This document discusses liver tests and their interpretation. It describes how transaminases like ALT and AST are released from liver cells during injury and can indicate the level of hepatocyte death. Elevated alkaline phosphatase suggests cholestasis or reduced bile flow. Bilirubin levels rise with any impairment of bilirubin excretion from the liver. Certain patterns of liver test abnormalities can suggest the general type of liver disease present.
Serum Protein and Albumin-Globulin RatioASHIKH SEETHY
For MBBS Biochemistry Practical. Explains various methods of protein estimation and estimation of AG ratio, conditions leading to alterations in AG ratio etc.
Normal & abnormal hemoglobin derivativesrohini sane
Comprehensive presentation on Normal & abnormal hemoglobin derivatives for medical ,dental ,biotechnology & pharmacology students Comparison of molecular aspects & absorption spectra of normal & Meth-Hb are illustrated. Congenital & acquired Meth hemoglobinemia is described. briefly.Treatment of Meth-hemoglobinemia is presented along with its biochemical basis.Formation & clinical manifestations of Carboxy-hemoglobinemia is illustrated.Identification of Carboxy-hemoglobin in a diagnostic laboratory has been described for perusal of technologists.Google images are used to convey the aspect in a lucid way.
Serum Protein and Albumin-Globulin RatioASHIKH SEETHY
For MBBS Biochemistry Practical. Explains various methods of protein estimation and estimation of AG ratio, conditions leading to alterations in AG ratio etc.
Normal & abnormal hemoglobin derivativesrohini sane
Comprehensive presentation on Normal & abnormal hemoglobin derivatives for medical ,dental ,biotechnology & pharmacology students Comparison of molecular aspects & absorption spectra of normal & Meth-Hb are illustrated. Congenital & acquired Meth hemoglobinemia is described. briefly.Treatment of Meth-hemoglobinemia is presented along with its biochemical basis.Formation & clinical manifestations of Carboxy-hemoglobinemia is illustrated.Identification of Carboxy-hemoglobin in a diagnostic laboratory has been described for perusal of technologists.Google images are used to convey the aspect in a lucid way.
GGT is one of a large group of enzymes “Peptidases”.
A membrane bound enzyme whose active site faces the external side of cell.
Hepatobiliary tract enzyme.
Renal function test (RFT), also known as kidney function test is a group of tests used to assess the functions of kidney.
It is used screen for, detect, evaluate and monitor acute and chronic kidney diseases.
These are simple blood and urine tests that are used identify kidneys problems.
Tests of renal function have utility in-
Identifying the presence of renal disease
Monitoring the response of kidneys to treatment
Determining the progression of renal disease
RFT is ordered, if your doctor
thinks your kidneys may not be working properly which is known from signs and symptoms
and if you have other conditions that can harm the kidneys, such as diabetes or high blood pressure
It is characterized by a yellow appearance of the (1) Skin (2) Mucous membranes and (3) Sclera caused by bilirubin deposition. It is the most specific clinical manifestation of Hepatic dysfunction.
Jaundice is usually present clinically when the plasma bilirubin concentration reaches 2 to 3 mg/dl.
When bilirubin clearance from the Liver to the Intestinal tract is impaired (as in acute hepatitis and bile duct obstruction) it may be accompanied by alcoholic (Gray coloured) stools.Solubility increases in water , soluble conjugated bilirubin leads to Tea coloured urine.
Liver function tests (LFT’s) are groups of laboratory blood assays designed to give information about the state of patients liver
They include
Liver enzymes (SGOT, SGPT, ALP, GGT etc.,)
Bilirubin(Direct and indirect)
Albumin
Prothrombin time / INR
billirubin production billirubin transport and metabolism, different laboratory methods of billirubin estimation ,normal and abnormal levels of billirubin, different classification and types of jaundice and liver diseses, liver functioning, enterohepatic circulation, billirubin production and degradation, benefits and diseases of abnormal level of billirubin
Estimation of Blood Urea Nitrogen by Dr. TehmasTehmas Ahmad
Lecture/Demonstration of Biochemistry Practical of Blood Urea Nitrogen estimation in serum Delivered on 11-04-2018 to 2nd year MBBS students of Bannu Medical College, Bannu.
ALT is an enzyme present in liver, heart skeletal muscles, highest concentration is present in Liver. it value increases when there is abnormality in liver, ALT is an amino transferase which transfer one amino group from an amino acid and transfer to another substance for production of non essential amino acid
GGT is one of a large group of enzymes “Peptidases”.
A membrane bound enzyme whose active site faces the external side of cell.
Hepatobiliary tract enzyme.
Renal function test (RFT), also known as kidney function test is a group of tests used to assess the functions of kidney.
It is used screen for, detect, evaluate and monitor acute and chronic kidney diseases.
These are simple blood and urine tests that are used identify kidneys problems.
Tests of renal function have utility in-
Identifying the presence of renal disease
Monitoring the response of kidneys to treatment
Determining the progression of renal disease
RFT is ordered, if your doctor
thinks your kidneys may not be working properly which is known from signs and symptoms
and if you have other conditions that can harm the kidneys, such as diabetes or high blood pressure
It is characterized by a yellow appearance of the (1) Skin (2) Mucous membranes and (3) Sclera caused by bilirubin deposition. It is the most specific clinical manifestation of Hepatic dysfunction.
Jaundice is usually present clinically when the plasma bilirubin concentration reaches 2 to 3 mg/dl.
When bilirubin clearance from the Liver to the Intestinal tract is impaired (as in acute hepatitis and bile duct obstruction) it may be accompanied by alcoholic (Gray coloured) stools.Solubility increases in water , soluble conjugated bilirubin leads to Tea coloured urine.
Liver function tests (LFT’s) are groups of laboratory blood assays designed to give information about the state of patients liver
They include
Liver enzymes (SGOT, SGPT, ALP, GGT etc.,)
Bilirubin(Direct and indirect)
Albumin
Prothrombin time / INR
billirubin production billirubin transport and metabolism, different laboratory methods of billirubin estimation ,normal and abnormal levels of billirubin, different classification and types of jaundice and liver diseses, liver functioning, enterohepatic circulation, billirubin production and degradation, benefits and diseases of abnormal level of billirubin
Estimation of Blood Urea Nitrogen by Dr. TehmasTehmas Ahmad
Lecture/Demonstration of Biochemistry Practical of Blood Urea Nitrogen estimation in serum Delivered on 11-04-2018 to 2nd year MBBS students of Bannu Medical College, Bannu.
ALT is an enzyme present in liver, heart skeletal muscles, highest concentration is present in Liver. it value increases when there is abnormality in liver, ALT is an amino transferase which transfer one amino group from an amino acid and transfer to another substance for production of non essential amino acid
Pada penilaian luaran klinik pasien diperlukan berbagai indikator yang meliputi : respons klinik pasien, pemeriksaan fisik, data laboratorium dan diagnostik (misalnya: imejing, elektrografi). Pernyataan American Pharmacists Association 2008 yang mendukung peran apoteker dalam keselamatan pasien antara lain perlunya apoteker mempunyai akses data klinik pasien.
This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
Liver Function Tests - An Approach for Primary CareJarrod Lee
This presentation is aimed at primary care physicians. It covers the fundamentals of liver function tests, including the basic principles of interpretation, and the key patterns of abnormalities. The focus is on how to approach liver function tests in a primary care setting.
Enzymes are dynamic proteins that accelerate biochemical reactions.
Each enzyme acts on a specific reactant, the substrate.
Enzymes are characterized by greater activity, specificity and susceptibility to the influence of pH, temperature and other environmental changes.
Enzymes act in the presence of non-peptide cofactors or coenzymes.
An enzyme lacking its cofactor is called apoenzyme and the active enzyme with its co-factor, the holoenzyme.
This presentation is about Medical importance of Enzymes and their role in clinical medicine. The types of Enzymes are mentioned along with their normal roles and in pathologies. The measurements of enzyme levels are given as well as fluctuations in their levels in the presence of pathology. Hope this will help you.
1.Detect presence of liver disease.
2.Distinguish among different types of liver diseases.
3.Estimate the extent of known liver damage.
4.Follow the response of treatment
The multiple forms of an enzyme catalyzing the same chemical reaction are called isoenzmyes. They, however, differ in their physical and chemical properties.
Examples: Isozymes of numerous dehydrogenases, and several oxidases, transaminases, phosphatases, transphosphorylases, proteolytic enzymes, aldolases.
10.03.08(a): Approach to the Patient with Acute Renal FailureOpen.Michigan
Slideshow is from the University of Michigan Medical School's M2 Renal sequence
View additional course materials on Open.Michigan:
openmi.ch/med-M2Renal
This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
This is a lecture by Jim Holliman, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
GEMC- Alterations in Body Temperature: The Adult Patient with a Fever- Reside...Open.Michigan
This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
GEMC- Rapid Sequence Intubation & Emergency Airway Support in the Pediatric E...Open.Michigan
This is a lecture by Michele Nypaver, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
GEMC- Disorders of the Pleura, Mediastinum, and Chest Wall- Resident TrainingOpen.Michigan
This is a lecture by Andrew Barnosky, DO from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
GEMC- Dental Emergencies and Common Dental Blocks- Resident TrainingOpen.Michigan
This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
GEMC- Arthritis and Arthrocentesis- Resident TrainingOpen.Michigan
This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
GEMC- Bursitis, Tendonitis, Fibromyalgia, and RSD- Resident TrainingOpen.Michigan
This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
GEMC- Right Upper Quadrant Ultrasound- Resident TrainingOpen.Michigan
This is a lecture by Jeff Holmes from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
This is a lecture by Joe Lex, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
GEMC: Nursing Process and Linkage between Theory and PracticeOpen.Michigan
This is a lecture by Jeremy Lapham from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
2014 gemc-nursing-lapham-general survey and patient care managementOpen.Michigan
This is a lecture by Dr. Jeremy Lapham from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
This is a lecture by Dr. Jessica Holly from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
GEMC: The Role of Radiography in the Initial Evaluation of C-Spine TraumaOpen.Michigan
This is a lecture by Dr. Stephen Hartsell from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
This is a lecture by Dr. Jim Holliman from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
GEMC- Sickle Cell Disease: Special Considerations in Pediatrics- Resident Tra...Open.Michigan
This is a lecture by Hannah Smith, MD from the Ghana Emergency Medicine Collaborative. To download the editable version (in PPT), to access additional learning modules, or to learn more about the project, see http://openmi.ch/em-gemc. Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution Share Alike-3.0 License: http://creativecommons.org/licenses/by-sa/3.0/.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
1. Author(s): Rebecca W. Van Dyke, M.D., 2012
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3. M2 GI Sequence
Liver Tests: Use and
Interpretation
Rebecca W. Van Dyke, MD
Winter 2012
4. Learning Objectives
• A. General: Understand the laboratory tests that are used in the clinical
approach to liver disease and the pattern of abnormalities that occur in specific
forms of liver injury.
– 1. When do we suspect a patient has liver disease? What tests can be used to accept or deny the
presence of liver disease?
– 2. Can we define the type of liver disease the patient has by analyzing the results of the liver tests?
– 3. How much functional liver tissue is present in a patient?
•
• B. Specific:
– 1. Be able to interpret panels of biochemical liver tests in terms of general type of liver disease,
chronicity and severity.
– 2. Be able to construct a differential diagnosis for different patterns of liver test results.
– 3. Be able to identify potential problems in interpreting liver tests.
6. How Do We Tell Someone Has Liver
Disease?
Clues that may lead to a suspicion of liver disease:
Anorexia
Fatigue
Nonspecific Nausea
Vomiting
Mental confusion
Jaundice (“yellow eyes”)
More specific Dark urine (“coca-cola” urine)
(late findings) Abdominal swelling; ascites
Peripheral edema; leg swelling
Unfortunately none of these are specific markers of liver disease
and for many patients these are very late findings.
7. Purpose of Liver Tests
1. Screen for clues to the presence of liver injury/disease
liver cell injury
bile flow/cholestasis
2. Quantitate degree of liver function/dysfunction
quantitative liver tests
3. Diagnose general type of liver disease
pattern of liver test abnormalities
4. Diagnosis of specific liver disease
disease-specific tests such as serology for
viral hepatitis
9. Transaminases are enzymes that catalyze the transfer of α-
amino groups from amino acids to α-keto acids.
These enzymes are important in gluconeogenesis.
ALT (alanine aminotransferase)
alanine pyruvic acid
+ +
ketoglutarate glutamate
AST (aspartate aminotransferase)
aspartate oxaloacetic acid
+ +
ketoglutarate glutamate
10. Transaminases:
AST(SGOT) ALT(SGPT)
Many tissues Liver only
Cytosol/mitochondria Cytosol
Normal blood levels: 20-70 IU/liter (depending on method)
Some AST/ALT release occurs normally
Require pyridoxal 5’-phosphate as an essential cofactor
11. Multi-channel Automated Analysis of Enzymes in Blood
lamp
Patient λ
serum
ALT Colored
+ product
substrate
Substrate
λ
Absorbance
converted to
enzyme activity
Photodetector
12. Release of AST/ALT from Liver Cells
during Acute Hepatocellular Injury
AST
ALT
13. Transaminases
Why do we used these enzymes to indicate liver damage?
1. Convenient to measure
2. Present in liver cells in large amounts
3. Direct release of enzymes into blood through
fenestrated endothelium allows rapid
“quantitative” assessment of ongoing
hepatocyte necrosis
4. Blood level roughly proportional to the number
of hepatocytes that died recently (hours-days)
14. Patterns: AST and ALT in Various Liver Diseases
30
00
20
00
AT
S
500 AT
L
Serum
Enzyme
Level
(IU/ml)
200
10
0
Acute viral Acute viral Mild chronic Cirrhosis
hepatitis A hepatitis A hepatitis C (little ongoing
(clinically severe) (clinically mild) (asymptomatic) injury)
16. Transaminases
Special considerations:
1. AST is also present in other tissues
(muscle, brain, kidney, intestine).
ALT is more specific for liver.
2. Even very mild liver abnormalities can cause
slightly elevated AST/ALT
- for example, mild fatty liver.
18. Transaminases
Problems with using transaminases to assess liver injury:
3. Only assess injury over the past 1-2 days as enzymes
are cleared efficiently from blood by RES
5. May not accurately assess hepatocyte death from
apoptosis
7. Magnitude of elevation does not necessarily correlate
with extent of liver function or dysfunction at the
present time or in the future.
AST and ALT = rate of destruction of hepatocytes
Liver function = number of functional hepatocytes left
19. Not all liver abnormalities cause liver cell
death: simple liver cyst with
normal liver tests
20. Transaminases and Alcoholic Liver
Disease: A Twist
Pyridoxal 5’-phosphate (P5P) deficiency:
q AST and ALT require P5P (vit. B-6) as an enzymatic
cofactor
q Alcoholics are often deficient in P5P as their major
calorie source is alcohol
q P5P deficiency results in lower synthesis of AST/ALT
(less in hepatocytes) and very low enzymatic activity
(ALT worse than AST)
q Less AST/ALT released into blood and it isn’t
measured by lab assays
21. Transaminases and Alcoholic Liver
Disease
Further: Mitochondrial AST and alcohol
q Alcohol shifts mAST from mitochondria to plasma
membrane where it readily enters blood – thus AST
easier to remove from hepatocytes.
Therefore: AST>>ALT is released into blood
from damaged hepatocytes
AND
both AST/ALT enzymatic activities in blood
are lower than expected from the extent of liver
damage/dysfunction.
22. AST/ALT and Pyridoxal 5’ Phosphate
AST is Affected Less than ALT so AST>ALT
P5’P
Numerous active enzymes with P5’P Few inactive enzymes without P5’P
Poorly measured by lab assays
23. Release of AST/ALT from Liver Cells After Alcohol Exposure
A T
S
ALT
Alcohol increases mitochondrial AST on liver cell plasma membrane
where it readily enters blood. Thus AST>>ALT in blood.
24. Patterns: AST versus ALT
1000 Ratio 2.4 Ratio 0.65 Ratio 0.8
650 AST
Serum
Enzyme ALT
Level
(IU/ml)
200
100
Alcoholic Acute viral Mild chronic
hepatitis hepatitis A hepatitis C
25. Tests of Cholestasis/Reduced Bile Flow
Enzymes released as a Accumulation in liver/blood
consequence of decreased of substances normally
bile flow excreted in bile
Alkaline phosphatase Bilirubin
or
5’-nucleotidase Bile salts
Leucine aminopeptidase
γ-glutamyl transpeptidase
27. Alkaline phosphatase
Origin of enzyme and mechanism of increase in
cholestatic liver disease:
1. Apical membrane of hepatocyte and bile duct cells
2. Very sensitive to any changes in bile flow,
obstruction of large or small bile ducts.
3. Amplified by bile acid retention
4. Easily released into blood as it is a GPI-anchored
protein solubilized from membrane by
detergents (bile acids)
Easily measured spectrophotometrically
Purpose: ? Detoxifies lipopolysaccharide (LPS) from bacteria
28. Bile Acids
(Bile Salts) such as
Taurocholate
stimulate production
of alkaline
phosphatase
molecules.
30. Release of GPI-Anchored Proteins From
Liver During Cholestasis GPI-Anchored Proteins
Alkaline
Phosphatase
5’ Nucleotidase
GGTP
Hepatocyte
Bile canaliculus
Blood
31. Alkaline Phosphatase in Various Liver Diseases
10
50
10
00 Degree of elevation of AP is highly variable
depending on duration and extent of
cholestasis and other unknown factors.
50
0
Serum
Enzyme
Level
(IU/ml)
20
0
10
0
Long-standing Acute bile Mild early Hepato-
bile duct duct partial cellular
obstruction obstruction bile duct disease
obstruction
32. Alkaline Phosphatase
Interpretation of elevated levels:
1. Cholestasis (especially in extrahepatic
obstruction
2. Infiltrative diseases (granulomas)
3. Neoplastic disease infiltrating liver
Sensitive test as will go up if only some small ducts are
obstructed and/or if there is only partial obstruction of
major ducts.
Disadvantages:
Not completely specific because of isoenzymes
in other organs (bone, intestine, placenta)
Ex: bone disease, intestinal obstruction, pregnancy.
33. Serum Bilirubin (Bile Acids)
Rationale:
Liver is virtually the only mechanism for excretion
Cholestasis from any cause results in “back-up”
of these compounds in blood
Interpretation:
Cholestasis: extrahepatic or intrahepatic
Disadvantages:
Does not distinguish hepatocellular disease,
in which hepatocytes don’t make bile,
from bile duct obstruction
34. Bilirubin
An organic anion
The byproduct of heme breakdown
In mammals bilirubin must be conjugated to
glucuronic acid and excreted in bile
Blood levels go up if any steps in production or
hepatocyte excretion are altered. However
obstruction at the level of bile ducts must be
complete or virtually complete for bilirubin
levels in blood to change
35. Hepatic Bilirubin Transport
SER
UDP-glucuronide
RBC +
breakdown Unconj BR
in RES
Conj
BR
Unconj BR Bile
Unconj Canaliculus
Bilirubin
Conj
BR
MRP-2:
Multispecific organic
anion transporter
Conj Conjugated bilirubin
BR Glutathione S-conjugates
other organic anions
ATP
Blood
Hepatocyte
36.
37. Hepatic Bilirubin Transport and Mechanisms
of Hyperbilirubinemia
Gilbert's syndrome (mild)
Crigler-Najjar syndrome (severe)
SER
Hemolysis
Unconj BR Bile
Unconj Canaliculus
Bilirubin
Conj
BR
Multispecific organic
anion transporter
Conj Conjugated bilirubin
BR Glutathione S-conjugates
other organic anions
ATP
Blood
Hepatocyte
Dubin-Johnson syndrome
Rotor's syndrome
?estrogen/cyclosporin
38. Mechanism of Hyperbilirubinemia
in Liver Disease
SER
UDP-glucuronide
+
Unconj BR
Conj
BR
Unconj BR
Unconj
Bilirubin
Conj
BR
Conj
BR
Albumin
Overall
Rate-Limiting
Step
39. Interpretation of Elevated Serum Bilirubin
Conjugated hyperbilirubinemia:
BR reached liver and was conjugated but not excreted in bile
1. Cholestasis/biliary obstruction (must be essentially complete)
2. Hepatocellular damage (collateral damage to all liver functions)
bile formation impaired >> conjugation impaired
3. Rare disorders of canalicular secretion of conjugated bilirubin
Unconjugated hyperbilirubinemia:
BR didn't reach liver efficiently or wasn't conjugated
1. Massive overproduction - acute hemolysis
2. Impaired conjugation
common: Gilbert's syndrome (mild)
rare: Crigler-Najjar syndrome (severe)
40. Further: Bilirubin Undergoes Non-Enzymatic Reaction
with Albumin
Formation of Bilirubin-Albumin Conjugates
Bili-albumin conjugate
or "delta bilirubin"
Blood
Alb Hepatocyte
B -G
R lu Alb ER
BR
BR
Alb BR
B -G
R lu B -G
R lu Bile
B -G
R lu
41. Why is Bili-Albumin of Clinical
Interest?
• Not of interest during liver disease as this form of
bilirubin is measured as conjugated bilirubin.
• However, after resolution of cholestasis/liver disease,
bili-albumin is cleared like albumin
– Albumin half-life: several weeks
– Conj. bilirubin half-life: hours to days
–
• Thus resolution of jaundice is often SLOW compared
to improvement of other liver functions.
42. Purpose of Liver Tests
1. Screen for clues to the presence of liver injury/disease
liver cell injury
bile flow/cholestasis
2. Quantitate degree of liver function/dysfunction
quantitative liver tests
3. Diagnose general type of liver disease
pattern of liver test abnormalities
4. Diagnosis of specific liver disease
disease-specific tests such as serology for
viral hepatitis
43. TESTS OF LIVER FUNCTION
Blood Level
Production Albumin
Clotting factors
Blood Level
Elimination
Bilirubin
Bile Acids
Metabolism
C-Aminopyrine
14
Metabolites CO2
14
44. Albumin
• Rationale
– Liver is the sole source
• Interpretation of Decreased Level
– Decreased liver production
– Increased renal/GI loss (nephrotic syndrome;
protein losing enteropathy in inflammatory bowel
disease
– Protein malnutrition
• Disadvantages
– Prolonged half-life
– No unique interpretation
45. Prothrombin Time
• Rationale
– Liver is sole source of vitamin K-dependent
clotting factors, including those critical for PT
– Factor VII has very short half-life (hours)
• Interpretation of Increased PT
– Hepatocyte protein synthesis impaired
– Vitamin K deficiency/Coumadin therapy
– Disseminated intravascular coagulopathy
• Advantages
– Rapidly reflects changes in liver function
46. Interpretation of Abnormal
Albumin/Prothrombin Time
Liver markedly diseased - reserve function gone
Albumin: monitors slow changes in liver function
(months to years)
reflects long-term liver dysfunction
Protime: monitors rapid changes in liver function
(hours to days/weeks)
reflects either short or long-term liver
dysfunction
47. Other Clues to Globally Impaired Liver Function
Bilirubin: goes up with any disease that globally impairs
liver function (OR blocks bile flow)
Glucose: hypoglycemia (late finding; indicates
very poor liver function)
BUN: low BUN is a late and poorly specific finding
in liver dysfunction due to poor urea
synthesis
48. Purpose of Liver Tests
1. Screen for clues to the presence of liver injury/disease
liver cell injury
bile flow/cholestasis
2. Quantitate degree of liver function/dysfunction
quantitative liver tests
3. Diagnose general type of liver disease
pattern of liver test abnormalities
4. Diagnosis of specific liver disease
disease-specific tests such as serology for
viral hepatitis
49. Interpretation of Liver Tests
A. Consider nonhepatic causes of abnormal liver tests
B. Examine the pattern of liver test abnormalities to
categorize liver disease:
1. cholestatic versus hepatocellular
2. acute versus chronic
3. decompensated versus mild functional
function impairment
52. Clues to Acute vs Chronic Liver Disease
Abnormalities of PT versus albumin
Known duration of abnormal liver tests
History of exposure to potential causative agents
Clinical signs of consequences of long-standing liver disease
Tempo of subsequent changes in AST/ALT, bilirubin, PT
chronic tends to change slowly
acute tends to change quickly
53. 20 Patterns: Chronic Liver Disease with Impaired Liver Function
Fold
Increase
10
2
1
Albumin
AST or ALT Alkaline Bilirubin PT
Phosphatase
-2
54. Clues to Severity of Liver Dysfunction
Prothrombin time
Albumin
(Bilirubin, glucose)
(Clinical signs of consequences
of severe liver dysfunction such
as hepatic encephalopathy)
55. Clues to severity
of liver damage
and, potentially, to
severity of liver
dysfunction may
come from the
temporal sequence
of changes in
readily available liver
tests.
For example, rapid
fall in AST/ALT
in severe hepatitis
may not be a good
sign.
56. Purpose of Liver Tests
1. Screen for clues to the presence of liver injury/disease
liver cell injury
bile flow/cholestasis
2. Quantitate degree of liver function/dysfunction
quantitative liver tests
3. Diagnose general type of liver disease
pattern of liver test abnormalities
4. Diagnosis of specific liver disease
disease-specific tests such as serology for
viral hepatitis
These are discussed in future lectures
57. Summary
• Use biochemical tests to assess
– Presence of liver disease
– General type of liver disease
– Sense of severity of liver dysfunction
– Sense of acute versus chronic disease
• Use liver tests with other data to work
through differential diagnosis
– See algorithms in syllabus and textbook
58. Approach to the Patient with Jaundice (Bilirubin)
History, PE
Lab tests: AP, AST/ALT, Alb. PT
Normal liver tests Abnormal findings suggesting
liver disease
Suspect intrahepatic Suspect extrahepatic
Fractionate bilirubin cholestasis or cholestasis
hepatocellular
disease
Noninvasive imaging of the
Unconjugated biliary tree: ultrasound or CT
hyperbilirubinemia Specific diagnostic tests (may go to direct duct
hepatitis screen visualization in some cases)
AMA, ANA, SMA
Ceruloplasmin
Hemolysis Fe/TIBC, ferritin
Gilbert’s syndrome Normal Normal ducts, Dilated
Stop drugs
Crigler-Najjar syndrome ducts still suspect ducts
Consider liver biopsy
extrahepatic
Consider CT to r/o structural
cholestasis
disease
Medical management/
Conjugated observation Relief of biliary
hyperbilirubinemia Direct duct obstruction:
visualization surgical
(ERCP or PTC) endoscopic
percutaneous
Dubin-Johnson
syndrome
Rotor syndrome No obstruction
visualized Obstruction
visualized
59. Approa ch to Pa tie nt with Incre a se d Alka line Phospha tase
Alkaline phosphatase (AP)
Exclude pregnancy, physiologic causes
Obtain additional biochemical markers of cholestasis
(GGTP, 5'-NT, or AP isoenzymes, serum bilirubin)
Nonhepatic cause of AP Hepatic cause of AP
Consider: bone disease
(eg, Paget's disease, Large (> 3-fold) Modest (< 3-fold)
hyperparathyroidism, bone elevation of AP elevation of AP
metastasis)
ectopic AP secretion
Consider:
hepatocellular injury
Abdominal ultrasound or CT scan (eg, viral and
alcoholic hepatitis)
Dilated ducts Non-dilated ducts
Consider:
choledocholithiasis, Normal or diffusely
Focal hepatic defects abnormal liver
cancer of the pancreas,
cholangiocarcinoma,
biliary stricture, pancreatitis
Consider: primary or Liver biopsy and
metastatic cancer of the consider: primary
liver, pyogenic/amebic biliary cirrhosis,
abscess granulomas
Modified from: Kelley Textbook of Internal Medicine, 3rd edition, 1997, pp 663.
60. A variety of cases are provided in your
syllabus to allow practice in analyzing
liver tests.