الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 78 |  |  |
| | | from | 78 | | |
Abstract
Psoriasis is a chronic, immune-mediated, inflammatory disease of the skin which has been estimated to affect 2% to 3% of the population. It is a multifactorial disease with genetic background, environmental triggering factors, and immunological mediators.
The most common form of psoriasis is plaque psoriasis which affects 80-90% of psoriatic patients and characterized by sharply demarcated erythematous silvery scaling plaques occur most commonly on the extensor surface of the elbows, knees, scalp, and sacral regions.
Psoriasis is probably best placed within a spectrum of autoimmune-related diseases characterized by chronic inflammation in the absence of known infectious agents or antigens with central importance to an interaction between acquired and innate immunity. At the onset of the disease, special dendritic cells (DCs) in the epidermis and dermis are activated; among other effects, these cells produce the messenger substances, which, in turn, promote the development of T helper Th1, and Th17 cells. These T cells secrete mediators that contribute to the vascular and epidermal changes of psoriasis, although endothelial cells, neutrophils, and natural killer T cells may play an adjunctive role.
High mobility group box-1 (HMGB1) is a nonhistone nuclear protein, expressed by almost all cells, and can be translocated to the cytoplasm and then released into the extracellular space by active or passive process. Extracellular HMGB1 then becomes a pro inflammatory mediator via binding to various receptors on the surface of immune competent cells to stimulate the immune system.
It has been proposed to contribute to the pathogenesis of various chronic inflammatory and autoimmune diseases, including rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, ankylosing spondylitis as well as in cancer pathogenesis.
The aim of the present study was to assess the role of High mobility group box 1 in the etiopathogenesis of psoriasis.
The present study was conducted on 50 patients with psoriasis (group A) and 20 age and sex matched healthy control subjects (group B) collected from the dermatology and phototherapy outpatient clinics of Alexandria Main University Hospital.
Both patients and control subjects were subjected to full history taking, clinical examination and estimation of serum level of HMGB1 using ELISA technique.
Patients were further subdivided according to PASI score into 3 groups (mild, moderate, severe) to assess the role of HMGB1 in the disease progression.
In the present study the patient group included 28 males and 22 females with mean age of 46.88 years, and 32 of them had localized plaque psoriasis (64%), while 18 had generalized plaque psoriasis (36%).