| |
by Robert G. Gish, MD, Pacific
Hepatology, California
Pacific Medical Center
Hepatitis B is a virus that infects the liver and
usually causes progressive damage by bringing the
immune cells into the liver and invoking an
inflammatory response. The general word
"hepatitis" indicates the presence of this
inflammatory response. Once the inflammation (presence
of pus cells) begins, fibrosis (scar tissue) may form
and eventually a patient may develop cirrhosis liver
failure and liver cancer. Liver transplantation is a
possible treatment for hepatitis B induced liver
failure but recurrence of the infection in new the new
liver is still a problem in some patients.
Hepatitis B infected patients are contagious:
- Hepatitis B can be sexually transmitted either
through heterosexual or homosexual relations.
- Hepatitis B can be acquired just by living in the
same household as a person who has hepatitis B.
- Hepatitis B can be acquired through needle stick
exposure, blood transfusion or sharing needles by IV
drug abusers.
Laboratory Terms:
surface antigen (HBsAg):
This means a patient has the virus and is
infected with hepatitis B and is infectious to
others.
surface antibody (sAby or anti-HBs):
If this test is positive it means that a person
is immune to the hepatitis B virus and does not
carry infection.
core antibody (cAby or anti-HBc):
This test if positive means the patient has be
exposed to the hepatitis B virus but does not mean
immunity or active infection, please refer the two
tests above.
e antigen (HBeAg):
This is a crude marker of active reproduction
(and infectivity) of the virus.
e antibody (HBeAby or anti-HBe):
This test is used to show low reproduction of
virus a patient is positive if the e antigen test
is negative.
Hepatitis B DNA:
This is the genetic code for the virus and is
also a blood test If this test is positive, shows
that the patient has a very actively reproducing
the virus in the body. The presence of HBV DNA in
the blood is also a marker of infectivity.
Types of hepatitis B infection:
Active infection with inflammation (immune active):
patients with active infection have elevated
liver enzymes and inflammation on liver biopsy.
These patients are the most likely to respond to
interferon and may spontaneously convert from a
state of high viral replication to low or even
spontaneous clear the virus from the body and liver.
Silent carrier (immunotolerant phase):
patient with normal liver enzymes and a normal
liver biopsy do not recognize the presence of the
hepatitis B infection. These patients have a low
likelihood of spontaneous conversion (1% per year)
or respond to therapy such as interferon. The best
management for such patients is to observe for
liver enzyme abnormality and then consider a liver
biopsy and therapy. This type of patients is the
most common worldwide. Such patients usually
acquired the hepatitis B infection at birth or in
childhood. These patients have a high risk of
liver cancer starting at age 30-50. If there is a
family history of liver cancer and/or other causes
of liver found (such as hepatitis C or alcohol)
blood test for alpha-fetoprotein and ultrasound
should start at age 40. If there is no family
history of liver cancer and no other cause of
liver disease, I recommend ultrasound and AFP
annually starting at age 50.
Cirrhosis:
This is the scarring process for ongoing
inflammation and is found in l0-30% of patients with
active hepatitis but can also occur, rarely, in
silent carriers. This diagnosis is difficult to
determine by physical exam and laboratory testing
early. All patients with hepatitis B, as with other
causes of liver disease should have a liver biopsy
if the liver enzymes are elevated. If cirrhosis is
present the risk of liver cancer (the most common
cancer in the world) is 200 times as common as in
normal people.
The immune system attempts to rid the body of the
Hepatitis B virus using lymph cells and proteins
(cytokines) such as interferon. The effect of
interferon, according to the published studies, on
patients with hepatitis B infection is to decrease
or halt the replication (the virus reproducing
itself) of the hepatitis B virus. 40% of patients
have a fall in liver enzymes, and a fall or
disappearance of the DNA of the virus. The
inflammatory changes seen on liver biopsy improve in
most of the patients who improve their liver
enzymes. 10% of patients clear the virus (convert
from surface antigen positive to surface antigen
negative) and can be stated to be cured. A long-term
follow-up study showed that patients treated with
interferon will eventually lose HBsAg and be cured
of hepatitis B.
Treatment:
Interferon:
Patients likely to respond to interferon:
- Hepatitis B duration less than 4 years
- HBeAg positive
- Hepatitis B DNA positive
- Elevated liver enzymes
Patients not likely to respond to interferon:
- Long duration of disease
- Hepatitis B acquired at childbirth
- Hepatitis B DNA negative (the virus is not
reproducing)
- Presence of HIV (AIDS) virus
- Older age
- Normal liver enzymes
Interferon is given by subcutaneous injection
and is usually given at higher dose (5 million
units per day or 10 million units three times a
week) for 16 weeks. The side effects of interferon
include soreness at the injection site, slight
fever, muscle aches, elevated blood sugar, mood
swings, hair loss, nausea, joint aches, head ache,
decreased blood cell counts, including white blood
cells (those used to fight infection), platelet
count (used for blood clotting), and anemia (a
decrease in red blood cells which~are used for
carrying oxygen). There is no known risk of HIV or
AIDS (immunodeficiency disease) from the use of
these treatments.
Newer forms of interferon will also act against
HBV infection:
- Wellferon
- Consensus interferon (Infergen) (alfacon-1)
- Roferon (alfa-2a)
- Oral medications
that can be prescribed at a
pharmacy that suppress KB infection but do not cure
disease are:
- lamivudine
- famciclovir
- ganciclovir
These medications could be used with
interferon, complete information on the utility of
combination therapy has not been published.
Combination therapy could increase the chance of
cure and decrease the chance of mutations that
lead resistance.
- Medications in trial
in the United States:
These oral medications have few side effects
and are not give by injection.
- Newer experimental medications
that may be
used to treat chronic hepatitis infection include:
- Cyl899 - a therapeutic vaccine
- monoclonal antibodies (experimental)
- tucaresol (experimental)
Hepatitis B vaccination:
The hepatitis B vaccine is produce my recombinant
technology (genetic engineering) and has no risk of
transmission of the AIDS virus. Minor local reactions
or fever are the side effects most noted. There is no
increased risk ot severe reactions or side effects
such as Guillan-Barre.
There is a vaccine available for
hepatitis B and all household contacts and
sexual contacts of a person infected with the
Hepatitis B virus should be vaccinated. All
homosexuals should be vaccinated. All patients of
Asian origin should be vaccinated. All health care
workers should be vaccinated.
The hepatitis B vaccine should be administered to
high risk individuals. There currently no reason not
to take the vaccine.
HIGH RISK INDIVIDUALS:
- All health care workers
- Emergency workers
- Pregnant women
- International travelers
- Military personnel
- Morticians and embalmers
- Patients and personnel at institutions of
mentally handicapped and incarceration
- High risk ethnic groups
- Male homosexuals
- Intravenous drug users
- Infants born to HBsAg positive mothers
The vaccination process involves 3 injections at 0,
1 month and 6 months. No booster is required.
Evaluation of patients who are at high risk for HBV
infections:
Best screening test: HBcAby
Hepatitis B core antibody >>>>
negative >>>> vaccinate
- if positive order HBsAg
- positive HBsAg = infectious
Order liver enzymes >>>> abnormal
>>>> liver biopsy
If cirrhosis: start bi-annual liver cancer
screening with U.S. and AFP
If no cirrhosis by liver biopsy or if liver
enzymes are normal:
- Ask if family history of liver cancer
- if yes, start liver cancer screening at age 40
by AFP and US yearly
- if no, start liver cancer screening at age 50
by AFP and US yearly
Liver enzymes should be measured bi-annually in
all patients
ROBERT G. GISH, MD
STEPHEN L. STEADY, MD
ADIL "ED" WAKEL, MD
FRANCIS YAO, MD
FRED POORDAD, MD
Pacific Hepatology
2340 Clay St.
California Pacific Medical Center
Department of Transplantation
San Francisco, California 94115
Fax: 415-474-8543
Tel: 415-202-1530 or 923-3450
|
