02-24-2006, 01:59 PM
A small 9-month-old male with a history of recurrent pyogenic infections is seen in a clinic. Immunoglobulin levels and a CBC are performed. The CBC is normal except for slight neutropenia and thrombocytopenia. Determination of immunoglobulin levels indicates elevated IgM, but deficiencies of IgG and IgA. The underlying defect involves which of the following molecules?
A. CD40 ligand (CD40L) on the T cell
B. CD40 molecule on the B cell
C. Gamma interferon
D. Interleukin-2 (IL-2)
E. Interleukin-3 (IL-3)
A. CD40 ligand (CD40L) on the T cell
B. CD40 molecule on the B cell
C. Gamma interferon
D. Interleukin-2 (IL-2)
E. Interleukin-3 (IL-3)