The Expression And Significance Of Leukotriene B4, 5-hydroxytryptamine, And IL-1β In Pityriasis Rosea

Objective: Pityriasis rosea (PR) is an inflammation skin disease, which is common in the Department of Dermatology. The lesions tend to be distributed on the trunk and extremities. The primary macules are yellow-red ,oval or circular and covered with small, thin scales like a collar. The etiology and pathogenesis of PR remain unkown. Now many people consider that it is related with virus infection, hypersensitivity reaction, autoimmunity, genetic anaphylaxis and so on. Leukotrinene B4(leukotriene B4,LTB4)plays an important role in the hypersensitivity,inflammation,and immune system.LTB4 is synthesised immediately by mast cells and basophilic leukocyte degranulate when they are activited and realeased through degranulated way.LTB4 partcipated hypersensitivity reaction through other cells and issues.LTB4 enhances lymphocytes to produce IgE with IL-4 together in typeⅠhypersensitivity early stage, and it is factor synthesized by inflammation cells such as macrophages and neutrophil infiltrated in typeⅠhypersensitivity late stage, it is the classic inflammation factor realeased in typeⅠhypersensitivity late stage. LTB4 can cause wide inflammation in typeⅠhypersensitivity. Hypersensitivity reaction is a protected immune reaction for human body, but witch can hurt the body sometimes.5-hydroxytryptamine is one of inflammatory mediators.When fluids or cells immune is responsed then the meditors are activated or realeased witch hurt the issues through their receptor cell and cause inflammation.5- hydroxytryptamine is one of vasoactive amines material realeased in late stage on typeⅠhypersensitivity ,it can cause smooth muscle shrinkages and increased vascular`s permeability just like histamine and allergic slow-reacting substance. 5-hydroxytryptamine may cause smooth muscle shrinkages, capillaries expansion and enhance the permeability then cause skin erythema, edema, cyanosis, bleeding, itching, and other inflammatory response. IL-1βis an hormone-like peptide substance and its main function is to regulate immune. IL-1βis mainly generated by the activated monocytes– phagocytes. Reased IL-1βis the primary and the most important immune reponse phenomenon. This study detected the serum concentration of IL-1βby ELISA(Enzyme linked immunosorbent assay) and observe the expressions of 5-hydroxytryptamine and IL-1βin PR lesions to explain their function in the pathogenesis of PR. At the same time to explore the relation between PR and hypersensitivity.Materials and Methods: Thirty PR serum samples includigng 14 males and 16 females were collected from PR patients diagnosed by clinic of the dermatological department of the Forth Affiliated Hospital of Hebei Medical University during Dec,2006 to June,2007. Age ranged from 15 to 40 years(mean 24.58±6.19); Course from 2 days to 2 months,(mean 17.50±14.46). And random select 10 out–hospital healthy volunteers as controls. There are no significant differences in sexes and ages between controls and patients. All patients and volunteers have no LTB4 novel diseases(for example respiratory diseases, other allergic diseases, inflammatory diseases, autoimmune diseases), and had on systematic mediation history as well as swim history (to exclusion durg eruption and PR-type secondary syphilis) within one month, had no taken immunodepressants and antihistamine at the same time.Thirty lesion case diagnosed as PR clinically and histopathologically were collected from the dermatological department of the Forth Affiliate Hospital of Hebei Medical University during Mar. 2003 to May.2007, who had no other systemic disease or other skin diseases,and had not received any treatment since they were selected. These cases included 14 males and 16 females, age arranged from 10 to 42 years (mean29.73±3.85), course arranged from 5 to 40 days (mean19.89±3.88). The ten normal controls were healthy volunteers in the hospital, and had no significant difference in sex, age and position between patients and controls.The sera concentration of LTB4 were measured by enzyme linked immunosorbent assay (ELISA), the result were analyzed by 2-independent sample compared T test. The result of gender was analyzed by2-independent sample compared T test and the results of different age and pruritus degree were analyzed by one-factor analysis of variance. The lesion samples were investigated with histopathological method.The levels of 5-HT and IL-1βexpressions were measured by immunohistochemical method. HE-staining was used in histopathology and histostain-SP in immuno-histochemistry. The results were analyzed by Mann-whitney U rand sum test and Spearman's rank correlation test.Results1 ELISA results1.1 The mean concentrations of sera LTB4 of PR patients and normal controls were1.8632±0.1605, and1.4484±0.1044, compared with each other, there was statistal significance (p<0.05).1.2 The mean concentrations of sera LTB4 of PR patients, which compared from gender, age phases and pruritus degrees, there were no statistal significance (p>0.05).2 Immunohistochemistry results Positive staining was submitted Buffy grains.2.1 5-HT stained on cytoplasm of stratum spinosum and stratum granulosum cell. Among these positive cells, 0 cases (+++), 5cases (++), 17 cases (+), 8 case (-).The level of its expression was markedly increased comparing with the controls (p<0.01).3.2 IL-1βstained on cell membranes and cytoplasm of full epidermis cell . Among these positive cells, 3 cases (+++), 11cases (++), 14 cases (+), 2 case (-).The level of its expression was markedly increased comparing with the controls (p<0.05).3.3 There was significant correlation between the expression degree of HSP-70 and TNF-α(p<0.01).Conclusion1 In this study, the concentration of serum LTB4 of PR patients is significantly increased, this implies LTB4 participants the development of PR. The mechanism may be LTB4 chemokines leukocyte aggregated to inflammation site and induces leukocyte to degranulate and prduce superoxide ions to hurt issue directly, then make leukocyte adhesion to endothelial cells, increase interleukin-dependent vascular permeability and induce the development of PR with other factors. LTB4 be the classic factor in typeⅠhypersensitivity late stage implies typeⅠhypersensitivity maybe participate the development of PR.2 The expression of 5-hydroxytryptamine in the lesions is stronger than that of controls , it explains that 5-serotoin may be take part in the development of PR.( It may be vasoactive amines material in typeⅠhypersensitivity late stage cause skin`s capillaries expansion ,permeability enhanced lead the skin emergy erythea and other inflammation reaction to participant the produce of PR It is perhaps that 5-HT takes part in the development of PR by it`s other fuction.3 The expression of IL-1βin the lesions is stronger than that of controls implies that it be of an important inflammation factors take part in the development of PR.The mechanism maybe IL-1βmake vascular endothelial cells expression endothelial cells-leukocyte adhesion molecule-1 and intercellular adhesion molecule-1,then enhancing the adhesion between interleukins, promoting exudation and migration of inflammatory cells and activating inflammation ,cause the immune hurt to the body with other factors.4 There was significant correlation between the expression degree of 5-HT and IL-1β,that implies they be of inflammation factors promting eatch other to take part in the development of PR.