Primary and Secondary Immunodeficiency

Question 1

What are the principal defects in Hyper IgM?

Answer 1

a) CD40 ligand on T cells (x-linked and is the most common defect)
b) CD40 on B cells (autosomal recessive)
c) DNA modifying enzymes required for normal immunoglobulin class switching and somatic hypermutation
i) Activation Induced Cytidine Deaminase (AID) and Uracil Nucleotide Glycosylase (UNG).

Question 2

What is the etiology of Hyper IgM?

Answer 2

High IgM, LOW G, E, and A

Question 3

How does Common Variable Immunodeficiency present?

Answer 3

Reduced levels of IgG, A, M