Hepatitis

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Hepatitis

• Chapter 42

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www.liverdoctor.com/ 02_liverdetox.asp
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The Liver

• Holds 13 (500 ml) of total blood volume
• Functional units 100,000 lobules
• Cells types
• Hepatocytes 60
• Biliary cells 40
• Receives blood from hepatic artery 30
• Receives blood from hepatic portal vein 70

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Major Functions of the Liver

• Metabolism of CHO, protein, fat
• Detoxification of drugs
• Bile production
• Excretion of bilirubin, hormones, ammonia,
  cholesterol, and drugs
• Storage of glycogen, vitamins, fatty acids,
  minerals, amino acids
• Macrophage system

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Functional Unit Liver Lobule
faculty.spokanefalls.edu/. ../slide0039.htm
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Microscopic Liver Lobule
www.biologymad.com/ Kidneys/Kidneys.htm
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Bilirubin Metabolism
www.umanitoba.ca/.../ Frank_II/biliOverview.html
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• Unconjugated bilirubin
• (indirect, insoluble, bound to albumin)
• Conjugated bilirubin
• (direct, conjugated with glucuronic acid in
  liver, soluble)
• Total bilirubin

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Bile

• Contains water, cholesterol, bile salts,
  electrolytes, phospholipids, and bile pigments
  (mainly bilirubin)
• Excreted by the liver about 1 liter/day
• Concentrated and stored in the gallbladder
  (gallbladder holds about 45 ml of bile)
• Used for fat emulsification and digestion

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Hepatitis

• Widespread inflammation of the liver tissue
• Acute viral hepatitis A, B, C, D, E, G
• Toxic and drug-induced hepatitis
• Autoimmune hepatitis

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Hepatitis A HAV RNA Virus

• Fecal-oral transmission
• Incubation 15-20 days
• Most infectious 2 weeks before the onset of
  symptoms 1-2 weeks after symptoms start
• Presence of IgG antibody lifelong immunity
• Lab test Anti-HAV IgM acute infection, Anti-HAV
  IgG for previous or long-term
• Prevention Hepatitis A vaccine, Immune globulin

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Hepatitis B HBV DNA Virus

• Transmission
• Percutaneous (IV drug use, accidental needle
  sticks)
• Permucosal infectious blood and body fluids
• Perinatal mother to infant
• Sexually transmitted semen, vaginal secretions,
  saliva)

www.hepalife.com/ HBV/HBV.html
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Hepatitis B HBV DNA Virus

• Incubation 45-180 days
• Infectious before and after symptoms appear, for
  4-6 months
• Lab tests 3 antigens (HBsAg, HBcAG, HBeAG)
• Chronic carriers HBsAG for 6-12 months
• Prevention hepatitis B vaccine
• Treatment a-Interferon, immune globin

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Hepatitis B Virus
www.hon.ch/Library/ Theme/HepB/viroligy.html
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Hepatitis C HCV RNA Virus

• Percutaneous transmission IV drug use,
  permucosal exposure to blood/blood products,
  transfusion/organ recipient (before 1992),
  clotting factors recipient (before 1987), sexual,
  perinatal
• Incubation 14-180 days
• Infectious 1-2 weeks before symptoms

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Hepatitis C HCV RNA Virus

• Chronic infection 55 85 of the infected
• Chronic liver disease 70 of the chronically
  infected
• Lab tests Anti-HCV (acute or chronic), Enzyme
  immunoassay (EIA) screening, Recombinant
  immunoblot assay (RIBA)
• Treatment - a-Interferon, Ribavirin

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Hepatitis D HDV single-stranded RNA virus

• Requires HBV to replicate ? HDV can be acquired
  as a co-infection with HBV or a superinfection in
  people with HBV infection
• Percutaneous transmission as with HBV
• Incubation 2-26 weeks, HBV must precede HDV,
  chronic carriers of HBV at risk
• Infectious blood is infectious at all stages of
  HDV infection

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Hepatitis D HDV single-stranded RNA virus

• Lab tests Anti-HDV (current or past infection)
• Prevention Hepatitis B vaccine to prevent
  HBV/HDV co-infection
• Treatment supportive for acute HDV,
  a-Interferon for chronic HDV

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Hepatitis E HEV RNA Virus

• Fecal-oral transmission contaminated water
• Incubation 15-64 days
• Infectious not known, no chronic infection
• Lab tests IgM IgG anti-HEV
• Prevention - avoid drinking water, hygiene
• Treatment - supportive

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Hepatitis G HGV RNA Virus

• Transmission parenteral sexual
• A newly identified virus
• May coexist with other hepatic viral infections
  such as HBV HCV
• Lab test - developing
• Prevention no vaccine available
• Treatment - supportive

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Pathophysiology of Hepatitis

• Infection ? cytotoxic cytokines and natural
  killer cells ? lysis of infected hepatocyes
• Hepatic cell necrosis
• Proliferation enlargement of Kupffer cells
• Interruption of bile flow ? cholestasis
• Activation of the complement system systemic
  immune response

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Clinical Manifestations

• Preicteric Phase (prodromal phase)
• 1-21 days before jaundice
• GI symptoms anorexia, nausea/vomiting, RUQ
  discomfort, constipation/diarrhea
• Malaise, HA, low-grade fever
• Arthralgias, skin rash
• Hepatomegaly, lymphadenopathy
• Splenomegaly

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Clinical Manifestations

• Icteric Phase
• 2-4 weeks of jaundice
• Bilirubin diffuses into the tissue jaundice,
  dark urine
• If flow of conjugated bilirubin is blocked
  light/clay colored stool
• Accumulation of bile salt under skin pruritis
• Liver enlarged and tender

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Clinical Manifestations

• Posticteric phase (convalescent phase)
• Jaundice disappearing avg. 2-4 months
• malaise,
• Hepatomegaly remains for weeks, splenomegaly
  subsides
• May relapse

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Complications

• Most people recover completely
• Overall mortality lt 1
• Fulminant hepatic failure severe impairment or
  necrosis of liver cells, liver failure
• Chronic hepatitis
• Cirrhosis of liver
• Hepatocellular carcinoma

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Management

• Supportive drugs such as antiemetics, sedatives,
  hypnotics
• Antiviral drugs such as Lamivudine, a-Interferon,
  Adefovir dipivoxil
• Nutrition high CHO and protein, low fat
• Vitamin supplements B-complex, Vit K
• Rest
• Fluid intake 2500-3000 ml/day
• Education on prevention