Immunoglobulin A (IgA) Nephropathy: Tests and Diagnosis

What tests are used to diagnose IgA nephropathy?

Blood and urine tests are used to see how well the kidneys are working and to see if there are any abnormalities that point to more serious kidney disease. If bloody urine seems to come and go, especially at the time of colds, flu or other stress, it may be due to IgA nephropathy, but it can only be diagnosed by looking at the filters with a microscope. In order to look at the filters through a microscope, the pediatric nephrologist must perform a kidney biopsy to extract a tiny piece of kidney with a needle.

If a protein called Immunoglobulin A (IgA) is found when looking at the kidney filters under a microscope, then IgA nephropathy is diagnosed. No one knows why this blood protein gets into kidney filters, or why it causes them to leak blood. However, it is the most common cause of kidney inflammation.

What to expect

If the doctor thinks your child may have IgA npehropathy, he or she may obtain the advice of a pediatric nephrologist who can help with diagnosis and treatment. Your child may not need to see a pediatric nephrologist until some basic tests are performed to try to separate IgA nephropathy as a possibility from other kinds of kidney disease (like glomerulonephritis), and especially to prove the kidneys are working normally. IgA nephropathy is more serious if kidney function is less than normal, protein is leaking into the urine (proteinuria) and/or high blood pressure (hypertension) is present.

How do providers at Children’s Hospital Colorado make a diagnosis?

Not all kids with suspected IgA nephropathy need a biopsy. Although blood in urine can be scary and can sometimes cause backaches, IgA nephropathy doesn't cause permanent damage in 85% of cases, though the symptoms can last for years. The nephrologists at Children’s Hospital Colorado have the experience and knowledge to help, especially in severe cases where kidney function is compromised.