Digital immunohistological dissection of immune privilege collapse in syringotropic autoimmune diseases: Implication for the pathogenesis.

BACKGROUND: Syringotropic cell infiltration is a histological hallmark of some autoimmune diseases. However, its underlying mechanism remains unclear. OBJECTIVES: To assess the immune privilege (IP) of the human sweat gland (SwG) in homeostasis and in syringotropic autoimmune diseases. METHODS: We combined quantitative digital image microdissection with immunohistochemisty to analyze IP molecule expression in SwG of normal and diseased skin. The human skin organ culture model was used to examine the influence of proinflammatory conditions on IP in SwG. RESULTS: In the normal subjects (n = 10), major histocompatibility complex (MHC) class І expression was significantly reduced in SwGs compared to the epidermis. In contrast, IP-guardians, macrophage migration inhibitory factor (MIF) and alpha-melanocyte stimulating hormone (α-MSH) were upregulated in SwGs. MHC class І was upregulated in whole SwGs in lupus erythematosus (LE; n = 7) and scleroderma/morphea (Scl; n = 9), whereas differential expression was noted only in the secretory portion in Sjögren's syndrome (SjS) (n = 4). MIF expression level inversely correlated with that of MHC class I in all samples tested, and downregulation of α-MSH was detected in LE SwGs alone. The severity of inflammatory changes and MIF and ⍺-MSH expression were inversely correlated in LE. CD200 expression was decreased exclusively in atrophic stage of Scl. In a human skin organ culture model, intratissue injection of interferon-gamma up-regulated MHC class I and downregulated MIF and α-MSH. CONCLUSIONS: These findings indicate that SwGs enjoy IP. Dysregulated IP molecule expression may lead to SwG IP collapse and contribute to distinct inflammatory cell distribution in syringotropic autoimmune disorders.

Diagnostic Value of Linear Fluorescence Along the Basement Membrane of Sweat Gland Ducts in Bullous Pemphigoid.

Linear IgG deposits along the basement membrane of adnexa has been proposed to be useful in the diagnosis of bullous pemphigoid (BP), but no controlled studies have been performed. This study evaluated linear IgG fluorescence of the basement membrane of sweat gland ducts (SGD) and other adnexa in perilesional biopsies from patients with BP (n = 64) and controls (n = 82), using direct immunofluorescence microscopy. Fluorescence intensity was graded semi-quantitatively. Positive SGDs were found in 58 (90.6%) patients with BP and 44 (53.7%) controls, a statistically significant difference (p < 0.0001). The sensitivity of positive SGDs for BP was high (90.6%), but the specificity was low (46.3%). Only strong fluorescence intensity was associated with high specificity. In conclusion, positive SGDs in direct immunofluorescence microscopy are highly sensitive for BP; however, only strong fluorescence has acceptable specificity. Weak positivity of SGDs without linear fluorescence of the epidermal basement membrane may not be sufficiently specific for BP.

Role of CFTR in epithelial physiology.

Salt and fluid absorption and secretion are two processes that are fundamental to epithelial function and whole body fluid homeostasis, and as such are tightly regulated in epithelial tissues. The CFTR anion channel plays a major role in regulating both secretion and absorption in a diverse range of epithelial tissues, including the airways, the GI and reproductive tracts, sweat and salivary glands. It is not surprising then that defects in CFTR function are linked to disease, including life-threatening secretory diarrhoeas, such as cholera, as well as the inherited disease, cystic fibrosis (CF), one of the most common life-limiting genetic diseases in Caucasian populations. More recently, CFTR dysfunction has also been implicated in the pathogenesis of acute pancreatitis, chronic obstructive pulmonary disease (COPD), and the hyper-responsiveness in asthma, underscoring its fundamental role in whole body health and disease. CFTR regulates many mechanisms in epithelial physiology, such as maintaining epithelial surface hydration and regulating luminal pH. Indeed, recent studies have identified luminal pH as an important arbiter of epithelial barrier function and innate defence, particularly in the airways and GI tract. In this chapter, we will illustrate the different operational roles of CFTR in epithelial function by describing its characteristics in three different tissues: the airways, the pancreas, and the sweat gland.

Abberant Sudomotor Functions in Sjögren's Syndrome: Comparable Study with Atopic Dermatitis on Dry Skin Manifestation.

This chapter summarizes recent advances in the pathogenesis and management of Sjögren's syndrome (SS). Major topics are newly described pathomechanisms and cutaneous manifestations of SS, with special references to hypohidrosis and related mucocutaneous manifestations. Although the significance of cutaneous manifestations in SS has been gradually recognized in rheumatologists, sudomotor function has not been fully evaluated and recognized in the diagnosis of SS except by dermatologists. SS is a relatively underestimated collagen disease in contrast to systemic lupus erythematosus, systemic sclerosis, or dermatomyositis, and special care is needed not to misdiagnose SS when we see patients with common skin diseases such as drug eruption, infectious skin disease, or xerosis in daily practice. In contrast to SS, the reduced sweating function seen in atopic dermatitis (AD) is restricted only to axon reflex-induced indirect sweating, which is usually restored to normal levels after improvement of the dermatitis. Therefore, the xerotic skin lesions seen in SS and AD might be attributable to different pathomechanisms with similar dry skin manifestations. It is well known that dry skin is occasionally seen in SS, and clinical use of muscarinic M3-receptor agonists occasionally improves this condition through recovery of sweating function. Therefore, this M3-receptor agonist might be a promising drug and should be evaluated for the treatment of impaired sweating in AD complicated with or without SS.

Specificity of granular IgM deposition in folliculosebaceous units and sweat gland apparatus in direct immunofluorescence (DIF) of lupus erythematosus.

BACKGROUND: Diagnosis of lupus erythematosus (LE) in direct immunofluorescence testing is based on the finding of positive immunofluorescence at the dermoepidermal junction (DEJ). OBJECTIVES: We sought to evaluate the sensitivity of IgM deposition at the DEJ and adnexal structures in the diagnosis of lupus erythematosus. METHODS: We conducted a retrospective study of 100 previously diagnosed cases of lupus erythematosus and 158 cases of other immune-mediated dermatosis. Deposition of IgG, IgM, IgA, and C3 at the DEJ, follicular units, and sweat glands were recorded. Presence or absence of adnexal structures was documented. The immunoreactant deposition was documented as linear, coarse granular, or stippled. RESULTS: The most frequently deposited immunoreactant in lupus erythematosus cases was IgM along the DEJ and stromal-epithelial junction of hair follicles and sweat glands. IgM deposition along the stromal-epithelial junction of hair follicles and sweat glands was strongly associated with a diagnosis of lupus erythematosus compared with other immune-mediated diseases collectively (P value < .001). The pattern of IgM in lupus and dermatomyositis is granular, in contrast to the linear deposition in the other disorders evaluated. LIMITATIONS: This was a retrospective study of archived material. CONCLUSION: Granular IgM deposition at the stromal-epithelial junction of cutaneous adnexal structures suggests a diagnosis of lupus erythematosus or dermatomyositis.

Immunohistochemical evidence of leptin and its receptor in the carpal glands of domestic pigs and wild boar.

BACKGROUND: In recent years, the protein hormone leptin has been the subject of numerous studies designed to clarify and interpret its functional significance; it has been speculated that this goes well beyond the control of appetite and energy metabolism. In particular, the presence of leptin and its receptor has been observed in various glands anatomically and functionally related to the reproductive apparatus. This has led to the hypothesis that leptin may act directly in the functional control of these glands and, in general, the control of reproductive function. HYPOTHESIS/OBJECTIVES: The presence and distribution of leptin and its receptor in the carpal glands of domestic pigs and wild boar are examined, using immunohistochemical techniques. ANIMALS: Tissue samples were collected from five domestic pigs and five wild boar, following slaughter. RESULTS: The presence of leptin and its receptor was demonstrated in the glands, localized in the dark cells of the glandular secretory epithelium. In addition, no difference was observed between wild boar and domestic pigs. CONCLUSIONS AND CLINICAL IMPORTANCE: We hypothesize that leptin may be produced by the carpal gland and may act on the gland's secretory epithelial cells with an autocrine/paracrine mechanism, thus affecting the secretory activity of the gland itself.

Comparative histology and immunohistochemistry of porcine versus human skin.

BACKGROUND: Porcine skin is increasingly being employed as a model of human skin in various research fields, including pharmacology, toxicology and immunology, with particular interest in percutaneous permeation and organ transplantation. Porcine skin shows several anatomical and physiological similarities, but also some differences, with human skin, but few in depth comparative studies are so far available. OBJECTIVES: To study the immunohistochemical properties of normal porcine skin in comparison with human skin. MATERIALS AND METHODS: We performed a histological and immunohistochemical study on frozen and formalin-fixed, paraffin-embedded skin biopsies from domestic swine and normal human skin, using a panel of 93 monoclonal or polyclonal antibodies recognizing various human and porcine skin cell types or structures. RESULTS: We found that several antibodies used to detect normal human skin cells showed equivalent immunoreactivity on normal porcine skin. However, some antibodies commonly used to detect human skin antigens remained unreactive on porcine skin. CONCLUSIONS: Our findings highlight the main immunohistochemical properties of porcine skin in comparison with those of human skin and provide a morphological and immunohistochemical basis useful to researchers using porcine skin.

Autoantibodies to sweat glands detected by different methods in serum and in tissue from patients affected by a new variant of endemic pemphigus foliaceus.

Examining the patients with a new variant of endemic pemphigus foliaceus (EPF) in El Bagre, Colombia, (El Bagre-EPF), we noted several polymorphic clinical lesions around their axillary areas. Based on our clinical findings and on previous histopathological studies on the skin of these patients that showed abnormalities in their sweat glands, and the presence of mercuric selenides and iodines by autometallography assay, we decided to investigate immunoreactivity to the sweat glands in these patients. We tested for autoreactivity utilizing direct and indirect immunofluorescence (DIF, IIF). To be able to distinguish between non-specific immune deposits and real autoimmune response, and knowing that sweat glands have some intrinsic autofluorescence for the presence of lipofuscin granules (that naturally fluoresce under the UV light microscope), as well as by the presence of secretory IgA, we used simultaneously immunohistochemistry (IHC). We tested ten El Bagre-EPF patients, ten healthy controls from the endemic area and ten healthy controls from the United States. We were able to visualize a specific autoreactivity to sweat glands in 8/10 cases of El Bagre-EPF by DIF, IIF and by IHC. In addition when using anti-human monoclonal antibodies to CD3, CD68, and CD20, we confirmed the presence of several specific immune responses in situ, an around the sweat glands. No healthy control cases yielded positive findings. In some chronic cases, decrease and sometimes a complete absence of sweat glands and other skin appendices was found. In addition to this, sclerodermoid changes or early sclerodermatous changes sometimes extending into the adipose tissue as a membranous lipodystrophy were observed. Autoreactivity to the neurovascular components around the sweat glands were also observed. Our data demonstrate for the first time that there is immunoreactivity toward sweat glands in El Bagre-EPF patients that seems to destroy some of these structures.

Paraneoplastic pemphigus with negative direct immunofluorescence in epidermis or mucosa but positive findings in adnexal structures.

INTRODUCTION: Paraneoplastic pemphigus (PNP) is considered an autoimmune, multiorgan disease caused by antiplakin antibodies. We present three PNP patients who had negative epithelial direct immunofluorescence (DIF) findings in one or more biopsies. PATIENTS: An early lip biopsy of uninvolved oral epithelia in patient 1 was negative. A later biopsy from foreskin showed intense intercellular immunoglobulin G (IgG) deposits in the epithelia. In the early phase of the disease in patient 2, the intercellular fluorescence was negative in the epidermis, while intercellular IgG and C3 were observed in the sweat ducts. A later biopsy showed weak intercellular epidermal IgG and C3 fluorescence. Patient 3 showed intercellular IgG and/or C3 in follicular, sebaceous and sweat duct structures in several biopsies. No intercellular IgG or C3 was observed in the epithelia. DISCUSSION: The presence of immunoreactants in adnexal structures suggests that desmoplakins can be more strongly expressed in adnexa than in the epidermis, facilitating visualization of antibody deposits. CONCLUSIONS: Negative DIF findings in epithelia do not rule out the diagnosis of PNP, and the presence of IgG and/or C3 at the intercellular level of adnexal structures can help establish this diagnosis.

A histopathologic study of arthropod bite reactions in 20 patients highlights relevant adnexal involvement.

BACKGROUND: Insect bites produce diverse skin reactions. Although quite common, the histopathologic features of arthropod assaults have not ever been studied systemically. MATERIALS AND METHODS: Twenty biopsies from cases, clinically diagnosed as arthropod bite reactions between January 2003 and June 2007 were reviewed retrospectively. The aim of the study was to verify as to whether reliable histopathologic criteria could be established based on the frequency of findings observed. RESULTS: Epidermal spongiosis (present in 16 of 20 cases), in particular spongiosis of the infundibular epithelium and acrosyringia as well as eosinophilic spongiosis, emerge as relevant diagnostic clues. A moderately dense, superficial and deep infiltrate consisting mainly of lymphocytes and eosinophils was prevalent in the dermis, with eosinophils tending to interstitial and periadnexal distribution. Of note, 19 of 20 (95%) cases revealed periadnexal involvement, whereas 16 of 20 (80%) had the infiltrate extending particularly along the sweat ducts and the coiled glands. In three biopsies, concomitant involvement of sweat glands, hair follicles and sebaceous glands was noted. CONCLUSION: A practical histopathologic algorithm of arthropod bite recognition is proposed. The involvement of the sweat glands in the pattern of arthropod bite reaction is suggested as a new reliable diagnostic clue.

Age-associated decrease of CD1d protein production in normal human skin.

BACKGROUND: CD1d belongs to a family of antigen-presenting molecules structurally related to the classical major histocompatibility complex class I proteins. OBJECTIVES: To examine the expression pattern of CD1d protein in normal human skin with ageing. METHODS: Twenty normal human skin biopsy specimens were obtained from 20 healthy individuals. The latter were divided into three age groups: children (5-20 years), adults (21-50 years) and the elderly (51-81 years). The intensity of CD1d protein production was examined in human skin using immunofluorescent and immunoalkalinephosphatase staining methods. RESULTS: In the epidermis, CD1d protein production was strong in the skin of the children and declined gradually with age, being moderate in adults and weak in the elderly. As compared with values in children, there was a statistically significant decrease (P<0.05) in CD1d protein production in the elderly. In the dermis, CD1d protein production was strong in the fibroblasts, sweat glands, sebaceous glands, blood vessels and hair follicles regardless of age. CONCLUSIONS: Our study reports a decreased CD1d protein production in normal human skin with ageing. The clinical ramifications of these observations mandate further investigations.

Cathelicidin anti-microbial peptide expression in sweat, an innate defense system for the skin.

The eccrine gland is one of the major cutaneous appendages and secretes sweat. Its principal function is thermoregulation during exposure to a hot environment or physical exercise. In addition to this function, we show that LL-37, a member of cathelicidin family of anti-microbial peptides, is expressed in sweat. LL-37 protein and mRNA was seen in the eccrine structures of normal human skin by immunohistochemistry and in situ hybridization. LL-37 was localized to both the eccrine gland and sweat ductal epithelial cells, whereas dermcidin, a previously described natural antibiotic in sweat, was expressed only in the gland itself. The anti-microbial activity of LL-37 and dermcidin against various bacteria in the sweat ionic environment was demonstrated by solution colony forming assay using synthetic peptides, and in sweat obtained from normal volunteers. These results indicate that cathelicidin is secreted in human sweat, has potent anti-microbial activity against both gram-positive and gram-negative bacteria, and can, after processing from the preproform, provide a barrier for protection against infection. Thus, sweat represents a unique mode of delivery for potent innate immune effector molecules in the absence of inflammation.

Langerhans cells within the follicular epithelium and the intradermal sweat duct in equine insect hypersensitivity "Kasen".

Histopathologic and electron microscopic observations were given on Langerhans cells (LCs) within the follicular epithelium (FE) and intradermal sweat duct (ISD) of equine "Kasen". By light microscopy, LCs were present in the greatest numbers within the FE and ISD than within the epidermal layer and the normal skin, with an occasional formation of several aggregated foci. By electron microscopy, LCs within the FE and ISD widely extended their dendritic processes between the keratinocytes and contained Birbeck granules (Bgs), mitochondria, rough endoplasmic reticula and ribosomes in the cytoplasm. Numerous Type 2 LCs, with a number of Bgs and endocytosis, and Type 3 LCs, with multivesicular bodies and endosomes of various sizes, were recognized within the FE and ISD, although inactive Type 1 LCs, with a narrow and lucid cytoplasm, were rarely seen. LCs observed within the FE and ISD in the "Kasen" skin lesions might express the particular stage corresponded to recognize, intake and process the antigens which permeate them.

Applicability of different antibodies for immunohistochemical localization of CFTR in sweat glands from healthy controls and from patients with cystic fibrosis.

The hereditary disease cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Understanding of the consequences of CFTR gene mutations is derived chiefly from in vitro studies on heterologous cell cultures and on cells hyperexpressing CFTR. Data from ex vivo studies on human tissue are scarce and contradictory, a fact which is in part explained by secondary tissue destruction in most affected organs. The purpose of this study was to establish conditions under which wild-type and mutated CFTR can be studied in affected human tissue. Sweat glands carry the basic defect underlying CF and are not affected by tissue destruction and inflammation. Therefore, we used this tissue to test a panel of eight different CFTR antibodies under various fixation techniques. The antibodies were tested on skin biopsy sections from healthy controls, from CF patients homozygous for the most common mutation, DeltaF508, and from patients carrying two nonsense mutations. Of the eight CFTR antibodies, only three-M3A7, MATG 1104, and cc24-met the criteria necessary for immunolocalization of CFTR in sweat glands. The labeling pattern in the CF sweat glands was consistent with the postulated processing defect of DeltaF508 CFTR. The antibodies exhibited different sensitivities for detecting DeltaF508 CFTR.

Bikunin, a serine protease inhibitor, is present on the cell boundary of epidermis.

Bikunin, which is an inhibitor of serine proteases, is widely distributed in human tissues, including liver, kidney, and mucous membranes of the stomach and colon. The aim of this study was to clarify whether bikunin is expressed in human epidermis and its appendages. Immunoblot analysis using a specific polyclonal antibody to bikunin revealed that a single 43 kDa protein is present in the cell lysate from the human keratinocyte cell line HaCaT. Immunohistochemically, dotted reaction products stained with anti-bikunin antibody were localized on the cell boundary in both basal and spinous cell layers, except on the cell boundary of the basal cells facing the basal membrane. There were no reaction products in the granular-horny cell layers. Reaction products stained with anti-bikunin antibody were also observed on the hair bulb cells and eccrine sweat gland cells, but not on apocrine sweat glands. Also, reaction products were observed on the luminal surface of the renal proximal tubules and in the cytoplasm of these cells. In immunoelectron microscopy, gold particles were observed on the cell membranes close to the desmosomal structures. Reverse transcription-polymerase chain reaction and northern blot analyses showed that mRNA specific for bikunin was expressed in HaCaT cells and human epidermal keratinocytes obtained from suction blisters, and was contained in a commercially available human keratinocyte cDNA preparation. These findings indicate that bikunin is expressed in keratinocytes and may play an important part in regulating keratinocytes in either mitosis or inflammation.

[Acquired generalized cutis laxa with paraproteinemia (IgG lambda). Immunofluorescence study, clinical and histologic findings with review of the literature]. / Erworbene generalisierte Cutis laxa mit Paraproteinämie (IgG-lambda). Immunfluoreszenzstudie, Klinischer und histologischer Befund mit Literaturübersicht.

A 49-year-old patient developed acquired generalized cutis laxa, manifest as involvement of the elastic fibres of the dermis and the internal organs, leading to pulmonary emphysema, bilateral inguinal hernia and two oesophageal diverticula. The patient's serum levels of IgG lambda paraprotein were elevated. Direct immunofluorescence examination revealed intensive linear deposits of IgG lambda light chains, an early component of complement C1q and discrete C3 deposits. The deposits were found along the preserved elastic fibres in the dermis, especially in the papillary dermis, at the dermoepidermal junction around the sweat and sebaceous glands and in the walls of small vessels. Dermal alterations of this kind have not been described previously.

Sudoriferous acrosyringeal acantholytic disease. A subset of Grover's disease.

Three selected cases of transient acantholytic dermatosis were studied because of their definitive correlation with sweating due to fever and/ or bed-ridden situations. Biopsy specimens were serially sectioned and acantholysis was found in the acrosyringium or traced to connect to the acrosyringium in all biopsy specimens. Carcinoembryonic antigen (CEA) and eccrine gland-specific monoclonal antibody, IKH-4, were positive in acantholytic cells. Electron microscopy revealed electron dense material filling the lumen of intraepidermal eccrine ducts. This material leaked into lateral intercellular spaces of the luminal cells, passing tight junctions. Marked edema and numerous lysosomes were reminiscent of those found when eccrine acrosyringium is formed in the embryo; this suggested that an occluded and damaged eccrine intraepidermal duct was being rebuilt via lysosomal digestion.

Expression of epsilon BP, a beta-galactoside-binding soluble lectin, in normal and neoplastic epidermis.

The study of animal lectins and glycoconjugates has become an important area of research in biomedical sciences, as these molecules are believed to play important roles in a variety of biological processes. This report describes a study of the expression of an animal lectin, IgE-binding protein (epsilon BP), also known as Mac-2 and CBP35, in human skin. We have analyzed cultured human keratinocytes as well as normal human skin and a number of epidermal neoplasms, by immunoblotting, immunofluorescence and immunohistochemistry. We showed that epsilon BP is expressed in human keratinocytes, hair follicles, sebaceous and sweat glands. We found that epsilon BP expression retains in various epidermal neoplasms, including basal cell carcinoma, squamous cell carcinoma and keratoacanthoma, although the level of expression appears to be reduced as compared to normal epidermis. The immunohistochemical analysis also suggests that the level of epsilon BP expression appears to be dependent on the degree of cellular differentiation of keratinocytes.