Sunitinib induced nephrotic syndrome and thrombotic microangiopathy

Area of Science:

• Nephrology
• Oncology
• Pharmacology

Background:

• Sunitinib is a tyrosine kinase inhibitor used for metastatic renal cell carcinoma (RCC).
• Sunitinib use is linked to potential renal dysfunction and nephrotic syndrome.
• Simultaneous occurrence of these conditions is exceptionally rare.

Observation:

• A metastatic RCC patient on sunitinib for 22 months developed nephrotic syndrome and renal dysfunction.
• The patient presented with clinical signs of both conditions concurrently.
• This presentation prompted further investigation into the underlying pathology.

Findings:

• Renal biopsy revealed thrombotic microangiopathy (TMA).
• Diffuse effacement of podocytic foot processes was observed on biopsy.
• The findings indicate a specific glomerular injury pattern.

Implications:

• This case underscores the importance of monitoring renal function in sunitinib-treated patients.
• It highlights thrombotic microangiopathy as a potential cause of combined nephrotic syndrome and renal dysfunction.
• Early recognition and biopsy are crucial for managing sunitinib-induced renal toxicities.