In vitro release of interferon-gamma and macrophage migration inhibition factor in drug-induced urticaria and angioedema

T-cells are involved in the pathogenesis of cutaneous drug reactions, T-cel l phenotype and cytokine release pattern in vivo and in vitro might correla te with the type of immune response involved in cutaneous drug reactions. I n vitro release of interferon-gamma and macrophage migration inhibition fac tor (MIF) from peripheral blood lymphocytes, following in vitro challenge w ith the suspected unmodified drugs, was studied in 12 patients with drug-in duced urticaria and/or angioedema and in two group-matched controls. The oc currence of positive interferon-gamma and MIF responses was significantly h igher in patients with drug-induced urticaria and/or angioedema than in con trols. The sensitivity and specificity of the interferon-gamma test (50% an d 92%, respectively) were similar to that of the MIF test (58% and 96%, res pectively). Percentage agreement between both tests was 80.9 (kappa = 0.76) . In vitro release of interferon-gamma and MIF in drug-induced urticaria an d/or angioedema suggests a drug-specific immune response, and may implicate the drug as a possible inducer of the reaction.