Sickle Cell Kidney Disease

What is sickle cell kidney disease?

Sickle cell kidney disease happens because sickle-shaped red blood cells block normal blood and oxygen flow to the kidneys and inside the kidneys.  This form of kidney disease is a side effect of sickle cell disease.  

Sickle cell disease causes healthy red blood cells, which are round and soft, to become hard and shaped like a banana.  

Function of kidneys

The kidneys remove waste and extra water from the blood. They have many small blood vessels that help do this. The waste and extra water become part of the urine (pee) and go out of the body. 

Blood cells take oxygen to the body’s organs and tissues. The sticky, banana-shaped blood cells that are common with sickle cell disease do not carry oxygen as well as round, flexible blood cells.  Not getting enough oxygen affects how well the kidneys can remove waste and extra water.  

Your child’s care team might call sickle cell kidney disease “renal disease,” “sickle cell nephropathy,” or “kidney disease.” 

How sickle cell kidney disease affects patients

Here are some of the signs and symptoms your child’s sickle cell disease is affecting their kidneys:

• 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.
• 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 or brown or cola-colored. Or the blood might be invisible without 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.

Diagnosis of sickle cell kidney disease

Your child’s health care team might take a urine sample to check for kidney disease. The sample will be tested for:

• Protein
• Blood
• Creatinine

Your child’s blood will be checked to follow some waste components in the blood. It will be tested for:

• Blood urea nitrogen (BUN) - waste that occurs from digesting meats
• Creatinine – waste that occurs from general digestion
• Potassium – a chemical that is in many foods, which is difficult for a damaged kidney to keep within a normal limit

Too much of these substances can mean the kidneys are not working normally.

• If the test finds blood, protein, or creatinine, your child’s doctor might ask you to bring in a sample of their first urine in the morning.
• If your child has high blood pressure, they might need to wear a measuring device for 24 hours.

Treatment for sickle cell kidney disease

Blood pressure medicines are the usual treatment for sickle cell kidney disease. They help the kidneys stop losing protein your child’s body needs. They also lower your child’s blood pressure.

Controlling your child’s sickle cell disease with medication like hydroxyurea also helps prevent more kidney damage.

Reach out to your child’s care team if you have questions about sickle cell kidney disease.