Isolated proteinuria with dense deposit disease

This code signifies a kidney disorder characterized by the presence of protein in the urine (proteinuria) without other signs of kidney disease, specifically when the underlying cause is identified as dense deposit disease (DDD). DDD is a rare, chronic kidney disease involving abnormal deposits of complement proteins within the kidney's filtering units (glomeruli), leading to impaired kidney function.

Use this code when documentation explicitly states isolated proteinuria and confirms a diagnosis of dense deposit disease, often established through renal biopsy findings. This code is appropriate for patients presenting with proteinuria where DDD has been identified as the etiology, distinguishing it from other causes of proteinuria.

• Ensure documentation clearly links isolated proteinuria to a definitive diagnosis of dense deposit disease.
• Do not use this code if other significant kidney pathologies are present beyond isolated proteinuria, as more specific codes may apply.
• Consider sequencing this code as a primary diagnosis when isolated proteinuria due to DDD is the main reason for the encounter.