Renal Fibrinoid Necrosis - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 06-13-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 1,039
Threads: 189
Thanked 561 Times in 319 Posts
Reputation: 571
Kidney Renal Fibrinoid Necrosis

A 29-year-old man has developed marked abdominal pain over the past week. On physical examination, there is diffuse abdominal tenderness with decreased bowel sounds, but no masses are noted. The stool is negative for occult blood. Laboratory studies show a serum creatinine level of 4.4 mg/dl and urea nitrogen level of 42 mg/dl. Microscopic examination of renal biopsy specimen shows focal fibrinoid necrosis of the small arterial and arteriolar vascular media as well as intravascular microthrombi. Scattered neutrophils are seen in these areas of necrosis. Which of the following laboratory findings would most likely be present in this patient?

A) Increased IgE
B) Neutropenia
C) Decreased complement C3
D) Tuberculin skin test positivity
E) CD4 lymphocytosis

I would appreciate if you could provide reasoning for your answer
Reply With Quote Quick reply to this message
The above post was thanked by:
5hstar (06-14-2012), DefeatTheBeast (06-14-2012), dockhi (06-14-2012), Highlander (06-13-2012), Hope2Pass (06-14-2012), Master shifu (06-14-2012)



  #2  
Old 06-14-2012
curiousmind's Avatar
USMLE Forums Scout
 
Steps History: ---
Posts: 82
Threads: 5
Thanked 21 Times in 15 Posts
Reputation: 31
Default

is it decreased C3 ?
Intravascular microthrombi, means DIC like picture, where complement gets
used up, resulting in low complement levels.

plz give answer...
Reply With Quote Quick reply to this message
  #3  
Old 06-14-2012
Guest
 
Steps History: ---
Posts: 197
Threads: 9
Thanked 98 Times in 64 Posts
Reputation: 108
Default

It looks like an immune complex vasculitis of the renal vasculature. I'd go for lowered C3 levels. Also explains the microthrombi
Reply With Quote Quick reply to this message
 
  #4  
Old 06-14-2012
Master shifu's Avatar
USMLE Forums Addict
 
Steps History: Step 1 Only
Posts: 191
Threads: 14
Thanked 87 Times in 59 Posts
Reputation: 97
Default

Quote:
Originally Posted by smanthrav View Post
It looks like an immune complex vasculitis of the renal vasculature. I'd go for lowered C3 levels. Also explains the microthrombi
I would also go for that option (C) decreased complement C.
It's immune-complex mediated vasculitis evident from focal fibrinoid necrosis from renal biopsy.
Reply With Quote Quick reply to this message
  #5  
Old 06-14-2012
drhma's Avatar
USMLE Forums Addict
 
Steps History: 1 + CS
Posts: 193
Threads: 29
Thanked 134 Times in 71 Posts
Reputation: 144
Send a message via MSN to drhma
Default

thank u for these questions, keep posting the things the have unique ideas in them plz, at least for the next next,
my exam is in 10 days, and i find these things very helpful to stay refreshed on topics studied a long time ago
__________________
i'm so bad i make medicine sick,
Imma show you how great i am
Reply With Quote Quick reply to this message
The above post was thanked by:
dockhi (06-14-2012), Hope2Pass (06-14-2012)
  #6  
Old 06-14-2012
USMLE Forums Guru
 
Steps History: Step 1 Only
Posts: 452
Threads: 11
Thanked 354 Times in 197 Posts
Reputation: 364
Default

^agreed, thanks for posting these questions!!!

I'd go with c
Reply With Quote Quick reply to this message
  #7  
Old 06-14-2012
USMLE Forums Master
 
Steps History: Not yet
Posts: 674
Threads: 264
Thanked 959 Times in 393 Posts
Reputation: 969
Send a message via Yahoo to ricko335
Default

was thinking of polyarteritis nodosa initially but it looks more of a arthus reaction so it is c
Reply With Quote Quick reply to this message
  #8  
Old 06-14-2012
USMLE Forums Addict
 
Steps History: Not yet
Posts: 134
Threads: 12
Thanked 12 Times in 12 Posts
Reputation: 22
Default

i'd go w/ C
Reply With Quote Quick reply to this message
  #9  
Old 06-14-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 1,039
Threads: 189
Thanked 561 Times in 319 Posts
Reputation: 571
Default correct answer :)

Correct answer is C) Decreased complement C3

This patient has a localized immune-complex reaction (Arthus reaction), which activates and depletes complement of C3 and C4. IgE concentration is increased in persons with atopy and the potential for type I hypersensitivity. Although neutrophils are being recruited locally to the inflammatory reaction in this case, they are not depleted systemically, and they may be increased in the circulation. Skin tests are measures of type IV hypersensitivity when antigens such as tuberculin are used. CD4 lymphocytes assist in a variety of antibody- and cell-mediated immune reactions, but their number in peripheral blood do not change appreciably.

Thank you all for your explanations! When I was doing this question I excluded few answers but still wasn't sure what the right answer was... And their explanation didn't convince me enough...

I am only about to revise my immuno but still I have some doubts here... doesn't this picture presented in the question remind you a bit of a picture seen in acute graft rejection - I mean microthrombosis (type II and IV) and chronic rejection - fibrinoid necrosis? I'm not sure if saw that question again I would say right away it's Arthus reaction...I definitely should go back to reading immuno...
Reply With Quote Quick reply to this message
The above post was thanked by:
excellence (04-22-2014), Highlander (06-15-2012)
  #10  
Old 06-27-2012
USMLE Forums Newbie
 
Steps History: Not yet
Posts: 2
Threads: 0
Thanked 0 Times in 0 Posts
Reputation: 10
Correct Answer

Quote:
Originally Posted by Casandra View Post
A 29-year-old man has developed marked abdominal pain over the past week. On physical examination, there is diffuse abdominal tenderness with decreased bowel sounds, but no masses are noted. The stool is negative for occult blood. Laboratory studies show a serum creatinine level of 4.4 mg/dl and urea nitrogen level of 42 mg/dl. Microscopic examination of renal biopsy specimen shows focal fibrinoid necrosis of the small arterial and arteriolar vascular media as well as intravascular microthrombi. Scattered neutrophils are seen in these areas of necrosis. Which of the following laboratory findings would most likely be present in this patient?

A) Increased IgE
B) Neutropenia
C) Decreased complement C3
D) Tuberculin skin test positivity
E) CD4 lymphocytosis

I would appreciate if you could provide reasoning for your answer
The answer is E) CD4 lymphocytosis
Laboratory findings in acute vasculitis in general are increased in ESR,CRP,WBC count,Eosinophils,ANCA and Decreased C4 while C3 is normal.
Reply With Quote Quick reply to this message



Reply

Tags
Immunology-, Pathology-, Step-1-Questions

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pancreatic Necrosis Androide89 USMLE Step 1 Forum 7 12-12-2013 08:36 PM
Fibrinoid Necrosis; How is it important for Step 1 Exam? tyagee USMLE Step 1 Forum 0 05-09-2012 02:08 PM
Hypersensitivity Reaction and Fibrinoid Necrosis tyagee USMLE Step 1 Forum 0 04-29-2012 03:51 AM
Renal Failure Versus Renal Insufficiency! sfsheran USMLE Step 1 Forum 1 03-12-2012 06:32 AM
Pancreatitis with necrosis docoftheworld USMLE Step 2 CK Forum 2 01-22-2011 06:35 AM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)