Hepatitis Flashcards
Classify Hepatitis A (“infectious hepatitis”)
- belongs to the picornavirus group (i.e. poliovirus)
- (+)ssRNA, not enveloped and icosahedral
How does transmission of Hep A differ from Hep B and Hep C
Hep A is fecal oral while hep B and C are from blood/birth/sex
99% of Hep A = no chronic infection. Symptoms are mainly due to
immune system
Enzyme Immunoassay (EIA) to diagnose Hep A. If a patient has anti-Hep A IgM, then describe the type of infection she has
acute hep A
If EIA reveals anti-hep A IgG, it will indicate
past infection/vaccination
Hep A is a humorally controlled virus. Explain
It has one serotype; and IgG is protective
Explain Hep A prophylasix
Give immune serum globulins (Gammagard)
Classify Hepatitis B (“serum hepatitis”)
- belongs to hepdnavirus group
- dsDNA, enveloped
- CARRIES A REVERSE TRANSCRIPTASE & replicates thru an RNA intermediate
T/F: There are vaccines against Hep A and B, but not C
True, b/c hep A and B only have one serotypes while hep C has about four
4 stages of Hep B/immune interactions
1) immune tolerance -virus replicates without symptoms (serum Hep B DNA and Ag, but little Ab)
2) immunogenic symptoms -adaptive immunity response to virus causing increase in ALT and decrease in HepB DNA
3) Clearing the virus -viral replication closes down (can detect HBeAb detected; Hep B DNA not detected)
4) Virus cleared = no viral antigens
Which hepatitis is “messy” and has lots of decoys evading humoral immunity?
Hep B & Hep C
Classify Hep C genome
-part of flavivirus, RNA genome
If EIA revealed positive Hep C test, why is it necessary to do a Recombinant Immunoblast Assay (RIBA)?
RIBA can confirm HCV exposure and detect false positives
Unlike Hep A and B, immunoglobulins are not protective in Hep C. what is the drug regimen?
peg-IFN-Alpha + Ribavirin (nucleoside analog of guanosine)
Goal of treatment in Hep C is
Sustained viral response (SVR)
Efficacy of peg-IFNalpha in Hep C serotypes 2 &3 vs serotypes 1 &4
serotypes 2 & 3 = >50% SVR w/ 6 months of treatment while serotypes 1 & 4 require 1-2 yrs of treatment
EIA of HepB: you detect viral surface antigen will indicate
acute hep B
EIA of HepB: IgG against viral surface antigen
recovered/vaccinated
Treatment with polymerase inhibitors + IFN has many side effects, often ineffective, new protease inhibitors are improving treatment of which hep C serotype?
serotype 1 but still has side effects
Liver transplant alleviates liver failure, but if virus was not cleared from secondary sites of infection, new liver becomes infected. What should be done? Short course of antivirals preceding LDLT may be the answer.
Short course of antivirals preceding Living donor Liver Transplant may be the answer.
