الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 103 |  |  |
| | | from | 103 | | |
Abstract
Psoriasis and lichen planus (LP) are common chronic inflammatory skin diseases. The exact pathogenesis of these diseases until now is not fully determined. They may result from complex interactions of innate and adaptive immune responses based on a strong genetic predisposition and triggered by environmental factors as well as alternations to angiogenesis.
Recent advances have brought the evidence that angiogenesis is tightly connected to chronic inflammation that is in tight association with the pathogenesis of both psoriasis and lichen planus diseases
Angiogenesis is tightly regulated by a balance between pro- and anti-angiogenic mediators. It is generally supposed that in quiescent cutaneous microcirculation, a balance between proangiogenic and antiangiogenic factors maintains homeostasis. So it is initiated by angiogenic switch resulting from upregulation of angiogenic inhibitors.
More recently, the endothelial specific growth factor, Ang-2 has been clarified to interact with VEGF, the strongest angiogenic inducer, to determine the fate of blood vessels during angiogenesis. Ang2 regulates the transition between vascular quiescence and angiogenesis by antagonizing the interaction of Tie2 receptor with Ang1, a vascular stabilizing factor, on dermal microvascular endothelial cells.
Moreover, Ang-2 is discussed as a biomarker for diseases’ severity and development. Previous studies reported increased Ang-2 levels in patients with inflammatory diseases. So we aimed to assess the relation of Ang-2 serum level with angiogenesis and inflammation that occurs in psoriasis and lichen planus.
A total of thirty adult patients were included in this study; they were divided into 2 groups, 15 patients each, of psoriasis and lichen planus (8 patients with combined cutaneous and oral lp and 7 patients with cutaneous lp only). In addition to fifteen healthy subjects taken as control. The activity of the diseases was estimated at the time of examination using specific activity index for each disease. The serum level of angiopoietin 2 had been estimated by ELISA.
It has been found that these diseases had significantly higher serum levels of angiopoeitin 2 than the control group. The serum levels of angiopoitin 2 were higher in psoriasis compared with lichen planus, but the difference between psoriasis and lichen planus was not statistically significant. There was significant positive correlation between the serum levels of angiopoietin 2 and the clinical severity of psoriasis. On the other hand, there was no correlation between serum level of angiopoietin 2 and the clinical severity of lichen planus.
As regard lichen planus, patients who had both cutaneous and oral LP had significantly higher serum levels of angiopoietin 2 than patients of cutaneous LP only.
Besides, There was no statistical significant differences between male and female in serum angiopoietin 2 levels in any of the studied groups,age and previuos treatment of the studied groups. Meanwhile there was statistical significant Correlation between serum angiopoietin 2 level with duration of disease among lichen planus group.