Kidney biopsy in the diagnosis of immunoglobulin A nephropathy.

Immunoglobulin A nephropathy (IgAN) is a kidney disease characterized by deposition of galactose-deficient IgA1-containing immune complexes in the glomerular mesangium. It is the most common primary glomerular disease worldwide, affecting approximately 2.5 persons per 100,000 population annually. A definitive IgAN diagnosis requires a kidney biopsy. However, non-specific clinical signs, limited disease awareness, and lack of validated biomarkers can delay nephrology referral from primary care providers, prolonging time to diagnosis and negatively impacting patient outcomes. In this perspective, we aim to raise awareness of the importance of timely kidney biopsy in IgAN. To do so, we first outline the key clinical features of IgAN and kidney biopsy indications that should prompt nephrology referral. Subsequently, we highlight the diagnostic and prognostic significance of kidney biopsy findings, examine barriers to kidney biopsy completion, and provide our outlook on the ways in which kidney biopsy may be useful for IgAN management in the future.