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34 Cards in this Set
- Front
- Back
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What are the 2 broad outcomes for viral hepatitis?
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1. Acute Hepatitis - asymptomatic or symptomatic
2. Chronic Hepatitis - Asymptomatic or symptomatic |
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What Hepatitis viruses cause chronic infections?
Acute infections? |
Chronic - HBV, HCV, HDV
Acute - All (A-E) |
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What 3 clinical conditions can Viral Hepatitis lead to?
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1. Fulminant Hepatitis - quick liver failure, high mortality
2. Cirrhosis - liver scarring due to damage 3. Hepatocellular carcinoma - malignant cancer often induced by HBV or HCV (but NEVER HAV) |
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What causes jaundice?
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Systemic retention of pigmented bilirubin in the tissues
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What type of bilirubun is often dominant in Hepatitis?
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Mostly unconjugated bilirubin (liver converts from unconjugated to conjugated)
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What are the 5 liver function tests?
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1. ALT (alanine aminotransferase) - more specific for liver abnormalities that others
2. AST (aspartate aminotransferase) - less specific, AST present in other tissues 3. AP (alkaline phosphotase) - less specific, indicative of bile duct injury 4. GT (gamma glutamyl transpeptidase) - often elevated in those who use alcohol or drugs 5. Bilirubin |
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What are the cellular characteristics of HAV?
How many serotypes? |
1. Picornavirus (very small)
2. Non-enveloped (stable outside of body) 3. +ssRNA 4. ONLY 1 serotype |
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What are the main pathogenic steps of HAV?
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- enters via oropharynx
- replicates in HEPATOCYTES - shed in stool - Disease results of host's own Immune Response |
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How is HAV spread?
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- Via fecal-oral route
- Often via contaminated food/water (shellfish) from a single point source |
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What symptoms does HAV generally cause?
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- ONLY acute infection, self limited
- NO cancer, NO chronic infection - fever, vomiting, fatigue, etc - Adults symptomatic, kids asymptomiatic - Hepatomegaly, jaundice - RARELY fulminant hepatitis |
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How is acute HAV infection diagnosed?
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- IgM detection is the gold standard
- Also, elevated liver function tests - Observe IgG for prior exposure |
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How is HAV treated?
Vaccine? |
- Only supportive treatment because virus is self limited
- 2 inactivated vaccines: protection for 20-30 years bc only 1 serotype |
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What are the cellular characteristics of HBV?
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- dsDNA
- enveloped - Uses Reverse Transcriptase - Has Core Protein (HBcAg) - Has Surface Antigen (HBsAg) |
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What are the main components of HBV pathology?
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- Infects hepatocytes
- NOT cytopathic - Genome can integrate - Symptoms arise from host immune response - Subviral particles composed of HBsAg can "soak up" Ig's |
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In the US, what are the 2 main routes of transmission of HBV?
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1. Sexual Transmission
2. IV drug use |
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What are the percentages of acute vs. chronic infections of HBV in adults?
When a perinatal infection? |
Adults: 95% acute, 5-10% chronic
Perinatal: 95% chonic, 5% acute |
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What are the symptoms of acute and chronic HBV infection?
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Acute HBV: Mostly asymptomatic, standard HAV symptoms if not
Chronic: many asymptomatic. In not, cirrhosis, hepatocellular carcinoma (25-30 years later) |
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How is acute and chronic HBV infection diagnosed?
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Acute: IgM+ and HBsAg+
Chronic: IgM-, IgG+ to HBsAg and HBcAg, HBsAg+, HBcAg+ Note: HBcAg NOT part of vaccine, so if this is seen must mean infection |
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How is acute and chronic HBV infection treated?
Vaccine? |
Acute: No treatment
Chronic: PEG Alpha Interferon and HBV genome replication blockers (lemivudine, adeforir, tenofovir) - 2, 3 dose vaccines based on HBsAg |
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What are the cellular characteristics of HCV?
How many genotypes? |
- Flavavirus
- enveloped - +ssRNA - 6 genotypes |
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What are the basic components of HCV pathology?
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- Infects hepatocytes
- NOT cytopathic (symptoms arise from immune response) - Viral genome does NOT integrate - evades immune response via high mutation rate and viral proteins |
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What is the leading cause of chronic liver disease?
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HCV - type 1 most common in US
- 85% chronic / 15% acute |
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What are the symptoms of acute and chronic HCV infection?
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- Both usually asymptomatic
- Chronic: cirrhosis, hepatocellular carcinomas |
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How is HCV diagnosed?
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- Test for antibodies to HCV
- PCR to determine viral load - genotype virus (2&3 more treatable) |
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How is HCV treated?
Vaccine? |
- PEG-Interferon and ribavirin (biopsy to see if treatment necessary)
- No vaccine |
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What are the 2 new drugs that are specific against HCV genotype 1?
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Boceprevir and Telaprevir
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What are the cellular characteristics of HDV?
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- Deltavirus
- enveloped - -ssRNA - NEEDS to use HBsAg (co-infection) |
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What are the main steps in HDV pathogenesis?
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- Can only infect those with HBV
- Either via COINFECTION (simultaneous HBV and HDV) or SUPERINFECTION (HDV infects someone with chronic HBV) |
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What are the symptoms of HDV?
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- Major cause of fulminant hepatitis
- Both chronic and acute |
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How is HDV treated?
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Only supportive treatment
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How is HDV diagnosed?
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ELISA for Ig's to delta antigen
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Where is HEV usually located?
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Rare in the US, endemic in other parts of the world
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What does HEV cause?
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- Acute, self-limited viral hepatitis
- NO CHRONIC infection |
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How is HEV treated?
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Only supportive care
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