Bilirubinuria
September 10th, 2020
Overview
Bilirubin is a breakdown product of the haem portion of haemoglobin. Urine does not normally contain bilirubin, and the presence of bilirubin suggests the presence of hepatic or cholestatic disease.
Only conjugated bilirubin is filtered into urine, as it is water soluble while unconjugated biluribin is fat soluble. Therefore, bilirubinuria is an indicator of the presence of any cause of conjugated hyperbilirubinaemia.
| Bilirubin | Urobilinogen | |
| Normal | Negative | Weak Positive |
| Haemolysis | Negative | Positive |
| Hepatic Disease | Positive | Positive |
| Cholestasis | Positive | Negative |
Causes of Bilirubinuria
- Acute hepatitis - viral hepatitis, HSV, EBV, CMV, VZV, alcoholic hepatitis, drug-induced hepatitis, ischaemic hepatitis, autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis, Wilson's disease
- Cirrhosis - chronic hepatitis B or C, alcoholic liver disease, non-alcoholic fatty liver disease, autoimmune hepatitis, primary biliary cirrhosis, chronic bile duct obstruction, primary sclerosing cholangitis, haemochromatosis, Wilson's disease, alpha-1 antitrypsin deficiency, hepatocellular carcinoma, sarcoidosis, glycogen storage disease type IV, methotrexate, methyldopa, amiodarone, Budd-Chiari syndrome, right heart failure
- Intrahepatic cholestasis - primary biliary cirrhosis, primary sclerosing cholangitis, sepsis, HCC, liver metastases, cystic liver disease, intrahepatic cholestasis of pregnancy, cystic fibrosis, total parenteral nutrition, viral / alcoholic hepatitis, amyloidosis, sarcoidosis, augmentin, isoniazid, rifampicin, chlorpromazine
- Extrahepatic cholestasis - choledocholithiasis, bile duct stenosis, bile duct strictures, primary sclerosing cholangitis, bile duct / ampullary / pancreatic malignancy
- Inherited secretion disorders - Dubin-Johnson syndrome, Rotor's syndrome
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