Introduction:
Gold and Penicillamine are used to treat rheumatoid arthritis and other autoimmune conditions to relieve the symptoms associated with the disease. It is found that patients under long-term treatment by these components developed kidney disease associated with proteinuria. This may occur due to the hypersensitivity reaction of the body to gold and Penicillamine. Both drugs share the same pharmacological mode of action. Hence, the pathogenesis that causes nephropathy and clinical and pathological presentation remain the same. The outcome of the disease is good when treated promptly, and most of the time, the kidney reverts to its normal function.
What Is Penicillamine?
Penicillamine is a d-isomer of dimethyl cysteine grouped under the heavy metal antagonists and is a breakdown product of Penicillin. It has a strong affinity for various metals; hence it is used in the treatment of lead poisoning. Penicillamine binds with extra copper in the body and eliminates it in the urine; hence it is used in treating Wilson's disease. It is also used in treating rheumatoid arthritis, kidney stones, and many other conditions.
What Is Gold Therapy?
Gold therapy is nothing but the salt from the metal element gold is used in treating the disease conditions of the body. It is used to treat autoimmune conditions where it is found to relieve pain in the joints. The conditions include rheumatoid arthritis, bullous pemphigoid, pemphigus foliaceus, idiopathic polyarthritis, and many others.
How Do Penicillamine and Gold Share the Same Pharmacological Properties?
Studies have shown that both Penicillamine and gold used in the treatment of rheumatoid arthritis share the same mode of action in exhibiting their anti-rheumatoid effect. They found that both drugs delay chemotaxis by the white blood cells and thereby exhibit anti-inflammatory action. They are also reported to reduce the circulating immune complexes in rheumatoid arthritis.
What Is the Epidemiology of Gold and Penicillamine Nephropathy?
The occurrence of this condition may affect any age group under treatment, but it is reported to be more prevalent in older age groups, and no reported gender prediction.
What Is the Pathogenesis of Gold and Penicillamine Nephropathy?
In patients with rheumatoid arthritis who exhibit low levels of IgA (Immunoglobulin A), IgG (Immunoglobulin G), and two B-cell antigens DRW2, DRW3 is found to react with gold and Penicillamine. It is reported to be a result of an immune hypersensitivity reaction by the body to the gold salts and the Penicillamine used in the treatment of the diseases. The body may recognize this as a foreign body and start producing antibodies against it. As a consequence, antibodies will be directed against the body tissues where the gold particles have deposited, particularly skin, bone marrow, and kidneys, causing the disease.
What Are the Signs and Symptoms of Gold And Penicillamine Nephropathy?
The clinical presentation of both gold and Penicillamine nephropathy is similar, and the symptoms include,
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Proteinuria - Excretion of protein in the urine.
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Hematuria- Presence of blood in the urine.
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Foamy Urine - Due to the presence of protein in the urine, the appearance of the urine may be foamy.
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Hypertension - Increased blood pressure may be caused as a result of damage to the kidneys.
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Fatigue - Feeling tired may be due to impaired kidney function.
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Loss of Appetite - Due to impaired kidney function, the waste products may build up in the blood suppressing the appetite.
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Edema - In patients progressing to end-stage renal disease, generalized swelling of the body, especially the foot and the hands, will be noted.
How Is Gold and Penicillamine Nephropathy Diagnosed?
The steps in diagnosis involve,
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Medical and Drug History: A thorough medical history, such as the history of preexisting rheumatoid arthritis, autoimmune conditions, and Wilms disease. The use of medications such as gold and Penicillamine by the patient for any disease condition provides a good clue in provisionally diagnosing this disease.
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Urinalysis: Urine analysis may show the presence of protein (proteinuria) and blood (hematuria) in the urine.
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Microscopic Examination: Microscopic examination of the biopsied kidney tissue provides the confirmatory diagnosis of the condition. Light microscopic examination of silver-stained renal tissue (in the case of both gold and penicillamine nephropathy) reveals the common features of membranous nephropathy with multiple subepithelial immune complex deposits giving a point hole to spike appearance. The presence of dense granular gold inclusions in the cytoplasm of the proximal convoluted tubules may be noted in the case of nephropathy induced by gold therapy.
Immunofluorescence findings would reveal the deposition of IgG and the complement along the subepithelial membrane. Electron microscopic findings may reveal the extensive foot process effacement with matrix spike reaction. The deposits in the subepithelial membrane may be overshadowed by this spike reaction producing the laddering appearance.
How Is Gold and Penicillamine Nephropathy Treated?
The main motto of management is to preserve kidney function and to prevent the condition from progressing to renal failure. The steps in management involve,
1) Stoppage of the Drugs:
The drugs causing this condition, such as Penicillamine, and gold, should be stopped immediately as the condition is diagnosed.
2) Antihypertensive Drugs:
The drugs such as Angiotensin-converting enzyme (ACE) inhibitors and Angiotensin II receptor blockers (ARBs) or other antihypertensive medications can be used to reduce the increased blood pressure.
3) Dietary Changes:
Patients should be advised to take a low protein and low salt diet to prevent further kidney damage.
4) Dialysis:
In advanced cases where it has progressed to end-stage renal disease, dialysis is indicated to improve survival.
5) Renal Transplant Surgeries:
In cases presenting with renal failure, transplantation surgeries may be indicated based on the patient's condition, age factor, etc.,
What Are the Complications of Gold and Penicillamine Nephropathy?
The complications may include skin reactions and nephropathy. Nephropathy can slowly progress to chronic kidney disease and subsequently develops into an end-stage renal disease.
What Is the Prognosis of Gold and Penicillamine Nephropathy?
Studies have shown that the prognosis of nephropathy caused by gold and Penicillamine is good. Withdrawing the drug has resulted in the reversal of the disease and normal kidney function. Early recognition of the side effects would help in a better prognosis as, in later stages, it would develop into an irreversible end-stage renal disease.
Conclusion:
It has been shown that treating rheumatoid arthritis and other conditions with gold and Penicillamine is okay. But close monitoring is indicated in patients under long-term treatment to avoid the side effects of this drug on kidneys. Nevertheless, it shows a good prognosis with the timely withdrawal of the offending drug and treatment of the associated symptoms.
