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14 Cards in this Set
- Front
- Back
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Hepatitis target
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- Hepatocytes, hence the name...
- Almost all varieties from different viral families - Disease state results from immune response! |
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Hepatitis varieties
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- Hep A (HAV) - Picornavirus
- Hep B (HBV) - Hepadnavirus - Hep D (HDV) - Delta hepatitis - only infects people with active Hep B! - Hep C (HCV) - Flavivirus - Hep G (HGV) - Flavivirus (very similar to C) - Hep E (HEV) - Calicivirus - disease resembles HAV |
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Common hepatitis symptoms
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- Jaundice - yellow skin/eyes
- Elevated alanine, aspartate amino transferases (ALT, AST) - Hepatocytes die, release into blood - Tea-colored urine - White/pale stools - Normally, RBC's die, release Hb -> bilirubin -> processed by liver - Bilirubin digested with liver enzymes, exits via GI, makes poop brown - Damaged hepatocytes -> don't process bilirubin -> excess in blood -> also don't make it to GI - Excess from blood filters into urine -> tea urine - Lack in stool creates pale stool |
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Other patient symptoms
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- Malaise, anorexia, nausea, abdominal pain, +/- fever
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Hepatitis B/C/G progression courses
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- Symptomatic - elevated ALT, jaundice
- Possible fulminant hepatitis (very rare) -> Very high mortality! - Asymptomatic = HBV/HCV - chronic carriers, disease reservoir... - Eventual cirrhosis, fibrosis, hepatocellular carcinoma |
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Hepatitis carriers/duration/transmission
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- A, E = acute infections, no carriers!
- Usually fecal/food contamination = diarrhea, dehydration, usually recover -> lifelong immunity - B, C/G, D - chronic infections, cirrhosis, fibrosis, cancer, death - Transmission via blood, sexual transmission |
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Hep A overview
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- non-enveloped picornavirus, RNA in icosohedral capsid with HA
- Vaccine target is surface HA receptor - GI -> blood -> liver - Incubation time = ~1 mo. - hard to ID source of disease... - Disease cause = not cytolytic! - Symptoms from immune response - Diarrhea, dehydration ensues - Children less than 1yo. = no immune system, no immune response, no disease - Acute disease and fever, lifelong immunity, low mortality, no carriers! - Diagnosis = anti-HA IgM - Treatment = hydrate patient - Transmission = close contact, food handlers, health workers, child care, contaminated water/shellfish |
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Hepatitis B overview
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Hepadnavirus - Enveloped, icosohedral, incomplete dsDNA
- Incomplete circular dsDNA - convert DNA -> RNA -> back to DNA via reverse transcriptase - Transmission = blood, saliva, genital secretions, breastmilk (same as HIV) - Viral load 1000x higher than HIV - more easily infected! - Prevention = universal precausions, block sex transmission, screen blood - Treatment = For chronic cases only = reverse transcriptase inhibitors, interferon-α - No physical exercise when hepatitis symptomatic - Will stimulate liver activity, hepatocyte mitosis = makes more virus too! - Pathogenesis - NOT cytolytic - immune mediated response causes disesae - Symptoms = liver problems - also potential joint (arthritis) and kidney complications |
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Hep B life cycle
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- Enter hepatocyte, uncoat core
- incomplete DNA -> RNA -> complete circular DNA in cytoplasm - Synthesize mRNA's for HBc, HBs, and HBp (polymerase for cytoplasmic activity) |
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Hep B Ag/Ab
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- HBcAg = antigen of viral capsid
- HBeAg = capsid protein that is short-lived - produced at replication, consumed quickly - High levels indicate rapidly replicating virus - If viral replication at lower levels - won't show up even if virus still present - Rough indicator of therapy success - HBsAg - Detectable whenever virus is present in any state - Surface antigen = used for vaccine! - Ab to HBsAg indicate virus cleared from system = lifelong immunity! |
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2.5 tests for infection
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- HBcAg tends to disappear from serum relatively early in infection course
- Only see HBeAg, HBe-Ab, HBc-Ab, HBsAg, HBs-Ab - Previously infected person has Ab to HBc, HBe, and HBs! |
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Hep B particles/vaccine
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- Dane particle - complete virion
- surface-antigen studded envelope, HBcAg, whole genome present = live, real virus - Spherical/fiber particles - antigen studded envelope, but NO core proteins or genome... - 1/2-diameter of Dane particle - These particles purified, used as 1st vaccine - Current vaccine = yeast expressing surface antigen - People worried about accidentally getting Dane particles from purified particles |
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Hep B - Acute vs. chronic
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Acute = If initial immune response is very strong - can generate Ab to HBsAg
- Strong response will clear virus from system with lasting immunity via Ab's - ~90% will clear virus - make complete recovery - Chronic = NO Ab to HBsAg! (10-20%, many children) - intial immune response not strong enough - some virus lingers in cells away from immune system - Will continue to have mild symptoms, eventual cirrhosis, hepatocellular carcinoma - Hep D (delta agent) - can infect, cause fulminant hepatitis |
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Chronic diagnosis
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- Usually see presence of HBc, s, e - NO HBs-Ab!
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