Importance of enzymes : The two aminotransferases that are checked are the alanine aminotransferase (ALT or SGPT) and aspartate aminotransferase (AST or SGOT). These liver enzymes form a major constituent of the liver cells. They are present in lesser concentration in the muscle cells.

1. CLINICAL SIGNIFICANCE OF
ENZYMES
SHELVY S.
2011-09-123
KERALA AGRICULTURAL UNIVERSITY

2. GOALS
• Helps in making the diagnosis/differential diagnosis/ early
• Detection of a disease
• Helps in ascertaining prognosis of a disease
• Helps in ascertaining the response to drugs in a disease
• Also help in ascertaining the time course of disease.

3. WHERE
Helpful in
the
diagnosis of
Myocardial Infarction
Liver Diseases
GI Tract Diseases
Muscle Diseases
Bone Disesases
Cancer

4. DIAGNOSTIC ENZYME
Tissue damage or necrosis resulting from injury or disease is generally
accompanied by increases in the levels of several nonfunctional plasma enzymes.

5. Enzymes routinely measured
NAME OF THE ENZYME PRESENT IN
Aspartate Amino transferase (AST)
Serum glutamate-oxaloacetate
transaminase (SGOT)
Heart and Liver
Alanine Amino transferase (ALT)
Serum glutamate-pyruvate
transaminase (SGPT)
Heart and Liver
Alkaline Phosphatase (ALP) Bone, intestine and other
tissues
Acid Phosphatase (ACP) Prostate
 glutamyl Transferase ( GT) Liver
Creatine kinase (CK) Muscle Including cardiac
muscle
Lactate Dehydrogenase (LDH) Heart, liver, muscle, RBC
 Amylase Pancreas

6. sGPT and sGOT

7. ALT or sGPT (Serum Glutamate Pyruvate Transaminase)
ALT
GPT (ALT) catalyses the transfer of amino-groups from alanine to 2-oxoglutarate and thus the
formation of glutamate and pyruvate.
Alanine Transaminase

8. ALT is an enzyme produced in hepatocytes and is
highly concentrated in the liver.
organ GOT GPT
heart 156000 7100
liver 142000 44000
skeletal 99000 4800
kidney 91000 19000
organ GOT GPT
pancrease
spleen
lung
serum
28000 2000
14000 1200
10000 700
20 16

9. GPT (ALT) is widely distributed in cells throughout the body. GPT
(ALT) is found predominantly in the cytoplasm and is widely considered
to be specifically for the liver. In addition, it is also active in the heart,
skeletal muscle, pancreas, and the kidney.
GPT (ALT) activity in the liver is about 3,000 times higher than its
activity in the serum. Only if cells are damaged GPT (ALT) will be
excreted into the blood. In the plasma, GPT (ALT) has no biological
function because the necessary substrates and co-substrates are lacking
there.
Source & biological action

10. Elevated levels of ALT may indicate :
Alcoholic liver disease
Cancer of the liver
Cholestasis or congestion of the bile ducts
Cirrhosis or scarring of the liver with loss of function
Death of liver tissue
Hepatitis or inflammation of the liver
Noncancerous tumor of the liver
Use of medicines or drugs toxic to the liver
Therefore, when the liver is injured, ALT is
released into the bloodstream.

11. • Normal level :- 0-41 IU/L.
• The Aminotransferases are normally present in the serum in low concentrations. These
enzymes are released into the blood in greater amounts when there is damage to the liver
cell membrane resulting in increased permeability.
• Levels of up to 300 U/L are nonspecific and may be found in any type of liver disorder.
• Striking elevations i.e., aminotransferases > 1000 IU/L occur almost exclusively in
disorders associated with extensive hepatocellular injury such as
– viral hepatitis
– Ischemic liver injury (prolonged hypotension),
• In most acute hepatocellular disorders, the ALT is higher than or equal to the AST.

12. AST or sGOT (Serum Glutamate Oxaloacetate Transaminase)
AST
Aspartate aminotransferase (AST)

13. organ GOT GPT
heart 156000 7100
liver 142000 44000
skeletal 99000 4800
kidney 91000 19000
organ GOT GPT
pancrease
spleen
lung
serum
28000 2000
14000 1200
10000 700
20 16
Both these enzyme are found in most tissues, but the relative amounts vary.
heart muscles are richer in AST, whereas liver contains both but more of ALT.
Aspartate aminotransferase (AST)

14. • AST also reflects damage to the hepatic cells and is less
specific for liver disease. It can also be released with heart,
muscle and brain disorders.
• Therefore, this test may be ordered to help diagnose
various heart, muscle or brain disorders, such as a
myocardial infarct (heart attack).

15. Elevated levels of AST may indicate:
 Acute hemolytic anemia,
 Acute pancreatitis or inflammation of the pancreas.
 Acute renal failure or loss of kidney function.
 Cirrhosis of the liver.
 Hepatitis
 Heart attack
 Primary muscle disease
 Recent surgery
 Severe burns
 Muscle injury

16.  The level is significantly elevated in Acute MI.
 Normal Value:- 0-41 IU/L at 37°C
 In acute MI- Serum activity rises sharply within the first 12 hours,
with a peak level at 24 hours or over and returns to normal within
3-5 days.
 The rise depends on the extent of infarction.

17.  Levels> 350 IU/L are due to massive infarction (Fatal),
 > 150 IU/L are associated with high mortality and levels,
 < 50 IU/L are associated with low mortality.
Other diseases-
 The rise in activity is also observed in muscle and hepatic diseases. These can
be well differentiated from simultaneous estimations of other enzyme activities
like SGPT etc, which do not show and rise in activity in Acute MI.

18. In infectious hepatitis and other inflammatory
conditions affecting the liver, ALT is characteristically
as high as or higher than AST, and the ALT/AST (De
Ritis) ratio becomes greater than unity, >1.5.
sALT/sAST (De Ritis) ratio, normally is less than 1,
about 0.7~0.9.
 Ratios between ALT and AST are useful to physicians
in assessing the etiology of liver enzyme abnormalities.

19. 19
Serum enzymes in liver diseases:-
In viral hepatitis:-
Rapid rise in
transaminases (AST
& ALT) in serum
occurs even before
bilirubin rise is seen

20. LEVELS OF ENZYMES IN MYOCARDIAL INFARCTION
CK-MB
CK
AST
LDH
HBDH
AST and CK rise in 6 hours
following acute
myocardial infarction
HBDH and LDH are
elevated much later and
remains high for a longer
period of days