Identification of mononuclear cells in situ in skin lesions of lichen planus

Cryostat sections of lesional skin of lichen planus were examined for receptors for sheep erythrocytes (T lymphocytes), Fcgamma and C3b receptors (B lymphocytes and macrophages) and C3d (B lymphocytes). The indicator cells were applied using a closed chamber technique. The combination of the closed chamber technique and treatment of the sheep erythrocytes with a strong sulphydryl reagent enabled us to detect T lymphocytes by their membrane receptors in situ. T lymphocytes were the predominant mononuclear cells in the dermal infiltrate, with less macrophages and only a few B lymphocytes.     

Immunological in situ identification of the lymphoid cells in the skin infiltrate of lichen planus

A specific rabbit anti-human T-lymphocyte antiserum has been used in an indirect immunofluorescence technique to identify T lymphocytes in situ in tissue sections from lichen planus skin lesions. T lymphocytes were also identifiedin situ by means of aminoethylisothiouronium bromide-treated sheep red blood cells, using an immune adherence technique. Various types of coated sheep red blood cells were utilized to detect cells with receptors for FcIgG and complement factor C₃b. The results demonstrated the presence of predominantly T lymphocytes, and probably some macrophages and few B lymphocytes in the skin infiltrate of lichen planus. Total and differential white count as well as relative and absolute numbers of B and T lymphocytes in peripheral blood were also determined, and found to be within the normal range.     

T cell subsets and macrophages in lichen planus. In situ identification using monoclonal antibodies and histochemical techniques

Skin lesions from 6 patients with lichen planus were studied for the presence of T cells and T cell subsets using monoclonal antibodies and indirect immunoperoxidase technique. Small numbers of Leu-2a-reactive suppressor-cytotoxic cells were present early in the basal cell layer in 2 patients with recent lesions. The analysis of T cell subsets revealed the predominance of anti-pan-T-cell (Leu-1)- and Leu-3a-reactive helper-inducer cells in 4 patients with older active lichen planus lesions. Significant numbers of suppressor-cytotoxic cells were observed in the papillary dermis and within the epidermis associated with hydropic degeneration of the basal cell layer. Activated T lymphocytes with focal acid phosphatase activity, together with activated histiocytes-macrophages with strong diffuse activity of acid phosphatase and non-specific esterase, were identified in the dermis and within the epidermis. These findings suggest that a cytotoxic immune process directed against the basal cell layer of the epidermis is the dominant pathogenic event in lichen planus.     

Half-and-half cells in lichen planus

In the course of a study of wound healing in four patients with lichen planus, we found transformed keratinocytes with a hitherto undescribed ultrastructure in both wounded and undisturbed papules. We have called these epidermal cells half-and-half cells because they showed changes on the one hand of increased synthetic activity and, on the other hand, of fibrillar transformation closely resembling that seen in fully developed colloid bodies. We suggest that these half-and-half cells may provide a useful clue to the early changes occurring in colloid body formation.     

In situ identification of mononuclear cells infiltrating cutaneous carcinoma: an immuno-histochemical study.

The present study was undertaken in order to investigate the exact nature of the cells surrounding cutaneous tumours. Formalin-fixed, paraffin-embedded sections were tested with a horse antihuman T lymphocyte serum and with IgG, IgA and IgM rabbit antihuman serum. All the sections were respectively treated with rabbit anti-horse or swine antirabbit peroxidase-labelled serum. The advantages offered by the immunoperoxidase technique are briefly discussed. T cells are in overwhelming proportion in comparison with IgG, IgA and IgM bearing cells. This seems a further demonstration that mononuclear infiltrate surrounding cutaneous carcinoma mainly represents a cell-mediated immune response.     

Bullous lichen planus and lichen planus pemphigoides-clinico-pathological comparisons

Two patients with lichen planus pemphigoides and two with bullous lichen planus were compared. Lichen planus pemphigoides was clinically distinguished by a more generalized lichen planus, more extensive blistering, the need for systemic corticosteroids and by a longer course. The blister of bullous lichen planus was a subepidermal bulla showing degeneration of the epidermal basal layer and other features of lichen planus, whereas in lichen planus pemphigoides the bulla was similar to that of bullous pemphigoid albeit with rather more neutrophils than are usually seen. Direct immunofluorescence was positive in lichen planus pemphigoides and negative in bullous lichen planus. Lichen planus pemphigoides and bullous lichen planus are separate entities: the former is an auto-immune disease precipitated by lichen planus and not related to bullous pemphigoid, the latter is probably not auto-immune but represents the extreme consequence of the lymphoid infiltrate at the dermo-epidermal junction.     

In situ identification of mononuclear cells in cutaneous infiltrates in discoid lupus erythematosus, sarcoidosis and secondary syphilis

The inflammatory mononuclear cell infiltrates observed in lesional skin from patients with discoid lupus erythematosus (DLE), sarcoidosis, and secondary syphilis have been characterized in situ. Immunological markers (human T lymphocyte antigens and receptors for sheep erythrocytes, C3b, C3d and Fc gamma) were studied by using immunofluorescence tests with IgG F (ab')2 preparation of anti-T lymphocyte serum, hemadsorption with tissue sections, and tests with soluble immune complexes of peroxidase. In DLE, T lymphocytes were the dominant cell type. In sarcoidosis, the epithelioid cells, including giant cells, had markers similar to macrophages. The lymphohistiocytic cells consisted mainly of macrophages, some T lymphocytes and a few B lymphocytes. In secondary syphilis (condylomata lata), macrophages and T lymphocytes were the dominant cell types, and relatively few B lymphocytes were detected.     

T cell subsets and Langerhans cells in lichen planus: in situ characterization using monoclonal antibodies

Skin biopsies from four patients with lichen planus were studied using monoclonal antibodies directed against T lymphocytes. Anti-T1 and anti-T3 antibodies, which react with all peripheral T cells, stained most cells in the dermal infiltrates. The majority of infiltrating cells also stained with anti-T4 and anti-T4b antibodies, which react with helper/inducer cells, whereas a minority of cells stained with anti-T8 antibody, which reacts with cytotoxic/suppres-sor cells. Surface IgM was not identified on any infiltrating cells, providing evidence against B cell participation. Intraepidermal and dermal cells with long cytoplasmic extensions stained with anti-T6 antibody in all cases, defining them as Langerhans cells or their precursors. T6-positive cells were seen in greater number than in normal control epidermis and dermis. The results indicate that well-developed lesions of lichen planus are characterized by an influx of helper/inducer T lymphocytes and increased numbers of Langerhans cells. These observations support the contention that cellular immunity is important in the pathogenesis of this disorder.     

Functional studies of skin mast cells in lichen planus

In order to identify possible functional differences between mast cells obtained from the skin of lichen planus (LP) patients and healthy donors, biopsies from lesional skin of 11 lichen planus patients and from normal skin of 7 healthy donors were sampled. Mast cells were obtained from the skin using an enzymatic dispersion technique. The cells were challenged in vitro with substance P (SP), tumor necrosis factor α (TNF-α) and anti-IgE. Their reactivity was estimated on the basis of histamine release. LP skin mast cells and healthy skin mast cells showed similar sensitivity to stimulation with TNF-α at a concentration of 10 ^–7 M (15.2% histamine release, as a proportion of total cellular content vs 15.9%) and to stimulation with anti-IgE at a dilution of 1:100) (38.8% vs 37.0%). Spontaneous histamine release was also very similar in both the populations of mast cells (10.2% vs 12.7%, respectively). However, LP skin mast cells showed significantly higher ( P < 0.01) sensitivity towards stimulation with SP at a concentration of 10 ^–4 M than healthy skin mast cells (15.9% histamine release vs 7.0%). This finding could suggest that neurogenic inflammatory mechanisms contribute to the pathogenesis of LP. Received: 3 July 1996     

经典和色素性扁平苔藓常见皮肤镜特征的比较

目的：比较经典扁平苔藓与色素性扁平苔藓常见皮肤镜的特征。方法：选取13例经典扁平苔藓和6例色素性扁平苔藓患者共99处皮损进行皮肤镜检查并对其特征进行比较。结果：经典扁平苔藓常见的皮肤镜特征有Wickham纹,以片状模式为主的黄棕色色素结构和点状、线状及球状等血管;色素性扁平苔藓常见的皮肤镜特征有以点状、球状模式为主的蓝灰色、黄棕色色素结构和毛囊角栓。结论：皮肤镜可用于经典扁平苔癣和色素性扁平苔藓的辅助诊断。     

Lichen planus and chronic graft-versus-host reaction. In situ identification of immunocompetent cell phenotypes

The purpose of the present study was lo examine the phenotype of the cutaneous immunocompetent cells in lichen planus and chronic graft versus host (GVH) reaction infiltrates, by the use of monoclonal antibodies directed against T cell populations and Langerhans cells.
Our results in lichen planus suggest an immunological reaction similar to the delayed hypersensitivity reaction, including all the immunocompetent cell sub-populations, with a first stage of antigenic information by Langerhans cells (OKT6 +, BL6 +, HLA-DR+) and helper cells, and a second stage mediated by suppressor/cytotoxic cells.
The results from the study of GVH reaction also suggest an effect mediated by suppressor/cytotoxic cells (OKT3+, OKT4−, OK.T8+, HLA-DR+).
Our results favour the existence of a lymphocytotoxic process in lichen planus and chronic GVH reaction.