If you can't read please download the document
Upload
margaretmargaret-walker
View
222
Download
0
Embed Size (px)
DESCRIPTION
LOCATION OF THE LIVER THE BODY’S LARGEST ORGAN The liver, a wedge shaped organ is located underneath the rib cage. The liver which weighs close to 3 pounds is the body’s largest organ. The liver is an important organ that receives blood from 2 different sources. Many of the substances carried in the blood are modified as the blood passes through the liver
Citation preview
Xie Qing Department of Infectious Diseases Shanghai Ruijin
Hospital
VIRAL HEPATITIS Xie Qing Department of Infectious Diseases Shanghai
Ruijin Hospital LOCATION OF THE LIVER THE BODYS LARGEST ORGAN
The liver, a wedge shaped organ is located underneath the rib cage.
The liver which weighs close to 3 pounds is the bodys largest
organ. The liver is an important organ that receives blood from 2
different sources. Many of the substances carried in the blood are
modified as the blood passes through the liver Functions of the
liver your bodys chemical factory
The liver performs many varied and complex functions. It cleans and
purifies the blood supply, breaks down certain chemical substances
in the blood, and synthesizes others Functions of the liver
Purification: substances such as drugs and alcohol are converted
into an inactive form in the liver. In addition some drugs may be
activatedrather than inactivated by the liver before they can start
working Synthesis; the liver manufactures most of the proteins
found in the blood. Proteins needed to prevent bleeding are also
manufactured in the liver FUNCTIONS OF THE LIVER Storage: Sugars,
fats, vitamins and minerals are stored in the liver until they are
needed. The liver changes blood sugar(glucose) into a storage form
(glycogen). When the body needs energy, the sugar is then released
by the liver. Functions of the liver Transformation: The liver uses
enzymes to transform small building blocks (amino acids, sugars,
and fatty acids) into other building blocks. An excess of one of
these enzymes, alanine aminotansferase (ALT) is found in the blood
when liver cells are damaged. The liver which also inactivates
certain hormones , regulates the amount of testosterone and
estrogen in the blood. Plays a major role in breaking down and
building up cholesterol. Classification of Viral Hepatitis
Hepatitis A Hepatitis B Hepatitis C Hepatitis D Hepatitis E
Etiology Hepatitis A Virus 28 nm RNA virus(picornavirus)
Antigen HAV Ag(in stool; also in blood) Antibodies Anti-HAV(IgM and
IgG or total) Epidemiology Fecal-oral, rarely parenteral Mortality
% Chronicity None Modes of Transmission of Heaptitis A
Common Rare Fecal-oral Percutaneous Household (water)
Institutional(Mollusk) Intimate (Food) Transfusion (Inoculation)
Epidemiologic Characteristics of Endemic Patters of HAV
Infectiion
Prevalence of HAV Infections (%) Endemicity of Infection Age
Group(Years) Geographic areas >40 High > >85 >85
Africa, Middle East, most of Asia, South america, Central America
Intermediate >80 Eastern Europr and former SU, most Caribbean
islands Low >40 Western Europe, Astralia, New Zealand, Japan,
Canada, US VeryLow Scandinavian countries Hepatitis B Virus 42 nm
DNA virus (hepadavirus)
Antigen Surface antigen or HBsAg Antibodies Anti-HBc IgM( acute,
rarely chronic) and anti-HBs (neutralizing, seen post-recovery or
after vaccination ; rarely chronic) Mortality % Chronicity %
Characteristics of Endemic Patterns of HBV Infection
Endemicity of Infection Characteristic Low Intermediate High
Chronic infection prevalence 0.1-1% % % Past infection prevalence
4-15% % % Perinatal infection Rare(20%) Early childhood infection
Rare(60%) Adolescent/adult infection Very common
Common(20-50%)Uncommon(10-20%) (70-90%) Global Distribution of
Chronic HBV Infection
Key messages Hepatitis B is one of the most common infectious
diseases in the world. There are 350 million chronic carriers of
the hepatitis B virus worldwide. Hepatitis B is the ninth leading
cause of death worldwide. Geographical prevalence varies widely
throughout the world. Nearly 75% of HBV chronic carriers are Asian.
Points of explanation The geographical prevalence of hepatitis B
varies from a highly endemic disease in Asia and Africa to a
disease of low prevalence in North America and Western Europe.
Additional information More than 2 billion people worldwide have
been infected with HBV though not all of these have become
chronically infected. The majority of hepatocellular carcinoma in
Asia results from hepatitis B virus infection References Margolis
HS, Alter JH, Habler SC. Hepatitis B: evolving epidemiology and
implications for control. Sem Liver Dis 1991;11:84-92 Mast EE,
Alter JH. Epidemology of viral hepatitis: an overview.Sem Viral
1993;4: World Health Organisation Data HBsAg Prevalence (%) 8:High
2-7:Intermediate 50% of cases progressinto chronic condition. HC HD
Coinfection with HBV, superinfection with HBV Similar to HA, often
cholestatic, in older and pregnantmore severe HE Mild form
intermediate form
Mild or nonspecific symptoms: fatigue, anorexia, abdominal
discomforts, jaundice, mildly tender hepatomegaly. Extrahepatic
manifestaion; less common than in grave. Lab tests: ALT elevation,
bilirubin and globulins are mild. Mild form Between mild and grave.
Local and constitutional symptoms: fatigue, malaise, fever,
anorexia, jaundice, palmar erythema, spider telangiectasias,
moderate enlargement of liver and spleen. Extrahepatic: prominent.
Lab tests: n persist loger. ALB is low. intermediate form Grave
Hepatitis Fulminant Subacute Grave Chronic Grave
Hepatic failure with encephalopathy developing within 10 days
without pre-existing liver disease Fulminant Subacute Grave Hepatic
failure with encephalopathy developing within 10 days Chronic Grave
Similar to subacute grave, but having prehistory of liver diseases.
Cholestatic Hepatitis
Usually due to intrahepatic biliary obstruction Cholestatic signs
are prominent: jaundice, lightish stools, itching Lab test: ALP
Laboratory Finding Liver Function Tests Serum enzyme Serum
Bilirubin
Prothrombin Time Serum Protein Ammonia ALT ALP AST r-GT Tests in
Hepatitis Viral Markers
Agent Terminology Significances Anti-HAV IgM IgG HAV: Serum Current
or present infection, immunity Current or recent infgection, or
convalencen Stool HAV-RNA Infectivity HBV: HBsAg Acute, chronic
infection Anti-HBs Protective HBeAg Active viral replication
Anti-HBe Low or absent viral replication Anti-HBc IgM Acute
infection IgG Chronic infection HBV-DNA Active viral replication
HCV Anti-HCV infection HCV-RNA Active replication HDV Anti-HDV
Infection, not protective HEV Anti-HEV IgM Current infection,
convalescence IgG Previous infection, immunity Compensated
Cirrhosis
Complications Cirrhosis Compensated Cirrhosis Resolution
Stabilisation Acute Infection Chronic Hepatitis Liver Cancer Death
Key message Progression of hepatitis B is variable.Acute hepatitis
B is usually self limiting and benign, but may progress to chronic
hepatitis B in a proportion of patients.Chronic hepatitis B may
lead to more serious conditions including cirrhosis, liver failure
and hepatocellular carcinoma. Points of explanation In the liver,
acute infection (short term infection) with hepatitis B causes the
body to mount an immune response to eliminate the virus.The immune
system attempts to eradicate the virus by destroying HBV infected
liver cells.In some patients the immune response succeeds and the
patient makes a complete recovery (resolution). However in other
HBV-infected people, the immune response to the infection is
insufficient to eliminate the virus for many months / years or not
at all; slowly destroying more and more infected liver cells as the
virus spreads (long-term infection).This slow persistent
destruction of liver cells by the immune system can lead to
fibrosis, cirrhosis and even hepatocellular carcinoma. Patients
infected with HBV whose immune systems cannot eliminate the virus
are referred to as chronic HBV carriers. Chronic HBV carriers can
pass the virus to others. Hepatitis B surface antigen (HBsAg) is
the first serological marker to appear in the serum and is present
in high levels during acute and chronic infection.Persistence of
HBsAg for more than 6 months defines a chronic infection.
References Feitelson MA.Biology of disease: biology of hepatitis B
virus mutants.Lab Invest 1994; 71: Chronic Carrier Progression
Decompensated Cirrhosis (Death) Fulminant hepatic failure Years
Adapted from Feitelson, Lab Invest 1994 Treatment Acute Hepatitis
Rest Diet Supportive Medication
Hospitalization Chronic Hepatitis Symptomatic and Immunomodulators
nutritional support
HBV (Lamivudin, Interferon) Medication ALT, SB Antiviral treatment
HCV(IFN, IFN+Ribavirin) Indications of Antiviral Treatment
Hepatitis B Hepatitis C Chronic Hepatitis B Active viral
replication: HBsAg +, HBeAg+, Anti-HBc+,HBV DNA+ Or HBsAg+, HBeAg-,
Anti-Hbe+, Anti-HBc+, HBV DNA+ Abnormal of Liver function Acute or
chronic Hepatitis C Active viral replication HCV RNA+ General and
supportive Liver cell regeneration
enhancer Grave Hepatitis Symptomatic Hepato-renal Syndrome
treatment Anti-Bleeding Anti-Hepatic encephalopathy Anti-Secondary
infection Prevention Control of infections sources, improve
plublic
health and personal hygiene Cut off the transmission routes
Pretection of susceptible individual Active immunization:
HA--Hepatitis A vaccines(Havrix) HB--Hepatitis B vaccines Passive
immunization: HA--immune globlin HB--HBIG Thank you