Gout and High Uric Acid in ADTKD-UMOD

While the decline in kidney function in ADTKD-UMOD is often “silent” and slow, the most visible and painful symptom for many patients is gout. This condition is caused by high levels of uric acid in the blood, a state known as hyperuricemia ^[1]. Understanding why this happens and how to manage it is a key part of living with this disease.

Why Uric Acid Builds Up

Uric acid is a normal waste product the body creates when it breaks down certain foods and tissues. Usually, the kidneys filter uric acid out of the blood and send it into the urine. In ADTKD-UMOD, the genetic mutation damages the kidney’s tubules, which are responsible for this removal process ^[2].

The damaged tubules in ADTKD-UMOD patients often have a reduced fractional excretion of uric acid (FEUA). This means that even when the kidneys are still filtering the blood fairly well (measured by eGFR), they hold onto uric acid instead of letting it leave the body ^[3][4]. While a low FEUA is supportive of the clinical picture, it is not a stand-alone diagnostic test and is affected by eGFR, volume status, diet, and medications ^[5].

Gout: Timing and Symptoms

For many, gout is the first clear signal that something is wrong.

• Early Onset: While gout in the general population usually affects older adults, people with ADTKD-UMOD often experience their first “flare” in their teenage years or early 20s ^[6].
• The Flare: A gout flare is characterized by sudden, intense pain, swelling, and redness in a joint—most commonly the big toe, but also the ankles, knees, or wrists ^[7]. Note: A first or atypical hot, swollen joint with a fever could be an infection rather than ordinary gout and requires urgent assessment.
• Tophi: Over many years, if uric acid remains very high, it can form hard, chalky lumps under the skin called tophi ^[8].

It is important to note that while hyperuricemia is very common (affecting about 87% of patients in studied cohorts), not everyone gets gout. About 24% of patients in some cohorts will experience actual gout flares ^[1]. In rare cases, some families with the UMOD mutation have neither high uric acid nor gout ^[9].

Managing High Uric Acid

The goal of treatment is twofold: to stop the pain of active flares and to lower the overall level of uric acid in your blood to prevent future problems.

Treating Active Flares

When you have an active, painful flare, your doctor may suggest:

• Colchicine: A medication that reduces gout inflammation. Because this drug is cleared by the kidneys, the dose must be carefully adjusted based on your kidney function to avoid serious toxicity ^[7][10].
• Steroids: Oral or injected corticosteroids can calm inflammation, though they carry risks for blood pressure, glucose, and infection ^[7].
• NSAIDs: Medications like ibuprofen or naproxen are often used for gout, but they can be risky for people with kidney disease depending on kidney stage. Always follow a clinician-approved flare plan ^[10].

Long-Term Urate-Lowering Therapy (ULT)

To prevent flares, doctors use medications to lower uric acid levels. The most common is allopurinol ^[7]. Urate-lowering therapy is generally considered based on gout flares, tophi, or urate stones; it is not routinely given solely to protect the kidneys in someone with asymptomatic hyperuricemia.

• Treat-to-Target: The standard goal is to keep your blood uric acid level below 6.0 mg/dL (or below 5.0 mg/dL if you have tophi) ^[7][11].
• Dosing and Hypersensitivity: The starting dose of allopurinol must be individualized to your kidney function and titrated up to the target ^[7][12]. Seek urgent care if you develop a rash, fever, facial swelling, mucosal lesions, or systemic illness, as allopurinol hypersensitivity can be severe. HLA-B*58:01 testing is considered for higher-risk ancestries before starting ^[7].
• Alternatives: If allopurinol isn’t a good fit, febuxostat is an alternative. However, its use involves cardiovascular safety considerations ^[13][14].

Does Lowering Uric Acid Save the Kidneys?

A common question is whether lowering uric acid will slow down the progression of the kidney disease itself. Currently, there is no strong evidence that urate-lowering therapy delays kidney failure or slows the decline of eGFR in ADTKD-UMOD patients ^[15][16].

While it is essential to treat uric acid to prevent the agony of gout and joint damage, you should not expect these medications to “fix” the underlying genetic kidney problem ^[16][17]. Management focuses on your comfort and quality of life while other strategies are used to monitor and protect your kidney health over the long term.