Exploring the mechanisms and legacy of chrysotherapy - the therapeutic use of gold compounds in medicine.
The term "chrysotherapy," derived from the Greek chrysos for gold, refers to the therapeutic use of gold salts. For much of the 20th century, it was a standard treatment for rheumatoid arthritis and was also explored for certain autoimmune skin diseases like pemphigus and discoid lupus erythematosus 6 .
Gold's mechanism of action is not fully understood, but it is known to accumulate within the immune system, particularly in cells like macrophages and other components of the reticuloendothelial system 6 .
In vitro studies suggest that gold salts can inhibit the phagocytic and chemotactic responses of immune cells, dampening their overactivity 6 . Some theories also propose that gold inhibits specific lysosomal enzymes and components of the complement cascade.
Introduction of gold salts for rheumatoid arthritis treatment
Gold therapy becomes standard treatment for severe rheumatoid arthritis
Development of oral gold formulation (auranofin)
Gradual decline in use due to newer biologics, but legacy continues in nanoparticle research
While detailed, modern experimental data is scarce, one four-year prospective clinical study from 1976 offers a window into how chrysotherapy was evaluated 2 .
The researchers compared a standard weekly 50 mg injection of gold with a dosage based on the patient's body weight (1 mg/kg). They found no significant difference in effectiveness between these two dosing regimens 2 .
However, they did discover that the formulation of the drug mattered. A slowly absorbed, oil-based gold thioglucose solution resulted in fewer side effects and a higher percentage of patient improvement compared to a rapidly absorbed, water-based gold thiomalate 2 .
Perhaps the most encouraging finding was that among patients who did not respond to the standard regimen, 43% experienced a satisfactory clinical response when the dosage was increased, and this was achieved without a corresponding increase in toxicity 2 .
This suggested that treatment could be optimized for individual patients, paving the way for personalized medicine approaches.
| Comparison Factor | Standard Regimen | Experimental Finding |
|---|---|---|
| Dosage | Fixed 50 mg weekly | No significant advantage over 1 mg/kg body weight 2 |
| Drug Formulation | Aqueous (water-based) thiomalate | Oil-based thioglucose caused fewer side effects and higher improvement rates 2 |
| Non-Responder Strategy | Discontinuation of therapy | 43% responded to higher dosage levels without increased toxicity 2 |
Although the specific reagents from the 1976 study are not listed, the following table details the gold compounds and supporting tools that were central to chrysotherapy research and treatment, based on historical sources 6 .
| Research Reagent / Material | Function in Chrysotherapy |
|---|---|
| Parenteral Gold Salts (e.g., aurothiomalate, aurothioglucose) | Injected gold compounds that are completely absorbed and have a half-life of about 6 days, primarily excreted in urine 6 . |
| Oral Gold (e.g., auranofin) | An oral formulation introduced later; only 25% absorbed, with a longer half-life of ~21 days and primarily fecal excretion 6 . |
| Complete Blood Count (CBC) with Differential | A mandatory laboratory test to monitor for hematologic adverse effects like leukopenia and thrombocytopenia 6 . |
| Platelet Count | A crucial test performed before each parenteral injection to monitor for gold-induced thrombocytopenia 6 . |
| Urinalysis | A routine test to check for gold-induced proteinuria and other signs of nephrotoxicity 6 . |
Gold salts administered via injection for complete absorption and predictable pharmacokinetics.
Later development of oral gold (auranofin) with different absorption and excretion profiles.
Rigorous laboratory monitoring required to manage potential toxicities of gold therapy.
Chrysotherapy has largely been superseded by newer, more targeted, and often more effective treatments with better safety profiles, such as biologic drugs.
The use of gold salts declined due to its unpredictable and potentially severe side effects, which could include:
These adverse effects required intense and costly monitoring 6 8 , making the treatment less practical compared to newer alternatives.
However, the legacy of gold in medicine is not entirely lost. The property of gold being retained in tissues like the liver and spleen has found new applications:
This modern research avenue shows how an old therapy can inspire new technological frontiers.
The journey of gold in medicine demonstrates how historical treatments can inform cutting-edge research
The evolution of gold-based medicine from traditional chrysotherapy to modern nanotechnology applications