Description of Renal Involvement in Wilson's Disease

Wilson's disease (WD) is a rare genetic disorder that leads to copper accumulation in various tissues, including the liver, nervous system, heart, and kidneys. Renal involvement in WD has been poorly studied, and systematic screening is not currently recommended.

Indirect renal complications are the most common, such as hepatorenal and cardiorenal syndromes, as well as severe complications like hemolysis or rhabdomyolysis. However, literature suggests that copper may exert a direct toxic effect on renal tubular cells, leading to both proximal and distal tubular dysfunction. These may manifest through often subtle signs, such as aminoaciduria, glycosuria, hypouricemia, and low-molecular-weight proteinuria. Electrolyte imbalances of varying severity may also occur, including hypokalemia, which can cause muscle cramps and cardiac arrhythmias, as well as acid-base disorders (proximal or distal renal tubular acidosis), and/or phosphate-calcium metabolism abnormalities (phosphate diabetes and hypercalciuria). These latter issues may lead to complications such as urinary stones, nephrocalcinosis, and even fracture-related osteoporosis.

In addition, long-term treatment with D-penicillamine (DPA), a common therapy for WD, can cause renal damage in 10-20% of cases, mainly affecting the glomeruli. This includes membranous nephropathy, severe proliferative glomerulonephritis, or nephrotic syndrome with minimal change disease.

Without appropriate monitoring and preventive care, both direct and indirect renal complications can lead to acute or chronic kidney failure. It is likely that the prevalence and systemic impact of renal involvement in WD are currently underestimated.