Lymphocyte transformation test in allergic contact nickel dermatitis.

Twenty-five patients with clinically proven, patch test positive nickel dermatitis were studied with the lymphocyte transformation test (LTT). Serial dilutions of NiSO4 were present in the lymphocyte culture. None of the controls showed lymphocyte blast transformation. In fourteen patients maximal incorporation of thymidine occurred at the highest dilutions (I:50,000-I:100,000). In eleven patients the highest incorporation occurred at the lower dilutions. The nature of the antigen responsible for the specific reaction remains unknown.