10.13 Hepatitis B and D – Flashcards
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| What are downey cells? |
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| a reactive lymphocyte with distinctive morphology that is commonly associated with viral infections. Not typically observed in circulating blood. Nucleus of a reactive lymhpocyte can be round, elliptic, indented cleft or folded and the cell with be enlarged with abundent vacuoles. Cytoplasm is often gray to pale blue in color |
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| Along with EBV infection, what other infection is a cofactor for development for development of burkitt's lymphoma in africa? |
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| malaria (P. falciparum is highly mitogenic for B cells) |
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| T/F ALl forms of Burkitt's lymphoma contain a dysregulated form of the c-myc oncogene activated thru a chromosomal translocation onto the immunoglobulin locus |
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| true |
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| What is the viral family of hepatitis B? |
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| hepadnavirus |
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| Describe the virion and genome of hep B. |
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| enveloped; pleomorphic structure; smallest of enveloped animal viruses. DNA virus with nuclear replicaiton |
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| T/F Hepatitis B uses reverse transcriptase to replicate. |
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| true |
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| What disease procesess are associated with hep b infection? |
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| acute and chronic hepatitis; HCC |
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| How do you diagnose hep B? |
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| Hep B surface antigen means you are currently infectted Hep B core antigen antibody means you currently are or have been infected PCR for E antigen (a secreted protein that determines severity of liver infection) also, liver fxn tests and histology |
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| How do you treat hep B? |
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| RT inhibitors and interferon; hep B immunoglobulin |
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| How is hep B transmitted? |
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| birth (esp HBeAg+ moms), blood (IVDU, health care workers, tatoos), sexual contact (also sharing personal items |
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| How does Hep B help evade the immune system? |
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| produces 22nm spheres and filamentous tubes consisting solely of HBsAg which outnumber virions by about 1000:1 |
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| Describe the stability of HBV. |
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| although it has an envelope, HBV is remarkably soluble to organic solvents, heat, and pH. |
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| Describe the antigenic parts of hep B. |
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| surface= HBsAg and internal= HBcAg, HBeAg |
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| T/F Antibodies against HBsAg confer life-long immunity. |
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| true, although these ab/ag complexes can cause type III hypersensitivity during acute infection |
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| How long is the incubation period for hep B? |
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| 45-180 days |
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| What are the symptoms of hepatitis B? |
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| tiredness with loss of appetite, abdonimal discomfort, vomiting, joint pain, dark urine, clay colored bowel movements, jaundice |
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| T/F For both HBV and HCV there is very little cytopathic effect. |
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| true |
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| T/F Like HCV, HBV targets monocytes and lymphocytes before targeting hepatocytes. |
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| false!!! HBV goes straight to hepatocytes |
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| What causes and who gets chronic hepatitis from hep B? |
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| a weak cell-mediated immune response; infants and very young patients |
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| What percent of patients below the age of 5 show symptoms when infected with hep B? What percent develop chronic disease? |
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| 10%; 30-90% |
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| What percent of patients older than 5 develop chronic disease after HBV infection? What percent display clinical symptoms? |
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| 30-50% display clinical symptoms 2-10% develop chronic disease |
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| What percent of pts chronically infected with hep B get liver cirrhosis? |
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| 25% |
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| What percent of patients with liver cirrhosis from HBV develop liver failure or HCC? |
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| 25% |
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| How many people are affected by chronic HBV? |
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| affects between 350-500 million people worldwide; chronic hep B accounts for about 1million deaths per year. 10th leading cause of deaths world wide |
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| How many people in the US have chronic hep b? |
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| 1-1.25 million people |
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| How many people in the US die each year form hep B complications? |
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| 4,000-5,000 |
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| T/F Hepatitis B chronic infection leads to severe chronic liver disease. |
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| false, progression of chornic hepatitis is highly variable from mild asymptomatic infection to severe chronic liver disease |
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| What percent of pts iwth chronic hep B infection have complications including liver cirrhosis and HCC? |
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| 15-25% |
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| What are the serological characteristics of chronic hep B infection? |
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| production of S, E, and C antigens are sustained. Antibodies against S antigen are no longer detected meaning NO PROTECTION |
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| What serological test can you perform to determine whether your patient with chronic hep c is at a higher risk of developing HCC? |
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| high HBsAg increases risk of HCC HBsAg and HBeAg double positive increases their risk even more |
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| What percent of deaths in HBsAg carriers are caused by liver cirrhosis or HCC? |
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| 50% |
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| How does infection with Hep B lead to cancer? |
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| there is destruction of hepatocytes as a result of the immune reponse to the virus. This results in regeneration via cell division of liver cells that may ultimately cause the cancer. An HBV protein X isknown to activate the src kinase and may also interact with p53. Also, HBV genomes can integrate near myc gene |
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| How do you initially diagnose someone with acute hep B infection? |
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| initially by clinically symptoms and elevated liver enzymes |
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| What are you testing for when you get a hep B panel? |
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| detection of antigen: HBsAg and HBcAg detection of antibodies: HBsAg, HBeAg, and HBcAg |
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| What is the histological appearance of a liver biopsy of someone with hep b? |
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| ground glass hepatocytes. HBsAg expression causes observed cytoplasmic abnormalities. only observed in chronic infections |
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| If a patient is neg for HBsAg, positive fo ranti-HBcAg, and positive for anti-HBsAg then... |
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| pt is immune to HBV as result of previous exposure |
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| If patient is negative for HBsAg, negative for anti-HBcAg, and positive for anti-HBsAg, then the patient is... |
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| immune to HBV because of vaccination |
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| If a patient has + HBsAg, + anti-HBcAg, + anti-HBcAg IgM, and negative for anti-HBsAg? |
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| acute HBV infection. antibodies for HBSAg may be undetectable by being complexed with decoy particles |
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| What if patient is + HBsAg, + anti-HBcAg, - anti-HBcAg IgM, and - for anti-HBsAg... |
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| chornic HBV infection |
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| If patient is - HBsAg, + anti-HBcAg, and - for anti-HBsAg... |
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| patient in recovery phase and anti-HBsAg is complexed with particles or below detection levels. also could be false positive |
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| Describe the hep B vaccine. |
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| subunit vaccine produced in yeast and engineered to express HBsAg |
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| How do you prevent verticle transmission of hep b? |
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| when mother is HBsAg+, you give vaccine along with HBV immune globulin (HBIG-passive immunization) |
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| How do you treat someone with hep B? |
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| passive immunization with HBIG immediately after exposure. IFN-alpha or pegylated IFN alpha. Nulceotide that inhibits reverse transcriptase |
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| What the nucleotide analogs that inhibit RT and can be used to treat hep B infection? |
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| lamivudine (epivir), adefovir dipivoxial (hepsera), entecavir, and telbivudine |
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| What type of virus is hep D? (genome, virion, classification) |
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| enveloped, satellite virus circular ssRNA genome |
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| What types of disease does Hep D cause? |
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| acute and chronic hepatitis; exacerbates severe hepatic diseaes |
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| How is hep D transmitted? |
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| perenteral; IVDU; sexually, but less efficient |
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| How do you diagnose hep D? |
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| presence of delta antigen in liver; delta antigen in blood (pre-clinical) |
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| How do you treat hep D? |
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| eliminate pt's hep B |
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| Why does hep D need hep B coinfection? |
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| outer envelope protein of hep D is HBsAg so hep B needs to make HBsAg for hep D so hep D can infect other cells |
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| Where does hep D replicate? |
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| inner core contains an extensively base-paired circular RNA genome associated with delta antigen that targets RNA to nucleus. Replicates in nucleus nucleus using host RNA polymerase II |
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| What does the hep D genome encode? |
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| has one open reading frame that encodes 2 proteins: small and large delta antigens |
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| What is the serology of acute infection with hep D? |
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| breif appearance of delta antigen in blood, brief appearance of anti-delta IgM, with little or no IgG, anti-HBsAg titers are high and persist after clearance |
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| What is the serology of chronic hep D infection? |
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| breif appearance of IgM followed by high titers of anti-delta IgG. Delta antigen persists in the liver but it is rapidly cleared from serum. Anti-delta IgG persists at high level. HDV RNA detectable long term |
