ROLE OF HIGH-MOBILITY GROUP BOX1 PROTEIN IN PSORIASIS VULGARIS

Abstract

SUMMARY P soriasis is a chronic inflammatory skin disease with polygenic predisposition combined with triggering environmental factors. It is a chronic papulosquamous skin disease characterized by complex alterations in epidermal growth and differentiation, and multiple biochemical, immunologic and vascular abnormalities. Autoimmunity is believed to play a central role in the development of PV. The immune response in PV is associated with aberrant lesional expression of IFN-γ, IL-2, and TNF-α. Together with these cytokines, HMGB1 may constitute a proinflammatory loop and may act as an important player in the inflammatory processes in PV. Activated HMGB1 mediates cellular responses including chemotactic cell movement and release of proinflammatory cytokines such as TNF-α, IL-1 β, and IL-6, and effects on various immune cells, such as macrophages, monocytes, T cells, and B cells. With the discovery of HMGB1 as a potent mediator of inflammation and the presence of extranuclear HMGB1 in several inflammatory conditions, investigations of possible beneficial effects of HMGB1-targeted therapies were initiated. Many studies have concluded that HMGB1 is a key player in the pathogenesis of several autoimmune diseases such as R.A, SLE and AA. The aim of this study was to evaluate serum HMGB1 levels in patients with PV, and to correlate it with the disease severity according to PASI score. It was done on 40 patients with PV of different grades of severity (divided into 3 subgroups according to PASI score) and 20 age and sex matched healthy controls. Each patient was subjected to a detailed history taking and full examination. Blood samples were taken from each individual to assess serum level of HMGB1. Comparison between all patients and controls as well as between patients subgroups regarding serum HMGB1 level were done. Correlation between serum HMGB1 levels and the disease duration and severity were done. Our results revealed that serum levels of HMGB1 were highly significantly increased in psoriatic patients, with a highly significant positive correlation to the duration of the disease and the disease severity when compared to the healthy controls.