Table 1 Immunological defects in brain-injured patients

T cells

Reduced number of total circulating T cells, T-helper cells, T-suppressor cells, natural killer cells and IL-2 receptor-bearing cells [11–15]

Disproportionate high percentage of T cells of the CD4⁺/CD45⁺ (suppressor/inducer) phenotype relative to the percentage of T cells of the CD4⁺/CDw29⁺ (helper/inducer) phenotype [16]

Reduction in the proliferative response of T cells to mitogen stimulation [11–14]

Decreased IFN-γ and IL-2 production [13, 17]

Anergy to delayed-type hypersensitivity skin testing [11–13]

Depression in lymphokine-activated killer cell cytotoxicity [13, 17]

B cells [14, 15]

Reduction in IgG and IgM

Reduction in components of complement system (C1q, C2, properdin)

Neutrophils [15, 18]

Decrease in superoxide generation

Monocytes [19–21]

Increased IL-6 and IL-10 production