title: Plasma and scales levels of interleukin 18 in comparison with other possible clinical and laboratory biomarkers of psoriasis activity.
abstract: The aim of the study was to assess plasma and scales levels of interleukin (IL) 18 collected from psoriatic patients with different disease activity. IL-18 concentrations were measured using an enzyme immunoassay in the plasma and scales of 34 patients with chronic plaque type psoriasis. IL-18 levels were analysed with respect to plasma-transforming growth factor beta1 (TGF-beta1), the disease duration and the duration of the present relapse, and psoriasis area and severity index (PASI). Plasma IL-18 concentration varied from 90 to 1300 pg ml-1 and means (368.2 +/- 42.4 pg ml-1) were significantly elevated in comparison with healthy controls (205.9 +/- 31.8 pg ml-1). The presence of IL-18 was also demonstrated in scales from skin lesions. Treatment caused a significant decrease of plasma IL-18 concentration to 250.2 +/- 13.8 pg ml-1. There was a significant correlation between plasma IL-18 levels and PASI values (r = 0.554). There was no correlation between IL-18 concentration in scales and PASI, between IL-18 concentrations in plasma and scales, and between plasma IL-18 and the disease duration or duration of present relapse. Plasma TGF-beta1 concentration demonstrated a significant correlation with PASI (r = 0.353), but not with IL-18 levels in plasma (r = 0.063) and scales (0.141). The sum of plasma levels of IL-18 and TGF-beta1 divided by the optimal coefficient demonstrated a statistically significant correlation with the highest r-value. The findings confirm an association between plasma IL-18 concentration and psoriasis severity. Moreover, it was shown that combined measurement of IL-18 and TGF-beta1 in plasma can be considered as a possible biomarker of psoriasis activity.
authors.affiliation: Department of Dermatology and Venereology, Medical University of Bialystok, Bialystok, Poland.
authors.forename: I
authors.initials: I
authors.lastname: Flisiak
authors.forename: A
authors.initials: A
authors.lastname: Klepacki
authors.forename: B
authors.initials: B
authors.lastname: Chodynicka
mesh_terms: D015415:Biomarkers / Q000097:blood / Q000378:metabolism*; D006801:Humans; D020382:Interleukin-18 / Q000097:blood / Q000378:metabolism*; D011565:Psoriasis / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D015415:Biomarkers; D020382:Interleukin-18; D016212:Transforming Growth Factor beta