Sickle cell kidney disease is a type of kidney problem where sickle-shaped red blood cells block the flow of blood and oxygen in and around the kidneys. Your child’s care team might call this disease sickle cell nephropathy (SCN) or renal disease. This condition may occur in some people with sickle cell disease.
Kidney problems can happen suddenly. This is known as acute kidney injury.
Sometimes kidney disease develops slowly over time. This is known as chronic kidney disease. In severe cases, kidney disease can lead to kidney failure. People with sickle cell disease are at higher risk of chronic kidney disease later in life.
How the kidneys work
The kidneys are 2 organs located below the rib cage on each side of the spine. They are shaped like beans and are about the size of a fist. You might hear the terms renal, nephro-, or nephron, which mean relating to the kidneys.
The kidneys filter the blood. Blood flows to the kidney through the renal artery. It is filtered by many tiny blood vessels. The filtered blood leaves the kidney through the renal vein.
The kidneys remove waste and extra liquid from the blood to make urine (pee). Urine flows from the kidney through 2 tubes, called ureters, which drain into the bladder. Urine is stored in the bladder and emptied from the body through the urethra. The kidneys, ureters, and bladder are part of a system called the urinary tract.
Sickle-shaped red blood cells can decrease the flow of blood and oxygen in and around the kidneys, leading to kidney damage and decreased kidney function.
The kidneys help to:
Regulate fluids in the body
Remove waste from the blood
Balance salt, potassium, and other chemicals
Make hormones that control blood pressure and red blood cell formation
Symptoms of sickle cell kidney disease
Signs and symptoms of kidney problems may include:
Pain in the side, back, or abdomen (belly): Your child might have pain on the sides of the body where the kidneys are. People with sickle cell disease may have painful episodes when parts of the body do not get enough oxygen. This is known as a pain episode.
Urine with too much water in it: Normal urine has a certain amount of waste in it. Urine that is mostly water, with less waste than usual, could be a sign of sickle cell kidney disease.
Blood in the urine: Your child’s urine might look bloody, brown, or tea colored. Or the blood might be too small to see without using a microscope.
High blood pressure: If your child has sickle cell disease, they usually have low blood pressure. Sickle cell kidney disease can cause high blood pressure. This is because the kidneys produce chemicals that can increase or decrease blood pressure.
Protein in the urine: Protein does not normally leave the blood through the kidneys. Having a lot of protein in the urine is a sign of sickle cell kidney disease.
Causes of sickle cell kidney disease
Normal red blood cells are round and flexible. They flow easily through the body’s blood vessels. People with sickle cell disease have red blood cells that are hard, sticky, and shaped like a banana (sickle-shaped).
Sickle cells clump together and clog blood vessels. The cells block tiny blood vessels and slow the delivery of blood and oxygen to the body’s organs. The sickled cells do not carry oxygen as well as healthy red blood cells, and they do not last as long in the blood as normal red blood cells.
Sickle cells can decrease blood flow and cause damage to blood vessels in the kidney. This can cause short-term and long-term kidney problems.
Diagnosis of sickle cell kidney disease
Several types of tests are used to check for kidney problems. This often involves checking a sample of your child’s urine and blood. Because sickle cell disease increases the risk of kidney problems, your child will have routine screenings for kidney problems as part of their regular checkups. These screenings usually start between 3 and 10 years of age.
Physical exam and health history
Your care team will ask questions and do tests to learn about your child’s kidney disease risk factors such as medicines, diabetes, and high blood pressure.
Urine tests (urinalysis)
Your health care provider will collect a urine sample to test for:
Blood in the urine
Albumin: a protein found in urine when kidneys are damaged
Blood tests
Lab tests include blood draws to measure different aspect of kidney function such as:
Blood urea nitrogen (BUN): Urea nitrogen is made when the body breaks down proteins from food. The kidneys normally filter urea nitrogen from the blood. A high BUN level may signal a kidney problem.
Serum creatinine: Creatine is a waste product of the body’s muscles. Creatinine levels measure how well kidneys filter waste from the blood. Your child may have an increase in creatine in the blood if the kidneys are not working well.
Electrolyte tests: Electrolytes are minerals that help the body function. These include sodium, chloride, magnesium, potassium, and calcium. High or low levels can be a sign of kidney problems.
Cystatin C: This test measures the amount of cystatin C protein in your child’s blood. A high level of cystatin C may mean that your child’s kidneys do not work well.
Glomerular filtration rate (GFR): The GFR measures how well the kidneys filter the blood to remove waste, toxins, and fluid. A low GFR may mean that your child’s kidneys are not working properly.
Ambulatory blood pressure monitoring: If your child has high blood pressure, they might need to wear a device that measures heart rate and blood pressure over 24 hours.
Kidney biopsy: In rare cases, a biopsy may be done to take a small sample of kidney tissue to look at under a microscope.
Treatment of sickle cell kidney disease
Treatment for kidney problems depends on your child’s medical needs. In some cases, your care team might include specialists such as a nephrologist or urologist. A nephrologist is a doctor who specializes in the diagnosis and treatment of kidney disease. A urologist is a doctor who diagnoses and treats conditions of the urinary tract.
General treatments for sickle cell kidney disease include:
Medicines like hydroxyurea can help manage sickle cell disease and prevent or slow kidney damage.
Blood pressure medicines can reduce the loss of protein in the urine and lower blood pressure.
People who have severe kidney disease or kidney failure may need dialysis or a kidney transplant.
Dialysis is a procedure that uses a machine to do the work of the kidneys to filter waste and fluid and fluid from the blood.
A kidney transplant is a surgery to replace a patient’s damaged kidney with a healthy one from a donor.
Prognosis for sickle cell kidney disease
Sickle cell kidney disease can impact health and quality of life for people with sickle cell disease. In some cases, it can result in a poorer prognosis and shorter life span.
Be sure to keep all medical appointments and follow your care team’s instructions to help prevent problems.
Seek medical care right away if you notice symptoms such as:
Fever
Pain in the chest, side, belly, or back
Trouble breathing
Confusion or loss of consciousness
Pain or bleeding when peeing
Peeing less than normal or not at all
Always talk with your care team about any questions or concerns.
Tips for families
If your child has sickle cell disease, it is important that they get regular medical care to address their health needs throughout their life.
Some steps you can take to help protect kidney health include:
Talk to your care team about your child’s risk for kidney problems.
Make sure your child has regular exams to check blood pressure and monitor kidney function.
Keep track of your child’s test results and know the normal healthy ranges for lab tests.
Be sure your child drinks enough fluids, especially during physical activity or hot weather.
Talk to your doctor about your child’s medicines, vitamins, and supplements, especially before starting something new. Some medicines are more likely to cause kidney damage, especially when used often or when combined with other medicines.
Contact your care team right away if your child has symptoms of a kidney or urinary tract infection. Symptoms may include:
Fever
Belly or back pain
Pain or burning while urinating
Urinating more than usual
Feeling an urgent need to pee.
Ask your doctor before using non-steroidal anti-inflammatory drugs (NSAIDs). These medicines include aspirin, ibuprofen, and naproxen. They can cause kidney damage and need to be avoided if your child already has signs of kidney injury. This is especially true in large doses, when used often, or when taken with other medicines.
Encourage healthy toilet routines. Holding in urine for too long or not emptying the bladder can cause kidney problems.
Promote healthy habits. Make sure your child gets enough exercise and stays a healthy weight for their age. Eat a healthy diet and limit caffeine intake. Avoid smoking and alcohol intake.
Get vaccinations as recommended by your care team.
Questions to ask your care team
How does my child’s sickle cell disease affect their risk for kidney problems?
Does my child have other risk factors for kidney disease?
What signs and symptoms of kidney problems should I watch for?
What tests or monitoring does my child need?
What can I do to lower my child’s risk of kidney problems?
What medicines should my child avoid?
What dietary changes does my child need? Do I need to monitor my child’s fluid intake?
Key points about sickle cell kidney disease
Sickle cell kidney disease or sickle cell nephropathy is a complication of sickle cell disease, where sickle-shaped red blood cells impair kidney function and cause kidney damage over time.
Signs and symptoms may include protein in the urine (proteinuria), blood in the urine (hematuria), high blood pressure, and reduced kidney function.
Your care team can check for kidney problems using lab tests and imaging studies.
It is important for your child to have ongoing monitoring to detect kidney problems early.
Always follow your care team’s instructions to help manage your child’s sickle cell disease and prevent complications.
Kidney problems can happen with some medical conditions and treatments. Learn how the kidneys work and ways to protect kidney health and prevent kidney disease.
A pain episode (pain crisis) occurs when sickle cells block blood vessels and decrease blood supply and oxygen to the body. Learn ways to manage pain episodes.
