An immunohistopathological study on the synthesis of immunoglobulins and complement in normal and pathological skin and the adjacent mucous membranes

Skin-Associated B Cells in Health and Inflammation

Traditionally, the skin was believed to be devoid of B cells, and studies of the skin immune system have largely focused on other types of leukocytes. Exciting recent data show that B cells localize to the healthy skin of humans and other mammalian species with likely homeostatic functions in host defense, regulation of microbial communities, and wound healing. Distinct skin-associated B cell subsets drive or suppress cutaneous inflammatory responses with important clinical implications. Localized functions of skin-associated B cell subsets during inflammation comprise Ab production, interactions with skin T cells, tertiary lymphoid tissue formation, and production of proinflammatory cytokines but also include immunosuppression by providing IL-10. In this review, we delve into the intriguing new roles of skin-associated B cells in homeostasis and inflammation.

A common mucosal chemokine (mucosae-associated epithelial chemokine/CCL28) selectively attracts IgA plasmablasts

IgA immunoblasts can seed both intestinal and nonintestinal mucosal sites following localized mucosal immunization, an observation that has led to the concept of a common mucosal immune system. In this study, we demonstrate that the mucosae-associated epithelial chemokine, MEC (CCL28), which is expressed by epithelia in diverse mucosal tissues, is selectively chemotactic for IgA Ab-secreting cells (ASC): MEC attracts IgA- but not IgG- or IgM-producing ASC from both intestinal and nonintestinal lymphoid and effector tissues, including the intestines, lungs, and lymph nodes draining the bronchopulmonary tree and oral cavity. In contrast, the small intestinal chemokine, TECK (CCL25), attracts an overlapping subpopulation of IgA ASC concentrated in the small intestines and its draining lymphoid tissues. Surprisingly, T cells from mucosal sites fail to respond to MEC. These findings suggest a broad and unifying role for MEC in the physiology of the mucosal IgA immune system.

Vulvitis plasmacellularis: two new cases

Vulvitis chronica plasmacellularis or Zoon's vulvitis is a rare benign circumscribed inflammation of the vulvar mucosa. It is found in women ranging in age from 26 to 70 years. Shiny, macular erythematous lesions, which are irregular in shape and sharply marginated are usually observed. The histologic findings show chronic subepithelial dense inflammation composed largely of plasma cells. We here report two cases of vulvitis plasmacellularis with typical clinical manifestations, courses and histopathologic findings.

Immunohistochemical demonstration of immunoglobulin A in human sebaceous and sweat glands

Immunoglobulin A (IgA) mediated humoral defense mechanisms have been detected on all mucous membrane surfaces. There are only a few papers about the presence of IgA in human skin. In order to demonstrate the occurrence of IgA in sebaceous and sweat glands, biopsies of normal human skin were investigated and compared to intestinal mucosa. Two different commercially available anti-IgA antibodies were used. For light microscopy peroxidase-anti-peroxidase (PAP) or avidin-biotin complex (ABC) staining was used, and for electron microscopy protein-A-gold (PAG) labeling was performed on tissue sections. Specifically decorated IgA was found in sebaceous glands as well as in various portions of eccrine glands. In sebaceous glands, the maximum of IgA concentration was seen near the mouth of pilosebaceous ducts. Sweat ducts exhibited a continuous coat of IgA, whereas secretory portions contained only singular scattered IgA positive cells. Immunoelectron microscopy suggests endocytotic uptake and processing of IgA in the glandular cells. These results indicate strongly that IgA are secreted by normal human sebaceous and sweat glands. Because it is well known that IgA plays an important role in inactivation of invading viruses, bacteria, and other antigenic structures on mucous membranes, it appears that IgA in sebum and sweat fulfil a similar function on the outer body surface.

Histamine H1-receptor in endothelial and smooth muscle cells of guinea-pig aorta

The location of histamine H1-receptors in the thoracic aorta of guinea-pigs was studied with a [3H]mepyramine binding assay. [3H]Mepyramine binding studies of whole and rubbed aortas, and of cultured endothelial and smooth muscle cells showed that the Kd values were all in the range 0.53-0.76 nM, but that the Bmax values were 19.1, 10.1, 63.3 and 11.6 fmol/mg protein, respectively. Thus, the whole aorta contained more H1-receptors than the rubbed one (free of endothelium), and cultured endothelial cells contained more H1-receptors than smooth muscle cells. These results indicate that more histamine H1-receptors were concentrated in the endothelial cells than in the smooth muscle cells in guinea-pig aorta.

Immunoglobulin-producing cells in human odontogenic cysts

Immunohistochemical staining of immunoglobulin-containing plasma cells was performed on odontogenic keratocysts, dental (periapical) and dentigerous cysts. IgG-containing plasma cells were the predominant species in all cyst types examined, with a much lower percentage of IgA- and few IgM-containing plasma cells. Statistically significant differences in the percentage contributions of IgG and IgA plasma cells were observed between the keratocyst and both the dental (periapical) and dentigerous cysts and for IgM between the keratocyst and dental (periapical) cyst. Intense extracellular staining was observed for IgG in all cyst types.

Necrotizing vasculitis within cutaneous lesions of mycosis fungoides

Mycosis fungoides is a T cell lymphoma with a predilection for cutaneous involvement. This paper describes the clinical manifestations and histopathologic features of a case of mycosis fungoides with necrotizing vasculitis localized to the lesions of cutaneous lymphoma. Elevated levels of circulating immune complexes were found in this patient. The large numbers of perivascular malignant helper T lymphocytes may have induced immunoglobulin synthesis, resulting in the formation of these complexes followed by deposition in vessel walls and subsequent necrotizing vasculitis. Possible alternative mechanisms include the presence of anti-T cell antibodies, or cytotoxic effector cells.

Identification of inflammatory cell phenotypes in human oral carcinomas by means of monoclonal antibodies

Monoclonal antibodies reacting with human T cell sub-populations, Langerhans cells and macrophages were used to examine the quantitative distribution of immune-competent cells in normal oral mucosa and invasive oral carcinomas. Both immunofluorescent and immunoperoxidase procedures were applied. In normal oral epithelia, the dominant immune-reactive cell was the Langerhans cell, positive for OKT 6 and expressing HLA-DR gene products (OKIa1+). Many intra-epithelial non-epithelial cells (non-keratinocytes), belonged to the lymphocyte system carrying the suppressor/cytotoxic phenotype (OKT 8+). This lymphocyte sub-population was also the most prominent cell type in the normal mucosal stroma. The quantitative evaluation of immune-competent cells in squamous cell carcinomas revealed elevated numbers of all the inflammatory cell sub-populations investigated (suppressor/cytotoxic lymphocytes, helper/inducer lymphocytes, Langerhans cells, macrophages) compared with the normal oral mucosa. There was a striking increase in suppressor/cytotoxic lymphocytes (OKT 8+) and in cells of the macrophage system, including Langerhans cells (OKIa1+, OKM 1+, OKT 6+). In the stroma distant to the tumour complexes, many helper/inducer lymphocytes (OKT 4+) were also observed.

Inflammatory cells, IgA, C3, fibrin and fibronectin in skin lesions in dermatitis herpetiformis

Skin lesions were produced by application of 50% potassium iodide to twelve patients with dermatitis herpetiformis (DH). Perivascular cellular infiltrates were found to be characteristic of developing lesions. The cells were mainly round cells; alpha-naphthyl acetate esterase staining revealed that in 24-h lesions the mean percentage of T-lymphocytes was 43%, that of mononuclear phagocytes 6% and that of non-T/non-M cells (mainly B-lymphocytes) 44%. The percentage of the latter was highest (mean 81%) in 6-h specimens, suggesting that these cells are participating in the early stages of lesion formation. The infiltrating cells in dermal papillae and within subepidermal vesicles were predominantly polymorphonuclear leukocytes (mean 86%) with some mononuclear phagocytes and non-T/non-M cells. Immunofluorescence examination confirmed that fibrin deposition is characteristic of the initial lesions of DH and showed that the same is true of fibronectin. Seven out of eight patients had fibronectin deposits in dermal papillae. IgA was found in all and C3 in most of the specimens and, with the exception of papillary vesicles and blister cavities, the intensity of IgA and C3 fluorescence showed no marked alterations during the development of lesions.

Analysis of immunological responses in psoriatic lesions: (1) immunopathological studies on psoriatic lesions

In order to understand immunological responses in psoriatic lesions, immunofluorescent findings have been compared in early psoriatic lesions and fully developed plaque lesions. IgG and IgA were detected as the main antibodies in the horny layer by immunohistology. The IgA at the site of leukocyte accumulation in the horny layer seemed to be associated with secretory component (S-component) and joining chian. Regarding complement, the alternate pathway might be related to the immune reaction as the initial response, because deposits of C3, properdin and glycine rich beta-glycoprotein were found more frequently than C1q-deposit in the both lesions. In the dermis S-component was also detected at the dermal papillae adjacent to the dermoepidermal (D-E) junction of the lesions and no deposit of S-component was observed in uninvolved skin of psoriatic patients. This, however, is not a specific pattern in psoriatic lesions since deposits of S-component were found at the dermal papillae and D-E junction in other dermatoses. These findings might suggest that the immunological response was initiated by secretory IgA in horny layer, which was composed of dimeric IgA and S-component at the D-E junction and which passed easily through the epidermal cells.

Buccal mucosa immunofluorescence in coeliac disease and dermatitis herpetiformis

The buccal mucosa in both coeliac disease and dermatitis herpetiformis behaves in the same manner as the skin with regard to immunofluorescence. The simple technique of buccal punch biopsy can be used to give further confirmation of the diagnosis of dermatitis herpetiformis and, especially in patients with an equivocal diagnosis, may prove easier than carrying out repeated skin biopsies.

Stereology of inflammatory connective tissue infiltrates in oral mucosa

In the present summary, different approaches to analyse inflammatory connective tissue infiltrates are reviewed. The most appropriate model for this purpose was found to be the stereological analysis at the electron microscopic level. This method furnishes data comparable with results obtained by other quantifying methods, such as biochemical analysis. The presently used methodology for the analysis of diseased portions of oral mucous membranes, as well as selected results thereof are described. The usefulness and reliability of the method are discussed and future developments are suggested.

Complement C3 and immunoglobulin in inflammatory acne vulgaris

In patients with moderate to severe inflammatory acne, complement (C3) was detected by immunofluorescence in sixteen early inflammatory acne lesions but in only one of thirteen biopsies of non-inflamed skin from acne sites. C3 deposition occurred particularly in the walls of small dermal blood vessels and at the dermo-epidermal junction. IgM was identified in vessel walls in four of sixteen early lesions. In eight late inflammatory lesions C3 deposition was much less prominent and was present in vessel walls in only two. None of the late lesions showed vascular deposition of IgM. The observations indicate that complement activation occurs in inflammatory acne and it is suggested that this may play a pathogenic role in the inflammation.

Absence of cutaneous IgA in coeliac disease without dermatitis herpetiformis

Skin biopsies from 17 patients with coeliac disease, but without dermatitis herpetiformis, were examined by direct immunofluorescence. In none of them was IgA detectable. In contrast, IgA was present in dermal papillae and/or in relation to the dermo-epidermal junction in 80 out of 83 patients with dermatitis herpetiformis. These findings confirm that cutaneous deposition of IgA at these sites is a very characteristic feature of dermatitis herpetiformis and is unrelated to coeliac disease itself.

Complement and immunoglobulin deposits in the skin of patients with atopic dermatitis

The immunofluorescent patterns of uninvolved and involved skin biopsies from eight patients with atopic dermatitis were studied, using direct immunofluorescence techniques to identify deposits of the immunoglobulins G, A and M as well as the complement factors C1q, C3, C4, C5, factor B and properdin. Immunoglobulin deposits (mainly IgG) were found in five patients, complement deposits in three patients in the basement membrane zone. In three patients the immunofluorescence was positive for C3, in two patients for C1q, C4 and C5. Regarding the factors of the alternative pathway of the complement system, two patients showed deposits of properdin, one of factor B. The changes were not confined to the eczematous lesions, but were found in uninvolved skin too. The most prominent changes were observed in patients with severe disease.

Gluten-free diet in dermatitis herpetiformis. II. Morphological and immunological findings in the skin and small intestine of 12 patients and matched controls

Twelve patients with dermatitis herpetiformis whose skin condition responded to a gluten-free diet (GFD) were re-examined after diet treatment. The findings were compared with those in matched patients on a normal diet. Jejunal histology revealed morphological improvement in every patient on a GFD whereas all patients on a normal diet continued to have villous atrophy. Intra-epithelial lymphocyte counts were normal in 8 patients on a GFD in contrast to one on a normal diet. Immunofluorescence examination of the jejunal mucosa revealed that the numbers of cells containing IgA and IgM were increased significantly in the normal diet group. The figures were lower in the GFD group but these also exceeded the values in the controls. IgA deposits were found in the uninvolved skin of every patient irrespective of the diet treatment, but the fluorescence seemed to be less intense in patients on a GFD. A clear difference was found in the occurrence of C3 deposits in the uninvolved skin. Three patients on a GFD had C3 deposits; two of these did not follow a strict diet. However C3 was found in 8 patients on a normal diet. Circulating dietary and auto-antibodies were found in two patients on a GFD and in 9 on a normal diet. Serum immunoglobulin (IgG, IgA, IgM) and complement (C3, C4) levels were within normal limits in both patient groups.

Characterization of mononuclear cells in the inflammatory infiltrates of cutaneous tumours

The identification of mononuclear cells extracted from cutaneous tumours (basal cell carcinoma, squamous cell carcinoma and superficial, spreading melanoma) has been investigated. The relative numbers of T cells and B cells have been determined using the E-rosette test and the EAC-rosette test. The results have been compared to those of delayed hypersensitivity type reactions. Different cell distribution patterns (E/EAC ratio) have been found in the infiltrates according to the type of tumour. An immunocytochemical technique has been developed for the identification in situ of immunoglobulin-producing cells in the inflammatory infiltrates. In each case the class of immunoglobulin (IgM, IgG or IgA) has been identified and the relative frequency of Ig-producing cells has been determined. The results indicate humoral and cellular immune responses with variations attributable to the type of tumour. In weakly malignant tumours, the infiltrate is characterized by an elevated number of T lymphocytes and numerous plasma cells which secrete all classes of Ig; in highly malignant tumours it is characterized by a reduced number of both T lymphocytes (E rosette) and plasma cells which do not secrete all classes of Ig.

Immunoglobulin-producing cells in the inflammatory infiltrates of cutaneous tumors. Immunocytologic identification in situ

An immunocytochemical technique has been developed for the identification in situ of immunoglobulin-producing cells in tissues fixed in Bouin's solution and embedded in paraffin. Technical details are discussed as well as the application of the technique to the study of plasma cells in the inflammatory infiltrate around cutaneous tumors. Preliminary results have been obtained with basal cell epitheliomas, squamous cell carcinomas, and malignant melanomas. IgA-producing cells were present in all tumors. IgG-producing cells were present in variable frequency, depending on the type of tumor, and IgM-producing cells were found only in basal cell epitheliomas and squamous cell carcinomas.

Immunofluorescent patterns in the skin in Besnier's prurigo. The eczema asthma syndrome

The immunofluorescent patterns in the skin of eighteen patients with Besnier's prurigo were studied at different stages of eczematous lesions. The presence, distribution pattern, and numbers of immunoglobulin and complement-positive lymphocytes in twenty-nine biopsies are reported. In all cases IgE-positive lymphocytes were present in both clinically uninvolved and involved skin. IgG, IgM and IgE-positive lymphocytes showed a characteristic distribution pattern in the dermis. In the acute stages IgM deposition was prominent in the basement membrane zone and it is suggested that damage to the basement membrane results in diffusion of immunoglobulin and complement into the epidermis. These features were not present in a control group of normal skin and of other dermatoses.

Serum IgE-concentrations in patients with contact sensitization

In 123 patients with contact sensitization (cs), of whom 23 had positive histories of atopy and/or positive prick tests (csa), the serum IgE-concentrations were determined and the following results were obtained: 1. A remarkable dispersal of IgE-concentrations was noted in cs--patients (1-3080 U/ml); 12% of them displayed IgE-concentrations of more than 1000 U/ml, even though they had no histories of clinical manifestations of atopy, liver of kidney diseases, or parasitic infestations. Their mean IgE-value of 396 U/ml +/- 60 differed considerably from the one of a comparable control group of healthy individuals. No statistically significant differences were noted between the IgE-levels, the age of our patients, the type and number of contact allergens, and the duration of skin lesions. 2. On an average, there were higher IgE-levels noted in cases of acute and extensive skin lesions than in cases of subacute to chronic, localised skin lesions. Controls of the serum IgE-concentrations and histologic examinations by means of immunofluorescence suggested that, depending on the individual patient, skin lesions might lead to an (unspecific?)activation of IgE-synthesising round cells. 3. In csa-patients with sensitization to metal, the skin lesions were of localised subacute to chronic character, while skin lesions of acute and extensive character were exceptional (5.9%).