A 49-year-old man has had 3 weeks of increasing jaundice, poor appetite and abdominal swelling. Results: AST 236 U/L and ALT 92 U/L (both below 40), GGT 710 U/L (below 50), ALP 168 U/L (40-130), total bilirubin 5.4 mg/dL [92 µmol/L], albumin 2.9 g/dL [29 g/L], INR 1.6, WBC 13.8 x 10^3/µL [13.8 x 10^9/L] with neutrophilia, MCV 106 fL. Viral hepatitis serology is pending. Ultrasound shows a fatty liver with no bile duct dilation. Which diagnosis fits these results best?

Extrahepatic bile duct obstruction

A 36-year-old man with poorly controlled type 2 diabetes has epigastric pain radiating to the back, and vomiting. He does not drink alcohol, and ultrasound shows no gallstones. His serum is milky. Results: lipase 1,140 U/L (reference below 60), amylase 96 U/L (30-110), triglyceride 3,200 mg/dL [36.1 mmol/L], ALT 30 U/L, ALP 88 U/L, total bilirubin 0.7 mg/dL [12 µmol/L], glucose 286 mg/dL [15.9 mmol/L], arterial pH 7.38, beta-hydroxybutyrate 0.4 mmol/L (below 0.6). The most likely diagnosis is:

Acute pancreatitis due to hypertriglyceridemia

Ketoacidosis with a nonspecific lipase rise

Gallstone pancreatitis with duct obstruction

Macrolipasemia without pancreatitis

Enzymes: interpretation and disease correlation

25 ASCP MLS practice questions on Enzymes: interpretation and disease correlation, part of Chemistry. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
A 49-year-old man has had 3 weeks of increasing jaundice, poor appetite and abdominal swelling. Results: AST 236 U/L and ALT 92 U/L (both below 40), GGT 710 U/L (below 50), ALP 168 U/L (40-130), total bilirubin 5.4 mg/dL [92 µmol/L], albumin 2.9 g/dL [29 g/L], INR 1.6, WBC 13.8 x 10^3/µL [13.8 x 10^9/L] with neutrophilia, MCV 106 fL. Viral hepatitis serology is pending. Ultrasound shows a fatty liver with no bile duct dilation. Which diagnosis fits these results best?
1. AExtrahepatic bile duct obstruction
2. BAcute viral hepatitis
3. CNonalcoholic steatohepatitis
4. DAlcohol-associated hepatitis
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Answer: D · Alcohol-associated hepatitis
An AST about 2.5 times the ALT, with AST below 300 U/L, is typical of alcohol-associated liver injury. Alcohol releases mitochondrial AST from damaged cells, and the pyridoxal phosphate deficiency of heavy drinkers lowers ALT activity more than AST. The very high GGT reflects enzyme induction, and the macrocytosis is a direct effect of alcohol on the marrow. Jaundice, a raised INR, low albumin and neutrophilia point to alcohol-associated hepatitis rather than simple fatty liver. Acute viral hepatitis gives much higher aminotransferases, with ALT above AST.
- A: ALP is only mildly raised and the bile ducts are not dilated.
- B: Acute viral hepatitis raises ALT above AST, often into the thousands.
- C: Steatohepatitis without alcohol usually has ALT above AST, without jaundice or macrocytosis.
Question 2 · Hard
A 56-year-old woman has 4 months of tiredness, muscle aches and cramps, cold intolerance and weight gain. She takes no medicines and has not exercised hard or fallen. Results: CK 1,380 U/L (reference below 200), AST 58 U/L and ALT 44 U/L (both below 40), LD 310 U/L (125-220), GGT 24 U/L (below 50), troponin I below the 99th percentile on two samples 3 hours apart, total cholesterol 286 mg/dL [7.40 mmol/L], TSH 62 mIU/L (0.4-4.0), free T4 0.3 ng/dL [4 pmol/L] (0.8-1.8 ng/dL). The raised CK is best explained by:
1. AAcute myocardial infarction
2. BExertional rhabdomyolysis
3. CHypothyroid myopathy
4. DStatin-associated myopathy
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Answer: C · Hypothyroid myopathy
Primary hypothyroidism (very high TSH, low free T4) commonly raises CK, often several times the upper limit, probably through altered muscle metabolism and slower CK clearance.The CK is of muscle origin, and AST, ALT and LD rise modestly from the same source; the normal GGT points away from liver disease. Serial normal troponin excludes myocardial infarction. Hypothyroidism also raises cholesterol, which may tempt a prescriber to start a statin; the thyroid should be treated first, since a statin would add to the muscle risk. CK returns to normal with thyroxine replacement.
- A: Troponin is normal on serial samples.
- B: She has not exercised hard, and her symptoms built up over months.
- D: She takes no medicines; the high cholesterol comes from the hypothyroidism.
Question 3 · Hard
A 36-year-old man with poorly controlled type 2 diabetes has epigastric pain radiating to the back, and vomiting. He does not drink alcohol, and ultrasound shows no gallstones. His serum is milky. Results: lipase 1,140 U/L (reference below 60), amylase 96 U/L (30-110), triglyceride 3,200 mg/dL [36.1 mmol/L], ALT 30 U/L, ALP 88 U/L, total bilirubin 0.7 mg/dL [12 µmol/L], glucose 286 mg/dL [15.9 mmol/L], arterial pH 7.38, beta-hydroxybutyrate 0.4 mmol/L (below 0.6). The most likely diagnosis is:
1. AAcute pancreatitis due to hypertriglyceridemia
2. BKetoacidosis with a nonspecific lipase rise
3. CGallstone pancreatitis with duct obstruction
4. DMacrolipasemia without pancreatitis
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Answer: A · Acute pancreatitis due to hypertriglyceridemia
Typical pain with a lipase about 19 times the upper limit meets the diagnostic criteria for acute pancreatitis. A triglyceride above 1,000 mg/dL [11.3 mmol/L] is a recognized cause, and poorly controlled diabetes is a common trigger. The normal amylase does not argue against pancreatitis: amylase is often normal in hypertriglyceridemic pancreatitis, partly because lipemic serum interferes with the amylase assay, which is one reason lipase is preferred. Normal liver tests and no stones make gallstones unlikely, and a normal pH and beta-hydroxybutyrate exclude ketoacidosis.
- B: The pH and beta-hydroxybutyrate are normal, so there is no ketoacidosis.
- C: No gallstones are seen, and ALT, ALP and bilirubin are normal.
- D: Macrolipasemia gives a stable lipase rise without acute pain or lipemia.
Question 4 · Hard
A 50-year-old man has a raised amylase on a routine panel and no abdominal pain. Serum amylase 380 U/L (reference 30-110 U/L), lipase 40 U/L (reference < 60 U/L), serum creatinine 1.0 mg/dL [88 µmol/L]. A random urine has amylase 60 U/L and creatinine 120 mg/dL. What is the most likely cause?
1. ASalivary gland inflammation
2. BAcute pancreatitis
3. CReduced renal function
4. DMacroamylasemia
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Answer: D · Macroamylasemia
The amylase-to-creatinine clearance ratio is (urine amylase x serum creatinine) / (serum amylase x urine creatinine) x 100 = (60 x 1.0) / (380 x 120) x 100 = 0.13%. A ratio below 1% means amylase is not being cleared, because it is bound in large complexes, usually with immunoglobulin, that cannot pass the glomerulus. The normal lipase and the absence of pain argue against pancreatitis, and salivary amylase would be cleared normally. Macroamylasemia is harmless, and recognizing it prevents needless imaging.
- A: Salivary amylase is small and cleared normally, giving a normal ratio.
- B: Pancreatitis would raise lipase too, and the clearance ratio would not be this low.
- C: The serum creatinine is normal, so renal clearance is not reduced.
Question 5 · Hard
A 58-year-old woman has acute epigastric pain radiating to the back. Lipase 2,100 U/L (< 60), ALT 340 U/L (< 40), ALP 190 U/L (40-130), bilirubin 2.6 mg/dL [44 µmol/L]. The most likely cause of her pancreatitis is:
1. AHypertriglyceridemia
2. BAlcohol
3. CHypercalcemia
4. DGallstones
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Answer: D · Gallstones
A stone passing through or impacted at the ampulla can block both the bile duct and the pancreatic duct. An ALT above about 3 times the upper limit in the first 48 hours strongly suggests a gallstone cause, and the raised ALP and bilirubin support biliary obstruction. Alcohol, the other common cause, usually gives little early ALT rise. Ultrasound of the gallbladder and bile ducts is the next step.
- A: Hypertriglyceridemia causes pancreatitis at levels above about 1,000 mg/dL [11.3 mmol/L] and gives no cholestatic pattern.
- B: Alcohol-related pancreatitis rarely gives an early ALT this high.
- C: Hypercalcemia is a rare cause and does not explain the liver results.
Question 6 · Hard
A 26-year-old man has ALT 95 U/L and AST 230 U/L (reference < 40 U/L for both) on a work-entry screen, two days after a weightlifting competition. GGT, ALP and bilirubin are normal. Which test should be added first?
1. AHepatitis B and C serology
2. BCeruloplasmin
3. CCreatine kinase
4. DSerum lipase
Answer and explanation in LearnFree account
Question 7 · Medium
Long-term phenytoin use or regular heavy drinking can raise serum GGT with otherwise normal liver tests, mainly because these:
1. AReduce GGT clearance by the kidneys
2. BRelease GGT from damaged red cells
3. CRelease GGT from bone osteoblasts
4. DIncrease GGT synthesis in the liver
Answer and explanation in LearnFree account
Question 8 · Medium
Reference: ALT and AST < 40 U/L, ALP 40-130 U/L, GGT < 50 U/L. Which result set best fits acute viral hepatitis?
1. AALT 70, AST 55, ALP 820, GGT 690 U/L
2. BALT 45, AST 230, CK 12,400 U/L
3. CALT 60, AST 170, GGT 420 U/L
4. DALT 1,850, AST 1,240, ALP 160 U/L
Answer and explanation in LearnFree account
Question 9 · Hard
A 68-year-old is resuscitated after a cardiac arrest. Next day: AST 4,800 U/L, ALT 3,900 U/L (both < 40), LD 6,500 U/L (125-220), bilirubin 1.4 mg/dL [24 µmol/L]. Two days later AST and ALT have fallen by more than half. The pattern most suggests:
1. AIschemic hepatitis
2. BDrug-induced cholestasis
3. CAcute viral hepatitis
4. DAlcoholic hepatitis
Answer and explanation in LearnFree account
Question 10 · Hard
A 22-year-old found on the floor after a drug overdose has dark urine. CK 48,000 U/L (reference < 200 U/L), AST 690 U/L, ALT 210 U/L, potassium 6.2 mmol/L; the urine is strongly positive for blood with 0-2 RBC/HPF. The most likely diagnosis is:
1. AAcute viral hepatitis
2. BAcute myocardial infarction
3. CIntravascular hemolysis
4. DRhabdomyolysis
Answer and explanation in LearnFree account
Question 11 · Hard
A patient on hemodialysis has mild, vague abdominal discomfort. Lipase is 110 U/L (reference < 60 U/L), amylase 160 U/L (reference 30-110 U/L) and abdominal CT is normal. What is the best interpretation?
1. AMacroamylasemia is the likely cause
2. BPancreatitis criteria have not been met
3. CHemolysis has raised both enzymes
4. DAcute pancreatitis is confirmed
Answer and explanation in LearnFree account
Question 12 · Hard
A 66-year-old man treated for colon cancer has ALP 780 U/L (40-130), GGT 520 U/L (< 50), ALT 45 U/L, AST 52 U/L (both < 40) and a normal bilirubin. What do these results most suggest?
1. AComplete bile duct obstruction
2. BLiver metastases
3. CPaget disease of bone
4. DAcute viral hepatitis
Answer and explanation in LearnFree account
Question 13 · Medium
A healthy woman at 34 weeks of pregnancy has ALP 260 U/L (reference 40-130 U/L), with normal GGT, ALT and bilirubin. What is the most likely source of the extra ALP?
1. APlacental ALP
2. BLiver ALP
3. CBone ALP
4. DIntestinal ALP
Answer and explanation in LearnFree account
Question 14 · Medium
A 74-year-old man has bone pain and an enlarging skull. ALP is 610 U/L (reference 40-130 U/L); GGT, calcium and phosphate are normal. What is the most likely diagnosis?
1. AMultiple myeloma
2. BPaget disease of bone
3. CPrimary osteoporosis
4. DObstructive jaundice
Answer and explanation in LearnFree account
Question 15 · Medium
In acute pancreatitis, serum lipase differs from serum amylase in that lipase:
1. AAlso rises in mumps and parotitis
2. BRemains raised for a week or longer
3. CRises only after several days
4. DReturns to normal sooner
Answer and explanation in LearnFree account
Question 16 · Hard
Results: ALP 340 U/L (40-130), GGT 25 U/L (< 50), calcium 8.1 mg/dL [2.02 mmol/L] (8.6-10.2), phosphate 2.0 mg/dL [0.65 mmol/L] (2.5-4.5), 25-hydroxyvitamin D 7 ng/mL [17 nmol/L], PTH raised. The raised ALP is best explained by:
1. AOsteomalacia
2. BOsteoporosis
3. CPrimary hyperparathyroidism
4. DPaget disease of bone
Answer and explanation in LearnFree account
Question 17 · Easy
When a raised ALP is accompanied by a raised GGT, the extra ALP most likely comes from the:
1. APlacenta
2. BLiver
3. CBone
4. DIntestine
Answer and explanation in LearnFree account
Question 18 · Hard
In suspected drug-induced liver injury, ALT is 480 U/L (upper limit 40 U/L) and ALP is 260 U/L (upper limit 130 U/L). What is the R ratio and the type of injury?
1. AR = 0.17; cholestatic injury
2. BR = 6; cholestatic injury
3. CR = 6; hepatocellular injury
4. DR = 1.8; cholestatic injury
Answer and explanation in LearnFree account
Question 19 · Easy
In which disorder is serum CK typically markedly raised?
1. AMultiple sclerosis
2. BGuillain-Barré syndrome
3. CMyasthenia gravis
4. DDuchenne muscular dystrophy
Answer and explanation in LearnFree account
Question 20 · Medium
A 47-year-old man had epigastric pain radiating to the back that began 6 days ago and has now eased. Using the typical enzyme course shown, which result pattern is expected if he is tested today?
Figure: MedExams
1. ALipase raised, amylase within reference
2. BAmylase raised, lipase within reference
3. CBoth enzymes raised above reference
4. DBoth enzymes back within reference
Answer and explanation in LearnFree account
Question 21 · Medium
The LD isoenzyme gel shown compares a normal control with a patient's serum. The patient's pattern most likely reflects injury to the:
Figure: MedExams
1. ALiver
2. BHeart
3. CLung
4. DRed cells
Answer and explanation in LearnFree account
Question 22 · Hard
A 24-year-old man was trapped under a collapsed wall for 5 hours. He develops acute kidney injury, with creatinine rising from 1.1 to 4.2 mg/dL [97 to 371 µmol/L] by day 4. His serial CK results are charted (reference < 200 U/L). The rise in CK from day 5 most likely indicates:
Figure: MedExams
1. ANew or continuing injury to muscle
2. BReduced renal clearance of CK
3. CA normal second peak of release
4. DFormation of macro-CK complexes
Answer and explanation in LearnFree account
Question 23 · Medium
Which marker is preferred for diagnosing acute myocardial infarction?
1. ACardiac troponin (I or T)
2. BCK-MB
3. CLactate dehydrogenase
4. DMyoglobin
Answer and explanation in LearnFree account
Question 24 · Medium
Which pattern suggests cholestatic (obstructive) liver disease rather than hepatocellular injury?
1. AALT and AST more than 10 times the upper limit, ALP mildly raised
2. BALP and GGT markedly raised, ALT mildly raised
3. CLow albumin with normal enzymes
4. DIsolated raised unconjugated bilirubin with normal enzymes
Answer and explanation in LearnFree account
Question 25 · Easy
Which enzyme is the most specific of these for acute pancreatitis?
1. ALipase
2. BAmylase
3. CAlkaline phosphatase
4. DALT
Answer and explanation in LearnFree account

Enzymes: interpretation and disease correlation

A 50-year-old man has a raised amylase on a routine panel and no abdominal pain. Serum amylase 380 U/L (reference 30-110 U/L), lipase 40 U/L (reference < 60 U/L), serum creatinine 1.0 mg/dL [88 µmol/L]. A random urine has amylase 60 U/L and creatinine 120 mg/dL. What is the most likely cause?

A 58-year-old woman has acute epigastric pain radiating to the back. Lipase 2,100 U/L (< 60), ALT 340 U/L (< 40), ALP 190 U/L (40-130), bilirubin 2.6 mg/dL [44 µmol/L]. The most likely cause of her pancreatitis is:

A 26-year-old man has ALT 95 U/L and AST 230 U/L (reference < 40 U/L for both) on a work-entry screen, two days after a weightlifting competition. GGT, ALP and bilirubin are normal. Which test should be added first?

Long-term phenytoin use or regular heavy drinking can raise serum GGT with otherwise normal liver tests, mainly because these:

Reference: ALT and AST < 40 U/L, ALP 40-130 U/L, GGT < 50 U/L. Which result set best fits acute viral hepatitis?

A 68-year-old is resuscitated after a cardiac arrest. Next day: AST 4,800 U/L, ALT 3,900 U/L (both < 40), LD 6,500 U/L (125-220), bilirubin 1.4 mg/dL [24 µmol/L]. Two days later AST and ALT have fallen by more than half. The pattern most suggests:

A 22-year-old found on the floor after a drug overdose has dark urine. CK 48,000 U/L (reference < 200 U/L), AST 690 U/L, ALT 210 U/L, potassium 6.2 mmol/L; the urine is strongly positive for blood with 0-2 RBC/HPF. The most likely diagnosis is:

A patient on hemodialysis has mild, vague abdominal discomfort. Lipase is 110 U/L (reference < 60 U/L), amylase 160 U/L (reference 30-110 U/L) and abdominal CT is normal. What is the best interpretation?

A 66-year-old man treated for colon cancer has ALP 780 U/L (40-130), GGT 520 U/L (< 50), ALT 45 U/L, AST 52 U/L (both < 40) and a normal bilirubin. What do these results most suggest?

A healthy woman at 34 weeks of pregnancy has ALP 260 U/L (reference 40-130 U/L), with normal GGT, ALT and bilirubin. What is the most likely source of the extra ALP?

A 74-year-old man has bone pain and an enlarging skull. ALP is 610 U/L (reference 40-130 U/L); GGT, calcium and phosphate are normal. What is the most likely diagnosis?

In acute pancreatitis, serum lipase differs from serum amylase in that lipase:

Results: ALP 340 U/L (40-130), GGT 25 U/L (< 50), calcium 8.1 mg/dL [2.02 mmol/L] (8.6-10.2), phosphate 2.0 mg/dL [0.65 mmol/L] (2.5-4.5), 25-hydroxyvitamin D 7 ng/mL [17 nmol/L], PTH raised. The raised ALP is best explained by:

When a raised ALP is accompanied by a raised GGT, the extra ALP most likely comes from the:

In suspected drug-induced liver injury, ALT is 480 U/L (upper limit 40 U/L) and ALP is 260 U/L (upper limit 130 U/L). What is the R ratio and the type of injury?

In which disorder is serum CK typically markedly raised?

A 47-year-old man had epigastric pain radiating to the back that began 6 days ago and has now eased. Using the typical enzyme course shown, which result pattern is expected if he is tested today?

The LD isoenzyme gel shown compares a normal control with a patient's serum. The patient's pattern most likely reflects injury to the:

A 24-year-old man was trapped under a collapsed wall for 5 hours. He develops acute kidney injury, with creatinine rising from 1.1 to 4.2 mg/dL [97 to 371 µmol/L] by day 4. His serial CK results are charted (reference < 200 U/L). The rise in CK from day 5 most likely indicates:

Which marker is preferred for diagnosing acute myocardial infarction?

Which pattern suggests cholestatic (obstructive) liver disease rather than hepatocellular injury?

Which enzyme is the most specific of these for acute pancreatitis?