine, the antimalarials, and cytotoxic drugs, can retard joint destruction in rheumatoid arthritis. We reviewed 60 published studies employing these drugs to evaluate critically the evidence that drug therapy can slow the radiographic progression of disease. Seventeen studies were found that included radiographic assessment of both treated and control groups; they were analyzed using methodologic criteria known to be important in affecting the results of drug trials. In addition to numerous qualitative methodologic deficiencies, many studies showed inadequacies in sample size and duration of treatment, and the drug dosage used varied from one study to another. We found evidence suggesting that both gold and cyclophosphamide can retard radiographic progression of joint destruction. At present, there are too few technically adequate studies to permit even provisional conclusions concerning other agents.

Clinical responses during gold therapy for rheumatoid arthritis. Changes in synovitis, radiologically detectable erosive lesions, serum proteins, and serologic abnormalities

Gold therapy given to 73 patients with rheumatoid arthritis was associated with remission of synovitis for 3 months or longer in 27 patients and 50% or greater improvement in 20 patients. New joint deformities did not develop in patients who experienced remission, and progression of radiologically detectable erosive changes was prevented. Serum protein and serologic abnormalities were improved in all groups, but patients who had a good response experienced the greatest improvement. No single clinical or laboratory feature in the pretreatment assessment predicted response, but, as a group, the patients with the best response also ranked best for most prognostic indicators.

Long-term chrysotherapy in rheumatoid arthritis

The efficacy of chrysotherapy appears to increase with prolonged administration. In patients who were followed for 3 years after gold therapy was started, remissions occurred in 73% of those who continued chrysotherapy. Only 6% of those who stopped gold injections during the first 18 months subsequently developed "spontaneous" remissions, although initially both groups had comparable moderately severe rheumatoid arthritis of 6 to 8 years' duration. Therefore, in the absence of definite toxicity, maintenance gold injections should be continued indefinitely.

A double-blind trial of high versus conventional dosages of gold salts for rheumatoid arthritis

In a double-blind study, patients were randomly selected for treatment using conventional doses (CD; 50 mg) or high doses (HD; 150 mg) of sodium aurothiomalate given weekly by injection. Twenty-three patients were assigned to the CD group and 24 to the HD group. Neither efficacy nor toxicity correlated with serum gold concentrations. Conventional doses were as efficacious as high doses with respect to both rapidity and degree of response. However, side effects were much more frequent and severe in the HD group. Thus there is no reason to recommend a 150 mg weekly dosage regimen.

Comparison of two dosage schedules of gold salts in the treatment of rheumatoid arthritis. Relationship of serum gold levels to therapeutic response

Two doses of gold sodium thiomalate were compared for their effect on rheumatoid arthritis. Thirty-seven patients with active disease for longer than 6 months were treated with 25 mg of gold sodium thiomalate for an average of 29.6 weeks, then at biweekly or monthly intervals to complete 2 years of treatment. Thirty-eight patients were given more than twice as much gold salt at the same intervals on a flexible dose schedule that produced serum gold levels which averaged 332 microgram/dl during the weekly injection phase. No differences were observed in the therapeutic responses of the two groups. Therefore the minimal dose of gold sodium thiomalate required to induce a response in rheumatoid arthritis is 25 mg or less per week. Serum gold levels in the steady state varied between 95 and 386 microgram/dl and were not related to response. Serum half-life for gold was calculated for patients who had an excellent response and for those who were treatment failures. The rate at which gold disappeared from serum was not related to therapeutic responses.

A multicentre controlled trial of the effects of different dosage of gold therapy, followed by a maintenance dosage

In a combined clinical trial with gold in patients with rheumatoid arthritis (RA) 95 patients were treated with a high initial dosage of 2,500 mg aurothioglucose in 21 weeks. Afterwards 48 of these patients received a maintenance dosage of gold and 47 patients placebo injections. Another group of 101 patients received 1,000 mg gold in 21 weeks. Finally a maintenance dose of gold was administered to 49 of these patients, to the other 52 patients placebo injections were administered. For the treatment of RA a high dosage of a gold compound offers no advantage over a low dosage. After a high dosage one can expect a significantly higher number of side effects. The development of toxicity does not influence the ultimate results. A second course of gold has hardly any benificial effect. Prolonged administration of gold is usually well-tolerated; whether it has substantial and sustained therapeutic value remains dubious. Progression of radiological abnormalities can be observed at the same moment that signs and other symptoms of the disease show improvement.