Uric acid nephropathy is a health condition that involves damage to the kidneys that result from excess uric acid in the body.
Uric acid is the end product of purine nucleotide metabolism that is not readily soluble in water, which is particularly evident in the acidic environment in the distal nephron of the kidney. As humans do not carry the uricase enzyme that can convert uric acid to a more soluble compound, it has the potential to cause damage to the nephrons and kidney disease.
This exact incidence of acute uric acid nephropathy is unknown and believed to be rare in the general population. However, up to 10% of patients that have undergone chemotherapy and radiotherapy for leukemia and lymphoma may experience deterioration in renal function linked to increased uric acid.
Uric acid nephropathy is caused by high levels of uric acid in the body, which may result from either overproduction of urate or reduced uric acid excretion.
The majority of cases of uric acid nephropathy are associated with chemotherapy treatment for cancer, which is linked to an increased production of uric acid in the body. It is also more common in patients that suffer from gout.
Uric acid nephropathy is usually asymptomatic until it leads to significantly reduced kidney function or failure. Signs of this may include:
- Reduced urine output
- Nausea and vomiting
- Abdominal pain
- Painful urination
Uric acid nephropathy can be diagnosed based on the presence of uric acid crystals in the joints, tissues of body fluids.
Blood tests can also help to detect abnormal levels of uric acid in the blood, but this does not always portray an accurate representation of the condition. Other diagnostic tests to monitor the function of the kidney such as a urinalysis may also be required to confirm the diagnosis.
The aim of treatment for uric acid nephropathy is to relieve symptoms, reduce the risk of complications and prevent recurrence of symptoms.
Pharmacological agents are usually used in the management plan to control the concentration of uric acid and reduce damage to the kidneys. For severe cases with reduced kidney function or failure, dialysis may be required.
It is important for affected individuals to ensure adequate fluid intake, which will help the body to continue the process of uric acid excretion and reduce the risk of crystal formation. Other general health advice, such as maintaining a healthy diet, keeping physically active and moderating alcohol intake are also thought to be useful.
Additionally, a specialized diet low in purines is also recommended for some patients. This typically involves avoidance of certain foods that are high in purine such as some meat products.
Historically, the mortality rate of acute uric acid nephropathy was quite high at almost 50%. However, this rate has dropped substantially in recent decades due to improved management techniques to prevent complications and the use of dialysis therapy. As a result, the current prognosis is excellent and the majority of patients can expect to make a good recovery.