IMMUNOLOGY: Viral Hepatitis
HEPATITIS
“Hepa-” = liver
“-itis” = inflammation
Thus, when we use the word “hepatitis” – it actually refers to the inflammation/infection of the liver.
An inflammatory disease involving the liver:
Necrosis of hepatocytes
Infiltration of the liver by immune cells causing immune mediated destruction of cells and
tissue
Whenever there is hepatitis, there is an equivalent death of cells or necrosis of hepatocytes. And since
there is an ongoing inflammation, expect that there will be an ongoing infiltration of the liver tissue by
immune cells and most of the time, the destruction or the killing of hepatocytes are brought about by
the presence of these immune cells.
Can be caused by:
Drugs
o Because there are hepatotoxic drugs – these are drugs that can damage the liver
o That is why if you are a doctor and you know that the drug you will give is hepatotoxic, you
really have to request some tests and determine the function of the liver. Because if the
patient has a problem with the functions of the liver then most likely you cannot give the
hepatotoxic drug or you will adjust the dose of the hepatotoxic drug so that it cannot add
on to the ongoing liver problem of the patient.
Alcohol
o That is why a lot of patients who are considered to be chronic alcoholic drinkers will really
develop liver problems when they get old
Metabolic disorders
o If you can remember from your biochemistry, some glycogen metabolic disorders can
actually cause hepatitis
Viruses
o These viruses contain antigens and these antigens can be processed in the immunology
and serology laboratory.
HEPATITIS: SIGNS AND SYMPTOMS
Swelling (hepatomegaly) and tenderness of liver
o Imagine a patient lying down then if you will act as a doctor, then if you palpate the upper
right quadrant of the abdomen of the patient, once you palpate a solid mass it would indicate
that there is a swelling of the liver or hepatomegaly.
o Sometimes the palpation can actually trigger pain and you call that as the tenderness
o Note: There is a difference between pain and tenderness. Pain is the one that is felt by the
patient, but if the pain was initiated by physical exam or by palpation then the doctor would
refer to it as “tenderness”.
Jaundice – yellowish discoloration of the skin
o There would also be jaundice because you know very well that the organ that eliminates
bilirubin (yellowish-colored pigment) from the body is actually the liver. So, if the liver is
having problems, if the hepatocytes are dying, then most likely the elimination of the
bilirubin would also be affected causing now the build-up of bilirubin in the blood and the
deposition of bilirubin into the skin, making the skin appear yellowish.
Note: If the causative agent is virus, then most likely the patients would develop:
Low grade fever Fatigue
Nausea and vomiting
, HEPATITIS: LABORATORY TESTS
How would you confirm hepatitis in the laboratory?
1. High levels of serum bilirubin
You can have the serum bilirubin of the patient to tested and expect that the bilirubin level will
be elevated in a case of liver problem
2. High levels of serum Alanine aminotransferase (SGPT)
The patient would also have a high level of alanine aminotransferase enzyme in their blood
(ALT). Another name is serum glutamic pyruvic transaminase (SGPT).
This enzyme is found intracellularly (within the cytoplasm of the hepatocytes). So, if the
hepatocytes are destroyed or killed, they will burst and undergo lysis, and this serum alanine
aminotransferase will now start appearing in the blood.
So, if you are going to check the blood of the patient, you will see high levels of alanine
aminotransferase and that would actually give you an idea that hepatocytes are bursting and
undergoing lysis because there is an ongoing problem in the liver.
3. Low levels of serum albumin and total proteins
Remember, the majority of the proteins in the body (except antibodies) are produced in the
liver. So, if there is an ongoing liver problem then most likely the production of these proteins
will also be affected.
The most abundant protein is serum albumin. If you are a doctor and you don’t want the patient
to spend a lot of money, then most likely you will just request for serum albumin because
serum albumin is the most abundant protein. So, if the level of serum albumin is low, then that
would also somehow reflect the function of the liver.
DIFFERENT VIRAL CAUSATIVE AGENTS OF HEPATITIS
Hepa A Hepa B Hepa C Hepa D Hepa E
Causative
agent
PicoRNAvirus/ Flavivirus/ Calicivirus/
HepaDNAvirus Deltavirus
Hepatovirus Hepacivirus Hepevirus
Enveloped
Description
of the virus
single Naked
Naked single Enveloped Enveloped
stranded single
stranded RNA double single stranded
virus stranded
virus stranded virus RNA virus
(envelope virus
from HBV)
Parenteral
Parenteral
Parenteral
Fecal-oral
Fecal-oral
(most common
route
route
MOT
blood
transfusion)
With Chronic
state (Hepato-
No Yes Yes Yes No
cellular
carcinoma)
Summarized in the table are the different viral causative agents of hepatitis. We have Hepatitis A, B, C,
D and E.
HEPATITIS
“Hepa-” = liver
“-itis” = inflammation
Thus, when we use the word “hepatitis” – it actually refers to the inflammation/infection of the liver.
An inflammatory disease involving the liver:
Necrosis of hepatocytes
Infiltration of the liver by immune cells causing immune mediated destruction of cells and
tissue
Whenever there is hepatitis, there is an equivalent death of cells or necrosis of hepatocytes. And since
there is an ongoing inflammation, expect that there will be an ongoing infiltration of the liver tissue by
immune cells and most of the time, the destruction or the killing of hepatocytes are brought about by
the presence of these immune cells.
Can be caused by:
Drugs
o Because there are hepatotoxic drugs – these are drugs that can damage the liver
o That is why if you are a doctor and you know that the drug you will give is hepatotoxic, you
really have to request some tests and determine the function of the liver. Because if the
patient has a problem with the functions of the liver then most likely you cannot give the
hepatotoxic drug or you will adjust the dose of the hepatotoxic drug so that it cannot add
on to the ongoing liver problem of the patient.
Alcohol
o That is why a lot of patients who are considered to be chronic alcoholic drinkers will really
develop liver problems when they get old
Metabolic disorders
o If you can remember from your biochemistry, some glycogen metabolic disorders can
actually cause hepatitis
Viruses
o These viruses contain antigens and these antigens can be processed in the immunology
and serology laboratory.
HEPATITIS: SIGNS AND SYMPTOMS
Swelling (hepatomegaly) and tenderness of liver
o Imagine a patient lying down then if you will act as a doctor, then if you palpate the upper
right quadrant of the abdomen of the patient, once you palpate a solid mass it would indicate
that there is a swelling of the liver or hepatomegaly.
o Sometimes the palpation can actually trigger pain and you call that as the tenderness
o Note: There is a difference between pain and tenderness. Pain is the one that is felt by the
patient, but if the pain was initiated by physical exam or by palpation then the doctor would
refer to it as “tenderness”.
Jaundice – yellowish discoloration of the skin
o There would also be jaundice because you know very well that the organ that eliminates
bilirubin (yellowish-colored pigment) from the body is actually the liver. So, if the liver is
having problems, if the hepatocytes are dying, then most likely the elimination of the
bilirubin would also be affected causing now the build-up of bilirubin in the blood and the
deposition of bilirubin into the skin, making the skin appear yellowish.
Note: If the causative agent is virus, then most likely the patients would develop:
Low grade fever Fatigue
Nausea and vomiting
, HEPATITIS: LABORATORY TESTS
How would you confirm hepatitis in the laboratory?
1. High levels of serum bilirubin
You can have the serum bilirubin of the patient to tested and expect that the bilirubin level will
be elevated in a case of liver problem
2. High levels of serum Alanine aminotransferase (SGPT)
The patient would also have a high level of alanine aminotransferase enzyme in their blood
(ALT). Another name is serum glutamic pyruvic transaminase (SGPT).
This enzyme is found intracellularly (within the cytoplasm of the hepatocytes). So, if the
hepatocytes are destroyed or killed, they will burst and undergo lysis, and this serum alanine
aminotransferase will now start appearing in the blood.
So, if you are going to check the blood of the patient, you will see high levels of alanine
aminotransferase and that would actually give you an idea that hepatocytes are bursting and
undergoing lysis because there is an ongoing problem in the liver.
3. Low levels of serum albumin and total proteins
Remember, the majority of the proteins in the body (except antibodies) are produced in the
liver. So, if there is an ongoing liver problem then most likely the production of these proteins
will also be affected.
The most abundant protein is serum albumin. If you are a doctor and you don’t want the patient
to spend a lot of money, then most likely you will just request for serum albumin because
serum albumin is the most abundant protein. So, if the level of serum albumin is low, then that
would also somehow reflect the function of the liver.
DIFFERENT VIRAL CAUSATIVE AGENTS OF HEPATITIS
Hepa A Hepa B Hepa C Hepa D Hepa E
Causative
agent
PicoRNAvirus/ Flavivirus/ Calicivirus/
HepaDNAvirus Deltavirus
Hepatovirus Hepacivirus Hepevirus
Enveloped
Description
of the virus
single Naked
Naked single Enveloped Enveloped
stranded single
stranded RNA double single stranded
virus stranded
virus stranded virus RNA virus
(envelope virus
from HBV)
Parenteral
Parenteral
Parenteral
Fecal-oral
Fecal-oral
(most common
route
route
MOT
blood
transfusion)
With Chronic
state (Hepato-
No Yes Yes Yes No
cellular
carcinoma)
Summarized in the table are the different viral causative agents of hepatitis. We have Hepatitis A, B, C,
D and E.
