Multiple myeloma is a type of blood cancer that affects plasma cells in the bone marrow. These cells produce abnormal proteins that can severely affect kidney function. Kidney damage is a common and serious complication of this disease.
How Does Multiple Myeloma Affect the Kidneys?
Abnormal plasma cells release excessive amounts of monoclonal (M) proteins or light chains into the bloodstream. These proteins are filtered by the kidneys, but they can clog and damage the kidney tubules, leading to a condition called myeloma kidney or cast nephropathy.
Types of Kidney Damage in Multiple Myeloma
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Cast Nephropathy (Myeloma Kidney):
- Most common type
- Light chains form plugs in kidney tubules
- Causes rapid decline in kidney function
-
Light Chain Deposition Disease (LCDD):
- Light chains deposit in kidney tissues
- Leads to progressive kidney damage
-
Amyloidosis (AL Type):
- Abnormal proteins form amyloid deposits
- Damages both kidneys and other organs
-
Hypercalcemia-Induced Kidney Injury:
- Bone breakdown raises calcium levels
- High calcium impairs kidney filtering ability
Symptoms of Kidney Involvement
- Fatigue and weakness
- Swelling in legs or face
- Decreased urine output
- High creatinine levels
- Bone pain or fractures
- Nausea and loss of appetite
- Frequent infections
Diagnosis of Kidney Involvement in Myeloma
Doctors use various tests:
- Blood tests: Creatinine, calcium, and protein levels
- Urine tests: Detect light chains (Bence Jones protein)
- Serum protein electrophoresis (SPEP)
- Kidney biopsy: In selected cases for confirmation
Treatment Strategies
- Hydration: Helps flush out harmful proteins
- Chemotherapy: Reduces abnormal plasma cell production
- Steroids: Control inflammation and support kidney recovery
- Dialysis: Required in severe cases of kidney failure
- Plasmapheresis: In some cases, removes light chains from the blood
Protecting Kidney Health in Myeloma Patients
- Avoid NSAIDs and nephrotoxic drugs
- Control calcium levels
- Treat infections promptly
- Stay hydrated
- Monitor kidney function regularly
Prognosis and Recovery
Early diagnosis and treatment improve outcomes. Kidney function may recover partially or fully if treated quickly. In advanced cases, dialysis or transplant may be needed.
