Cytokine Secretion and Proliferative Capacity of CD4+ T Cells in Delayed Type Hypersensitivity Reactions due to Ciprofloxacin

Abstract

Introduction: Ciprofloxacin (CPFX), a frequently prescribed quinolone, may induce cutaneous adverse drug reactions. Delayed type hypersensitivity reactions (DTHR) are often difficult to deal with, therefore, in vitro testing for DTHR is the long-anticipated method for their management. This study aimed to evaluate potential value of lymphocyte transformation test (LTT) and intracellular cytokine secretion of drug stimulated CD4+ T cells in patients with DTHR against ciprofloxacin. Material and Methods: Patients experienced DTHR with CPFX (n=8) and healthy subjects (n=10) were enrolled. CPFX skin prick, patch and intradermal tests were performed. LTT by flow cytometry aimed to determine CPFXspecific CD4+ T cell proliferation. Intracellular IL-4, IL-10, IL-2 & IFN-γ levels were analysed by flow cytometry in CPFX-specific CD4+ T cells. Cytokine contents of cell culture supernatants were evaluated by ELISA. Results: In patients with DTHR, 5 and 10 μg/mL CPFX induced significant CD4+ T cell proliferation (p=0.014 and p=0.05, respectively). IL-2 (p=0.02, p=0.001 and p=0.001, respectively) and IL-4 (p=0.001) secreting CD4+ T cell percentages were increased, while IFN-γ+ (p=0.001, p=0.011 and p=0.012, respectively) and IL-10+ (p=0.001, p=0.001 and p=0.002, respectively) CD4+ T cells were decreased. The cell culture supernatants revealed downregulated IL-10 (p<0.000, p=0.004, p=0.001 and p=0.0001, respectively) and upregulated IL-4 levels (p=0.003, p=0.013 and p=0.0001, respectively) in patients, regardless of CPFX stimulation. Intradermal test was positive in only one patient while all patch tests remained negative. Conclusion: Our findings suggest that the increase of IL-2 and IL-4-secreting CD4+ T cells together with the decrease of IL-10 and IFN-γ-secreting CD4+ T cells is related to DTHR seen in patients with delayed-type CPFX allergy. Intracellular cytokine measurement, together with LTT could ease the management of CPFX hypersensitivity when in vivo tests are non-available, remain inconclusive or negative. Keywords: Allergy, CD4+ T cells, ciprofloxacin, hypersensitivity, intracellular cytokine, LTT