How is the diagnosis of IgA nephropathy confirmed?

The diagnosis of IgA nephropathy is confirmed primarily through renal biopsy. This procedure allows for direct examination of kidney tissue, which can demonstrate the characteristic histological findings associated with this condition, such as IgA deposition in the mesangial areas of the glomeruli. While urinalysis can show signs of proteinuria or hematuria, and serum creatinine levels can indicate kidney function, these methods do not provide a definitive diagnosis of IgA nephropathy. Ultrasound may be used to assess kidney structure or to rule out other conditions, but it cannot confirm the presence of IgA nephropathy. Therefore, the renal biopsy is the gold standard for confirming this diagnosis, allowing for accurate assessment of the disease's extent and severity.