Proteinuria is a complication of kidney disease. The blood contains proteins that are essential for the body’s functions. Normally, proteins are blocked by the kidneys, and only a small proportion of them can pass through them and end up in the urine. When the kidneys are damaged, however, the excess protein can pass back to the blood, causing proteinuria. In some cases, proteinuria is the result of a kidney inflammation or elevated blood pressure. While this is rare, if left untreated, proteinuria can lead to end-stage renal disease.
Recent advances have improved our understanding of proteinuric nephropathies. Despite the fact that proteinuric nephropathies are generally progressive and irreversible, therapeutic strategies can be developed to prevent proteinuria and create new proteinuria therapeutics. One such gene has been identified in 2000 as angiopoietin-like 4 (Angptl4). The protein produced by this gene induces hypertriglyceridemia in rodents.
The diagnosis of proteinuria is often made through a urine test. In a laboratory, a urine sample is collected and analyzed under a microscope. The doctor may use a dipstick to test the urine. A chemical tip on the dipstick changes color if something is present in the urine. The urine is then viewed under a microscope to identify any other substances that may be present. These substances may include bacteria, red and white blood cells, and even crystals that will eventually form into kidney stones. The global proteinuria therapeutics market is growing due to increasing prevalence of chronic kidney disease.
Immunosuppressive therapies have also been developed as of proteinuria therapeutics. The aim of these drugs is to dampen the inflammatory effect of IgA1 by killing B and plasma cells. Immunosuppression therapy reduces proteinuria and delays the progression of the disease. However, the results of these therapies are not conclusive. Until a definitive treatment for proteinuria is identified, patients should be monitored for a few months and if they still show proteinuria, they should be given a course of corticosteroid therapy. In December 2021, the Food and Drug Administration (FDA) granted approval to Tarpeyo (budesonide) for reducing proteinuria in adults with primary immunoglobulin A nephropathy (IgAN) at risk of rapid diseases progression.