ENZYME REWORK Flashcards
DF of enzymes , Features , types ,general idea ,classification
-Enzymes are proteins capable of accelerating the flow of
biochemical reactions (having catalytic activity). They are produced
by cells of organs, and then enter the liquid environment of the body
as a result of physiological processes or as a consequence of the
disease.
-controlling the treatment of many diseases. To do this, the activity of
enzymes is most often determined in the blood serum of patients. But
they can be investigated in other body fluids: urine, liquor, lacrimal
fluid, digestive juices.
-According to the structure the enzymes are proteins that can be
simple and complex. The complex ones consist of a protein
component (apoenzyme) and a non-protein part (coenzyme).
Precursors of coenzymes are often vitamins. For example, thiamine
pyrophosphate is a product of phosphorylation of vitamin B1.
The active center of the enzyme plays a very important role in
catalysis.
-The rate of enzymatic reactions is determined by the following factors:
- enzyme quantity;
- pH environment;
- temperature;
- the concentration of substrate and reaction product;
- the presence of activators and inhibitors of the reaction
——————————
CLASSIFICATION OF ENZYMES
The current international classification distinguishes six classes of enzymes.
1. Oxidoreductase catalyzing oxidation-reduction reactions.
2. Transferases that carry out the transfer of groups of atoms
other than hydrogen atoms.
3. Hydrolases, splitting organic compounds with the addition of
elements of the water molecule at the place of rupture.
4. Liases that provide the formation of double bonds by
removing or adding groups of atoms.
5. Isomerases that carry out intramolecular transfer of groups of
atoms and the formation of isomeric forms.
6. Ligases connecting two molecules to form bonds C-C, C-O, C-S, C-N and the rupture of the pyrophosphate bond ATP.
–In clinical laboratory diagnosis, all of these enzymes are divided into two groups:
1 - plasma specific (plasma enzymes, serum specific);
2 - organ specific (non-plasma enzymes).
Plasma-specific enzymes act directly in the blood plasma, where
they are secreted mainly by the liver. Often a decrease in their
activity is a sign of liver failure. Examples of these enzymes are
cholinesterase, coagulation factors, and fibrinolysis.
Organ-specific enzymes perform their functions in cells. In the
cells integrity violation in large quantities, they enter the plasma and
reflect the degree and depth of organ damage. For example, an
increase in plasma creatine kinase levels depends on the size of the
necrotic focus of myocardial infarction.
explain PLAZMA ENZYMES ( Lecithin-cholesterol-acyltransferase (LCAT))
-1. Lecithin-cholesterol-acyltransferase (LCAT)
Reference interval in serum: 92 ± 14.2 µmol/l/h (5.4±1.1 mg / l).
LCAT is involved in the metabolism of lipoproteins and
converts the free cholesterol into ester of cholesterol (reaction of
esterification of cholesterol) on the surface of HDL. Cholesterol
esters are highly hydrophobic and move from the surface of
lipoproteins to the nucleus, freeing up space on the surface of the
particles to capture new free cholesterol. The particle of HDL as a
result increases in diameter. Thus, due to this reaction, the peripheral
tissues are purified of cholesterol.
–The enzyme activity is reduced in case of:
- liver diseases (acute and chronic hepatitis, liver cirrhosis, its
toxic damage);
- renal failure;
- hereditary LCAT deficiency.
Reduced activity of LCAT is accompanied by an increase in
blood plasma cholesterol and lecithin.
Hereditary deficiency of LHAT is a recessive inherited disease
manifested in homozygotes by opcity of the clear front surface of the
eye (corneal opacities), hemolytic anemia, proteinuria, renal
insufficiency and early atherosclerosis. In hetero-zygotes, the
enzyme defect is manifested only by the corneal opacity (fish-eye
disease).
explain PLAZMA ENZYMES ( Cholinesterase (PCE))
Cholinesterase (PCE)
The normal level in the serum: 5300 - 12900 U/l (160-340
mmol/h*l).
There are two types of cholinesterases: the so-called true
cholinesterase (acetylcholinesterase found in red blood cells, nervous
and muscle tissue) and pseudocholinesterase (serum cholinesterase,
PCE). True CE catalyzes the breakdown of acetylcholine to choline
and acetic acid, and pseudocholinesterase catalyzes the breakdown of
butyrylcholine. Serum PCE is secreted by the liver, contained in
blood serum, liver, pancreas, excreted from the body by filtration
through the kidneys.
Increasing in the PCE level in serum cause:
- arterial hypertension;
- nephrosis;
- breast cancer;
- obesity;
- alcoholism;
- diabetes;
- tetanus;
- manic depressive disorder.
PCE in the serum is reduced in:
- liver diseases (cirrhosis, hepatitis, metastatic liver cancer);
- acute poisoning with organophosphorus compounds;
- heart attack;
- oncological disease.
The main reason for the decrease in the PCE activity in the
blood serum is a protein-synthesizing liver function disorder. Thus, a
decrease in the PCE activity by 30-50% is characteristic of acute
hepatitis and long-term chronic hepatitis, and by 50-70% – for
cirrhosis and tumors with liver metastases
-the PCE level in serum is determined for
the diagnosis of organophosphorus insecticide poisoning, as well as
for the detection of atypical forms of the enzyme in patients before
surgery to prevent the effect of recurarization against the background
of the muscle relaxants use.
which is clinically manifested by repeated muscle relaxation and
respiratory depression. One of the measures to prevent this terrible
complication is timely desuralization with the introduction of
anticholinesterase drugs.
explain plasma enzyme Lysozyme
Lysozyme
Lysozyme (muramidase) is an antibacterial agent produced by
macrophages, monocytes and neutrophils. Lysozyme hydrolyzes the
polysaccharides of the cell wall of gram-positive bacteria and
destroys their cell membranes. The enzyme is contained in the places
of body contact with the external environment: in the lacrimal fluid,
saliva, mucus of the nasopharynx, in the mucous membrane of the
gastrointestinal tract, etc., as well as in urine and serum and gives
biological fluids antibacterial properties. Due to the small size of the
molecules lysozyme passes through the renal filter. After it lysozyme
is reabsorbed in the renal tubules.
Reference intervals in different fluids:
serum-8-12 mg /l;
urine-1,3-3,6 mg/day;
saliva-1,7±0,2 mg/l;
lacrimal fluid – 0.96 – 1.44 g/l.
Determination of activity has a certain diagnostic value in
hematological (leukemia, granulomatosis), nephrological, infectious
and endocrine diseases.
Causes of the increased lysozyme level in serum:
- monocytic and myelocytic leukemia;
- polycythemia;
- diseases of the kidney filtration;
- tuberculosis;
- sarcoidosis.
The level of lysozyme decreases in serum during neutropenia.
The enzyme content in the urine increases with damage to the
proximal tubules of the kidneys, and in saliva – with Sjogren’s
syndrome (autoimmune damage to the salivary and lacrimal glands).
explain plasma enzyme Rinin
Renin
Renin is a plasma-specific enzyme synthesized by
juxtaglomerular apparatus cells of the kidneys. Renin acts on the
protein angiotensinogen and turns it into angiotensin I, which under
the action of angiotensin converting blood enzyme (ACE) passes into
an active vasopressor ‒ angiotensin II.
Angiotensin II:
- leads to vasoconstriction of the peripheral vascular bed;
- increases the secretion of aldosterone by the adrenal glands
followed by sodium and water retention;
- increases ADH secretion and water retention;
- makes a patient thirsty.
Thus, the action of the renin-angiotensin-aldosterone system
(RAAS) contributes to increased blood pressure.
The level of renin in the blood plasma depends on the position
of the patient’s body for 3-4 hours before taking blood. In the supine
position, the standard is 0.2-1.6 µg/ h·l, and in the standing position –
0.7 – 3.3 µg / h·l.
Causes of the increased rennin level in the blood:
- renovascular hypertension;
- renin secretion tumor;
- taking oral contraceptives;
- liver pathology (hepatitis, cirrhosis);
- pheochromocytoma;
- insufficiency of the adrenal cortex, taking diuretics.
Causes of the reduced rennin level in the blood:
- arterial hypertension, not associated with the kidneys;
- primary hyperaldosteronism;
- taking potassium preparations, ß-blockers
ORGAN-SPECIFIC ENZYMES
- Lactate dehydrogenase.
Catalyzes the conversion of pyruvic acid into lactic acid, and
vice versa. Lactate dehydrogenase (LDH) is a tetramer consisting of
two subunits: H (heart) and M (muscle). There are five isoenzymes
of lactate dehydrogenase: LDH1 (HHHH); LDH2 (HHHM); LDH3
(HHMM); LDH4 (HMMM) and LDH5 (MMMM). Isoenzymes, in
which the H subunit predominates, are isolated from organs with
aerobic metabolism (brain, heart). Subunit M is typical for organs,
dominated by anaerobic glycolysis (skeletal muscle, liver, kidney,
neoplasms).
LDH1 gets into the plasma mainly from heart tissue, erythrocytes
and leucocytes. Activity LDH2, LDH3 and LDH4 is the highest in
platelets and LDH3 ‒ also in pancreas, lungs and kidneys. LDH5 is
the most rich in skeletal muscles, liver, skin, mucous membranes and
cells of some malignant tumors.
The normal concentration in the serum total LDH up to 195 IU/
L. Activity LDH1 is 19-25%, LDH2 – 23-37%, LDH3 – 17-25%,
LDH4 – 8-17%, LDH5 – 8-18% of the total activity.
Causes of the increased LDH1/2 level in the blood:
- acute myocardial infarction;
- leukaemiae;
- hemolytic anemia.
Causes of the increased LDH3 level in the blood:
- pulmonary embolism;
- pulmonary infarction;
- acute pancreatitis;
- kidney disease;
- failure of the cardiovascular system with a predominance of
insufficiency in the small circle of blood circulation.
Causes of the increased LDH4/5 level in the blood:
- liver disease;
- diseases of skeletal muscles;
- stagnation of blood in the systemic circulatory system.
————————————————- - Aminotransferases.
Aminotransferases catalyze the processes of transamination
(transfer of NH3-group from amino acid to keto acid), widely
distributed in all organs and tissues. In clinical laboratory diagnosis,
two enzymes of this class are most often identified: alanine
aminotransferase (ALT) and aspartate aminotransferase (AST). ALT
is excreted from the bloodstream somewhat slower than AST, so the
activity of ALT is normally higher than AST
Higher ALT activity is also associated with predominant
localization of the enzyme in the cytoplasm, and AST has both
cytoplasmic and mitochondrial isoenzymes.
Normal serum levels: ALT−28-191 nmol/s*l, AST−28-125 nmol
/ s·l. The activity of ALT and AST in persons older than 17 years for
women is up to 31 U/l, for men is up to 41 U/l.
—–Causes of the ALT increasing in serum:
- any liver failure (hepatitis, fat dystrophy, cirrhosis, mechanical
jaundice, toxic damage, tumors);
- hemolytic anemia;
- burn disease;
- extensive trauma and skeletal muscle disease;
- acute myocardial infarction, myocarditis.
AST in high concentrations is present in the cells of the heart
and skeletal muscles, liver, kidneys, red blood cells. The lesion of
any of these organs will lead to an increase in serum AST levels.
—–Causes of the AST increasing in serum:
-artifact hemolysis of erythrocytes in vitro;
-physiological activity in newborns is 1.5 times higher, than in
adults;
-pathological circulatory failure in shock and hypoxia;
-heart attack;
-acute viral or toxic hepatitis;
-infarction of lungs, mesentery or kidney;
-liver cirrhosis;
-mechanical jaundice;
-metastases of the tumor to the liver;
-skeletal muscle damage;
-injuries and surgery;
-an intravascular hemolysis;
-pancreatitis;
-dermatomyositis.
A slight increase in aminotransferases may occur after taking
vitamin C, antibiotics (especially from groups of aminoglycosides
and macrolides), cholinergic drugs, morphine. Hypovitaminosis B6,
repeated hemodialysis, renal failure and pregnancy can lead to a
decrease in transferases.
———————————————————- - Creatine phosphokinase (CPK) or creatine kinase (CK)
It takes part in the energy exchange of cells of muscle, nervous
and other tissues. It catalyzes the reversible reaction of
phosphorylation of creatinine: creatine phosphate ⇄ creatine + ATP.
In this reaction a phosphocreatine breaks down to creatine, giving its
inorganic phosphate for ATP formation.
The creatine kinase molecule is a dimer consisting of two types
of subunits: B (brain) and M (muscle). The combination of subunits
forms three isoenzymes: BB-CK (brain), MB-CK (heart) and MMCK (muscle).
The normal concentration of serum total CK is 10-110 IU/L. The
activity of MM-CK in serum is 94-96% of total CK and of MB-CK
is about 4-6%. In normal conditions BB-CK is determined only in
trace amounts or not detected in peripheral blood.
—Causes of the MM-CK increasing in serum:
- injuries and diseases of skeletal muscles;
-emergency conditions (poisoning, coma, pulmonary embolism).
—Causes of the MB-CK increasing in the serum:
- acute myocardial infarction;
- myocarditis, myocardiodystrophy;
- unstable angina;
- prolonged arrhythmias.
—-Causes of the BB-CPK increasing in serum:
- acute disorders of cerebral circulation;
- traumatic brain injury;
- cancer of the bladder, lung, prostate, intestine, liver, uterus,
testicle;
- some mental illnesses (schizophrenia, epilepsy, maniacaldepressive disease).
———————————- - Phosphatases
It is a group of enzymes that are found in almost all organs and
tissues. They catalyze the cleavage of phosphoric acid residue from
organic substances. Depending on the optimal pH, alkaline and acid
phosphatase they are distinguished into:
(1)-Alkaline phosphatase: - Bony alkaline phosphatase. It is secreted by osteoblasts,
- Hepatic alkaline phosphatase is a marker of cholestasis, is released from the damaged epithelium of bile ducts. Serum activity of alkaline phosphatase increases sharply due to the hepatic isoenzyme in obstructive jaundice,
- Intestinal phosphatase is synthesized by enterocytes, enters the lumen of the small intestine and is partially absorbed into the blood.
- Renal phosphatase is partially absorbed into the blood, but is
mainly excreted in the urine. Its determination in urine is used for the
diagnosis of kidney diseases (glomerulonephritis, pyelonephritis) - Placental phosphatase appears in the serum of the mother during pregnancy, especially in the third trimester. This indicator can be used as an additional criterion for function of the placenta detection in pregnancy complicated by bacterial or viral infections
- Unidentified phosphatase isoenzymes (the so-called Regan and Nagao isoenzymes) are of tumor origin and are most commonly identified in lung cancer and in occult renal cell carcinoma
–Causes of the increased alkaline phosphatase activity in serum:
- liver diseases (hepatitis, cirrhosis, cancer, toxic damage);
-biliary tract diseases (obstructive jaundice, cholecystitis,
cholangitis);
- bony failure (rickets, fractures, osteomyelitis, osteomalacia);
- the parathyroid glands increased function;
- leukemia, multiple myeloma;
- infectious mononucleosis.
Causes of decreased alkaline phosphatase level in serum:
- hypothyroidism;
- hypovitaminosis C, hypervitaminosis D;
- senile osteoporosis;
- severe anemia;
- pituitary dwarfism.
Isolated elevations of alkaline phosphatase occur in the absence
of any apparent liver or biliary disorder, as in the following:
- some cancers without apparent liver involvement (e.g.,
bronchogenic carcinoma, Hodgkin lymphoma, renal cell
carcinoma);
- after ingestion of fatty meals (because of an enzyme
produced in the small intestine);
- pregnancy (because of an enzyme produced in the
placenta);
- children and adolescents who are still growing (because
of bone growth)
(2)-Acid phosphatase
This acid phosphatase refers to a group of lysosomal enzymes
having an optimum pH below 7.0 and detected in almost all organs
and tissues. In men, half of the acid phosphatase contained in the
blood is a prostate isoenzyme, the rest – hepatic, erythrocyte and
platelet. In women, acid phosphatase occurs mainly from the liver,
red blood cells and platelets.
Normal serum levels of total acid phosphatase: 0.05-0.13 mmol/
h·l.
Causes of the acid phosphatase increasing in serum:
- prostate cancer, especially in bone metastasis;
- diseases of the hepatobiliary system;
- sphingolipidoses (Gaucher disease, Niemann-Pick disease);
- hemolytic anemia.
————————————————————– - α-Amylase.
This enzyme cleaves α-1,4-bonds in glycogen and starch
molecules. Human blood plasma contains two isoenzymes,
pancreatic α-amylase (type P) and salivary (type S)
The normal activity of α-amylase in serum is 13-32 g/h * l or 0-
137 U/L.
Causes of the increased α-amylase activity in serum:
- acute pancreatitis in the first 3-4 days of the disease;
-acute surgical diseases of the abdominal cavity (acute
appendicitis, intestinal obstruction, mesenteric thrombosis,
peritonitis, perforation of ulcers, etc);
- mumps;
- renal failure;
-recent Endoscopic Retrograde Cholangio-Pancreatography
(ERCP) procedure.
Decrease in α-amylase activity is observed at:
- pancreatic necrosis;
The normal activity of α-amylase in serum is 13-32 g/h * l or 0-
137 U/L.
Causes of the increased α-amylase activity in serum:
- acute pancreatitis in the first 3-4 days of the disease;
-acute surgical diseases of the abdominal cavity (acute
appendicitis, intestinal obstruction, mesenteric thrombosis,
peritonitis, perforation of ulcers, etc);
- mumps;
- renal failure;
-recent Endoscopic Retrograde Cholangio-Pancreatography
(ERCP) procedure.
Decrease in α-amylase activity is observed at:
- pancreatic necrosis;
————————————- - Gammaglutamiltransferase (GGTP) or gammaglutamyltranspeptidase (GGT).
It is a membrane bound enzyme found in many parenchymal
organs. Its greatest activity is observed in the kidneys, pancreas,
liver, spleen, prostate and small intestine. GGTP is considered one of
the markers of hepatocyte cytolysis and cholestasis syndrome. For
the diagnosis of cholestasis, it is desirable to determine GGTP
activity in parallel with alkaline phosphatase. Slightly elevated serum
GGT has also been found to correlate with cardiovascular diseases
and is under active investigation as a cardiovascular risk marker.
The reference interval of enzyme in serum:
in men - 15-106 IU or 250-1770 nmol/(s * l);
in women-10-66 IU or 167-1100 nmol/(s * l).
Causes of the increased GGTP activity in plasma:
- intra-and extrahepatic cholestasis;
- acute viral hepatitis;
- toxic and radiation damage to the liver;
- heart attack;
- chronic alcohol intoxication;
- taking antiepileptic drugs, rifampicin.
explain LABORATORY SYNDROMES IN DIFFUSE LIVER
DISEASE (Syndrome of cytolysis)
A. Syndrome of cytolysis
The morphological basis of cytolysis syndrome is dystrophy and
necrosis of hepatocytes, which leads to damage of cell membranes
and to increase their permeability.
Laboratory signs of cytolysis syndrome:
1) increasing in plasma activity of indicator enzymes: ALT,
AST, LDH and its isoenzymes-LDH4 and LDH5;
2) the appearance of specific liver enzymes in the blood:
fructose-1-phosphataldolase, sorbitol dehydrogenase;
3) increasing in concentration of ferritin, serum iron, vitamin B12;
4) increasing in level of bilirubin, mainly by indirect fraction
explain LABORATORY SYNDROMES IN DIFFUSE LIVER
DISEASE (Cholestasis syndrome)
B. Cholestasis syndrome
There is intrahepatic and extrahepatic cholestasis. With
intrahepatic cholestasis, the accumulation of bile in the interlobular
passages is detected, and with extrahepatic the obturation and
expansion of extrahepatic bile ducts is found.
Signs of cholestasis include an increase in plasma the levels of:
1) marker enzymes like alkaline phosphatase, GGT, leucine
aminopeptidase, 5’ - nucleotidases;
2) direct fraction of bilirubin;
3) components of bile-cholesterol, bile acids, phospholipids, β-
lipoproteins.
Also, it is possible to find bilirubinuria that reflects the
presence of conjugated bilirubin in urine; bilirubin spills into urine
because blood levels are markedly increased, indicating severe
disease
-For the diagnosis of cholestasis in children, it is preferable to
determine the level of GGTP, rather than alkaline phosphatase. This
is due to the high activity of bony isoenzyme alkaline phosphatase in
childhood.
-Levels of gamma-glutamyl transpeptidase or 5′-nucleotidase,
which are more specific to the liver, can differentiate hepatic from
extrahepatic sources of alkaline phosphatase better than fractionation
of alkaline phosphatase, which is technically difficult.
alcohol and certain
-drugs (e.g., some anticonvulsants, warfarin) can induce hepatic
microsomal (cytochrome P-450) enzymes, markedly increasing GGT
and thus somewhat limiting its specificity.
explain Syndrome of hepatic-cellular insufficiency
Syndrome of hepatic-cellular insufficiency
The morphological substrate of the syndrome is expressed by
dystrophic changes in hepatocytes and / or a significant decrease in
the functioning liver parenchyma due to its necrotic changes
Laboratory signs of the syndrome often appear only when more than
80% of the liver parenchyma is affected.
In the blood of patients, an increase in indirect bilirubin and a
decrease in the level of the following indicators are detected:
1) total protein and especially albumin;
2) transferrin;
3) cholesterol;
4) coagulation factors (II, V, VII);
5) cholinesterase;
6) HDL.
Serum albumin commonly decreases in chronic liver disorders
because of an increase in volume of distribution
explain Mesenchymal inflammatory syndrome.
Mesenchymal inflammatory syndrome.
Morphological studies of the liver in patients revealed activation
and proliferation of lymphoid and reticulohistiocytoma cells,
increased fibrogenesis, the formation of partitions with hepatocyte
necrosis, intrahepatic leukocyte migration, vasculitis.
In the blood, the syndrome is characterized by
hypergammaglobulinemia, an increase in protein-sedimentary tests
(thymol test), an increase in erythrocyte sedimentation rate (ESR),
-changes in the number and functional activity of T-and Blymphocytes, as well as increased levels of immunoglobulins.
Antibodies may help in diagnosis of the following:
1– autoimmune hepatitis: smooth muscle antibodies
2– primary biliary cholangitis: antimitochondrial
3– primary sclerosing cholangitis:
LABORATORY DIAGNOSIS OF MYOCARDIAL
INFARCTION
-According to modern diagnostic criteria of AMI, the most interesting is cardiospecific troponin I, which is associated with high sensitivity and specificity of this marker, as well as with an early and prolonged increase in its concentration in the blood
—tests: troponin I, CK and MB-CK, myoglobin level, AST, LDH and
LDH1-2, CRP. To diagnose AMI,
1. Cardiospecific troponin level
Causes of the increased levels of cardiac troponins in the blood
in the absence of obvious manifestations of ischemic heart disease:
1) heart injuries (contusion, ablation, surgery, etc.));
2) stagnant heart failure (acute and chronic);
3) aortic dissection;
4) pathology of aortic valve;
5) hypertrophic cardiomyopathy;
6) tachy - or brady-arrhythmia, heart block;
7) rhabdomyolysis in heart surgery;
8) pulmonary embolism, heavy pulmonary hypertension;
9) renal failure;
10) acute neurological disease (including stroke or subarachnoid
hemorrhage);
11) infiltrative disease (amyloidosis, hemochromatosis,
sarcoidosis, scleroderma);
12) inflammatory diseases (myocarditis, myocardial
involvement in endocarditis or pericarditis);
13) cardiotoxic effects of drugs and toxins;
14) extremely serious condition of the patient, including
respiratory failure and sepsis;
15) burns, especially with damage to more than 30% of the body
surface;
16) very intense physical activity.
————————–
2. Activity of CK and MB-CK.
———————-
3. Myoglobin.
Because of myglobin is not a specific test there’s a lot of
other reasons for increasing in myoglobin level. They are:
1) coma or another situation in which you don’t move for a long
period of time;
2) surgery;
3) certain infections;
4) poisons and certain medicines;
5) conditions such as muscular dystrophy;
6) unusually strenuous exercise;
7) kidney failure;
8) shock;
9) electrical shock.
Lower results may mean a patient has rheumatoid arthritis,
myasthenia gravis or antibodies to myoglobin in blood
———————-
4. AST activity;
——————–
5. Levels of LDH and LDH
———
–Additional tests.:
1. Activity of γ-glutamyl transferase (GGT) :GGT levels are related to cardiovascular emergencies of chronic heart failure, and an elevated GGT level has been shown to be an independent predictive maker for cardiac death and cardiac
transplantation
2. Activity of the BB isozyme of glikogenogenez (GPBB).: This enzyme catalyzes the transfer of glucose residues, glycogen molecules
3. Malondialdehyde concentration :It is used to assess the severity of lipid peroxide oxidation (LPO) and control the effectiveness of antioxidant therapy
4. BNP and NT-proBNP level: B-type natriuretic peptide (BNP) is a hormone produced by your heart. N-terminal (NT)-pro hormone BNP (NT-proBNP) is a nonactive prohormone that is released from the same molecule that
produces BNP. Both BNP and NT-proBNP are released in response
to changes in pressure inside the heart
-A normal level of NT-proBNP is:
less than 125 pg/mL for patients aged 0-74 years
less than 450 pg/mL for patients aged 75-99 years
In myocardial infarction complicated by cardiogenic shock,
levels of BNP and NT-proBNP both provide valuable additional information Highest NT-proBNP values were associated mostly with heart failure and recurrent ischemic events in the first 6 months after AMI.
5. The number of white blood cells allows to monitor the dynamics of AMI,
6. ESR begins to increase by 2-3 days, reaches maximum values
by 7-10 days of the disease and is normalized with the complete replacement of the necrosis focus with connective tissue in 3-4 weeks
7. The level of eosinophils may increase in the 2nd week of AMI
and is often a harbinger of the development of autoimmune processes with the formation of Dressler syndrome.
8. The level of eosinophils may increase in the 2nd week of AMI
and is often a harbinger of the development of autoimmune processes
with the formation of Dressler syndrome.
9. According to the indications, the coagulation parameters
(ACT, PTI, platelet level and their aggregation, paracoagulation
tests, D-dimer) are determined for the timely diagnosis of one of the
dangerous complications of myocardial infarction – DIC syndrome.
The level of D-dimer is used for differential diagnosis of the cause of acute chest pain
—————-
Laboratory signs of unfavorable prognosis of AMI:
- leukocytosis above 15x109/l, neutrophilia with a pronounced
shift to the left;
- no decrease in erythrocyte sedimentation rate after 10 days;
- progressive increase in the concentration of sialic acids;
- sustained increased levels of C-reactive protein and fibrinogen;
- reappearance of C-reactive protein in the blood;
- increased enzyme activity: AST more than 7 days; LDH more
than 2 weeks; LDH1/2 more than 1 month.; CK more than 7 days, and
also excess of norm in 10 times in 1-2 days; CK-MB more than 5
days or increase more, than in 20 times in comparison with norm in
the first days; GGTF more than 1.5 months, re-hyperenzymemiae;
- hypermagnesemia more than 5 days or more than 900 µg/l in
the first day;
- re-hypermagnesemia;
- expressed metabolic acidosis (BE < -10);
- the presence of laboratory signs of the DIC syndrome
formation;
- 3-4-fold increase in the concentration of malonic dialdehyde in
1-2 days.
