Abstract
A vast majority of studies investigating cytokine profiles in contact dermatitis (CD) due to nickel have focused on cytokine release in response to nickel challenge. This study was performed to determine the Th1 and Th2 cytokine profile of un-stimulated circulating T lymphocytes in CD patients with positive nickel skin patch test. A total of 35 patients with positive nickel patch test presenting clinically with CD in allergy clinic at King Khalid University Hospital, Riyadh, were included in the study. Using lysed whole blood method peripheral blood T lymphocytes were analyzed for surface markers and intracellular cytokines by flowcytometry. The proportion of CD4+IL-10+ lymphocytes in the patients (3.3 +/- 1.1%) was significantly less than (p <= 0.000001) the normal controls (8.4 +/- 2.3%). The percentage of IL-4+CD4+ lymphocytes in the patients (1.9 +/- 1.9%) was also less (p <= 0.007) than that of the normal controls (3.1 +/- 1.4%). For CD8+ lymphocytes nickel sensitive CD patients had a remarkably low (p <= 0.00001) percentage of IL-10+ cells then the normal individuals (1.1 +/- 1.6% versus 3.3 +/- 1.5%). The proportion of CD8+IL-4+ lymphocytes was also lower (p <= 0.0005) in patients (0.42 +/- 0.41) compared to the normal healthy individuals (0.94 +/- 1.9%). There was no difference in the percentages of IFN-gamma+ and IL-5+ lymphocytes between the patients and controls. Percentages of IL-10+ and IL-4+ CD4+ lymphocytes (r = -0.758 and -0.653 respectively) and CD8+IL-10+ (r = -0.733) cells negatively correlated with patch test scores. These findings indicate that in the healthy state Th2 cytokine profile prevails however lymphocyte cytokine profile is skewed towards Th1 type in patients with nickel contact dermatitis.