IgA nephropathy (IgAN) is a chronic kidney condition that affects many individuals worldwide. It is characterized by immune system dysfunction leading to kidney damage.
What is IgA Nephropathy?
IgA nephropathy is an autoimmune disease where immunoglobulin A (IgA) antibodies deposit abnormally in the kidneys’ filtering units, called glomeruli. These tiny blood vessels are essential for filtering waste products and excess fluids from the blood to form urine. The abnormal IgA deposits trigger inflammation and damage within the glomeruli.
This ongoing inflammation can lead to scarring of the nephrons, which are the kidney’s functional filtering units. As a result, the kidneys’ ability to efficiently remove waste from the blood becomes impaired. While the exact cause for this abnormal IgA accumulation is not fully understood, genetic and environmental factors are believed to play a role.
IgA Nephropathy and Life Expectancy
IgA nephropathy can lead to serious complications, including chronic kidney disease and, for some, end-stage renal disease (ESRD). Despite these potential outcomes, many individuals diagnosed with IgAN can live a normal or near-normal lifespan. The impact on life expectancy varies significantly among individuals, reflecting the diverse ways the disease can progress.
Cardiovascular issues, such as heart failure, heart attack, and stroke, represent a major cause of death in patients with IgAN, especially after progression to ESRD. Studies indicate that about 25% to 30% of individuals with IgA nephropathy may develop ESRD within 10 to 25 years of diagnosis. However, some patients experience slow progression or even stable kidney function for many years.
Key Determinants of Long-Term Outlook
Several specific factors influence an individual’s prognosis and long-term outlook with IgA nephropathy. The level of protein in the urine, known as proteinuria, is a significant indicator. Higher levels of proteinuria, particularly those reaching nephrotic range, generally suggest a less favorable prognosis and a higher risk of faster progression to kidney failure. Studies consistently show a strong relationship between the amount and duration of proteinuria and the loss of kidney function.
Blood pressure control also plays a major role in disease progression. Uncontrolled high blood pressure accelerates kidney damage and is linked to a worse outcome. Conversely, effective management of blood pressure can help slow the rate of kidney decline. The estimated Glomerular Filtration Rate (eGFR) at the time of diagnosis provides insight into initial kidney function. A lower eGFR at diagnosis indicates more advanced disease and a less positive long-term outlook.
Kidney biopsy findings provide information about the disease’s severity and potential aggressiveness. Pathological features such as significant scarring (fibrosis), severe inflammation, or the presence of crescent formations can indicate a more aggressive disease course.
Additionally, how well an individual responds to initial treatments, particularly in controlling blood pressure and reducing proteinuria, influences their long-term prognosis. Age at diagnosis can also be a factor, with older age at diagnosis associated with a less favorable course, and men often experience a more aggressive form of the disease compared to women.
Strategies for Preserving Kidney Function
Effective management strategies slow the progression of IgA nephropathy and improve long-term outcomes. Controlling blood pressure is fundamental, often with ACE inhibitors or ARBs. These medications are considered first-line therapy, not only for blood pressure reduction but also for their ability to lower protein in the urine.
Reducing proteinuria is a primary therapeutic goal, as lower levels are associated with better outcomes. ACE inhibitors and ARBs significantly reduce proteinuria and have been shown to improve kidney survival. Newer medications like SGLT2 inhibitors can also contribute to proteinuria reduction and slow kidney disease progression.
Lifestyle modifications are important in managing IgAN. These include dietary adjustments, such as limiting sodium intake to help control blood pressure and reduce swelling. Maintaining a healthy weight, engaging in regular physical activity, and avoiding kidney-toxic medications like NSAIDs are also beneficial. Regular monitoring with a nephrologist, including blood and urine tests, is essential to track kidney function and adjust treatment. In some cases, immunosuppressive therapies, including corticosteroids, may be considered for aggressive disease.