Enzymes, markers, diseases diagnosis, importance of enzymes, assessment of condition , types of enzymes, biomarker

1. ENZYMES IN DISEASE
DIAGNOSIS
Presented by :
K. Anil kumar.
M.sc Biosciences
first year

2. Introduction
Enzymes are the Biocatalyst synthesized by living cells, which are
protein in nature, specific in their action
Enzymes are present virtually in all organs but slightly in different
forms and in different locations
They also act as reagent for various Bio-chemical estimation and
detections
 Isoenzyme – multiple forms of an enzyme catalysing the same
reaction

3. Estimation of enzyme activities in biological fluids (particularly
plasma/serum) is of great clinical importance
The normal serum level of an enzyme indicates the balance between
its synthesis and release
Factors responsible for raises serum level
1. cellular damage
2. increased rate of cell turnover
3. proliferation of cells
4. increased synthesis of enzymes

4. Source: internet
Serum Enzymes are used as markers to detect the cellular damage
which ultimately help in diagnosis of diseases
Types: 1. Functional plasma enzymes
2. Non-functional plasma enzymes
i. Secretory enzymes : pepsin, amylase ,trypsin etc.
ii. Constitutive enzymes: LDH, ALP ,CPK

5. Clinical significance of Enzyme estimation
Useful in the diagnosis and early detection of diseases
Helpful in the detection of progress of diseases
Helpful in the detection of response to drugs in a diseases
 Serum Enzyme activity is measured in: International units (IU/L)

6. Diseases
Myocardial infection
Liver diseases
Muscle diseases
Cancers
Bone diseases
GI Tract diseases

7. Source: U.Satyrnarayana , textbook of biochemistry

8. Myocardial infraction (MI)
Besides chest pain ,changes in ECG, increase in biochemical markers
can also indicate the MI
Biochemical markers have excellent sensitivity for diagnosing
Acute myocardial infraction (AMI)
• Creatinine phosphokinase (CPK)
• Aspartate transaminase (AST)
• Lactate dehydrogenase (LDH)
• Cardiac troponins
• myoglobins
Source: internet

9. Creatinine phosphokinase: first enzyme to be
released into circulation with in 6-18 hours after
the infraction (CPK-MB)
Reaches a peak value in within 24-30 hours and
returns to normal level by second or third day
Aspartate transaminase (AST): Rises level in acute
MI after the CPK , Reaches to the peak in 48
hours and return normal with in 5 to 6 days
Lactate dehydrogenase: it rises generally from the
second day of infraction , Reaches peaks very fast
and returns to normal with in 15 days
Magnitude of rise is proportional to extent of
myocardial infraction
Source: U.Satyanarayana , textbook of biochemistry

10. Cardiac Troponins (CT): 3 components
Myoglobin: earlier marker for diagnosis of MI
Level rises with in 4 hours of infraction
False positive can occur in patients with renal failure
• Troponin T - increase with in 6 hours of MI and remain
elevated up to 7 days
• Troponin I - with in 4 hours of onset of MI
• Troponin C – calcium binding protein which helps in
activation of muscle contraction

11. Liver diseases
Enzyme level in serum is increased either by the damage to
hepatocytes and cholestasis
Amino transferases: sensitive indicator of liver cell injury and most
helpful in recognizing Hepatitis, jaundice, cirrhosis, hepatic necrosis
Cholestasis: Alkaline phosphatase
serum-glutamyl transpeptidase
1.Alanine transaminase
2.Aspartate transaminase
3.Lactate dehydrogenase

12. Cancer
Prostate cancer: Enzyme involved is Acid phosphatase
Found in great concentration in prostate gland and seminal fluid
Prostatic isoenzymes are more specific for prostatic cancer
Acid phosphatase levels drop by 50% with in one hour in RT , to
prevent preservatives should be added or stored in ice pack
High level : indicates tumor spread
Intermediate level: indicates prostatic infraction
Low levels: successful treatment of prostatic cancer

13. BONE DISEASES
Alkaline phosphatase: Rises in Rickets, hyperparathyroidism,
secondary malignancies of bone
Amylase: Acute pancreatitis, perforated intestinal ulcers, intestinal
obstruction
Lipase: level are rise in acute pancreatitis, perorated duodenal and
peptic ulcers
GI Tract

14. Reference ranges
Source: U.satryanarayana, textbook of biochemistry

15. Source: internet