Leukocyte procoagulant activity as an in vitro index of nickel contact hypersensitivity

Following 20-hour incubation with nickel sulphate, peripheral blood mononuclear cells from patients with nickel contact dermatitis showed increased procoagulant activity compared with healthy controls. The Ni-induced response was dose-related and specific as judged by the use of cobalt as a control. This convenient new assay may prove valuable not only in contact dermatitis, but also in other types of skin disorder where at present there are no satisfactory in vivo or in vitro methods of assessment.