Hepatitis Flashcards
The hepatitis viruses are NOT
closely evolutionarily related to each other, but symptoms are similar because they all infect HEPATOCYTES
All hepatitis viruses can cause
acute hepatitis, treated with supportive care; A and E usually more severe ACUTE than B and C
A and E are _____; B/C/D are
fecal-oral;
sex/birth/blood transmitted
A, B, and hopefully now E are controlled by
vaccination
A is endemic in; E is endemic in ____ and causes
Mexico and South America;
Asia and Mexico, also causing complications of pregnancy
D has high risks for
bad outcomes but is totally dependent on coinfection with B (“helper virus,” complementation), so HepB vaccination is PROTECTIVE
Diagnosis of hepatitis is by _____:
serology;
for HepA, IgM is acute, IgG is recovered/vaccinated; for HebB, viral surface antigen is acute, IgG against viral surface antigen is recovered/vaccinated; for HepC, EIA is real or false positive, with RIBA serving for confirmation;
for HepD delta antigen means infection
B and C can cause
chronic hepatitis leading to cirrhosis and/or cancer; treatment with IFN has many SE’s, often ineffective. Second-gen protease inhibitors combined with IFN improves SVR rates for HepC serotype 1. Third-gen inhibitors of HepC protease, polymerase, and Ns5A are exciting but still brand-new
B produces a large number of
immune decoys composed of its surface antigen alone; Ag-Ab complex disease may follow (think glomerulonephritis)
C once established forms a
huge constellation of point mutant forms, difficult for either immunity or drugs to target effectively
Liver transplant alleviates
liver failure caused by chronic B or C, but new liver may become infected from secondary sites (lymph nodes?)
Chronic B and C pose particular treatment problems
in the context of HIV
