myeloma cast nephropathy

Etiology

• multiple myeloma

Epidemiology

• 20% of patients with multiple myeloma

Pathology

• Ig light chains
• renal tubular injury
• obstructive uropathy of tubular origin

Laboratory

• 24 hour urine protein
  • urine dipstick detects albumin, not Ig light chains
• serum protein electrophoresis
• high serum free light chains
• urine protein electrophoresis
• immunofixation electrophoresis

Management

• treatment of multiple myeloma
  • reduce free Ig light chains with chemtherapy
• avoid bisphosphonates
  • pamidronate may induce acute renal failure & nephrotic syndrome
  • zoledronate may induce acute tubular necrosis
  • contraindicated if GFR > 30 mL/min
• avoid NSAIDs, especially in patients with volume depletion

More general terms

• nephropathy

Additional terms

• multiple myeloma; plasmacytoma/plasma cell myeloma