Abstract
OBJECTIVE: To study the expression of interleukin-1β (IL-1β), interleukin-4 (IL-4), interferon-γ (IFN-γ) and tumour necrosis factor α (TNF-α) in different tissue in a dinitrochlorobenzene (DNCB)-induced ear swelling test in mice and further evaluate the correlation between the cytokine expression in different tissues and the degree of ear swelling. METHODS: The mice were sensitised with a 0.50% DNCB solution on their back for 3 days. After 7 days, the thickness of their ears was measured and grouped. Different concentrations of the DNCB solution were challenged in the left ear of each group of mice, and the right ear was used as the control. The thickness of both ears was measured every 24 h, and the mice were sacrificed 72 h after the challenge. The expressions of IL-1β, IL-4, IFN-γ and TNF-α in the mouse serum, lymph node and ear tissue were quantified by enzyme-linked immunosorbent assay, respectively. RESULTS: There was a linear positive correlation between the swelling index of the mouse lateral ear and the challenge concentration of DNCB (r = 0.96, p < 0.01). The high expression of IL-1β and IL-4 in the lateral ear tissue of the mice was positively correlated with the ear swelling index 48 h after the challenge. The correlation coefficient was 0.78 (p < 0.01). Furthermore, IFN-γ and TNF-α had no significant correlation with the ear swelling index 48 h after the challenge. CONCLUSION: There is a correlation between the degree of ear swelling in mice and the concentration of DNCB and the expression of IL-1β and IL-4 in the lateral ear tissue. There is a sub-clinical skin sensitivity state in contact allergy.