Proteinuria

The protocol treats 24-hour urinary protein as a surrogate endpoint rather than a hard clinical endpoint. Foamy urine after intense exercise or a high-protein meal does not necessarily indicate kidney disease; concern arises only with foamy urine at baseline. Assessment visits collect UPCR, UACR, and 24-hour urinary protein repeatedly during the trial. In a healthy kidney, protein molecules are too large to pass through the nephron filter. Foamy urine reflects excess protein leaking through glomerular capillaries damaged by kidney disease. The same protein-loss mechanism can cause fluid buildup beyond the eyes, especially in the ankles and feet. Proteinuria is an independent risk factor for CKD progression. Foamy urine can indicate protein loss in the urine and point toward kidney damage. Fluid retention in the ankles and feet may present as pitting edema. Pitting edema is described as a classic kidney-related sign when it occurs with protein loss and tissue fluid leakage. Proteinuric kidney disease occurs in individuals with high-risk APOL1 genotypes and is treatable with inaxaplin.