Bile Cast Nephropathy: Causes, Symptoms, Diagnosis, Treatment

Bile cast Nephropathy is caused by excretion of excessive bilirubin in urine. Liver damage causes restricted metabolism of the bilirubin resulting in jaundice and higher concentration of bilirubin in blood. In this article, we will discuss about the various aspects of Bile Cast nephropathy.

• Serum Bilirubin- Hemoglobin breaks down into Heme and globulin. Heme breaks down in to bilirubin. Bilirubin is excreted in bile and urine. Increased bilirubin concentration in blood causes jaundice.
• Bilirubin Serum Level- High levels of bilirubin are usually nephrotoxic.¹
• Bilirubin Cast- High bilirubin level forms a cast when excreted in urine in high concentration.
• Renal Tubular Injury- Bilirubin cast are deposited within distal renal tubule and obstruct urine flow and excretion. The bilirubin cast eventually results in acute tubular injury.¹
• Bile Cast Nephropathy- The disease is known as Bile Cast Nephropathy.
• Reversible Injury- The kidney injury is generally reversible if bilirubin levels are decreased early.²

• Hemolysis- Increased breakdown of red blood cells.
  • Hemolytic anemia
  • Autoimmune disease
  • Blood Transfusion reaction
  • Sickle Cell Anemia
• High Serum Bilirubin Level-
  • Gilbert Syndrome- Genetic disease causes abnormal bilirubin metabolism resulting in high serum level of bilirubin.
  • Hepatitis- Liver infection
  • Cirrhosis– Liver failure³
  • Obstruction to flow of bile secretion- Bile duct obstruction, gall bladder infection
  • Medication Side Effects-
    • Sulphonamides
    • Testosterone
    • Anti-psychotic
    • Chemotherapy

• Loss of appetite
• Weakness and fatigue
• Weight loss
• Jaundice-
  • Yellow conjunctiva (eye)
  • Yellow skin discoloration
  • Yellow discoloration of urine
  • Pale Stool

• Itching
  • Caused by bilirubin deposits in skin
• Frequent infection
• Confusion
  • Bilirubin deposits in brain causes confusion

• Nausea and vomiting
• Urine output- decreases in volume
• Retention of Fluid-
  • Edema of feet
  • Shortness of breath
• Flank Pain

• Increased potassium concentration in blood
• Cardiac arrhythmia and irregular heart beats

• Proteinuria
• Hematuria
  • Frank Blood In Urine- Reddish discoloration of urine.
  • Microscopic RBCs seen in urine.

• Complete Blood Count
  • Hemolysis observed on blood smear examination.
  • Increased white blood cell count if nephropathy is associated with infection.
• Electrolytes
  • Hyperkalemia (increase serum potassium) level
  • Hyponatremia (low sodium level)
  • Metabolic Acidosis
• Serum Bilirubin Level-
  • Increased
• Liver Function Test
  • Increased alanine transaminase enzyme level
  • Increased aspartase transaminase enzyme level
  • Increased alkaline phosphatase level

• Evidence of cirrhosis

• Biliary cast seen on renal tubules.

• Rehydration
  • Prevent volume depletion and
  • Treat dehydration with intravenous fluid
• Avoid Nephrotoxic Drugs
  • Do not use contrast medium
  • Avoid nephrotoxic medications

• Treat sickle cell anemia by preventing sickling of red blood cells
• Treat adverse blood transfusion reaction with diuretics and corticosteroids

• High dosage of prednisolone²
• Adequate hydration

• Correction of albumin and globulin loss in urine
• Diuretics to treat water retention.
  • Spironolactone is a loop diuretics and causes less proximal pressure within renal tubule, which is blocked by bile cast.
• Dialysis¹– Persistent high bilirubin is treated with dialysis.

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