Albumin is the major protein found in blood plasma and helps maintain osmotic pressure between blood vessels and tissues. It also serves as a carrier for many substances. Low albumin levels can be caused by conditions that damage the liver like cirrhosis, or by issues that cause excessive protein loss from the kidneys, intestines or burns. Albumin is essential for fluid balance and transport throughout the body.

1. Albumin & Globulin

2. Contents :
Total protein
Albumin
Globulin
A/G (ALBUMIN/GLOBULIN) ratio
Proteinurea
Microalbuminuria/(ACR)
Porotein in other body fluids

4. Definition
Protein
A large class of complex organic chemical
compounds that are essential for life.
Proteins play a central role in biological
processes and form the basis of living
tissues.
They consist of long chains of amino acids
connected by peptide bonds .

5. Proteins are required for the structure,
function, and regulation of the body's
cells, tissues, and organs; and each protein
has unique functions. Examples are
hormones
enzymes
and antibodies.

6. Unlike carbohydrates and fats, proteins are
not stored in the body.
They are continuously broken down
(metabolized) into amino acids that can
be used to make new
proteins, hormones, enzymes, and other
compounds needed by the body .

7. Amino acids
Are biologically important organic
compounds made from amine group
(-NH2) and carboxylic acid group
(-COOH) ,functional groups, along with
a side-chain specific to each amino acid.
The key elements of an amino acid
are carbon, hydrogen, oxygen,
and nitrogen, though other elements are
found in the side-chains of certain amino
acids.

8. Zwitter ion
amino acids
contains a negative
carboxylate
and a positive
ammonium
group,so has net
zero charge. This
molecular state is
known as a
zwitter ion,it is a
neutral molecule .

9. A peptide bond (amide bond)
Is a covalent chemical bond formed
between two molecules when
the carboxyl group of one molecule
reacts with the amino group of the
other molecule, causing the release of a
molecule of water (H2O), and usually
occurs between amino acids.

11. Proteins
 From the Greek proteios, meaning first
are a class of organic compounds which
are present in and vital to every living
cell,they are macromolecules made up
of amino acid linked together by
peptide bonds .

12.  In the form of skin, hair, cartilage, muscles,
tendons and ligaments.
 proteins hold together, protect, and provide
structure to the body of a multi-celled
organism

13. Proteins
 In the form of enzymes, hormones,
antibodies, and globulins, they
catalyze, regulate, and protect the body
chemistry.
 In the form of hemoglobin, myoglobin
and various lipoproteins, they effect
the transport of oxygen and other
substances within an organism.

14. classification of protein’s amino acids
 Proteins are made up of some 20 different
amino acids,they are classified into :
1-Essential amino acids
They are nine A.As,they cannot be synthesised
in humans but are required for synthesis of
important proteins . they are supplied by meat
and dairy products
2-Nonessential amino acids
 They are produced by our bodies, even if we
don't get it from the food we eat.

15. 3-Conditional amino acids
 They can be synthesised from other amino
acids, provided there is an adequate dietary
supply .
 The ‘biological’ value of different proteins
depends on the relative proportions of
essential amino acids they contain.
 Proteins of animal origin, particularly from
eggs, milk and meat, are generally of higher
biological value than proteins of vegetable
origin, which are low in one or more of the
essential amino acids .

16. Essential Amino Acids Non-Essential Amino Acids
 histidine
 isoleucine
 leucine
 lysine
 methionine
 phenylalanine
 threonine
 tryptophan
 valine
 alanine
 arginine*
 aspartic acid
 cysteine*
 glutamic acid
 glutamine*
 glycine*
 proline*
 serine*
 tyrosine*
 asparagine*
 selenocysteine
 *conditionally essential

17. Types of Amino Acid
 Aliphatic Amino Acids .
 Aromatic Amino Acids .
 Sulphur containing Amino Acids .
 Acidic Amino Acids .
 Basic Amino Acids .
 Neutral Polar Amino Acids .

18. Families of blood proteins
Serum albumin accounts for 55% of blood
proteins, and is a major contributor to
maintaining the osmotic pressure of
plasma to assist in the transport of lipids
and steroid hormones.
Globulins make up 35% of blood proteins
and transport ions, hormones and lipids
assisting in immune function.

19.  Fibrinogen make up 7% of blood
proteins; conversion of fibrinogen to
insoluble fibrin is essential for blood
clotting.
The remainder of plasma proteins (3%) is
made up of regulatory proteins such as
enzymes, proenzymes and hormones.
All blood proteins are synthesized in liver
except for the gamma globulins .

20. Families of blood proteins

21. Protein Synthesis
Proteins are synthesized in the body through
a process called translation. Translation
occurs in the cytoplasm and involves the
translation of genetic codes, unit
during DNA transcription, into proteins.
Cell structures called ribosomes help
translate these genetic codes into
polypeptide chains that undergo several
modifications before becoming fully
functioning proteins.

23.  The hepatocyte (liver ) is the site that
manufactures serum albumin, fibrinogen,
and the prothrombin group of clotting
factors .
 It is the main site for the synthesis
of lipoproteins, ceruloplasmin, transferrin,
complement, and glycoproteins.
 Hepatocytes also manufacture their
intracellular enzymes .
 immunoglobulins are produced by liver
and immune system .

24. The digestion of protein
The digestion of protein begins in the
mouth with chewing.
Protein digestion continues in the
stomach with the release of
hydrochloric acid and pepsinogen.
Hydrochloric acid converts pepsinogen
into pepsin, which begins to break
down the bonds between the amino
acids.

25. Your body uses the individual amino acids
that were broken down during digestion to
build the proteins needed for the various
functions .
 Glucogenic amino acids can also be
converted into glucose,
through gluconeogenesis.

28. FUNCTIONS OF PROTEINS
Movement
Without proteins, you could not move,
bend or even stand up straight.
Proteins support your connective tissues,
which are found in your tendons, ligaments
and bones. These tissues connect your
joints and allow movement.
Other proteins, called actin and myosin,
permit your muscles to contract. This allows
you to run, sit and lie down.

29.  Immune Response
 Antibodies - are specialized proteins involved
in defending the body from antigens (foreign
invaders).
 They can travel through the blood stream and
are utilized by the immune system to identify
and defend against bacteria, viruses, and other
foreign intruders.

30.  Transport Proteins
 are carrier proteins which move molecules
from one place to another around the body.
Examples include hemoglobin and
cytochromes.
 Hemoglobin transports oxygen through the
blood.
 Cytochromes operate in the electron
transport chain as electron carrier proteins.

31.  Acid-Base Balance
 Proteins also serve as buffers, helping maintain
the pH of a solution.
 When your blood becomes too acidic, protein
side chains pick up excess hydrogen ions to
increase the pH of your blood.
 If your blood becomes too basic, or alkaline,
other protein side chains donate hydrogen ions
to decrease the pH.

32. Fluid Balance
Your body contains approximately 60
percent water, making it the most
abundant substance in your body. For you
to stay healthy, this water must disperse
properly throughout your body, and
proteins help do this.

33. Proteins attract water, so they can pull fluid
into capillaries and prevent it from
accumulating in your body tissues. Without
proteins, your body tissues would become
bloated, leading to generalized swelling
called edema.

34. Enzymes
are proteins that facilitate biochemical
reactions.
They are often referred to as catalysts
because they speed up chemical reactions.
Examples include the enzymes lactase and
pepsin.
Lactase breaks down the sugar lactose
found in milk.
Pepsin is a digestive enzyme that works in
the stomach to break down proteins in food.

35.  Hormonal Proteins
 Are messenger proteins which help to
coordinate certain bodily activities. Examples
include :
 insulin, oxytocin, and somatotropin.
 Insulin regulates glucose metabolism by
controlling the blood-sugar concentration.
 Oxytocin stimulates contractions in females
during childbirth.
 Somatotropin is a growth hormone that
stimulates protein production in muscle cells.

37. Priciple of determination
BIURET method
BIURET reagent :
Sodium hydroxide, Na-K Tartrate, Potassium
Iodide, Copper sulfate
The peptide bonds of protein react with Cu⁺⁺
in alkaline solution to form a colored
complex which absorbance, proportional to
the concentration of total protein in the
specimen .
NORMAL VALUES: (64 -83) g/l .

39. Definition :
serum albumin,is aprotein found in
blood plasma that helps maintain the
osmotic pressure between the blood vessels
and tissues and serves as a carrier for many
substances .
Serum albumin accounts for abuot 55
percent of the total protein in blood plasma .
It is important for tissue growth and healing.
Very stable protein with a high net negative
charge at physiological PH .

40. Water-soluble .
Moderately soluble in concentrated salt
solutions
Experience heat denaturation .
 It stay in the blood for about 20 days .

41. Synthesis
 Albumin is synthesized in the liver as
 preproalbumin
 Proalbumin
 Albumin
 Albumin is not stored by the liver but is secreted
into the portal circulation as soon as it is
manufactured.

42. Damaged liver cells lose their ability to make
albumin .
But previously produced albumin may stay in
the blood for a bout 18 days, so it takes
about 2 weeks for damage to the liver to
show up as decreased serum albumin levels.
The liver's ability to make albumin may be
used to predict the course of certain liver
diseases.

43. Function of albumin
1- Albumin is responsible for much of the
colloidal osmotic pressure of the blood, and
thus is a very important factor in regulating
the exchange of water between the plasma
and the interstitial compartment (space
between the cells) .

45. Because of hydrostatic pressure, water is
forced through the walls of the capillaries into
the tissue spaces.
This flow of water continues until the osmotic
pull of protein (albumin) molecules causes it
to stop.
A drop in the amount of albumin in the plasma
leads to an increase in the flow of water from
the capillaries into the interstitial
compartment.
This results in an increase in tissue fluid which,
if severe, becomes apparent as edema.

47. 2- Albumin serves also as a transport protein
The presence of many charged surface groups
plus many binding sites, both ionic and
hydrophopic,gives albumin the ability to bind
and transport a large number of compounds
such as :
fatty acids
bilirubin
many drugs

48. And also hormones, such as cortisol and
thyroxine, when their specific binding
globulins are saturated.

49. Albumin also acts as a carrier for two
materials necessary for the control of blood
clotting:
(1) antithrombin, which keeps the clotting
enzyme thrombin from working unless
needed, and
(2) heparin cofactor, which is necessary for
the anticlotting action of heparin.
3- Acid–base function, it can act as an
effective plasma buffer.

50. 4- Antioxidant function .
Under physiological conditions,
albumin may have significant
antioxidant potential. It is involved in
the getting rid off of oxygen free
radicals, which have been involved in
the pathogenesis of inflammatory
diseases .

51. Clinical significance
 (Hyperalbuminemia) : High albumin
concentrations in plasma .
 There are no pathological conditions other
than dehydration associated with a high
albumin concentration.
 With prolonged use of a tourniquet .
 After excessive albumin infusion .
 Some drugs like , steroids, androgens, growth
hormones, and insulin.

52. (Hypoalbuminemia ) low blood albumin levels
can be caused by:
1- Nephrotic syndrome .
It occurs when the filters in the kidney leak an
excessive amount of protein.
The level of protein in the blood then falls and
this allows fluid to leak across very small blood
vessels into the tissues.
Swelling around the eyes, abdomen and legs is
then noted.

55. 2 - Liver failure
is the inability of the liver to perform
its
normal synthetic and metabolic functi
on as part of normal physiology.
Two forms are recognised, acute and
chronic.

56. Acute liver failure is defined as "the rapid
development of hepatocellular
dysfunction, specifically coagulopathy and
mental status changes (encephalopathy),
(disease in which the functioning of the
brain is affected by some agent or
condition (such as viral infection or toxins
in the blood).

57. Chronic liver failure ,usually
occurs in the case of cirrhosis,
itself potentially the result of
many possible causes, such as:
excessive alcohol intake
Hepatitis B or C,
Autoimmune, hereditary and
metabolic causes (such
as iron or copper overload ) .

58. 3- Malabsorption
It is a state arising from abnormality
in absorption of food nutrients across
the gastrointestinal (GI) tract.
Impairment can be of single or
multiple nutrients depending on the
abnormality.
This may lead to malnutrition and a
variety of anaemias.

59. 4 - protein losing enteropathy
Protein losing enteropathy (pathological
conditions in the intestines that are
characterized by the gastrointestinal loss of
serum proteins, including serum albumin;
immunoglobulins) .
Common causes of protein losing enteropathy
include celiac disease, Crohn's disease, short
bowel syndrome (where the absorptive area
for proteins is decreased).

60.  5 -Water overload
water intoxication, also known as water
poisoning, If a large amount of fluid is
consumed over a short period of time, the
cells will begin to swell because the kidneys
cannot process the water quickly enough. The
water starts to dilute the electrolyte levels in
the body, and if enough water is consumed,
the cells could actually burst. A low level of
electrolytes can result in an irregular
heartbeat, brain malfunction, and ultimately
death.

61.  6 - Intestinal enteropeptidase deficiency
Enteropeptidase is an enzyme secreted
from intestinal glands following the entry
of ingested food passing from the
stomach. Enteropeptidase
converts trypsinogen into its active
form trypsin, resulting in the subsequent
activation of pancreatic digestive
enzymes.

62.  7- Burns
There is massive protein loss from
the burn site due to :
 increased vascular permeability .
decreased albumin synthesis .
and protein losing nephropathy.

63.  8- Kwashiorkor
It is an acute form of childhood protein-energy
malnutrition .
It may develop after a mother stop feeding her
child from breast milk, replacing it with a diet
high in carbohydrates, especially starches, but
deficient in protein.
occurs in areas of famine or poor food
supply. Cases in the developed world are rare.

64.  9- Other causes
Fluid retention, as in pregrant women during
late pegrancy .
Administration of an excess of protein –free
fluid .
Recumbency,plasma albumin con. May be 5-
10% g/l lower in the recumbent than in the
upright position because of the redistribution
of fluid .
Artefactual changes ,due to taking blood from
the arm into which an infusion is flowing .

65. Priciple of determination
BROMOCRESOL GREEN method
BROMOCRESOL GREEN reagent
Succinic acid, Bromocresol green, Sodium
hydroxide .
In buffer solution at PH 4.2,
Bromocresol green + albumin colored
compound .
NORMAL VALUES: (34 − 48) g/L .

66.  certain drugs increase albumin in
the blood, including anabolic
steroids, androgens, growth
hormones, and insulin .
 Transfusions of serum albumin are
used to combat shock and whenever
it is necessary to remove excess fluid
from the tissues.

68. Definition
Any of a class of proteins that are found
extensively in blood plasma, milk,
muscle, and plant seeds and that are
insoluble in pure water, soluble in
dilute salt solution, and coagulable by
heat.
 They play a key role in the body's
immune system and act as a carrier .

69. The plasma globulins are separated into
four major groups by serum protein
electrophoresis (SPE) according to size and
charge these fractions are :
Alpha1
Alpha2
Beta
And the gamma globulins,which usually
makes up the largest portion of the
globulins .

71. Synthesis
Some globulins are produced in the
liver, while others are secreted by the
immune system.
most of the proteins in the alpha and
beta fractions are made in the liver.
γ globulins are produced by
lymphocytes and plasma cells in
lymphoid tissue.

72. Function
The globulins include carrier proteins,
which transport specific
substances(transferrin that transports iron).
acute phase reactants, which are involved in
the inflammatory process (C-reactive
protein) .
clotting factors ( fibrinogen ).
 complement components.
And immunoglobulins,(IgM, IgA, IgG, IgE ).

73. Clinical significance
The globulin level may be elevated in:
Chronic infections (parasites, some cases of
viral and bacterial infection) .
Liver disease (biliary cirrhosis, obstructive
jaundice).
Carcinoid syndrome.
Rheumatoid arthritis.
Ulcerative colitis.
Multiple myelomas, leukemias .

74. Autoimmunity (Systemic lupus, collagen
diseases ) .
Kidney dysfunction (Nephrosis) .

75. The serum globulin level may
be decreased in:
Nephrosis .
Alpha-1 Antitrypsin Deficiency
(Emphysema),it is a long-term lung disease.
Acute hemolytic anemia .
Liver dysfunction .
Hypogammaglobulinemia/Agammaglobuli
nemia .

76. For the routine chemistry profile,
total globulins are calculated as
follows:
TP - albumin = globulin
NORMAL VALUES: (27 − 39) g/L .

78.  The ratio of albumin to globulin can also
help determine whether certain disorders
are occurring.
The A/G ratio may provide a clue as to the
cause of the change in protein levels.
The proper albumin to globulin ratio is
 2:1
 Optimal Range: 1.7-2.2

79. The AG ratio may be elevated in:
Hypothyroidism .
High protein/high carbohydrate diet with
poor nitrogen retention .
Hypogammaglobulinemia (low globulin) .
Glucocorticoid excess .

80. The AG ratio may be decreased in:
Liver dysfunction .
Overproduction of globulin .
an underproduction of albumin
loss of albumin due to kidney disorders .

82. Definition
Proteinuria(from protein and urine) means
the presence of an excess of serum
proteins in the urine.
The condition is often a sign
of kidney disease.
Healthy kidneys do not allow a significant
amount of protein to pass through their
filters. But filters damaged by kidney
disease may let proteins such as albumin
leak from the blood into the urine.

83. The mechanism
Albumin (when ionized in water at pH 7.4,
as found in the body) is negatively charged.
The glomerular basement membrane is also
negatively charged in the body; some
studies suggest that this prevents the
filtration of albumin in the urine.
 According to this theory, that charge plays a
major role in the selective exclusion of
albumin from the glomerular filtrate.

84. Causes include
Due to disease in glomerulus .
Because of increased quantity of proteins
in serum (overflow proteinuria).
Due to low reabsorption at proximal
tubule (Fanconi syndrome) .
Diabetes .
High blood pressure (hypertension) .
Preeclampsia (high blood pressure and
proteinuria in pregnancy) .

85. Excessive fluid intake (drinking in excess of
4 litres of water per day) .
Some medications used in cancer
treatment.
With cardiovascular disease .
Severe emotional stress .
severe exercise .
Age over 65 .

86. Measurement
 A semi-quanititative test such as a dipstick
urine protein is used to screen for the
presence of protein in the urine as part of a
routine urinalysis.
If slight to moderate amounts of protein are
detected, then a repeat urinalysis and
dipstick protein may be performed at a later
time to see if there is still protein in the
urine or if it has dropped back to
undetectable levels .

87. If there is a large amount of protein in the
first sample and/or the protein persists in
the second sample, then a 24-hour urine
protein may be used as a follow-up test.
Since the dipstick primarily measures
albumin, the 24-hour urine protein test
then may be ordered to find if there is
proteins other than albumin are being
released.
A 24-hour urine sample gives the protein
excretion rate over 24 hours. It will be
accurate only if all of the urine is collected.

88. The reagent on the test strips, bromphenol
blue,which is highly specific for albumin.
False negative reading
 If the urine is dilute .
if the protein in the urine is composed
mainly ofglobulins or Bence-Jones proteins .
Dye (contrast media) if you have a radiology
scan within 3 days before the urine test .
Severe emotional stress .
Strenuous exercise .
Urinary tract infection .

89. Urine contaminated with fluids from the
vagina .
The normal value is less than 80 milligrams
per day .

90. Protein dipstick grading
Designation
Approx. amount
Concentration[
Daily
Trace 5–20 mg/dL
1+ 30 mg/dL Less than 0.5 g/day
2+ 100 mg/dL 0.5–1 g/day
3+ 300 mg/dL 1–2 g/day
4+
More than
2000 mg/dL
More than 2 g/day

92. Definition
 It is a very small increase in urinary
albumin below the detection level of
routine dipstick analysis. The condition is
an early indicator of altered glomerular
permeability .
In a properly functioning body, albumin is
not normally present in urine because it is
retained in the bloodstream by the kidneys.

93. Microalbuminuria can be diagnosed from a
24-hour urine collection (between 30–
300 mg/24 hours) or, more commonly, from
elevated concentrations in a spot sample (30
to 300 mg/L).
Both must be measured on at least two of
three measurements over a two- to three-
month period.

94. Measurement of albumin excretion in
a 24-h urine collection has long been the
“gold standard” for quantitative evaluation
of albuminuria ,however, collection errors
due to improper timing and missed samples
may lead to significant over- and
underestimation of albuminuria.
 For convenience and accuracy the American
Diabetes Association and the National
Kidney Foundation have recently
recommended measurement of albumin-to-
creatinine ratio (ACR) .

95. For convenience and consistency, the
American Diabetes Association and the
National Kidney Foundation have recently
recommended measurement of albumin-to-
creatinine ratio (ACR) in a random spot
urine collection for diagnosis of
microalbuminuria.

96. For the diagnosis of microalbuminuria, care
must be taken when collecting sample for
the urine ACR.
An early morning sample is preferred.
 The patient should stop doing heavy
exercises 24 hours before the test.
A repeat test should be done 3 to 6 months
after the first positive test for
microalbuminuria.

97. The test is inaccurate in :
A person with too much or too little muscle
mass. This is due to the variation in
creatinine level which is produced by the
muscle.
Women during the menstrual cycle .
If there is more than 7 pus cell .
If there is more than 3 RBC .

98. Clinical Significance
An indicator of subclinical cardiovascular
disease
An important prognostic marker for
kidney disease .
 In diabetes mellitus .
 In hypertension .
 In Post-streptococcal
glomerulonephritis .

99. Normal value
Men- < 2.5 (mg/mmol) or
 < 23 (mg/g)
Women - < 3.5 (mg/mmol) or
 < 32 (mg/g)

101. Ascites fluid : it is an accumulation of fluid
in the peritoneal cavity .
The most common due to cirrhosis, severe
liver disease or metastatic cancer .
 Patients with ascites generally will
complain of progressive abdominal
heaviness and pressure as well as shortness
of breath .

102.  Pleural fluid :
It is excess fluid that
accumulates between the
two pleural layers, the
fluid-filled space that
surrounds the lungs .
Excessive amounts of such
fluid can impair breathing
by limiting the expansion
of the lungs during
ventilation.

103. CSF total protein : (CSF) is the fluid that
surrounds the brain and spinal cord.
This test is done to
determine the amount of protein in the
spinal fluid, also called cerebrospinal fluid
(CSF).
To help diagnose tumors, infection,
inflammation of several groups of nerve
cells, vasculitis, blood in the spinal fluid, or
injury.