Studies on poison ivy

The isolation and purification of poison ivy urushiol is described.The preparation of urushiol-skin protein and urushiol human serum albumin is also described.Lymphocytes from eleven donors naturally sensitized to poison ivy and from four non-sensitive individuals have been cultured for 5 days in the presence of urushiol-carrier conjugates.Lymphocytes from seven of the eleven sensitive donors responded with a stimulation index greater than 30 to urushiol-albumin conjugate.When urushiol-skin protein conjugate was used as a stimulant,lymphocytes from only three of the eleven sensitive donors responded.The results suggest that urushiol-protein conjugates can stimulate sensitive lymphocytes in uitro,although a response is not observed in every individual naturally sensitized to poison ivy.