recurrent infections NBME f1 S4

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recurrent infections NBME f1 S4

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7 Posts

docsrinu
Forum Elite

Topics: 26
Posts: 213

09/13/06 - 09:40 PM

A 6-year-old boy with a history of recurrent ear infections receives his preschool booster immunization against diphtheria-tetanus-pertussis. He is participating in a community-sponsored study to determine the humoral immune response to tetanus toxoid (tt). His response is well below normal for age- and sex-matched children. Peripheral B lymphocyte count and T lymphocyte count and function are within the reference range. The antibody he makes is positive in both the passive hemagglutination and complement-mediated lysis of tt-coated erythrocytes. His antibodies do not opsonize tt-coated latex particles for phagocytosis and do not directly precipitate tt efficiently. This child most likely has a defect in which of the following processes?
A) Affinity maturation of immunoglobulins
B) Immunoglobulin isotype switching
C) Recombination of heavy chain variable region genes
D) Recombination of light chain variable region genes
E) Somatic mutation of immunoglobulin genes

vanshita
Forum Guru
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Topics: 25
Posts: 839

09/13/06 - 09:46 PM

sridevibandaru24
Forum Guru

Topics: 33
Posts: 434

09/14/06 - 09:14 PM

immunoglobulin isotype switching

DanVitor
Forum Junior

Topics: 4
Posts: 34

09/26/06 - 04:51 AM

drsabica
Forum Newbie

Topics: 0
Posts: 7

09/26/06 - 05:16 AM

can any one explain it to me rolling eyes

docswapna
Forum Senior

Topics: 61
Posts: 229

09/26/06 - 07:08 AM

complement IgM present
opsonisation IgG absent

ManuNastai
Transilvanian..
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Topics: 55
Posts: 838

09/29/06 - 02:37 AM

B

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