Association of Intracellular T(H)1-T(H)2 Balance in CD4+ T-cells and MIP-1α in CD8+ T-cells with Disease Severity in Adults with Dengue

Abstract

Background: We tested the hypothesis that dengue haemorrhagic fever (DHF) is associated with a T(H)1-skewed immune response as opposed to dengue fever (DF).

Methods: We estimated intracellular (in T-cells) and serum levels of designate T(H)1/T(H)2 cytokines [interferon-γ (IFN-γ), interleukin-4 (IL-4), and tumor necrosis factor-α] and macrophage inflammatory protein-1α (MIP-1α) at admission, 48 h, and day 5 in 20 adults with dengue (DF=10, DHF=10) and 10 dengue-naïve healthy controls.

Results: At admission, intracellular IFN-γ/IL-4 ratio in CD4+ T-cells and proportion of MIP-1α-positive CD8+ T-cells were significantly higher in patients with DHF [7.21 (5.36~10.81) vs. 3.04 (1.75~4.02); p=0.011 and 6.2% (3.2~8.2%) vs. 2.4% (2.0~3.6%); p=0.023]. The latter showed a significant positive correlation with IFN-γ/IL-4 ratio in CD4+ T-cells (Spearman's rho=0.64; p=0.003), percentage-change in haematocrit (rho=0.47; p=0.048), and serum alanine aminotransferase level (rho=0.61; p=0.009).

Conclusion: We conclude that DHF is associated with a T(H)1-skewed immune response. Further, MIP-1α in CD8+ T-cells is an important immunologic correlate of disease severity in dengue.

Keywords: Dengue haemorrhagic fever; Disease severity; Interferon-γ; Interleukin-4; Macrophage inflammatory protein-1α.

Figure 1

Representative Flowcytometry Plots: Flow cytometry plots showing CD8 positive cytokine and chemokine producing T cells in DHF/DSS (Dengue hemorrhagic fever/Dengue shock syndrome), DF (Dengue fever) along with DN-H (Dengue negative healthy) individuals peripheral blood. X-axis of the graph shows CD8+ T cells and Y axis has cytokine and chemokines as measured in vitro on polyclonal stimulation.

Figure 2

A group-wise plot of the ratio of interferon-γ-(IFN-γ) positive to interleukin-4-(IL-4) positive CD4+ T-cells (A) and CD8+ T-cells (B) in dengue-naïve healthy controls (controls), patients with dengue fever (DF), and dengue haemorrhagic fever (DHF); horizontal lines across the data points depict the group median; a non-parametric test (Cuzick test) was applied to test for a linear trend across the three groups.

Figure 3

Scatter plots of percentage of MIP-1α-positive CD8+ T-cells against IFN-γ/IL-4 ratio in CD4+ T-cells (A), percentage-change in haematocrit (B), and serum alanine aminotransferase level (C); Gray lines represent the linear regression lines.

Figure 4

A plot of the IFN-γ/IL-4 ratio at baseline in CD4+ T-cells against the duration of fever at enrollment. Closed triangles (▴) depict dengue fever and the closed squares (▪) depict dengue haemorrhagic fever.