Bile pigments

Bile pigments, mainly bilirubin is emphasized here...Type of jaundice, diagnosis...

1. E L C O M E

2. Bile Pigments Presented By: Md. Sohrab Ali Mollah Reg. no. 13-05-3052 A Presentation on Course Title: Clinical Pathology and Necropsy Course Code: PBL 501

3. Pigment Bile pigments are endogenous (formed inside the body) , coloured compounds – breakdown products of the blood pigment haemoglobin – that are excreted in bile The two most important bile pigments are- Bilirubin , which is orange or yellow, and It’s oxidized form  Biliverdin , which is green.

4. Formation of BILIRUBIN Globin (Protein ) Heme (pigment) Iron+Porphyrins Open Chained Porphyrin Biliverdin (Greenish Yellow ) Bilirubin

5. Formation of UROBILINOGEN Bound to albumin, bilirubin is then transported from the mononuclear phagocytic cells to the liver via the circulation. In the hepatocyte, the pigment is cleaved from albumin, conjugated with glucuronic acid and excreted in the bile as bilirubin- glucuronide by the help of enzyme uridine diphosphoglucose glucuronyl transferase . The conjugated bilirubin in the intestine is reduced by bacteria to urobilinogen ( mesobilirubinogen and stercobilinogen ).

6. Fate of BILIRUBIN

7. CLINICAL OCCURRENCE Normal Serum Bilirubin: 0.3-1.0 mg/ dL ( SI Units: 5.1-17 mmol /L). Increased Bilirubin: Hyperbilirubinemia Unconjugated Hyperbilirubinemia C onjugated Hyperbilirubinemia Decreased Bilirubin: Hypobilirubinemia

8. Hyperbilirubinemia (Jaundice ) It is an important disorder clinically and postmortem in which the levels of bilirubin reach such a high concentration in the blood that all tissues of the body have yellow tinge.

9. Hyperbilirubinemia (Jaundice) General Signs and symptoms The main symptom of jaundice is a yellow discoloration of the white part of the eyes and of the skin. The conjunctiva of the eye are one of the first tissues to change color as bilirubin levels rise in jaundice. This is sometimes referred to as scleral icterus . However, the sclera themselves are not "icteric" (stained with bile pigment) but rather the conjunctival membranes that overlie them.

10. Figure: Jaundice in a Foal Figure: Jaundice in a Sheep Figure: Jaundice in a Dog Figure: Jaundiced-cat

11. Hyperbilirubinemia (Jaundice) Depending on the causative mechanism, Jaundice ( Hyperbilirubinemia ) is divided into 3 types: Hemolytic Jaundice ( Prehepatic ) Toxic icterus (hepatic) and Obstructive icterus ( posthepatic )

12. Hyperbilirubinemia (Jaundice) Hemolytic Jaundice ( Prehepatic ) Hemolytic jaundice results from excessive hemolysis of erythrocytes, ordinarily in the circulating blood

13. Hyperbilirubinemia (Jaundice) Toxic Jaundice (Hepatic) Toxic jaundice is caused by toxic substances acting on cells of the liver and producing hydropic changes, fatty changes, and necrosis and subsequent release of conjugated and unconjugated bilirubin into the bloodstream

14. Hyperbilirubinemia (Jaundice) Obstructive Jaundice (Post-hepatic ) Occurs subsequent to obstruction to the normal flow of bile anywhere in the biliary system. This results in the accumulation of conjugated bilirubin in the bloodstream and in the urine

15. Hypobilirubinemia Lower than normal bilirubin levels are usually not a concern

16. DIAGNOSIS OF ICTERUS The hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid. Concentration of bilirubin in blood plasmosis normally below 1.2mg/ dL (<25µmol/L). A concentration higher than 2.5mg/ dL (>50µmol/ dL ) leads to Jaundice

17. DIAGNOSIS OF ICTERUS In mild cases the clinical discoloration may be equivocal; therefore, laboratory tests are often required to establish a definitive diagnosis of jaundice. No single test can differentiate between various classifications of Jaundice. A combination of liver function tests is essential to arrive at a diagnosis

18. Table of Diagnostic Tests Function test Pre-hepatic Jaundice Hepatic Jaundice Post-hepatic Jaundice Total Bilirubin Normal/ Increased Increased Conjugated Bilirubin Normal Increased Unconjugated Bilirubin Normal/ Increased Increased Normal Urobilinogen Normal/ Increased Decreased Decreased/ Negative Urine color Normal Dark ( Urobilinogen + Conjugated Bilirubin) Dark (Conjugated Bilirubin) Stool color Normal Normal/Pale Pale Alkaline Phosphatase levels (ALP) Normal Increased Alanine Transferase (ALT) and Aspartate Tranferase (AST) levels Normal Increased Conjugated Bilirubin in Urine Not present Present Splenomegaly Present Present Absent

19. TEST FOR BILE PIGMENTS For diagnosis of bile ointments in case of mild case, laboratory tests are required. Such as- Icterus Index Direct Bilirubin Determination Test Van den Bergh reaction Fouchet’s test Ehrlich’s test