Interleukin 2, soluble interleukin 2 receptor, and interferon-gamma in the suction blister fluids from psoriatic skin.

Psoriasis represents inflammatory skin disorders characterized by significant changes in cellular immunity, particularly exhibiting alterations in T lymphocyte-related functions. Early psoriatic lesions have been reported to show an infiltration of activated helper T cells. Elevated levels of interleukin 2 (IL-2), IL-2 receptor (IL-2R), and interferon-gamma (INF-gamma) are associated with an early activation of T cells. To examine local activation of T cells in psoriatic skin, the amounts of activated T cell products, IL-2, secretory form of IL-2R (sIL-2R) and INF-gamma were measured in the fluids of suction blisters raised on psoriatic skin. sIL-2R levels were significantly elevated in the suction blister fluids raised on psoriatic involved skin compared with those on normal and psoriatic uninvolved skin. On the other hand, neither IL-2 or IFN-gamma was detected in the suction blister fluids either from normal, psoriatic uninvolved, or involved skin. However, we could detect IFN-gamma and IL-2 in the psoriatic scale extracts. Although we failed to detect IL-2 and IFN-gamma in the suction blister fluids, the increased levels of sIL-2R in the suction blister fluids from the psoriatic lesional skin indicate local activation of T cells in psoriatic lesional skin.