Phenotypic and functional analysis of peripheral blood lymphocytes in oral lichen planus

Analysis of Immunologic Function Changes in Lichen Planus After Clinical Treatment

BACKGROUND Lichen planus (LP) is a common chronic superficial skin lesion that causes chronic or sub-acute inflammatory disorders. LP can affect the oral cavity, skin, mucous membrane, and other body parts, and features include repeat attacks and long duration, leading to lower quality of life. This study aimed to analyze the changes of immunologic function before and after treatment of LP. MATERIAL AND METHODS Thirty cutaneous LP patients were selected. Peripheral blood was collected in the morning before and after treatment. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient method. Flow cytometry was used to detect T cell subpopulation CD4⁺ T cells and CD8⁺ T to calculate CD4⁺ T/CD8⁺ T ratio. Enzyme-linked immunosorbent assay (ELISA) was adopted to detect the helper T-cell (Th) factor IL-2, IFN-γ, IL-4, IL-6, IL-17, and IL-22 levels. RESULTS Compared with before treatment, the expressions of CD4⁺ T cells and CD8⁺ T cells were decreased, while the proportion of CD4⁺ T/CD8⁺ T were significantly elevated after treatment. IL-2 and IFN-γ secretion were markedly increased, whereas IL-4, IL-6, IL-17, and IL-22 were significantly reduced after treatment (P<0.05). CONCLUSIONS LP treatment reduces the distribution of CD4⁺ T cells and CD8⁺ T cells, and promotes the changes of Th1, Th2, and Th17 cytokines secretion.

Unilateral lichen planus: A rare case report

Oral lichen planus (OLP) is a mucocutaneous disease with well-established clinical and histopathological features. It has a prevalence of approximately 1%. The etiopathogenesis is poorly understood. The annual malignant transformation is less than 0.5%. There are no effective means to either predict or to prevent such event. Clinically, OLP present as bilateral symmetrical lesion and hence lichen planus isolated to a single oral site other than the gingiva is very uncommon. On the other hand lichenoid reaction (LR) are the lesions which are similar clinically and histopathologically with OLP, but they are induced with some drug reaction and usually they do not show bilateral pattern like lichen planus. We reported a very uncommon case of unilateral lichen planus which was clinically diagnosed as LR, but in the absence of any cause-effective relationship biopsy was taken for histopathological examination Histopathologically, LR cannot be differentiated with OLP, so the final diagnosis was made on the immunohistochemical ground.

Reduced immune responses to purified protein derivative and Candida albicans in oral lichen planus

BACKGROUND

Impairment of cellular immunity is reported in lichen planus, an autoimmune disease affecting mucosae and skin. Our aim was to investigate immune responses directed against a set of microbial antigens in patients with oral lichen planus and in matched controls.

METHODS

Venous blood was obtained, and the mononuclear cells were enriched by density gradient centrifugation. The proliferation of peripheral blood mononuclear cells was assessed, following stimulation with purified protein derivative (PPD), Candida albicans, phytohemagglutinin or when cells were left unstimulated, after three or six days of cell culture. The production of interleukin-1ß (IL-1ß), IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-17, interferon-γ (IFN-γ), tumour necrosis factor-α (TNF-α), G-CSF, GM-CSF, MCP-1, MIP-ß was assessed in supernatants using the Bio-plex(®) assay and was complemented with ELISA for selected cytokines.

RESULTS

Patients with oral lichen planus demonstrated reduced proliferative responses against PPD (P < 0.05) and C. albicans (P < 0.05). The majority of investigated cytokines, including the pro-inflammatory, IFN-γ and TNF-α were expressed at reduced levels in PPD-stimulated supernatants from patients with oral lichen planus.

CONCLUSIONS

Collectively, the findings suggested that memory lymphocytes from patients with oral lichen planus (OLP) may have an impaired functional ability to react against certain recall antigens, as part of a generalized response, which may reflect immune regulatory processes. Further studies are needed to clarify the mechanisms of down-regulation in OLP pathogenesis and progression.

Assessment of the peripheral immunocompetent cells in patients with reticular and atrophic-erosive lichen planus

OBJECTIVE

To assess the cellular and humoral immunity in patients with reticular and atrophic-erosive oral lichen planus (OLP).

STUDY DESIGN

Lymphocyte phenotype analysis of 50 patients with OLP and 16 control subjects was performed by means of flow cytometry. The results were analyzed by the Mann-Whitney U test.

RESULTS

In the patient group the percentage of naïve helper T cells was significantly decreased, while that of memory cells was increased, resulting in a significantly higher ratio of memory to naïve cells in the OLP group than in the control group. In the group of patients with atrophic-erosive OLP, the percentages of cytotoxic/suppressor T cells and cytotoxic/suppressor naïve T cells were found to be slightly decreased.

CONCLUSIONS

The results indicate that the relative ratio of immunocompetent cells in the peripheral blood is altered in patients with lichen planus and that the exact character of these disturbances depends on OLP form. Some of the alterations observed in these patients are typical to autoimmune diseases, thus promoting the concept of autoimmune etiopathogenesis of lichen planus.

Perforin expression in peripheral blood lymphocytes and skin-infiltrating cells in patients with lichen planus

BACKGROUND

Current evidence suggests that lichen planus is a T-cell-mediated autoimmune disease in which cytotoxic mechanisms have been poorly investigated.

OBJECTIVES

We investigated the expression of perforin in subpopulations of peripheral blood lymphocytes (PBL) in exacerbation and remission phases of the disease as well as in skin lesions.

METHODS

We performed a simultaneous detection of perforin (intracellular molecule) and cell surface antigens on PBL by flow cytometry, and skin lesions were investigated by immunohistochemistry.

RESULTS

The most interesting finding was a significant increase of perforin expression in cytotoxic T lymphocytes (CD3+ perforin+ cells) in the exacerbation phase of disease (P < 0.05), which was mostly located in the CD8+ subpopulation (CD8+ perforin+) (P < 0.01). Using immunohistochemistry we confirmed the infiltration of T lymphocytes in skin lesions, especially of CD4+ and CD8+ phenotypes, compared with uninvolved (P < 0.05) and healthy skin (P < 0.01). The expression of perforin was also significantly higher in lesional skin compared with nonlesional and healthy skin (P < 0.05).

CONCLUSIONS

Our results clearly show the upregulation of perforin expression in peripheral blood as well as in lesions of patients with lichen planus and therefore suggest an important role for perforin in this autoimmune disease.

Oral lichen planus: immunohistology of mucosal lesions

BACKGROUND

Current evidence suggests that immunological mechanisms are involved in oral lichen planus (OLP) pathogenesis. The events implicate activated epithelia that comprise antigen-presenting Langerhans cells, immunocompetent keratinocytes and subepithelial inflammatory infiltrate. Also, the presence of a high density of leucocyte cells may occur for the expression of a variety of adhesion molecules. The aim of this study was to analyse the immunoexpression of some adhesion molecules as well as lymphocytic markers in order to determine the disease pathogenesis in a Venezuelan population.

METHODS

The 18 OLP and 10 normal oral mucosa biopsies were immunostained for CD4, CD8, CD1a, LFA-1, VCAM-1 and ICAM-1.

RESULTS

The results showed an increased number of CD4+, CD8+, CD1a+ cells in OLP. Serial sections showed CD4+ and CD8+ cells also expressed LFA-1. The expression of ICAM-1 and VCAM-1 were significantly higher in OLP.

CONCLUSIONS

The immunological reaction begins with Langerhans cells activation, which presents an antigen to CD4+ lymphocytes. Those cells through ICAM-1 and LFA-1 promote epithelial destruction. Afterwards, cytokine production, ICAM-1 and VCAM-1 expression can activate CD8+ lymphocytes leading to the chronic form of the disease.

Peripheral T-cell subsets in patients with reticular and atrophic-erosive oral lichen planus

OBJECTIVE

Oral lichen planus (OLP) presents with various clinical forms that can be classified into 2 major types: reticular OLP and atrophic-erosive OLP. Our objective was to investigate immunologic differences between these 2 types.

STUDY DESIGN

We investigated possible immunologic differences between 26 patients with reticular OLP and 26 patients with atrophic-erosive OLP.

RESULTS

No differences were detected in serum Ig levels or complement levels. However, the mean proportions of CD4+CD45RO+ and DR+ lymphocytes were significantly higher in patients with atrophic-erosive OLP than in patients with reticular OLP, whereas the mean proportion of CD8+CD45RA+ lymphocytes was significantly lower in patients with atrophic-erosive OLP.

CONCLUSION

These findings suggest that the 2 clinical types of OLP might have different immunopathogenic mechanisms.

Reduced in vivo cell-mediated immune responses to mumps, tuberculin, and streptokinase/streptodornase but not to Candida albicans in oral lichen planus

Oral lichen planus is considered to be a T-cell-mediated disease. The purpose of this study was to investigate the capacity of T-lymphocytes in oral lichen planus patients to respond to a number of commonly encountered environmental antigens in vivo. To do this, we assessed dermal delayed-type hypersensitivity responses to mumps, streptokinase/streptodornase, Candida albicans, and purified protein derivative of tuberculin (PPD) in 17 oral lichen planus patients and in matched controls. Reduced induration in response toward mumps, PPD, and streptokinase/streptodornase was demonstrated in oral lichen planus patients compared with controls. In addition, the total sum of induration diameters was decreased in the patients. However, C. albicans stimulation resulted in similar levels of response in both groups. The differences in induration size between matched patients and controls for mumps and PPD were thus significantly greater than the corresponding differences for the C. albicans antigen. This suggests that a selective difference in the response to these antigens exists in oral lichen planus patients. The results may point to a loss of memory T-helper function to infrequently encountered environmental antigens, represented by mumps, PPD, and streptokinase/streptodornase, contrarily to memory function to common antigens (C. albicans), which seem to be unaffected.

Intra-epithelial subpopulations of T lymphocytes and Langerhans cells in oral lichen planus

This study has addressed the question of whether there is selective recruitment and distribution of intra-epithelial leucocytes in lesions of oral lichen planus (OLP). T-lymphocyte subsets were examined in the epithelium and peripheral blood of patients and controls using flow cytometry and double immunofluorescence, and the relationship between keratinocyte intercellular adhesion molecule-1 (ICAM-1) expression with T-lymphocyte and Langerhans cell (LC) distribution was examined. The circulating 'memory' subset (CD45RO+) of T-helper cells (CD4+) was increased from 49.1% in controls to 65.7% in patients (P=0.005), while the 'naive' subset (CD45RA+), which was absent from control epithelium, comprised 24% of helper cells in OLP (P=0.016). Fewer LC expressed CD45RO in OLP than in controls (P=0.037) and all T-cell and LC counts were significantly raised in ICAM-1-expressing areas of epithelium. These data demonstrate changes in intra-epithelial T-lymphocyte and LC populations compared with normal oral mucosa and suggest there is selective recruitment in OLP. In addition, keratinocyte ICAM-1 expression does appear to be associated with accumulation of infiltrating T lymphocytes and LC.

Immunopathogenesis of oral lichen planus and recurrent aphthous stomatitis

Oral mucosal bullous/desquamative/ulcerative diseases involve immunopathological mechanisms that account for loss of adhesion between contiguous keratinocytes or to structures within the basal lamina. Some are antibody mediated, in which specific adhesion molecules of the desmosome, hemidesmosome, and basement membrane become antigenic targets. Oral lichen planus and recurrent apthous ulcers, although manifesting disparate clinical appearances and natural history, share immunopathological features that involve T cell-mediated immunity. Although the antigens, haptens, or autoantigens are not usually apparent, current research poses the hypothesis that both of these common oral mucosal diseases are a delayed-type hypersensitivity or cell-mediated response to an antigenic stimulus residing within the epithelium. This article reviews the research evidence for this hypothesis.

Cellular immune correlates of clinical severity in oral lichen planus: preliminary association with mood states

OBJECTIVES

We investigated cellular immune and psycho-immune dysfunctions in patients with erosive and non-erosive oral lichen planus (OLP) lesions.

METHODS

Patients with erosive or non-erosive OLP were screened at the UCLA Dental Clinic. The profile of mood states (POMS) was administered. T lymphocyte subpopulations were monitored by dual fluorescence. T lymphocytes were stimulated with phytohemagglutinin (PHA) for assessment of markers of activation by flow cytometry and of interleukin (IL)-2 production by ELISA. Plasma cortisol and neopterin levels were assessed by radioimmunoassay.

RESULTS

Circulating T cells that express the cluster of differentiation no. 4 (CD4+) but devoid of the CD45RA marker, and POMS score were significantly associated (r = 0.83, P < 0.05) in the patients we studied. We found a significantly higher (P < 0.05) per cent and absolute lymphocyte numbers of circulating CD4+CD45RA- cells in the OLP patients with erosive lesions, compared to OLP patients with non-erosive lesions. The ratio of CD4+ CD45RA+ over CD4+CD45RA- cells was significantly (P < 0.05) biased toward the CD4+CD45RA- subpopulation in OLP patients with erosive lesions (ratio = 0.19 +/- 0.09) compared to patients with non-erosive OLP lesions (ratio = 0.47 +/- 0.15). The expression of CD54, but not that of CD69, was significantly blunted (P < 0.05) in OLP patients following CD3+ cell stimulation. IL-2 production and plasma neopterin were normal in these patients. There was no correlation between plasma cortisol and T cell populations.

CONCLUSIONS

We find fine differences in psycho-immune interactions between patients afflicted with non-erosive OLP lesions compared to those with erosive OLP lesions.

T-cell receptor V beta usage by lesional lymphocytes in oral lichen planus

To determine whether the T-cell inflammatory infiltrate in oral lichen planus (OLP) represents a selective activation and expansion of a limited repertoire of T-cell receptor (TCR) specific T-cells, V beta gene expression was investigated in lesional T-lymphocytes in OLP. A reverse transcriptase-polymerase chain reaction (RT-PCR) technique was used to amplify the 24 major V beta gene sub-families of infiltrating mucosal lymphocytes and peripheral blood mononuclear cells (PMNC) in seven patients with reticular OLP and four healthy control patients. Specificity of amplified products was confirmed by Southern blotting with a C beta internal probe. TCR V beta usage by lesional T-cells in OLP was markedly heterogeneous 5-23 V beta sub-families). In 6/8 patients with OLP, V beta usage was restricted with < or = 20/25 sub-families detected; only one of the V beta sub-families (V beta 8) was present in all of the OLP patients demonstrating TCR V beta restriction. In contrast, TCR V beta usage was unrestricted in PMNC from OLP patients and controls (> or = 23/ 25 sub-families detected). In three patients, certain V beta sub-families (V beta 13, V beta 14 & V beta 15) were present in the lesional T-cell population but were under-represented in PMNC. These results suggest a selective V beta gene usage by lesional infiltrating T-cells in oral lichen planus. The non-uniformity of V beta restriction in lesional T-cells does not support the concept of a common superantigen in OLP and reflects the heterogeneity of the disease.

Assessing the characteristics of patients with oral lichen planus

The authors assessed the medical history, lifestyles and health habits of 146 patients with oral lichen planus as confirmed by biopsy. The results support a relationship between stress and the development of oral lichen planus. Fifty-one percent of the subjects reported that they had experienced stressful events at the time of the lichen planus onset. Practitioners may want to consider the benefits of stress management and bereavement counseling in managing patients with oral lichen planus.

Dramatic response to levamisole and low-dose prednisolone in 23 patients with oral lichen planus: a 6-year prospective follow-up study

The purpose of this prospective study was to evaluate the short-term and long-term clinical efficacy of levamisole used with low-dose prednisolone in patients with refractory oral lichen planus. Twenty-three patients with OLP who had been treated unsuccessfully with other modalities were given 150 mg/day levamisole and 15 mg/day prednisolone for 3 consecutive days each week. Twelve patients showed dramatic remission of signs and symptoms within 2 weeks, whereas 11 had partial remission. All 23 reported significant pain relief and showed no evidence of erosive oral lichen planus after 4 to 6 weeks of treatment. All 23 also remained free from symptoms for 6 to 9 months after the treatment ended. There were few side effects from this treatment besides minor skin rash, headache, and insomnia from the levamisole in three cases. We conclude that the addition of levamisole to prednisolone may produce improved results in the management of erosive oral lichen planus.

Heat shock protein expression in oral lichen planus

To assess the potential role of heat shock protein (HSP) in the pathogenesis of oral lichen planus (OLP), sections of OLP, normal oral mucosa, non-specific oral ulceration (NSOU) and dysplastic OLP were assessed for HSP expression using avidin-biotin complex immunohistochemistry with an anti-HSP 70 polyclonal antibody. There were statistically significant differences in both the vertical and horizontal staining distribution when other groups were compared with the OLP group (p < 0.01). Using microdensitometry, the mean staining intensity in OLP, dysplastic OLP and NSOU was elevated in comparison with normal oral mucosa (p < 0.001). In a standard tritiated thymidine uptake assay, lymphocytes extracted from nine OLP lesions demonstrated significant proliferation when stimulated with purified protein derivative (PPD), of which HSP is a major constituent, with stimulation indices ranging from 2 to 132. These results are consistent with the hypothesis that, in OLP patients, diverse exogenous agents may cause upregulated expression of HSP by oral mucosal keratinocytes. A reaction of cytotoxic T lymphocytes to these activated keratinocytes may then result in the tissue destruction which is characteristic of OLP lesions.

Phenotype and suppressor activity of T-lymphocyte clones extracted from lesions of oral lichen planus

Lymphocytes were extracted from six biopsy specimens of oral lichen planus. T-lymphocyte lines were expanded in culture with phytohaemagglutinin and interleukin 2, and cloned by limiting dilution. Fifteen T-cell clones were isolated with a probability of clonality of 96.3%. The majority of clones (n = 13) expressed the alpha beta T-cell receptor, and of these, 11 were CD8+ and two were CD4+. Two clones were CD4- and CD8-, and expressed the gamma delta T-cell receptor. The ability of these clones (effectors) to suppress concanavalin-A-stimulated proliferation of autologous lesional T-cell lines (responders) was assessed. Maximum suppressor activity ranged from 17 to 100%. The majority of clones (n = 12), including a CD3+ CD4+ CD8-alpha beta+ clone, displayed suppressor activity which was proportional to the effector to responder ratio. A CD3+CD4+CD8-alpha beta+ clone and a CD3+CD4-CD8-gamma delta+ clone displayed substantial helper activity at higher effector to responder ratios. These results demonstrate differential helper and suppressor activity of T-lymphocyte clones extracted from oral lichen planus lesions. The balance between help and suppression may be a fundamental determinant of immunological activity within the lymphocytic infiltrate of oral lichen planus, and hence may dictate the clinical behaviour of the disease.

Disease mechanisms in oral lichen planus. A possible role for autoimmunity

Current evidence for the involvement of cell-mediated immunological mechanisms in the pathogenesis of oral lichen planus is reviewed. Both a spatial and temporal relationship between cytotoxic T Lymphocytes and epithelial damage have been reported. Although keratinocytes appear to be the target for destruction in oral lichen planus, their role in antigen presentation is unclear. We propose that in oral lichen planus patients, diverse exogenous agents such as drugs, trauma and infection, stimulate the expression of a common self molecule by oral mucosal keratinocytes. An autoimmune reaction by cytotoxic T lymphocytes to these activated keratinocytes may result in the tissue destruction which is characteristic of oral lichen planus.

Clonal expansion of lymphocytes from oral lichen planus lesions

Lymphocytes were extracted from 11 biopsy specimens of oral lichen planus (OLP) by collagenase digestion, and cell lines were expanded with repetitive cycles of stimulation (with phytohaemagglutinin) and rest in media supplemented with interleukin 2. Four OLP lines contained a majority of CD3+CD4-CD8+ cells, in six lines the CD4:CD8 ratio was between 1 and 2, and in one line the CD4:CD8 ratio was 5:1. Limiting dilution of nine lines at 0.3 and 1.0 cells/well resulted in viable wells (putative clones) with plating efficiencies ranging from 0.0 to 18.1 percent and 0.0 to 22.2 percent respectively. The majority of clones were CD3+CD4-CD8+alpha beta+gamma delta-, although three clones were CD3+CD4+CD8-alpha beta+gamma delta- and one clone was CD3+CD4-CD8- and expressed the gamma delta T cell receptor. T cell clones derived from lymphocytes extracted from OLP lesions may be generated and maintained in culture providing opportunity for their further phenotypic and functional characterisation. This strategy may facilitate the identification of a putative oral lichen planus-specific antigen and indicate the frequency of lichen planus-specific T cells within lesions of OLP.

Suppressor cell function in oral lichen planus

Oral lichen planus (OLP) is a common inflammatory condition of the oral mucous membranes which affects between one and two percent of the general population. In accordance with the protracted clinical course of OLP and its association with known auto-immune diseases, the level of self-tolerance is questionable and possibly diminished in patients with this disorder. Normal suppressor T lymphocyte function is reputedly an essential element in the maintenance of self-tolerance, and deficient cell-mediated suppressor activity is implicated in the pathogenesis of auto-immune diseases. For assessment of in vitro cell-mediated suppressor activity in OLP, peripheral blood mononuclear cells (PBMC) from ten patients with OLP and from 11 control subjects were activated with the plant mitogen concanavalin A (Con A), followed by co-culture with autologous responder cells. The ability of irradiated Con A-activated cells to suppress the proliferation of Con A-stimulated responder cells was determined. Con A-induced suppressor activity of PBMC in the OLP patients was significantly less than that in control subjects (p = 0.001). Results of the present investigation complement previous in vitro findings which provided indirect evidence of deficient cell-mediated suppressor activity in OLP, particularly a decreased proportion of circulating CD4+CD45RA+ lymphocytes and reduced Con A-stimulated PBMC proliferation. The depressed Con A-induced suppressor activity of PBMC in the OLP patients provides direct evidence of deficient in vitro cell-mediated suppressor function in OLP, and suggests that defective cell-mediated suppressor circuits and reduced self-tolerance may be involved in the pathogenesis of this disorder.