liver lab questions

Question 1

1. A 61 year-old man lost 8 kg during the last 4 months. He complains of pruritus and frequent dull epigastric pain. He has noted dark urine, but light stools lately. He has jaundice. The gallbladder is palpable, but non-tender.
   Laboratory results:
   serum bilirubin: 310 μmol/l, mostly direct
   urine Ubg: negative
   ASAT: 82 U/l
   ALAT: 91 U/l
   alkaline phosphatase: 540 U/l
   prothrombin time: INR = 2.6
   What is the cause of his jaundice? What further tests do you consider?

Answer 1

-> Serum bilirubin is very high (>17 umol/l) and mostly direct, indicating direct hyperbilirubinemia (no issue with UDP-glucuronyl transferase)

Clinical findings: Significant adult weight loss in a short time indicates cancer, diabetes, chronic infections, malabsorption, etc.
Puritius = itching, common complaint with biliary salt deposition in the skin; will see a dark yellow skin color.

A palpable, non-tender gallbladder is the Courvoisier sign for pancreatic carcinoma (the enlarged head elevates the GB)

Urine UBG is normally detectable. Here it is negative because there is no bilirubin secreted into the intestines.

->Lack of Ubg suggests total obstruction of bilirubin secretion into the GI tract.

• > ASAT/ALAT are high (>45 U/l) and ALP is very high (>150 U/l) indicating liver damage.
• > Alkaline phosphate is very high, which indicates biliary obstruction (like γGT).

Prothrombin time is long (>1.2 INR): INR indicates coagulation takes longer. There is no bile, which mean vitamin K can not be solubilized (it is fat soluble), thus there is no emulsification and aborption of fat and thus no synthesis of coagulation factors. (This can be checked by administering vitamin K and measuring the PPT again).

Conslusion: With all these symptoms together, we can suspect pancreatic cancer (weight loss due to the cancer and due to malabsorption since there are no pancreatic enzymes).

Dark urine = direct bilirubin; light stool = no stercobilin; both indicate obstruction.

diagnostic methods:

• > Endoscopic retrograde cholecysto-pancreatography
• > administer contrast to bile + pancreatic ducts to observe size of tumor

Imaging (US, CT, MRI) to observe size of tumor + presence of metastases

Question 2

2. An icteric woman has the following laboratory parameters:
serum indirect bilirubin: 54 μmol/l
serum direct bilirubin: 5,1 μmol/l
urine bilirubin: negative
ASAT: 19 U/l
ALAT: 22 U/l
LDH: 720 U/l
Ht: 0.33 l/l
plasma haptoglobin and hemopexin concentrations are significantly decreased
What is the cause of her jaundice?

Answer 2

Clinical findings: Icterus (jaundice) indicates hyperbilirubinemia.

Lab findings:
-> Direct bilirubin is normal, indirect bilirubin is very high.
Total bilirubin is 59.1, which is very high.
-> Urine bilirubin is negative, which is normal.
-> ASAT and ALAT are at normal levels (no liver damage)
-> LDH is high, which indicates hemolysis (LDH1 is abundant in RBCs, LDH5 in hepatocytes).

• > Hematocrit is below normal, indicating decreased RBCs.
• > Haptoglobin and hemopexin are acute phase proteins that easily bind hemoglobin. They are decreased, which indicates free hemoglobin (hemolysis). Haptoglobulin will bind to free hemoglobulin (if it gets out of RBC) and will be removed quite fast from the circulation. Hemoplexin will bind free heme (component without iron) if it gets into the plasma, it then is removed.

Conclusion: Altogether these findings indicate hemolytic jaundice with indirect hyperbilirubinemia.
This can occur due e.g. autoimmune attack on RBCs, RBC problem (e.g. sickle cell anemia), corpuscular anemia, incompatible blood tranfusion

Question 3

3. A 38 year-old man, who regularly drinks alcohol. He has never been ill before (acute!), but he has grown icteric in the last couple of days. He has a temperature, and is a little anemic.
His liver is palpable an inch below the ribs, it is slightly tender. Laboratory results:
urine color: dark brown
serum total bilirubin: 150 μmol/l
ASAT: 160 U/l
ALAT: 60 U/l
GGT: 490 U/l
MCV: 103 fl
What is the cause of his jaundice?

Answer 3

Clinical findings: The man is a regular drinker, so suspect alcoholic hepatitis. This is also indicated by the palpable liver (fatty liver).
Jaundice is an indication of hyperbilirubinemia.
Dark urine indicates bilirubinuria (positive conjugated bilirubin in the urine).

Lab findings:
Total serum bilirubin is above normal, which indicates jaundice.
ALAT is slightly above normal, indicating parenchymal damage.

ASAT is above normal, and above ALAT, which indicates alcoholic hepatitis.

GGT (gamma glutamyltransferase) is elevated here; it is a parenchymal liver enzyme that can be elevated due to biliary obstruction or drug / alcohol toxicity.

MCV (mean corpuscular volume; average size of RBC) is above normal, which indicates bone marrow depression effects of chronic alcoholism, which increases the size of a RBC.

Conclusion: Both findings together indicate chronic alcoholic hepatitis - hepatocellular jaundice. (Alcoholic steatic hepatitis)