Can HUVS Cause Chronic Kidney Disease or Kidney Failure?

Yes, hypocomplementemic urticarial vasculitis (HUVS) can affect the kidneys and, in severe cases, cause chronic kidney disease (CKD) or kidney failure, though this does not happen to everyone. Research estimates that kidney involvement occurs in 9% to 60% of people with HUVS ^[1][2]. This wide range exists because some studies count mild, temporary urine abnormalities, while others only count severe disease confirmed by a biopsy. It is important to know that most people with HUVS will not develop kidney failure. While many people maintain normal kidney function or respond well to treatment, a subset of patients can experience progressive damage that may eventually require dialysis or a kidney transplant ^[3].

How HUVS Affects the Kidneys

When HUVS attacks the kidneys, it typically causes glomerulonephritis, which is inflammation of the tiny filters (glomeruli) that clean your blood. Because the kidneys are highly resilient, early damage is often completely silent and causes no physical symptoms. However, it leaves microscopic clues:

• Hematuria and Proteinuria: Blood (hematuria) and protein (proteinuria) in the urine are the most frequent signs of kidney inflammation. In one review of HUVS patients with kidney involvement, 70% had both blood and protein in their urine ^[4].
• Reduced eGFR: The estimated glomerular filtration rate (eGFR) is a calculation based on a blood test for creatinine (a waste product). It estimates how well your kidneys are filtering. About one-third of people with HUVS kidney involvement already have a reduced eGFR when their kidney issues are first discovered ^[4].
• High Blood Pressure: Struggling kidneys can cause your blood pressure to rise, which in turn causes more stress on the kidneys.
• Acute Kidney Injury (AKI): In severe cases, patients may experience a sudden and sharp drop in kidney function, known as AKI ^[3].

If a doctor performs a kidney biopsy, they may see different patterns of inflammation on the pathology report, most commonly ones called membranoproliferative, mesangioproliferative, or crescentic glomerulonephritis ^[4][3]. These are simply medical terms for how the tissue looks under a microscope, and they help your doctor understand the specific type of injury.

Variable Outcomes and Severity

The outlook for kidney involvement in HUVS is highly variable. A study following 12 HUVS patients with biopsy-confirmed kidney damage over an average of nearly nine years highlights this variety ^[3]:

• Half (6 patients) maintained preserved kidney function over the long term.
• Two patients developed stage 3 or stage 4 (moderate to severe) chronic kidney disease.
• Four patients progressed to end-stage kidney disease (ESKD), meaning their kidneys failed requiring long-term dialysis or a transplant.
• Note: During the course of their disease, two of the 12 patients experienced AKI severe enough to require temporary dialysis, but they later recovered enough to stop dialysis.

It is important to understand that this specific study only looked at people who had kidney disease severe enough to require a biopsy; it likely overrepresents severe cases and does not mean one-third of all people with HUVS will develop ESKD ^[3].

While some case reports show that patients can experience a recovery of kidney function with immunosuppressive medications—even after requiring dialysis for months—this is not guaranteed ^[5]. In other instances, kidney disease can continue to worsen despite treatment ^[6]. Do not change or stop any immunosuppressive medications without consulting your care team.

Monitoring and Early Detection

Because kidney damage from HUVS can start silently, regular screening is important ^[7]. This typically involves:

• Urinalysis (a urine test) to catch early signs of blood or protein. Sometimes, a quantitative test (like a urine protein-to-creatinine ratio) is needed to measure the exact amount of protein.
• Blood tests to monitor your serum creatinine levels and calculated eGFR.
• Routine blood pressure checks at home or in the clinic.

There is no single testing schedule for everyone. How often you are monitored depends on whether your disease is active, your current medications, and any past kidney issues. If persistent blood or protein is found in your urine, or if your eGFR is dropping, you should be referred to a nephrologist (kidney specialist).

A kidney biopsy is not automatic for every abnormal test result. The decision to perform a biopsy depends on the degree of proteinuria, changes in kidney function, and whether the results will change your treatment plan ^[4]. Furthermore, blood or protein in the urine can be caused by things other than HUVS, such as infections, medication side effects, or other autoimmune conditions like lupus, so your doctor will consider the full clinical picture.

When to Seek Urgent Care
Do not wait for your next scheduled appointment if you experience signs of a severe kidney problem. Contact your care team promptly or seek urgent medical care if you develop:

• Markedly reduced urine output.
• Visible blood in your urine, or urine that looks dark (tea-colored or cola-colored).
• Rapidly worsening swelling in your legs, ankles, or face, or sudden unexplained weight gain.
• Severe headaches, visual changes, or confusion combined with very high blood pressure readings.
• Shortness of breath or chest pain.