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