Hyper-IgM syndrome usually presents with severe pyogenic infections. The typical immunoglobulin profile in a patient with this disease shows an elevat

Subject
Medicine
System
Allergy & Immunology

Kathryn

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Jul 29, 2020
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Hyper-IgM syndrome usually presents with severe pyogenic infections. The typical immunoglobulin profile in a patient with this disease shows an elevated level of IgM in contrast to the other immunoglobulin isotypes. Which of the following is the etiology behind the increased level of IgM in a patient with hyper-IgM syndrome?
(A) A defect in DNA repair enzymes
(B) A defect in LFA-1 adhesion proteins on phagocytes
(C) A defect in the CD40 ligand on CD4 T helper cells
(D) Failure of interferon-γ production
(E) Failure of the thymus and parathyroid glands to develop