IgA nephropathy (IgAN), also known as Berger disease, is a condition that develops when an antibody called immunoglobulin A (IgA) builds up in your kidneys. Over time, the buildup can lead to inflammation and damage your kidneys, reducing their ability to filter waste and toxins from your blood. Healthcare providers most often perform a physical examination, assess your symptoms, and ask about your medical history as the first step in diagnosis. They may then recommend tests to confirm the diagnosis of IgAN.
The diagnosis of IgA nephropathy usually involves urine tests, such as:
- Urinalysis: This is a general urine test that checks for protein or blood in your urine.
- Urine protein-creatinine ratio (uPCR): This test measures the level of protein compared to the level of creatinine (waste product) in your urine. This ratio can help to determine how well your kidneys are working.
- 24-hour urine collection: For this, you collect your urine all day and night, and the entire collection is measured for different components.
The estimated glomerular filtration rate (eGFR) is a blood test that assesses how well your kidneys are working. The test measures the wastes and toxins in your blood. Buildup of such toxins in your blood may suggest that your kidneys are not functioning properly.
While not specific to diagnosing IgAN, healthcare providers may also measure immunoglobulin levels and inflammation levels using erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) blood tests
A kidney biopsy is a procedure in which your provider removes a small piece of tissue from your kidneys and examines it under a microscope. This procedure can accurately diagnose IgAN because it shows IgA buildup in the glomerulus, which is your kidney’s filtering unit.
Many people do not show symptoms of IgA nephropathy at first. Symptoms usually start appearing as the disease progresses. Your healthcare provider may suspect IgAN if you have one or more of the following symptoms:
- Puffiness around your eyes
- Swelling of your legs, ankles, feet, abdominal area, or face
- Blood in your urine
- Foamy urine
- Change in your urine color
- High blood pressure
Your healthcare provider may also recommend a diagnostic test for IgAN if you are at higher risk for the condition. The risk of IgA is usually higher if you:
- Have a family history of IgAN or IgA vasculitis
- Are aged between 10-40 years
- Have been diagnosed with inflammatory bowel disease (IBD), celiac disease, cirrhosis, hepatitis, or HIV
- Are male and have Asian, Pacific Island, or White European ancestry
There is no cure for IgAN. Treatment usually involves managing your symptoms and slowing the kidney damage. Healthcare providers usually recommend medications that:
- Reduce your inflammation
- Remove excess fluid from your body
- Control your blood pressure
- Lower your cholesterol
Your provider may also recommend certain lifestyle changes, including:
- Reduction in protein and sodium intake
- Reduction in fluid intake
- Weight loss
- Avoidance of smoking
