Quantitative, Absolute Count–Based T-Cell Analysis of CD69 Upregulation as a New Methodology for In Vitro Diagnosis of Delayed-Type Hypersensitivity Reaction to Nickel

T cells play a major role in delayed-type hypersensitivity reactions. Their reactivity can be assessed by measuring the upregulation of the activation marker CD69, followed by assessment of proliferation and cytokine production. The aim of our study was to develop a novel, whole blood-based, quantitative, absolute count activation index (AI) for analysis of CD69 upregulation in various subsets of T cells in nickel-hypersensitive patients and...