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  #1  
Old 07-21-2014
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Default Immunology Question to test your self.

A 4-month-old boy is brought to the physician by his parents because of twitching of his facial muscles. A review of his records shows that he has previously been seen for several severe episodes of Candida infections. Physical examination shows low-set ears, hypertelorism, and a shortened philtrum. Which of the following additional findings is most likely to be seen in this patient?


A. Absence of type IV hypersensitivity
B. Decreased alpha-fetoprotein
C. Elevated IgE levels
D. Elevated IgM levels
E. Prominent telangiectasias around the eyes
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Last edited by nsesereso; 07-21-2014 at 04:09 AM.
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Old 07-21-2014
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A

DiGeorge?
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Old 07-22-2014
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A 7-month-old boy is brought to the physician because of a yeast infection of the diaper area that does not respond to therapy. A review of his records shows that he has had multiple acute pyogenic infections. A leukocyte differential count shows: 70 neutrophils, 20 lymphocytes, and 10 monocytes. Circulating lymphocytes are all CD-19 positive. Which of the following is the most common cause of this patient’s condition?

A. Adenosine deaminase deficiency
B. Defective CD40L molecule
C. Defective IL-7 receptor
D. Inability to produce MHC-II molecules
E. Nonsense mutation of rag genes
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Old 07-22-2014
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I see it as combined deficiency.. Is it A ? Not sure 50% vote for B too
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Old 07-22-2014
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Q 1: A
q 2: A
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Old 07-23-2014
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Q2 should be B (hyper IgM).
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Old 07-23-2014
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should be the AD deficiency( AR) for SCID as more common than the other options, and CD40L defect is for hyper IgM... so A?

Whats confusing is that SCID is a deficiency in t and B cells....but according to the question there are circulating pro b cells...as if the patient has Bruton's X....

do you have the answer?
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Old 07-23-2014
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You guys are doing well. I have the answers and explanation so more answers then I give the final answer and explanation.
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Old 07-23-2014
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i think both are A
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Old 07-24-2014
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A 14-year-old girl is brought to the emergency department because of dyspnea, tachycardia, and diaphoresis following a bee sting. Which of the following is the first immunoglobulin produced in response to this antigen?

A. IgA
B. IgD
C. IgE
D. IgG
E. IgM
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Old 07-24-2014
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Well guys question 1 is A. Yea Digeorge syndrome.
All of you got question 2 wrong so try again
It's not A nor B hmmmm. It's a killer question.

You can try now try question 3.
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Old 07-24-2014
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I think it is D.
D. Inability to produce MHC-II molecules
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Old 07-24-2014
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first immunoglobulin produced in response to any antigen is always IgM.

Quote:
Originally Posted by nsesereso View Post
A 14-year-old girl is brought to the emergency department because of dyspnea, tachycardia, and diaphoresis following a bee sting. Which of the following is the first immunoglobulin produced in response to this antigen?

A. IgA
B. IgD
C. IgE
D. IgG
E. IgM
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Old 07-24-2014
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In the question #2 I'd go with the IL-7 alpha, it is also associated with SCID. Also remember guys, that the most common cause of SCID is NOT ADA deficiency, in fact that is a rare cause, the MCC is IL-2R mutation.

Why did I pick IL-7? well because all points out to the kid having no T cells, NK's but mentions CD19 which points to some B-cell presence an in the list the only one that can have B(+) is IL-7.

#3 I'd go with E too.
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Old 07-24-2014
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Question 2: C
SCID
Is associated with deficiency in both B and T Cells.
50 percent of cases are caused by a gene defect on X chromosome. Leading to defective gamma chain of receptor for IL2,IL4, IL7, IL9,IL11,IL15 and IL21.

Becos of defective signalling from IL7,there is profound decrease in T cell number.

B cell number may be near normal, but antibody synthesis is impaired in d absence of T helper cells
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Old 07-24-2014
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#2- stumped on # 2, because i can't get passed the sentence "most common cause"..and if this was SCID, wouldn't A be correct?..i could be thinking too much..lol
#3- E IgM is always first no matter what.

looking forward to the answer and explanation for #2
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Old 07-24-2014
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ADA deficiency is not the MCC of SCID...First aid says its defective IL2R.
Pathoma says d causes of SCID include...
ADA deficiency,
MHC class 2 defi,
cytokine receptor defects.

These r all options in d above question...so u r right about d emphasis on d MCC.
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Old 07-24-2014
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Qs.3. E first immunogl is IGM
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Old 07-24-2014
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Qs.2 answer is C IL7 cuz FA says its the most common and kid is having SCID
NOW i got this well every word even dot in FA could be question
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Old 07-24-2014
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exactly, most common cause of SCID is IL2 def...which isn't an option, so id believe second best would be ADA def, followed by MHC-II def...
IL-7, rag mutation are all plausible, but not most common..and cd19 is a marker of PRO B cells, which leads me to think Bruton's x..however the diaper rash is throwing me off....

so i have no final answer for #2, lol
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Old 07-24-2014
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I m sorry i wrote IL 7 in place of IL 2
But i m confused
Plz give us answer
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Old 07-24-2014
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Its defective IL 7 receptor..
I just came across this question in kaplan q bank and got it right
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Old 07-26-2014
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IL-7 receptor a T– B+ NK– SCID
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Old 07-27-2014
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Answer is IL-7
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Old 07-27-2014
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Quote:
Originally Posted by Dr.ann View Post
Qs.2 answer is C IL7 cuz FA says its the most common and kid is having SCID
NOW i got this well every word even dot in FA could be question
Thank you very much that was the same impression I got after meeting this question. U guys have given the explanation.
In addition gamma interleukin is most common. Eg IL-2,5,7,9,15,21
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