Question

Enzymes can investigated/analyzed at individuals blood for aiding the diagnosis of a variety of conditions. What are these clinically important enzymes that can be analyzed in the blood?give 6 examples, explain the normal and deregulated values and and the clinicopathologic importance of these enzymes.

Answer 1

Alanine Aminotransferase (ALT; also called SGPT)

A liver enzyme. May increase when using cholesterol-lowering medications.

Goal value:

• 5 – 50 U/L

Preparation

• This test may be measured any time of the day without fasting.
• ALT is an enzyme that is measured to detect liver disease, hepatitis. It may increase with use of some medications.

Aspartate Aminotransferase (AST; also called SGOT)

A liver enzyme that is released into the bloodstream following injury or death of cells. Increased AST is seen with liver disease, myocardial infarction (MI) and some medications. May increase when using cholesterol-lowering medications.

Goal value:

• 7 – 40 U/L

Preparation

• This test may be measured any time of the day without fasting.

Creatine Kinase (CK)

A muscle enzyme found in the heart and muscles. Increased CK-MB is seen with heart muscle damage. Increased CK-MM is noted with skeletal muscle injury. Strenuous exercise, weight lifting, surgical procedures, high doses of aspirin and other medications can elevate CK. May increase when using cholesterol-lowering medications.

Goal value:

• 30 – 220 U/L.

CK may also be reported as percentages: CKBB: 0%; CKMB: 0 - 4% ;CKMM: 96 - 100%

Preparation

• This test may be measured any time of the day without fasting.

Lactate dehydrogenase (LDH)

LDH is an enzyme released in the blood with cell injury. It is often used as a late marker to detect a heart attack. It is also elevated with liver and kidney disease, pernicious and megaloblastic anemias, malignancy, progressive muscular dystrophy, and pulmonary emboli.

Goal value:

• 100 - 220 U/L

Preparation

• This test may be measured any time of the day without fasting.

Myoglobin (Mb)

Myoglobin is a protein found in certain types of muscle. Elevated myoglobin may indicate muscle injury or inflammation.

Goal value:

• 30 – 90 µg/mL

Preparation

• This test may be measured any time of the day without fasting. Vigorous exercise right before the test may raise myoglobin levels.

Creatinine (Cr)

Creatinine becomes elevated with illness, kidney disease, muscle injury and some medications.

Goal value:

• 0.7 – 1.4 mg/dL