Review Examines Proteinuria and eGFR as Alport Syndrome Trial Endpoints

Alport syndrome results from pathogenic variants in COL4A3, COL4A4, or COL4A5, which disrupt the type IV collagen network in the glomerular basement membrane. This review assesses evidence linking proteinuria and eGFR decline with kidney failure, with a focus on their potential roles as clinical-trial endpoints. The source does not report a new patient cohort or sample size.

The authors describe proteinuria as an earlier marker, arising from abnormal basement-membrane permeability and podocyte dysfunction, as well as podocyte loss and glomerulosclerosis. The relative contribution of these processes may differ by genotype, sex, age, and disease duration. eGFR decline is a later measure of cumulative nephron loss and progression toward kidney failure.

Biopsy findings—including collagen α3α4α5(IV) localization, basement-membrane ultrastructure, podocyte foot-process width, glomerulosclerosis, and tubulointerstitial fibrosis—can provide staging or evidence of target engagement. However, the quantitative relationship between changes in these markers and kidney-failure risk remains incompletely defined. The authors argue that endpoint selection should account for baseline proteinuria and eGFR, demographic and genetic factors, disease duration, and nonlinear disease trajectories; the review does not establish a treatment recommendation.