Lab case 367 interpretation

Answers:

Bilirubin = 107 umol/L. That is elevated.

Bilirubin gets elevated either due to increase production or reduced elimination (Like any other substance in the body). That can be caused by a malfunction in any of the three phases of bilirubin production.

  • Prehepatic phase:  That is excessive production of bilirubin,  before bilirubin enter hepatocytes. Excessive heme metabolism, from hemolysis or reabsorption of a large hematoma, results in significant increases in bilirubin, that overwhelms the conjugation process and lead to hyperbilirubinemia (Unconjugated).
  • Intrahepatic phase: viruses, alcohol, and autoimmune disorders are the most common causes of hepatitis. Intrahepatic inflammation disrupts transport of bilirubin and causes hyperbilirubinaemia. (Conjugated).
  • Post=hepatic phase: post-hepatic causes can be divided into intrinsic or extrinsic obstruction of the duct system. Cholelithiasis, tumors and pancreatitis are the most common causes.

Alkaline Phosphatase = 79 U/L, that is within normal range.

Alkaline phosphatases are a group of isoenzymes, located on the outer layer of the cell membrane; they catalyze the hydrolysis of organic phosphate esters present in the extracellular space. These enzymes get elevated in the presence of obstruction, usually in post-hepatic diseases/hyperbilirubinaemia. This patient unlikely to have an obstructive cause for his hyperbilirubinaemia.

GGT = 42 U/L, that is within normal range.

GGT is found throughout the body, but mostly in the liver. When there is damage to the liver, GGT leaks into the bloodstream. High levels of GGT in the blood is a sign of liver disease or damage to the bile ducts.

ALT = 47 U/L, that is within normal range

AST = 70 U/L, that is slightly elevated.

Both ALT and AST are intracellular enzymes, they get released in larger quantities with cellular damage. ALT is mainly related to hepatocytes while AST exist in other tissues (red blood cells, heart and other muscles).

Albumin = 25 g/L, that is low.

Low albumin can be caused by decreased production of albumin in the liver or increased loss of albumin through the kidneys, gastrointestinal tract, skin, or extravascular space or increased catabolism of albumin.

In sepsis, there is increased vascular permeability and capillary leakage leading to loss of albumin from the intravascular compartment. Also there is reduced synthesis and increased catabolism of albumin in the presence of severe sepsis.

This patient has low (reversed) Albumin to globulin ratio.

Total protein = Albumin + Globulin. Accordingly Globulin for this patient = 62 – 25, that is 37. This will give us a A/G ratio of 0.67 (Normal ratio value is 0.8 – 2). This indicates overproduction of globulins.

From the information above we can tell that the patient has an infection leading to or causing hemolysis. ( Liver enzymes are within normal range, so we have prehepatic hyperbilirubinaemia).

The most common infections causing haemolysis are:

  1. Malaria
  2. Bartonellosis (South Amerca/ Peru)
  3. Babesiosis (USA)
  4. Haemolytic uremic syndrome

On further history taking, the patient had returned from Kongo three weeks earlier. He was found to have Malaria.

With COVID, the tendency to ask travel history questions was reduced. Now with the opening of the borders we need to ask about travel history.