Infection 6) Viral hepatitis Flashcards
Describe histological stage 1 of hepatic fibrosis
Fibrous expansion of some portal areas
Describe histological stage 3 of hepatic fibrosis
Fibrous expansion of most portal areas with occasional portal to portal bridging
Describe histological stage 4 of hepatic fibrosis
Fibrous expansion of portal areas with marker bridging
What areas of the world have high prevalence of hepatitis B?
Canada
Africa
China
India
What are the risk factors for hepatitis B?
Ethnicity IVDU MSM HIV Health care worker
Describe the immunology of hepatitis B
PAMP recognised by TLR3 leading to RIG-1 signalling. Interferon regulatory factors and NF-kB
Interferon stimulating genes
INF - alpha/beta
Downregulation of viral protein synthesis, inhibit viral replication, promote adaptive immunity via MHC class I expression on APC
Activates NK, CD8 and dendritic cells
Activate cell death through secretions of perforins
What leads to a persistent infection of hepatitis B?
Age at infection Immunosuppression HBV X protein Foxp3 Programmed death-1 receptor up-regulated Cytotoxic T-lymphocyte antigen 4 IL-10
What does IL-10 do?
Downregulates antiviral immune responses
Attenuates inflammatory response but reduces efficiency of antiviral immune responses
What is the treatment for chronic hepatitis 6?
Pegylated interferon
Tenofovir / tenofovir alafenamide
Entecavir
What are some mutations in the Pre-S/S HBV region?
Pre-S1/pre-S2
S promoter
S
S splicing
What % develop chronic hepatitis C virus?
80%
Why does hepatitis C have a high rate of chronicity?
High replicative rate and viral antigen load
High error rate of RNA-dependent RNA polymerase
HCV proteins interfere with immune response
Neutralising antibodies develop too slowly, too late
