Th(2) immune response in patients with dengue during defervescence: preliminary evidence.

A shift from a T(H)1 to a T(H)2 immune response has been observed in vitro during dengue virus infection. Estimation of plasma IgE level (n = 28), CD4:CD8 lymphocyte ratio, and the intracellular interferon-gamma (IFN-gamma):interleukin-4 (IL-4) ratio (n = 9) was conducted in patients with various severities of dengue around the time of defervescence. The CD4:CD8 lymphocyte ratio was significantly lower (median = 0.45, interquartile range [IQR] = 0.4-0.47 versus 1.3, 1.0-1.9; P = 0.001), and IgE levels were significantly higher (mean = 300.4, SD = 252.5 versus 143.7, 117.9 IU/mL; P = 0.004) in patients than in healthy controls. The intracellular IFN-gamma:IL-4 ratio was significantly lower in patients compared with controls (0.28, 0.13 versus 0.99, 0.4; P = 0.001). These findings suggest that a T(H)2 immune response occurs in patients with dengue around the time of defervescence.