[Spoiler Alert] UW Immuno q

[MudPhud20XX]

A 32 yr old male with anorexia and fatigue is found to have persistently elevated serum ALT and AST levels. He is also positive for HBsAg. Which of the following best describes the mechanism of liver injury in this pt?

A. Viral cytotoxic effect and hepatocyte necrosis with following secondary inflammation
B. Antibody response to viral antigens on the cell surface with antibody-mediated cell damage
C. Circulating viral antigen-antibody complexes with small vessel deposition and immunologic vessel injury
D. Antigen mimicry with generation of self-antigen recognizing CD4+ T lymphocytes that damage hepatocytes
E. CD8+ T lymphocyte response to viral antigens on the cell surface resulting in hepatocyte damage

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[PaxRoma]

E is the best choice
A- HBV does not have cytotoxic effect directly by itself
B- Viral defense is usually via cell mediate mechanism, not antigen-antibody mechanism
C-This type III hypersensitivity reaction is usually seen in HCV
D- Antigen mimicry is a mechanism of strept induced valvular disease

 

[worldbeater]

Nice job. Also to the original poster, you can just put the UWorld question number in brackets in the title instead of writing "spoiler alert", that way posters can just ignore the thread if they don't want to see the question and others can look it up if they have done it before.

 

[Phloston]

A 32 yr old male with anorexia and fatigue is found to have persistently elevated serum ALT and AST levels. He is also positive for HBsAg. Which of the following best describes the mechanism of liver injury in this pt?

A. Viral cytotoxic effect and hepatocyte necrosis with following secondary inflammation
B. Antibody response to viral antigens on the cell surface with antibody-mediated cell damage
C. Circulating viral antigen-antibody complexes with small vessel deposition and immunologic vessel injury
D. Antigen mimicry with generation of self-antigen recognizing CD4+ T lymphocytes that damage hepatocytes
E. CD8+ T lymphocyte response to viral antigens on the cell surface resulting in hepatocyte damage

E is the best choice
A- HBV does not have cytotoxic effect directly by itself
B- Viral defense is usually via cell mediate mechanism, not antigen-antibody mechanism
C-This type III hypersensitivity reaction is usually seen in HCV
D- Antigen mimicry is a mechanism of strept induced valvular disease

Agree with PaxRoma that hepatic damage in viral hepatitis is significantly caused by the immune response. But HepB/C do cause direct viral damage and HepB is highly intrinsically carcinogenic (more so than C). The reason I'm responding to this post now that PaxRoma has answered it is to point out that "direct viral damage" is the answer to carditis/DCM caused by coxsackie (distinct from M-protein type-II HS with RF).

 

[worldbeater]

Also a general pattern I noticed when it comes to deciding on a question if the answer is hepatitis, and your left with something related to Hepatitis B or Hepatitis C, it's usually B. It's a nice strategy if you can't decide between 2 answer options.