Soluble IL-2 receptor and CD25 cells in psoriasis: effects of cyclosporin A and PUVA therapy.

A study was conducted to quantify soluble IL-2 receptor (sIL-2R) levels in sera of 57 chronic plaque psoriasis patients and correlate these measurements with disease activity and the number of IL-2R-positive (CD25+) lymphocytes in lesional biopsies of 11 cyclosporin A (CsA) and 13 psoralen plus ultraviolet radiation (PUVA) treated patients. Levels of sIL-2R showed a strong correlation with the psoriasis area and severity index (PASI). CsA and PUVA significantly reduced the PASI and sIL-2R levels to a similar degree after 4 weeks of treatment. Although the majority of CsA-treated patients who were biopsied showed reductions in lesional CD25+ cells, these did not reach statistical significance; in five patients biopsied who had PUVA treatment, no consistent effect on the numbers of CD25+ cells was observed. A significant correlation was found between CD25+ cells in lesional biopsies and the PASI score.