- have liver problems
- plan to have surgery
- have chicken pox or measles or have recently been near anyone with chicken pox or measles
- have an infection
- have high blood sugar levels (prediabetes or diabetes)
- have glaucoma or cataracts
- have a family history of diabetes or glaucoma
- have or have had tuberculosis
- have high blood pressure (hypertension)
UNDERSTANDING THE GUT-KIDNEY CONNECTION IN IgA NEPHROPATHY (IgAN)
What is IgAN?
IgAN is an autoimmune disease, meaning a disease in which the bodyʼs immune system attacks itself. The disease affects the kidneys and usually gets worse over time. In people with IgAN, there is an increase in a type of IgA1 that gets into the blood stream. This triggers the immune system to attack IgA1 and form clusters. These clusters build up in your kidneys, leading to inflammation and damage.

IgAN is caused by increased levels of a type of IgA1 in the blood

The body produces antibodies to IgA1

Clusters of these autoimmune complexes are deposited in the kidney

The kidneys become inflamed, and irreversible damage can occur
What may cause IgAN?
One of the main underlying causes of IgAN is thought to be an IgA1 antibody, which is mostly produced in the gut.


HOW COMMON IS IgAN?
IgAN is a rare disease. It is more common among Asian and Caucasian populations.

WHAT ARE THE POTENTIAL SIGNS AND SYMPTOMS OF IgAN?
Although IgAN is often asymptomatic in early stages, you may experience the following:

Lower back pain

Blood in the urine

Foamy urine due to excess protein

Swelling in feet, ankles, or legs
These symptoms may be subtle, and you may not experience any of them. Excess protein in the urine, also known as proteinuria, or even blood in your urine, may not be discovered until a routine urine test. A kidney biopsy by your doctor is needed to confirm a diagnosis.
HOW IS IgAN DIAGNOSED?
A diagnosis of IgAN is confirmed with a kidney biopsy


- A kidney biopsy is a procedure that involves taking a small piece of kidney tissue for examination
- A biopsy may reveal IgA deposits in the glomeruli
- The biopsy can also show how much kidney damage has already occurred
DID YOU KNOW?
By the time IgAN is diagnosed, some kidney damage may have already occurred.
HOW IS IgAN MONITORED?
IgAN is a progressive disease—UPCR and eGFR are 2 tests used to monitor its progress

Urine protein-to-creatinine ratio
A urine test that measures the levels of protein and creatinine in your urine.*

Estimated glomerular filtration rate
A measure of kidney function. The higher the number (the range is 0 to 120), the better your kidney function.
Your doctor may monitor UPCR and eGFR closely to track if your IgAN is progressing.
*Protein in your urine may be a sign of kidney damage.
WHAT YOU NEED TO KNOW
Use this guide to learn more about IgAN, including common tests to check your kidney health and what to look for and expect at different stages. Youʼll also find information on additional resources.