Living with immunoglobulin A nephropathy (IgAN) may feel overwhelming at times. You and your loved ones may face challenges every day. It’s important to educate yourself about IgAN to be better prepared for the journey ahead.

Learn more about IgAN below, including how it may affect the kidneys.

Your kidneys are the filtration system of your body. In IgAN, your immune system can damage the kidneys’ filtration system and affect how well your kidneys work. Over time, this may lead to loss of kidney function.

The main function of your kidneys is to filter your blood by:

• Removing waste and extra water to make urine

• Sending clean blood back into your body

Your kidneys also help keep the right balance of fluids and minerals. This is essential for controlling your blood pressure.

How the alternative complement pathway affects your kidneys in IgAN

The alternative complement pathway is the part of your immune system that helps protect your body by “complementing” or enhancing your immune system in fighting infections.

In IgAN, IgA antibodies that are supposed to fight infections become defective. This causes your immune system to work against itself. Unwanted IgA antibodies build up in your kidneys, leading to the activation of the complement system and other pathways, which can lead to kidney-related issues in IgAN.

Are you taking multiple supportive care treatments* and concerned about your kidney function loss?

Slowing kidney function decline is vital for adults with IgAN

IgAN is a chronic disease that may worsen over time and impact kidney function, which is how well the kidneys are working. Signs that IgAN is getting worse include ongoing high levels of protein in your urine (proteinuria) and loss of kidney function.

This was from a study that looked back at patient records from a California health care system in those diagnosed with IgAN. The purpose of this study was to assess multiple kidney outcomes. At the start of study, patients were on different treatments; 70% were on an ACEi or ARB with limited use of other therapies. At the start of study, the average eGFR was 59.9 mL/min/1.73 m² and average UPCR 2.5 g/g.

*Supportive care can involve lifestyle changes (limiting dietary sodium, exercising regularly, maintaining a healthy weight, and avoiding tobacco), blood pressure management, and treatment with an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB) and a sodium-glucose cotransporter 2 inhibitor (SGLT2i).

eGFR: Why your eGFR matters

Estimated glomerular filtration rate (eGFR) helps show how well your kidneys are functioning:

• eGFR is measured with a blood test and calculates the amount of blood filtered by the kidneys every minute

• The result is a number that represents a measure of kidney function

Changes in your eGFR over time show how fast your kidneys are losing function. Kidney function decline over time is reflected as a negative value.

Proteinuria: Ongoing high levels of protein in urine (proteinuria) may be a sign of kidney damage

One common way to measure proteinuria is a test called urine protein-to-creatinine ratio (UPCR). UPCR helps your health care team monitor how much protein leaks into your urine. UPCR can be measured in a couple of ways by:

• Collecting urine over a 24-hour period, called 24-hour UPCR

• Testing a single urine sample from your first urination of the day (called the first morning void, or FMV)