CLINICAL
BIOCHEMISTRY
Nguyễn Minh Phương Uyên
BTBTWE18086
01 DEFINITION
CONTENTS
02 FUNCTIONS and METHODS
03 CLASSIFICATION
04 PARAMETERS
( normal and abnormal)
DEFINITION
- Clinical Biochemistry is
the division of laboratory
medicine that deals with the
measurement of chemicals (
both natural and unnatural)
in blood, urine, and other
body fluids.
- These test results are
useful for detecting health
problems, determining
prognosis and guiding the
therapy of a patient.
-
Clinical Biochemists ensure that
consistent high quality, accurate and
precise biochemical test results are
provided so that high quality care
can be provided to the patient.
Clinical Biochemists lead the
development and implementation of
laboratory quality management
systems that encompass all aspects
of the testing process: pre-analytical,
analytical and post-analytical.
At the commencement of the
20th century “Clinical
Chemistry” really began to
develop into the discipline which
we know today.
Quantitative tests were carried out in
regard to sugar and urea of urine and
a series of qualitative tests for
acetone, albumin, bile, and sugar were
performed.
FUNCTIONS
Biochemical investigations are
involved, to varying degrees, in every
branch of clinical medicine.
-
-
Biochemical tests may also be of
value in screening for disease or in
assessing the prognosis once a
diagnosis has been made (fig. 1) 2
The biochemistry laboratory is often
involved in research into the
biochemical basis of disease and in
clinical trials of new drugs.
How Biochemical tets are used
Diagnosis &Treatment
The results of
biochemical tests
may be of use in
diagnosis and in the
monitoring of
treatment.
Screening
Pronosis
Biochemical tests
may also be of
value in screening
for disease or in
assessing the
prognosis once a
diagnosis has been
made
The biochemistry
laboratory is often
involved in research
into the biochemical
basis of disease and
in clinical trials of
new drugs.
Process of Clinical Biochemistry
METHODS
INCLUDING:
+ Technique
+ Instrucmentation
Instrucment:
Clinical biochemistry is an analytical and
interpretative science. The analytical part
involves the determination of the level of
chemical components in body fluids and
tissues. The interpretative part examines
these results and uses them in the
diagnosis of disease, the screening for
susceptibility to specific diseases, and the
monitoring of the progress of treatment.
This part is designed to name the major
techniques and analytical instruments
used in clinical biochemistry.
1.
2.
3.
4.
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14.
Spectrophotometry
Fluorimetry
Enzymology
Atomic Emission and Absorption
Ion Selective Electrodes
Oxygen and Carbon Dioxide Electrodes
Chromatography
Thin Layer Chromatography and Extraction
Techniques
Gas Chromatography
High Performance Liquid Chromatography
Electrophoresis
Molecular Diagnostics
Immunological and Radioisotope Techniques
Coulometry, Osmometry and Refractometry
Photometery
The principle of photometery is
base on the physical laws of
radiant energy or light.
Automation
It is a self regulating
process, where the specimen
is accurately pipetted by a
mechanical probe
and mixed with a particular
volume of the reagent and
results are displayed
in digital forms and also
printed by a printer.
MAJOR TECHNIQUE
Photometery is the most common analytical technique used in clinical
biochemistry. The principle of photometery is base on the physical laws
of radiant energy or light. In this method, the intensity absorbed
transmitted or reflected, light is measured and related to the
concentration of the test
substance.
- Photometeric principles
are applied in several
kinds of analytical
measurements:
1. Measurement of
absorebed or transmitted
light: colorimetery,
spectrophotometery,
atomic absorption,
turidometery
2. Measurement of emitted
light, Flame emission
photometery:
Flourometery
Photoelectric colorimeter
(diagrammatic)
Clinical Biochemistry Tests:
-
-
Speaking of clinical biochemistry, the starting point
is the metabolic profile, which tests an entire
battery of physiologic functions specific to different
organs by measuring the amounts of individual
products from these organs.
The metabolic profile blood test battery can give an
initial appraisal of several organs’ functions. Along
with the complete blood count (CBC), it can render
both an initial global view of general health as well
as pinpoint specific tests that can be used to track
abnormalities at intervals. Clinical biochemistry is a
crucial test for appraising organ function.
AUTOMATION:
●
●
The function of autoanalyser is to replace with
automated devices the steps of pipetting,
preparation of protein free filtrated, heating the colour
forming reagents in a waterbath and increase the
accuracy and precision of the methods
The automated instruments not only save the labour
and time but allow
reliable quality control, reduce subjective crrors and
work economically by using smaller quantities of
samples and reagents
The various types of
discrete
autoanalysers used
in the clinical
chemistry
laboratories are
BATCH ANALYSERS:
● These are convenient to analyse specimen in
batches such as of sugar,
urea creatinine etc.
● The batch analysers can be further differentiated
as
(1) semiautomated and (2) fully automated.
STAT ANALYSERS
● In the case of these analysers many reagents (8 to 20 or more)
can be pipetted one after another, so that various biochemical
determinations can be performed on one specimen, according to
the number of tests ordered for the patient. Hence, these are
patient (or specimen) orientated autoanalysers. For examples, if
serum specimen No. 1 requires following tests to be performed;
1) Urea nitrogen 2) Serum creatinine 3) Total proteins 4) Albumin
5) SGPT
and 6) SGOT
CLASSIFICATION
PARAMETERS
Albumin: protein made by the liver and documents
liver function.
Alkaline phosphatase (ALP), Alanine
aminotransferase (ALT), and Aspartate
aminotransferase (AST): biomarkers elevated with
liver disease.
Total protein: Mainly, globulin and albumin.
Bilirubin: rises with obstruction in the biliary tract or
in primary liver failure, such as cirrhosis.
Liver Paramters:
Glucose rises when insulin falls, as it
does absolutely in Type 1 DM and
relatively in Type 2 DM. It is also a
measure for how effectively the kidney
excretes excess glucose in the blood.
Pancreas Paramters:
Blood urea nitrogen (BUN): BUN is a
waste product of protein metabolism, and
its excretion falls with kidney disease,
raising its level in the blood. It is also
sensitive to dehydration.
Creatinine: A waste product of muscle
metabolism, which accumulates when the
kidneys fail to excrete them in kidney
disease.
BUN/creatinine ratio: An elevated ratio
> 20:1 indicates decrease in kidney
function.
Calcium: elevations indicate kidney
dysfunction and predict those at risk for
kidney stones.
Sodium, potassium,
chloride: Electrolytes whose balance is
maintained by normal kidney function.
Elevations indicate kidney disease.
Kidney Paramters:
Others Clinical Biochemistry Tests:
- Blood gases, drawn from an artery, give a picture as to how well
the blood is being oxygenated and how well carbon dioxide is being
removed. This is a part of the normal acid-base balance of the body,
and both biochemical processes and respiration can drive the acid
concentration (pH) up or down, which complicates further the
illnesses that create the abnormal pH, because biochemical reactions
need a normal pH in which to function, including the healing
reactions.
Blood Paramters:
Others Clinical Biochemistry Tests:
Cardiac enzymes: Useful in identifying biomarkers released from
damaged heart tissue, used to diagnose cardiac events such as
ischemia and infarction when there is confusion as to whether there
has been a cardiac event such as a heart attack.
Others Clinical Biochemistry Tests:
Immunological tests: Such as CRP (C-reactive protein) and ESR
(erythrocyte sedimentation rate) for inflammation, rheumatoid factor
(RA factor), anti-nuclear antibodies (ANA), and other immunological
biomarkers can be used as part of a diagnostic work-up for specific
autoimmune diseases. White blood cells (WBC) in a complete blood
count (CBC) can also be used to identify immune suppression, as
occurs with HIV/AIDS or chemotherapy for cancer.
Others Clinical Biochemistry Tests:
Clotting studies: Can identify D-dimers, part of the diagnostic
approach to coagulation problems. The INR (international normalized
ratio) is also a reflection of clotting used to titrate anticoagulation
therapy in thromboembolic disease. There is a narrow range between
just enough anticoagulation and too much, and the INR is used to
confirm that a patient is in that range.
Others Clinical Biochemistry Tests:
- Hemoglobin A1c monitors the long-term status of diabetics
- Lipid profiles: Measure cholesterol and triglycerides, which when
elevated, risk cardiovascular disease.
- Electrophoresis: Is a technique for separating out different
components of one thing, for example, the types of hemoglobin a
person may have, important in such diseases as sickle-cell anemia.
- Urinalysis: Of the urine can measure pH, glucose, protein, bilirubin,
ketone, and nitrite concentration for kidney function and as a quick
quantitation of the severity of diabetes.
- Spinal fluid examination: Can identify bacteria in it while
investigating meningitis, and measure protein and glucose, which are
altered with bacterial and viral infections.
Blood Paramters:
References:
+ Clinical Biochemistry: Techniques and Instrumentation. A Practical
Course. John S. Varoe. Singapore: World Scientific, 2001, 574 pp.
+ https://www.cscc.ca/en/about-us/what-is-clinical-chemistry.html
+ https://www.vascularhealthclinics.org/institutes-divisions/clinicallaboratory/clinical-biochemistry/
+ The Clinical Biochemistry Laboratory the use and the requirement of
laborlatory