Acute nephritic syndrome with C3 glomerulonephritis

This code describes a specific type of acute nephritic syndrome characterized by inflammation of the kidney's filtering units (glomeruli) due to the deposition of C3 complement protein. Patients typically present with sudden onset of blood in the urine, protein in the urine, high blood pressure, and kidney dysfunction. It represents a distinct immunologic mechanism of glomerular injury.

Use this code when documentation explicitly states a diagnosis of acute nephritic syndrome with C3 glomerulonephritis. This diagnosis is typically confirmed by kidney biopsy showing predominant C3 deposition without significant immunoglobulin deposition. It applies to cases where the acute presentation of nephritic syndrome is directly attributed to C3 glomerulonephritis.

• Differentiate from dense deposit disease (N00.6), which is an Excludes1 condition and should never be coded with this.
• Ensure the documentation specifies "C3 glomerulonephritis" and not just "C3 glomerulopathy" without the "nephritis" component, as this code is specific to the inflammatory syndrome.
• Look for biopsy results confirming C3 deposition as the primary immunologic finding to support this specific diagnosis.