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.
How Is Bile Cast Nephropathy Defined?
- 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
Causes of Bile Cast Nephropathy
- Hemolysis-Increased breakdown of red blood cells.
- 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-
Symptoms of Bile Cast Nephropathy
Symptoms Caused By High Bilirubin-
- Loss of appetite
- Weakness and fatigue
- Weight loss
- Yellow conjunctiva (eye)
- Yellow skin discoloration
- Yellow discoloration of urine
- Pale Stool
- Caused by bilirubin deposits in skin
- Frequent infection
- Bilirubin deposits in brain causes confusion
Symptoms Caused By Nephropathy4
- Nausea and vomiting
- Urine output- decreases in volume
- Retention of Fluid-
- Edema of feet
- Shortness of breath
- Flank Pain
Symptoms Caused By Hyperkalemia
- Increased potassium concentration in blood
- Cardiac arrhythmia and irregular heart beats
Diagnosis of Bile Cast Nephropathy
- 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.
- Serum Bilirubin Level-
- 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.
Treatment for Bile Cast Nephropathy
Preventive Therapy If Bilirubin Level Is High
- Prevent volume depletion and
- Treat dehydration with intravenous fluid
- Avoid Nephrotoxic Drugs
- Do not use contrast medium
- Avoid nephrotoxic medications
Treatment To Prevent Hemolysis
- Treat sickle cell anemia by preventing sickling of red blood cells
- Treat adverse blood transfusion reaction with diuretics and corticosteroids
Treatment of Autoimmune Disease
- High dosage of prednisolone2
- Adequate hydration
Treatment of Nephropathy
- 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.
1. Bile cast nephropathy is a common pathologic finding for kidney injury associated with severe liver dysfunction.
van Slambrouck CM1, Salem F, Meehan SM, Chang A.
Kidney Int. 2013 Jul;84(1):192-7.
2. Bile cast nephropathy
Samuel N Heyman, David Darmon, Zvi Ackerman, Christian Rosenberger and Seymour Rosen, Kidney International 85, 479 (February 2014)
3. Bile cast nephropathy.
Heyman SN1, Darmon D1, Ackerman Z1, Rosenberger C2, Rosen S3.
Kidney Int. 2014 Feb;85(2):479. doi: 10.1038/ki.2013.478.
4. Bile cast nephropathy: An often forgotten diagnosis.
Sequeira A1, Gu X
Hemodial Int. 2014 Apr 14.