CD40LG and Immunodeficiency: The immune deficiency in children with IS is mainly manifested by sensitization to 2,4-dinitrochlorobenzene (DNCB), intradermal reaction to Phytohemagglutinin (PHA), inhibition of leukocyte migration, blast transformation of lymphocytes (low CD4+/CD8+ ratio), T lymphocytes (low CD3+, low CD4+, and high CD8+), and B lymphocytes (high CD3−CD19+) in peripheral blood, and changes in the levels of serum immunoglobulins (high levels of IgG and IgM and low levels of IgA) (18, 19).