In this presentation pathological causes due to amino acid are discussed.

1. 1
Chemical Pathology
BS-MLt 5th semester

2. Contents
Presented by:
M. shazaib
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1 .Amino acid and Aminoacidurias
2.
2. Bence jones proteins , Calcium ,
Phosphates , Galactose, Coproporphyrins ,
creatanine , Urates and oxalates

3. Amino acids
Introduction:
Amino acids are organic compounds that combine to form proteins. Amino acids and proteins are the building blocks
of life. When proteins are digested or broken down, amino acids are left. The human body uses amino acids to make
proteins to help the body break down food.Amino acids are organic compounds that contain amine and carboxyl
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, although other elements are found in the side chains of certain amino acids.
Basic Structure:
A single amino acid contains at least one amino group and one carboxyl functional group. The N-terminal end of the
amino group (–NH2) and the C- terminal end of the carboxyl group (–COOH) are bonded to the α-carbon forming an
amino acid.Amino acids differ from one another by the chemical composition of their R group (side chains). The R
groups found on the 20 different amino acids used in building proteins.The amino group of one amino acid can be
linked with the carboxyl group of another amino acid forming a peptide bond. When a chain of amino acids is linked
by peptide bonds, it is known as a polypeptide, and a large polypeptide constitutes a protein. Proteins found in human
serum range from 100 to 150 amino acids in the length of their polypeptide chains.
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4. 4

5. Classification of Amino acids
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6. 20 Amino acids
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7. Essential and Non-essential
Amino Acids
 Essential amino acids are amino acids that cannot be made by the body. As a result,
they must come from food.The essential amino acids are arginine, histidine,
isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and
valine.
 Non-essential amino acids are amino acids that are produced our body, even if we do
not get it from the food we eat.Non-essential amino acids are alanine, asparagine,
aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
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8. Metabolism
-Amino acids are primarily used in the synthesis of body proteins such as plasma, intracellular, and
structural proteins; however, they are also used in the synthesis of nonprotein nitrogen-containing
compounds such as purines, pyrimidines, porphyrins, creatine, histamine, thyroxine, epinephrine, and
coenzyme NAD.
-In addition, proteins provide up to 20% of the total energy required daily by the body. To be utilized as an
energy source, proteins must first be broken down into their constituent amino acids. The amino group is
then removed from the amino acid by either deamination or transamination. The ammonium ion that is
produced during deamination of the amino acids is converted into urea via the urea cycle in the liver.The
resultant ketoacid enters into a common metabolic pathway with carbohydrates and fats to be converted
into useable energy.
-Glucogenic amino acids generate precursors of glucose, such as pyruvate or citric acid cycle
intermediates. Examples include alanine, which can be deaminated to pyruvate; arginine, which is
converted to α- ketoglutarate; and aspartic acid, which is converted to oxaloacetate. Ketogenic amino
acids, such as leucine and lysine, are degraded to acetyl-CoA or acetoacetyl-CoA and form ketone bodies.
Isoleucine, phenylalanine, tryptophan, tyrosine, and threonine are both ketogenic and glucogenic.
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9. Aminoacidurias
Aminoaciduria is an abnormal amount of amino acids in the urine.This may be caused by
congenital disorders of amino acid metabolism, for example, phenylketonuria, or may be
secondary to liver disease. In renal aminoaciduria, the renal tubules are unable to reabsorb
the filtered amino acids back into the blood, causing high concentrations of amino acids in
the urine.
Test to perform:
A clean-catch urine sample is needed.No special preparations are necessary.The test involves
only normal urination.This test is done to measure amino acid levels in the urine. There are
many different types of amino acids. It is common for some of each kind to be found in the
urine, but increased levels of individual amino acids can be a sign of an inborn error of
metabolism.
A normal amount of albumin in urine is less than 30 mg/g.
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10. Classification
It is characterized into three classes as follow:
1. Renal aminoaciduria.
This is due to defect in the kidney in which kidneys are unable to reabsorb all the amino acids
and thus appear in the urine.Example, Cystinuria which is a genetic inherited disease in which the
glomerulus fails to reasorb cystine, ornithine, lysine and arginine into the tubule and they are excreted into
the urine.
2. Overflow aminoaciduria or flood aminoaciduria.
Aminoaciduria can also occur when there is an increased amino acids in blood which can pass freely
through the kidney.This is because the sodium amino acid co-transporter channel becomes occupied more
and more with amino acids in which the extra amino acids excreted out with urine.Overflow
aminoaciduria can be because of many reasons, for example, surgery, consumes, and other physiological
conditions in which abundance of amino acids are available in blood.
3. Strange discharge of items got from amino acids.
This can also refers as the abnormal excretion of products derived from amino acids.
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11. Causes
Aminoaciduria is caused by different factors such as:
1. Congenital disorders of amino acid metabolism
Example. Phenylalanuria is the inherited disorder caused by deficiency of enzymes such as
Phenylalanine hydroxylases.
2. Renal cause aminoaciduria.
Example. Selective failure reabsorptions such as,
-Hartnup’s disease (Tryptophan).
-Cystinuria dibasic amino acid (Cystine, Orthinine, Lysin, and Arginine).
3. Defects in the transport protein in the renal tubules.
Example. The one which occur in Hartnupdisorder which is caused by mutations in the gene
encoding the neutral amino acid transporters.
4. Damage to the kidney tubule.
-Farconis syndrome.
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12. Pathogenesis
-Under normal circumstances, the renal tubules reabsorb in excess of 93% of the amino
acids filtered from the plasma, influenced by the glomerular filtration rate. When the
filtered load of amino acids is increased, there is an increase in both the amounts
reabsorbed and those excreted. However, the ability of the renal tubule to respond to an
increased filtered load of amino acids is so great that a maximum rate of reabsorption has
not been found in the human.
-In some instances, the aminoaciduria is generalised; there is increased excretion of all of
the amino acids occurring in the plasma. In other instances, the aminoaciduria is more
specific, in that there are increased amounts of some amino acids in the urine while all
others are excreted in normal amounts.
-Secondary or 'overflow' aminoaciduria can also be seen in conditions in which there is
hyperaminoacidaemia.
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13. Symptoms and Diagnosis
The general symptoms include,
i. Pain
ii. Diarrhea
iii. Headache
iv. Back pain
v. Constipation
vi. Visual change
The clinical diagnosis of aminoaciduria can be conducted using Blood or Urine samples.
For diagnosis perform the following test:
i. Blood test
ii. Cystitis test
iii. Kidney test (Urine protein test)
iv. Genetic testing
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14. Bence Jones Protein
Definition:
A Bence Jones protein is a monoclonal globulin protein or immunoglobulin light chain found in
the urine, with a molecular weight of 22-24 kDa.
Introduction:
Bence Jones proteins are named for Henry Bence Jones, a physician and chemist who first
isolated them in 1847. These proteins are not present in healthy urine samples and are usually a
sign of multiple myeloma. Multiple myeloma is a type of bone marrow cancer that is most
common in people who are older than 60 years.
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15. Bence Jones Protein test
Sample collection:
The BJP test is a urine test. For this urine test a Clean catch sample and 24 hr urine sample is needed.
Clean catch method
-Clean the area around your urethra with the wipe.
-Begin to urinate into the toilet.
-Move the collection cup into your urine stream.
-Collect 1 to 2 ounces of urine.
-Move the cup away and finish urinating into the toilet.
-Close the cup and return it to the lab.
24-hour collection
In this test, you collect samples of urine over a 24-hour period. When you first wake up in the morning, empty your
bladder. You won’t collect a sample this time, but instead note the time. For the next 24 hours, save all voided urine
into one container. The sample should be refrigerated throughout the duration of the collection process in order to
keep it viable.
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16. Test results
Bence Jones proteins are not normally found in urine, so a positive test indicates that you
probably have multiple myeloma. Other kinds of cancer may also be associated with a positive
result.
An abnormal test may indicate other types of cancer including lymphoma, chronic
lymphocytic leukemia, and macroglobulinemia. Macroglobulinemia is a type of white blood
cell cancer.
In some instances, an abnormal result may not indicate cancer at all. Amyloidosis is a
condition that causes amyloid deposits, which are abnormal buildups of proteins in organs and
tissues. Amyloidosis is rare, but it’s similar to multiple myeloma. It can have dangerous long-
term effects, including kidney failure, heart muscle damage, and nerve damage.
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17. Symptoms of Multiple myeloma
Symptoms of multiple myeloma are caused by the overgrowth of white blood cells. Myeloma cells take over your
bones from the inside out. This makes your bones more likely to break. If you break a bone while performing an
everyday task, your doctor might suspect multiple myeloma.
Other symptoms include:
-kidney problems (caused by antibody buildup)
-anemia, which causes fatigue or weakness
-swollen or weak legs
-pain in the ribs or back
-compressed spinal cord or nerves (due to bone fractures)
-excessive thirst
-dehydration
-frequent urination or constipation (from when bones break down and leave excess calcium in the blood)
-recurring infections
-excessive bleeding, even from slight injuries
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18. Calcium
Introduction:
Calcium is a mineral that is necessary for life. In addition to building bones and keeping them
healthy, calcium enables our blood to clot, our muscles to contract, and our heart to beat. About
99% of the calcium in our bodies is in our bones and teeth.
Physiology:
Calcium is an essential element that serves an important role in skeletal mineralization. More
than 99% of the calcium in the body is stored in bone as hydroxyapatite. Calcium in this form
provides skeletal strength as well as a reservoir for calcium to be released into the serum.
In serum, calcium exists in 3 forms: protein-bound, ionized (free), and complexed (chelated).
Protein-bound calcium, which accounts for 40% of the serum calcium, cannot be used by
tissues. Albumin and globulin are the primary calcium-binding proteins in the serum whereas
calmodulin is the primary calcium-binding protein in the cell.
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19. Calcium
Regulation:
Three hormones, Parathroid hormone(PTH), vitamin D, and calcitonin, are known to regulate
serum Ca2+ by altering their secretion rate in response to changes in ionized Ca2+.
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20. Calcium
Distribution:
Ninety-nine percent of the body calcium is located in the skeleton. The remaining 1 percent is equally distributed
between the teeth and soft tissues, with only 0.1 percent in the extracellular fluid (ECF).Ca2+ in blood is
distributed among several forms. About 45% circulates as free Ca2+ ions (referred to as ionized Ca2+); 40% is
bound to protein, mostly albumin; and 15% is bound to anions, such as HCO3−, citrate, and lactate. Clearly, this
distribution can change in disease.
Function:
Ionized calcium plays an important function in muscle contraction. Skeletal muscle function is governed by an
action potential that releases calcium stored in the sarcoplasmic reticulum. This calcium then binds to tropomyosin
and allows for the interaction of myosin and actin in the sarcomere, leading to muscle contraction. In smooth
muscle, second messenger systems trigger the release of calcium from the sarcoplasmic reticulum. Additionally,
ligand-gated and voltage-gated calcium channels on the smooth muscle membrane allow for extracellular calcium
to enter the cell. Calmodulin binds calcium ions and activates myosin light chain kinase to phosphorylase the
myosin head, which then binds actin and causes smooth muscle contraction.
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21. Clinical Significance
Deficiency of calcium leads to different conditions such as:
1.Hypercalcemia
Hypercalcemia is a condition in which the calcium level in your blood is above normal. Too much calcium in your
blood can weaken your bones, create kidney stones, and interfere with how your heart and brain work. Hypercalcemia
is usually a result of overactive parathyroid glands.
2.Hypocalcemia
Hypocalcaemia is low calcium levels in the blood serum.Common causes include hypoparathyroidism and vitamin D
deficiency.Others causes include kidney failure, pancreatitis, calcium channel blocker overdose, rhabdomyolysis,
tumor lysis syndrome, and medications such as bisphosphonates.
Dietary Use:
A balanced diet includes 1000 mg of calcium daily. The intestine absorbs 200 to 400 mg of this with the rest excreted
in the stool. Any excess calcium absorbed is secreted in urine. Calcium supplementation is common in elderly
individuals, where it is prescribed with Vitamin D supplements to improve bone mass that is lost with increasing age.
Pharmacologic Use:
The calcium salts of calcium chloride and calcium gluconate are administered in instances of severe hyperkalemia to
stabilize the membrane potential and prevent prolonged cardiac muscle depolarization.
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22. Phosphate
Introduction:
Phosphate is an essential electrolyte in the human body as it constitutes about 1% of the total body weight. In an
adult, the normal serum phosphate level ranges between 2.5 to 4.5 mg/d L. The normal serum levels of phosphate
tend to decrease with age and its highest levels i.e., 4.5 to 8.3 mg/dL are seen in infants, about 50% higher than
adults; this is because infants and children need more phosphate for their growth and development.
Physiology:
Found everywhere in living cells, phosphate compounds participate in many of the most important biochemical
processes. The genetic materials deoxyribonucleic acid and ribonucleic acid are complex phosphodiesters. Most
coenzymes are esters of phosphoric or pyrophosphoric acid. The most important reservoirs of biochemical energy
are ATP, creatine phosphate, and PEP.
Distribution:
Of the total phosphate in the body, 85% is n the bones and teeth,1% in the extracellular fluid and the remaining
14% is distributed in other tissues where it is an important constituent of cell membranes, nucleic acids, high
energy phosphate esters (ATP) and intracellular signaling proteins.
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23. Phosphate
Regulation:
Phosphate in blood may be absorbed in the intestine from dietary sources, released from cells into blood, and lost
from bone.Disturbances to any of these processes can alter phosphate concentrations in the blood; however, the
loss of regulation by the kidneys will have the most profound effect. Although other factors, such as vitamin D,
calcitonin, growth hormone, and acid–base status, can affect renal regulation of phosphate, the most important
factor is PTH, which overall lowers blood concentrations by increasing renal excretion.Vitamin D acts to
increase phosphate in the blood. Vitamin D increases both phosphate absorption in the intestine and phosphate
reabsorption in the kidney. Growth hormone, which helps regulate skeletal growth, can affect circulating
concentrations of phosphate.
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24. Phosphate
Function:
Phosphate is a charged particle (ion) that contains the mineral phosphorus. The body needs phosphorus to build and
repair bones and teeth, help nerves function, and make muscles contract. Most (about 85%) of the phosphorus
contained in phosphate is found in bones.
Phosphate is responsible for several functions in the human body. Its role in different parts of the body are as
follows:
Bone mineralization: phosphate is responsible for mineralization of the bony matrix. This process begins in the
matrix vesicle, which are extracellular structures derived from the cell membrane of the osteoblast and chondrocytes.
Matrix vesicles acquire phosphate by two pathways:
Tissue nonspecific Alkaline phosphatase present within matrix vesicles hydrolyzes phosphoric esters to inorganic
phosphate.Matrix vesicles uptake extracellular phosphate via Type II Na/Pi cotransporter.
Matrix vesicles form hydroxyapatite crystals from calcium and phosphate; these crystals mineralize the extracellular
matrix of the bone.
Endochondral Ossification: Phosphate is responsible for endochondral ossification of the bone as increased
intracellular phosphate levels induce apoptosis of the terminally differentiated chondrocytes.
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25. Phosphate
Clinical Significance:
Deficiency of phosphate leads to following conditions such as:
1.Hypophospatemia:
Hypophosphatemia is defined as serum phosphate levels of less than 2.5 mg/dL. It can be due to
any of the following mechanisms.
-Decreased dietary intake e.g., intestinal malabsorption, chronic alcoholism, malnutrition, and
vitamin D deficiency.
-Increased excretion e.g., hyperparathyroidism, forced saline diuresis, genetic causes that involve
proximal renal tubule i.e., Fanconi syndrome.
-The transcellular shift from extracellular fluid to intracellular fluid e.g., treatment of diabetic
ketoacidosis by insulin, refeeding syndrome
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26. Phosphate
2.Hyperphosphatemia:
Hyperphosphatemia, which is abnormally elevated levels of serum phosphate i.e.,> 4.5 mg/dL, is
an important laboratory finding as it can have several underlying causes.
-Acute phosphate load: it can develop by any of the following mechanism:
 Exogenous e.g., intake of phosphate-containing laxatives and vitamin D toxicity
 Endogenous e.g., tumor lysis syndrome, rhabdomyolysis
-Decreased phosphate excretion: it can be due to,
-Decreased filtered load e.g., kidney failure
-Transcellular shift from intracellular to extracellular fluid: diabetic ketoacidosis, lactic acidosis.
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27. Galactose
Introduction:
Galactose is a monosaccharide and has the same chemical formula as glucose, i.e., C6H12O6. It
is similar to glucose in its structure, differing only in the position of one hydroxyl group. This
difference, however, gives galactose different chemical and biochemical properties to glucose.
Function:
In the human body, most of the ingested galactose is converted to glucose, which can provide
4.1 kilocalories per gram of energy, which is about the same as sucrose.
Galactose can bind to glucose to make lactose (in breast milk), to lipids to make glycolipids (for
example, molecules that constitute blood groups A, B and AB), or to proteins to make
glycoproteins (for example, in cell membranes).
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28. Galactose
Dietary source:
-Galactose is found in dairy products, avocados (Fruit) , sugar beets, other gums and mucilages.
-The main dietary source of galactose is lactose from milk and yogurt, which is digested to
galactose and glucose.Foods containing small amounts of free galactose include low-lactose or
lactose-free milk, certain yogurts, cheeses, creams, ice creams and other foods artificially
sweetened with galactose. Plain natural foods (fruits, vegetables, nuts, grains, fresh meats, eggs,
milk) usually contain less than 0.3 g galactose per serving.
-Certain medications may contain galactose as a filler.
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29. Galactose
Absorption:
Galactose is absorbed in the small intestine by the same mechanism as glucose, that is by the help
of Sodium-glucose-transport protein 1(SGLT-1) and Glucose Transport proteins 2 (GLUT-2)
transport proteins in the small intestinal lining
Metabolism:
Most of the absorbed galactose enters the liver, where it is mainly converted to glucose, which is
then either incorporated into glycogen or used for energy.
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30. Galactosemia
Galactosemia reffers to accumulation of galactose in blood.It is a rare genetic metabolic disorder that affects an
individual's ability to metabolize the sugar galactose properly.
Causes:
Galactosemia is caused by mutations in genes and a deficiency of enzymes.
Diagnosis:
Galactosemia is usually diagnosed though tests such as:
-A blood test will detect high levels of galactose and low levels of enzyme activity.
-A urine test may also be used to diagnose this condition.
Symptoms:
-loss of appetite -vomiting -liver damage -weakness
-jaundice, which is yellowing of the skin and other parts of the body -weight loss
-liver enlargement -liver damage
-fluid building up in the abdomen and swelling -abnormal bleeding -diarrhea
-
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31. Galactosemia
There are 3 main types of galactosemia which are distinguished based on their genetic causes, signs and symptoms,
and severity:
Classic galactosemia (type 1) - the most common and severe type, caused by mutations in the GALT gene, and
characterized by a complete deficiency of an enzyme called galactose-1-phosphate uridyl transferase (GALT). Early
signs and symptoms include liver dysfunction, susceptibility to infections, failure to thrive, and cataracts. These can
usually be prevented or improved by early diagnosis and treatment, but other progressive or long-term problems are
common despite treatment. These include intellectual deficits, movement disorders, and premature ovarian failure
(in females).
Galactokinase deficiency (type 2) - caused by mutations in the GALK1 gene and characterized by a deficiency of
the enzyme galactokinase 1. This type typically causes only the development of cataracts, which may be prevented
or resolved with treatment. Rarely, this type causes pseudotumor cerebri (a condition which mimics the symptoms
of a large brain tumor when no brain tumor is present).
Galactose epimerase deficiency (type 3) - caused by mutations in the GALE gene and characterized by a
deficiency of the enzyme UDP-galactose-4-epimerase. Symptoms and severity of this type depend on whether the
deficiency is confined to certain types of blood cells or is present in all tissues. Some people with this type have no
signs or symptoms, while others have symptoms similar to those with classic galactosemia. Like in classic
galactosemia, many symptoms can be prevented or improved with treatment.
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32. Coproporphyrin
Coproporphyrin (Copro) has four carboxylic acid substituents and intermediate solubility.
Coproporphyrins are found in blood, urine, and feces. Solubility influences the type of
specimen selected for the measurement of particular porphyrin intermediates. Increased levels
of coproporphyrins can indicate congenital erythropoietic porphyria or sideroblastic anaemia.
Porphyria is a pathological state characterised by abnormalities of porphyrin metabolism and
results in the excretion of large quantities of porphyrins in the urine and in extreme sensitivity
to light.
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33. Creatinine
Introduction:
Creatinine is a waste product produced by muscles from the breakdown of a compound called
creatine. Creatinine is removed from the body by the kidneys, which filter almost all of it from
the blood and release it into the urine.
Normal value:
Normal value depends on your age, race, gender, and body size.
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34. Creatinine Test
A creatinine test, also called a serum creatinine test, is a test to measure how well kidneys are working.
Creatinine is a waste product from the normal breakdown of muscle tissue. As body makes it, it's filtered
through your kidneys and expelled in urine. Kidneys' ability to handle creatinine is called the creatinine
clearance rate, and this helps estimate how fast blood is moving through kidneys, called the glomerular
filtration rate (GFR).
There are two main test for measuring creatinine in body:
1.Urine tests. Creatinine clearance can be pinpointed by measuring the amount of creatinine in a sample of
pee collected over 24 hours. For this method, you store all your urine in a plastic jug for one day and then
bring it in for testing. This method is inconvenient, but it may be necessary to diagnose some kidney
conditions.
2.Blood tests.Doctors can estimate GFR using a single blood level of creatinine, which they enter into a
formula. The higher the blood creatinine level, the lower the estimated GFR and creatinine clearance.
For practical reasons, the blood test method for GFR is used far more often than the 24-hour urine
collection test for creatinine clearance. But urine collections may still be useful in people who have large
muscle mass or a marked decrease in muscle mass.
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35. Urates and oxalates
Uric acid stones are one of four major types of kidney stones, which include calcium stones (calcium
oxalate and calcium phosphate), struvite stones, and cystine stones. A kidney stone is a hard mass of
crystallized minerals that form in the kidneys or urinary tract.
Uric acid stones form when the levels of uric acid in the urine is too high, and/or the urine is too acidic
(pH level below 5.5) on a regular basis.
Symptoms:
All types of kidney stones produce similar symptoms, including one or more of the following:
Pain in the lower back, sides, abdomen or groin; the pain is the result of irritation or blockage inside the
kidneys or urinary system
Blood in the urine
Nausea or vomiting
Fever and chills
Urine that smells bad or is cloudy during a urinary tract infection
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