Effects of Serum from Normal and Psoriatic Subjects on the Proliferation of Fibroblasts from Involved and Uninvolved Skin of Psoriatic Patients

Abstract

Background: A framework hypothesis for the pathogenesis of psoriasis states that “there is an aberration throughout the skin of patients with psoriasis that is modified to disease expression by circulating factors.” Objective: A question to emerge from this hypothesis concerns whether fibroblasts could be more central to the aberration than other cells of the skin? This article focuses on the modulation of growth of fibroblasts from uninvolved and involved sites of patients with psoriasis as a function of the type of serum in which they are grown. Methods: Fibroblasts were generated from normal subjects and from involved and uninvolved sites of six untreated psoriatic subjects and their growth in vitro was assessed as a function of the type of serum (fetal bovine serum, normal human serum, and serum from psoriatic subjects) in which they are grown. Results: The data show (a) that fibroblasts from psoriatic subjects, especially from uninvolved sites, have an inherent capacity to proliferate at an enhanced rate relative to normal fibroblasts; (b) that this enhanced proliferation can be augmented by normal human serum and to a greater degree by serum from psoriatic subjects; (c) that ≈ 40% of the enhanced proliferation is secondary to the psoriasis serum phenotype; (d) that ≈ 30% of enhanced proliferation is secondary to the psoriasis fibroblast phenotype; and (e) that the magnitude of these features are independent of the severity of psoriasis, as assessed at the time of donation of biopsies for generation of test fibroblasts or of blood for serum. Conclusion: These data support the hypothesis that there is an aberration throughout the skin of patients with psoriasis (enhanced proliferation of fibroblasts in vitro, especially from uninvolved sites) that is modified by circulating factors (serum).