| Oral lichen planus(OLP) is a chronic inflammatory disease of the oral mucosa.The exact etiopathogenesis has not been disclosed,but the celluar immunologic system is believed to play a leading role in it. Langerhans cells (LCs) are dendritic cells of the epidermis and mucosa.They are highly specialized leukocytes that serve immunogenic and tolerogenic purposes.Although the morphological appearances of Langerhans cells in OLP epithelium have been examined by light and /or electron microscope,their three-dimensional appearance in the disease has not been clarified.Those microscopical methods are insufficient to describe the three dimensional morphology of cells because of distortion due to thin sectioning.OLP appears in different clinical forms,comprising white papular,reticular,plaq-ue,erythematous,or ulcerative pattern,which can alter and occur in solitary or combinatory form. As defined by clinical appearance and episodes of patient discomfort,ulcerative or atrophic OLP constitute more destructive disease form,while purely reticular forms are associated with fewer symptoms and therefore might reflect a milder disease phase. Varying degrees of increased epithelial proliferation ,apopto-sis,and HLA-DR and decreased epithelial thickness have been observed in OLP. These changes might to some extent reflect disease activity and the aim of this study was to examine whether they would vary according to selected clinical forms of OLP.The study includes the following three parts:Part I :The study on Langerhans cells in oral lichen planus Experiment oneMorphological observation of Langerhans cells in oral lichen planusAbstractObjective: To study the morphological Characteristics of langerhans cells in oral lichen planus (OLP). Materials and methods :Five normal and eight OLP in buccal epithelium had been collected from the stomatological college of Wuhan University . The distributive and morphological changes of LCs in those specimens were observed by light microscopy,electron microscopy and immunohistochemistry.LCs were labelled with immunofluorescence method and were scanned and reconstructed with laser scanning confocal microscopy.Results: LCs mainly appeared in the spinous layer and the number was mucn more in oral lichen planus than in the normal mucosa .Under electron microscopy, LCs were big with an irregular shape and a mount of mitochondria, ribosomes, Golgi complex and endoplasmic reticulum in cytoplasm.Most of LCs exhibited several dendritic in protrusions with irregular nucleus in shape. The cytoplasm procession of LCs increased in OLP and its structure inclined to be more irregular and the three-dimensional aspects of LCs disclosed that there was contact between two adjacent LCs in OLP ep'ithelium. Conclusion: The increase of cytoplasm procession of LCs and the contact between the adjacent LCs in OLP might indicate the increased antigen presenting function and the crossing-talk of LCs ,which may be one of the mechanisms of OLP. Experiment twoImmunohistochemical analysis of Langerhans cells in oral lichen planusAbstractObjective:To elucidate the functional status of langerhans cells (LCs) in the tissue of oral lichen planus(OLP) by analyzing characteristic phenotype of them. Materials and Methods: 30 specimens from oral lichen planus cases without any treatment before and 10 specimens of normal buccal mucosa from oral mucocele cases were collected.Distribution of LCs expressing cdla+,HLA-DR+ and cd83+ in OLP tissue and normal mucous membrane was observed by immunohistochemistry.The density of LCs in OLP and normal mucosa were statistically compared. Results The density of cdla +LCs and HLA-DR+ LCs in OLP,especially in atrophic OLP was significantly higher than that in normal mucosa. .There were no cd83+ LCs in normal mucosa and a few cd83+ LCs appeared at the junction of epthelium and lamina propria in both reticular and atrophic OLP and there was no significant difference between the two typies. Conclusion:The higher density of cdla +LCs and HLA-DR+ LCs in OLP,especially in atrophic OLP and the functional mature of LCs arresting at the junction of epithelium and lamina propia in OLP might reflect the immunological microenviorment of hosts with OLP.Part II:The disease activity of epithelium in oral lichen planusObjective:To investigate the disease activity of epithelium in oral lichen planus. Materials and methods: 30 specimens including atrophic OLP(n=16),reticular OLP(n=14) without any treatment before were selected as test group. In addition,10 specimens of normal buccal mucosa from oral mucocele cases were used as control. ?A11 samples were examined by HE. Morphometric parameters of cell and cell nuclei were quantitatively analyzed by image analysis system. ? Numbers of apoptoses cell by TUNEL and proliferative index by AgNOR and PCNA immuohistochemical method were analyzed in all samples. ?All samples stained byimmunohischemistorical method of survivin and by in situ hybridization method of caspase-3. Results: ?The epithelial thickness in atrophic OLP was thinner than in normal mucosa,where as reticular OLP showed values between atrophic OLP and normal mucosa. Cell morphometric parameters increased significantly in atrophic OLP as compared with reticular OLP and normal mucosa,with no difference between the two latter forms. ?In OLP specimens apoptotic cells,most with infiltrative lymphocytic cell,were seen in the basal cell and spinous cell zone.The number of epithelial apoptosis in OLP especially in atrophic lesion,was significantly higher than that in the normal mucosa. AgNOR counts and cell proliferation index in atrophic OLP were significant ly higher than that in normal mucosa and reticular OLP.(3)The expression of survivin in OLP were stronger than that in normal mucosa without statistical significance.The expression of caspase-3 gene was much stronger in atrophic OLP than that in normal mucosa and reticular OLP. Conclusion: ?The increased cell morphometric. AgNOR counts and proliferation index in atrophic OLP supports the notion that this form displays a higher disease activity as compared to reticular lesion. ?The higher expression of caspase-3 gene might contribute to epithelial cell apoptosis in OLP.Partm-.A Clinical Study of 674 PatientsWith Oral Lichen Planus in ChinaObjective: The purpose of this paper was to describe the clinical characteristics of OLP in 674 Chinese patients. Materials and Methods: 674 charts of patients with histologically confirmed OLP were collected from Stomatological Hospital of Wuhan University between 1963 and 2003 .Results: Of the 674 patients , 65.9% were women and 34.1% were men. The most common clinical presentation was the reticular type (51.3%),and symptomatic OLP was noted in 67.5 % of the patients,mainly in those with the erosive form. The erosive presentations showed significantly longer duration,more sites affected and a much greater old patients predominance thanreticular or atrophic ones. 90.9% of the patients had multiple oral sites of involvement and isolated lower lip lichen planus were observed in 60 cases(8.9%) and isolated gingiva lichen in only 1 case(0.2%).Skin involvement of lichen planus was found in 11.4% of patients.No statistically significant differences could be identified between OLP and diabetes,cardiovascular disease,smoking or alcohol use.Precipitating factors that resulted in an exacerbation of the disease were frequently noted and included foods,stress, dental cusp and poor oral hygiene.The transformation of OLP into malignancy was observed in 4 patients at sites previously diagnosed by clinical examination as erosive or atrophic lichen planus. ConcIusionsrPatients with OLP in China usually present with distinctive clinical morphology and characteristic distribution and few may display lesions with a confusing array of forms mimicking other diseases. A long time follow-up is of utmost importance to detect its malignant transformation. |
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