Role of humoral mechanisms in etiology of lichen planus.

AIM: To examine the role of IgA, CIC and component C3 as indicators of humoral immune response in the etiopathogenesis of oral erosive lichen planus (OELP). MATERIAL AND METHOD: The study comprised 19 patients with OELP whose samples of blood, saliva and tissue were obtained after carefully taken medical history and clinical examination. Samples of oral mucosa were taken from the site of lesion, i.e. exclusively from buccal mucosa (1 cm in width and length), and from the deep epithelium as well as a segment from the lamina propria. Determination of immunoglobulins in serum and saliva, and determination of component C3, was done using the micro-elisa technique by Rook&Cameron, Engvall and Ulman. Determination of CIC in serum and mixed saliva was done with the PEG (polyethylene glycol) method. Determination of immunoglobulin A and component C3 in biopsy material was done with direct immunofluorescence. RESULTS: Levels of immunoglobulin A in serum in OELP during exacerbation were decreased (1.04±0.49 gr/l) and during remission increased (5.92±0.62) in comparison with the control group (p<0.001). Levels of CIC during exacerbation and remission were increased (p<0.001), and component C3 levels were increased in both examined phases in the examined group compared with the control group (p<0.05). Deposits of IgA were registered in one (5.88%) patient with OELP and component C3 was registered in 3 (17.64%) patients. CONCLUSION: Changes in IgA values, as well as CIC and component C3, may correlate with changes in oral mucosa emphasizing the role of humoral immune response in the pathogenesis of oral lichen planus.

T-cell subpopulations in lesions of oral lichen planus.

AIM OF THE STUDY: To determine the distribution and frequency of T(CD3) cells and cell sub-populations in tissue specimens of erosive lichen planus (EOLP). MATERIAL AND METHOD: Tissue specimens from buccal mucosa were taken from 14 healthy individuals--control group (CG)--and 17 subjects with EF-OLP. Applying monoclonal antibodies, T(CD3) cells, T cell subpopulations, The CD4, CD8 and CD4/CD8 ratios in both groups were determined. Cells in the epithelium and lamina propria were quantitatively and qualitatively determined in both groups. Data were analysed using the Student's t-test. RESULTS: There were 5.95 2.12% T(CD3) cells in the control group as against 9.80 4.04% in the examined group (p<0.001). The distribution of T(CD3) cells in the lamina propria was 25.35 12.04% in the examined group compared to the control group (p<0.001). There were 3.45 2.05% CD4 epithelial cells in the control group and 4.00 1.95% in the examined group (p<0.4). There were 2.50 1.8% CD8 cells in the control group and 5.80 3.72% in the examined group (p<0.001). The CD4/CD8 ratio was 0.51 0.12% in the examined group and it was evidently reduced in comparison with the control group. An increased distribution of CD4 cells (10.30 7.60%) and CD8 cells (15.05 5.20%) in the lamina propria compared with the epithelium was observed in the examined group (p<0.001). The CD4/CD8 ratio in the epithelium was 0.51 0.12% as against the ratio of the lamina propria, which was slightly increased (0.68 0.48%) with a low statistically significant difference (p<0.05). CONCLUSION: Differences in the distribution of T-lymphocyte subsets between the control and examined groups were found (p<0.001). An increased distribution and frequency of CD4 and CD8 cells in the lamina propria was observed. These were predominantly located in the sub-basal region of the stratum papillare and rarely seen in the intra-epithelial region.