Human chorionic gonadotropin (hCG) in the male reproductive tract.

Normal hypothalamic-pituitary testicular and prostatic functions are essential for maintenance of male fertility, whereby glycoprotein hormones (GPH) as well as androgens are major endocrine and local regulators. We have investigated whether the GPH human chorionic gonadotropin (hCG) and the free alpha and beta subunits thereof are produced in the target organs themselves and potentially act as auto/paracrine modulators of fertility. Immunofluorometric assays (IFMAs) based on our panel of highly selective monoclonal antibodies, immunohistochemistry (IHC), confocal laser scanning microscopy (CLSM) and 1- and 2D gel electrophoreses with subsequent western blotting have been utilized for the detection of hCGalpha, hCGbeta and its metabolite hCGbeta core fragment (cf) in human testis, prostate and seminal plasma. Both organs synthesize hCGalpha and hCGbeta, which are subsequently detectable at high concentrations in seminal plasma of healthy probands (n=17): hCGalpha 2630+/-520 ng/mL (mean+/-S.E.M.), hCGbeta 2+/-0.28 ng/mL, hCGbetacf and hCG 0.19+/-0.039 ng/mL. These parameters significantly exceed physiological values, e.g. ten thousand-fold in the case of hCGalpha, in serum of young men (n=20): hCGalpha 0.142+/-0.054 ng/mL (mean+/-S.E.M.), hCGbeta 0.05 ng/mL and hCG 0.004+/-0.003 ng/mL. Levels of these markers were not correlated with sperm counts. Of all body fluids including those of pregnant women seminal plasma is the richest physiological source for genuine free i.e. non-dissociated GPHalpha (M(r,app) 23k) which may even appear as di- or tetramers. Its concentration is similar to that observed in maternal serum (weeks 10-12 of gestation) and in extra-embryonic coelomic fluid. In contrast to those fluids where ratios of free subunits to hCG are in the range of 1:100 highly inverse ratios in the range of 10.000:1.000:1 were observed for hCGalpha:hCGbeta:hCG in seminal plasma. hCGalpha is not derived from heterodimeric GPH suggesting hCG-independent functions of hCGalpha and hCGbeta in male and female fertility.

Endothelial cell apoptosis in systemic sclerosis is induced by antibody-dependent cell-mediated cytotoxicity via CD95.

OBJECTIVE: Apoptosis of endothelial cells is a key event in the pathogenesis of systemic sclerosis (SSc). The aim of the present study was to analyze in vitro the mechanism causing endothelial cell apoptosis in SSc. METHODS: Human dermal microvascular endothelial cells (HDMEC) or human umbilical vein endothelial cells (HUVEC) were cultured with native or heat-inactivated serum from SSc patients or controls with or without interleukin-2-activated natural killer (NK) cells or peripheral blood mononuclear cells. SSc and control sera were tested for the presence or absence, respectively, of anti-endothelial cell antibodies (AECA) by indirect immunofluorescence. Apoptosis was detected by the TUNEL technique. RESULTS: Native sera alone had no effect. Apoptosis induction was observed on HDMEC, but not on HUVEC, in the presence of AECA-positive SSc sera and activated NK cells, and could be inhibited by an anti-Fas ligand antibody. Inhibition of the perforin/granzyme pathway with concanamycin A had no effect on apoptosis induction in this in vitro model. Immunofluorescence analysis of cryosections from SSc skin showed Fas (CD95) expression by endothelial cells, supporting the in vitro findings. CONCLUSION: The results suggest that endothelial cell apoptosis in SSc is induced by antibody-dependent cell-mediated cytotoxicity via the Fas pathway. These data not only provide insight into the pathogenesis of SSc, but also may open new ways to rational therapy for this disease.

Gastric involvement in progressive systemic sclerosis: electrogastrographic and sonographic findings.

OBJECTIVE: To determine whether electrogastrography (EGG) can discern sonographically demonstrated motility disorders in patients with progressive systemic sclerosis (SSc) and to evaluate EGG as a possible diagnostic tool. DESIGN: Prospective study with control group and testing for reliability. SUBJECTS: 15 SSc patients [women aged 33-70 years (mean 53.3 years)] and 15 healthy volunteers. METHODS: Bipolar cutaneous EGG was recorded to obtain the following parameters: period dominant frequency (PDF), percentage of gastric dysrhythmia and normogastria (defined as 2-4/min), period dominant power (PDP) and its change after a standardized meal of 500 kcal (2093 kJ), and instability coefficients of dominant frequency and power (DFIC, DPIC). Simultaneously, real-time sonography was performed in the aortomesenteric plane (3.5-MHz curved-array probe). In 10 patients and 13 control subjects, the distance from the anterior wall of the gastric antrum to the abdominal skin was measured. RESULTS: Three patients (20%) showed hypomotility of the gastric antrum sonographically. The percentage of bradygastria was significantly lower in these patients, but the PDF, DFIC and DPIC values were not significantly different. The distance between the cutaneous electrodes and the antrum bore a greater relationship to the PDP values than did the sonographically demonstrated number of gastric contractions. CONCLUSIONS: Although cutaneous EGG can be performed in SSc patients without apparent derangement in frequency and stability of the signal, it offers no advantage over sonography in diagnosis and follow-up.

Modulation of irritation-induced increase of E-selectin mRNA in vivo by topically applied corticosteroids.

There is a continuous need for methods to evaluate the biologic effects of topically applied drugs in the skin. Irritation of the epidermis with sodium dodecyl sulfate leads to an upregulation of E-selectin on endothelial cells and E-selectin mRNA can be detected in vivo within a short time. This study was aimed to investigate whether this biologic response can be used as a read-out for the anti-inflammatory effect of topically administered corticosteroids. We investigated skin of healthy volunteers treated according to the two following experimental protocols: (i) topical application of different corticosteroids (versus basic ointments as controls) for 12 h and irritation with sodium dodecyl sulfate 1% for 4 h; (ii) irritation with sodium dodecyl sulfate 1% for 12 h and application of the corticosteroids for 5 h. The biopsy specimens were subjected to RNA extraction and reverse transcription and competitive reverse transcriptase-polymerase chain reaction was performed using defined concentrations of a pre-constructed mimic DNA. As result, we found strong positive signals for wild-type E-selectin mRNA in all biopsies pretreated with basic ointments, whereas in biopsies from areas pretreated with corticosteroids the bands for wild-type E-selectin DNA could be detected at 10-1000 lower levels of mimic DNA concentrations. The reverse experiment, application of corticosteroids after the irritation, again yielded significantly reduced signals for E-selectin mRNA. In both experimental settings, the different strength of the topical corticosteroids used was reflected by significant differences in the amount of E-selectin mRNA found in the biopsies. This study demonstrates the pharmacologic effect of topical corticosteroids on the irritation-induced E-selectin mRNA expression on dermal endothelial cells in vivo using very small tissue samples and this approach may be of value for further pharmaceutical studies.

In situ expression and serum levels of tumor necrosis factor-alpha receptors in patients with early stages of systemic sclerosis.

OBJECTIVE: Tumor necrosis factor-alpha (TNF-alpha) is an important cytokine in the early stage of systemic sclerosis (SSc), which is characterized by mononuclear cell infiltration and microvascular alterations. Most effects of TNF-alpha are mediated by its interaction with 2 types of TNF receptors and depend on their surface expression on individual cell subsets. Our purpose was to correlate the serum levels of soluble TNF receptors-TNF-RI(p55) and RII(p75)-with (1) their in situ expression and distribution in lesional skin and on peripheral blood mononuclear cells (PBMC), and (2) the clinical disease progression and inflammatory serum variables in patients with SSc. METHODS: Serum samples of 32 patients with SSc and 36 healthy probands were examined by ELISA. We performed immunohistological stainings and in situ hybridization on cryostat sections of skin lesions, cytometric analysis on PBMC, and reverse transcriptase polymerase chain reactions using RNA from cultured skin fibroblasts in 17 of these 36 patients. RESULTS: In contrast to healthy skin and chronic fibrotic SSc, TNF-RI is expressed on about 30% of mononuclear infiltrating cells in early skin lesions. Neither TNF-RI nor RII was detectable on fibroblasts by immunohistochemistry, but specific mRNA could be found on the transcriptional level. TNF-RII is found on most lymphocytes and on 30-50% of endothelial cells, especially in early SSc. Expression of both receptor types on PBMC in patients and controls was not significantly different. Serum levels of soluble TNF-RI and RII correlated well with their in situ expression and with clinical and laboratory signs of inflammation and disease progression in patients with SSc. CONCLUSION: Our data provide evidence for a central role of the TNF-alpha/TNF-R system in the early pathological events of scleroderma with prominent inflammation and endothelial cell damage. Determination of TNF-R serum levels provides a useful diagnostic tool for characterization of the disease stage and progression, and to guide experimental therapy in patients with SSc.

In situ expression and serum levels of tumour necrosis factor alpha receptors in patients with lichen planus.

In lichen planus (LP), an inflammatory skin disease of unknown origin, adhesion molecules and their ligands combined with the local and systemic release of various cytokines are fundamental in regulating inflammation. Therefore, we investigated the expression of tumour necrosis factor alpha receptor (TNF-R) I and II in lesional skin of 15 patients suffering from acute eruptive LP by means of immunohistochemistry. In addition, the serum levels of their soluble forms (sTNF-R) were measured by enzyme-linked immunosorbent assay (ELISA), compared with those of healthy volunteers (n = 10) and correlated with the in situ inflammatory response. In contrast to healthy controls, LP patients showed significantly increased serum levels of sTNF-RI as well as sTNF-RII (p < 0.02). These enhanced serum titres were correlated with a prominent expression of TNF-RI on lesional keratinocytes (basal > suprabasal) and of both receptors on skin-infiltrating lymphocytes. Our data suggest an important role of the TNF ligand/receptor interactions in the induction and/or perpetuation of the pathogenetical and apoptotic events in LP.

Up-regulation of class II major histocompatibility complex and intercellular adhesion molecule 1 expression on scleroderma fibroblasts and endothelial cells by interferon-gamma and tumor necrosis factor alpha in the early disease stage.

OBJECTIVE: To investigate the expression patterns of interferon-gamma (IFN gamma) and tumor necrosis factor alpha (TNF alpha), both of which are potent inducers of class II major histocompatibility complex (MHC) and intercellular adhesion molecule 1 (ICAM-1) expression, and their codistribution with HLA-DR and ICAM-1 in skin lesions, cultured fibroblasts, and peripheral blood mononuclear cells (PBMC) of systemic sclerosis (SSc) patients in different stages of disease. METHODS: Investigations were carried out using immunohistochemistry studies, reverse transcriptase-polymerase chain reaction, dot-blot hybridization, and cytometric analysis. Serum levels of TNF alpha were determined by enzyme-linked immunosorbent assay. RESULTS: In the early inflammatory stage of SSc, class II MHC and ICAM-1 expression could be detected on most endothelial cells and on fibroblasts located especially in perivascular areas surrounded by infiltrating lymphocytes, which belong to the T helper 1 phenotype expressing IFN gamma and TNF alpha. In this early disease stage, an enhanced expression of TNF alpha on cultured dermal fibroblasts and PBMC, as well as elevated serum titers of soluble TNF alpha, could be found. CONCLUSION: These data suggest that class II MHC antigens and ICAM-1 on fibroblasts and endothelial cells are induced by IFN gamma and TNF alpha in an early stage of SSc after the influx of mononuclear-cells, and may be important in the putative autoimmune response and in the perpetuation of fibrotic processes in SSc.

Endothelial cell apoptosis is a primary pathogenetic event underlying skin lesions in avian and human scleroderma.

The mechanism that may cause degenerative fibrotic skin lesions was studied in situ using skin biopsies from patients with systemic sclerosis (SSc), localized scleroderma, or keloids, and at the initial disease stage in the University of California at Davis (UCD) lines 200/206 chickens, which develop a hereditary systemic connective tissue disease resembling human SSc and permit study of disease stages not accessible in humans. Frozen skin sections were analyzed simultaneously for apoptosis by terminal deoxynucleotidyl transferase-mediated FITC-dUTP nick end labeling and indirect immunofluorescence staining of cell markers with tetramethylrhodamine isothiocyanate conjugates. The results showed that endothelial cells are clearly the first cells to undergo apoptosis in the skin of UCD-200/206 chickens, a process that seems to be induced by anti-endothelial cell antibodies. In human fibrotic skin diseases, apoptotic endothelial cells could only be detected in early inflammatory disease stages of SSc and localized scleroderma.

Cytokine levels in the seminal plasma of infertile males.

Cytokines released by various cell subsets in the male urogenital tract are capable of markedly influencing sperm function and fertility. We determined the cytokine content in the seminal plasma of patients with unexplained infertility and correlated the results with urogenital infections and sperm parameters. Routine sperm parameters, bacterial culture of seminal plasma and blood follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone were obtained from 14 infertile males and 8 healthy control subjects. Interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF alpha) levels in the seminal plasma were measured by enzyme-linked immunosorbent assay (ELISA). IL-1 beta, IL-6, and TNF alpha levels in the seminal plasma were negatively correlated with the number of progressively motile sperm, but there was no correlation with total sperm counts, viability, pH, morphological alterations, type of abnormality, and hormone parameters. Cytokine levels were significantly elevated in seminal plasma exhibiting bacterial or mycoplasmal infections of the urogenital tract. Urogenital infections lead to an release of inflammatory cytokines, most probably by immunocompetent cells of the lymphocyte/macrophage origin. Cytokines such as IL-1, IL-6, and/or TNF alpha might influence sperm motility via direct or indirect effects, resulting in reduced mucosa penetration properties. Therefore, our data suggest that cytokines may be involved in reduced male fertility.

Correlation of soluble adhesion molecules in the peripheral blood of scleroderma patients with their in situ expression and with disease activity.

OBJECTIVE: To correlate serum levels of the soluble adhesion molecules intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin, and P-selectin with (a) clinical disease activity and progression and (b) the in situ expression and distribution of these adhesion molecules in lesional skin, in patients with systemic sclerosis (SSc). METHODS: Serum samples from 12 SSc patients and 36 healthy controls were examined by enzyme-linked immunosorbent assay. Immunohistologic staining was carried out on cryostat sections of lesional skin. RESULTS: Patients whose SSc was in the early inflammatory stage or who had prominent disease progression showed elevated serum levels of soluble adhesion molecules. Serum levels correlated positively with the expression of these molecules on endothelial cells and fibroblasts in lesional skin. CONCLUSION: Serum levels of soluble ICAM-1, VCAM-1, P-selectin, and, to a lesser degree, E-selectin correlate well with their in situ activity and with clinical disease activity. These parameters therefore provide a useful tool for the characterization of disease stage, progression, and prognosis in SSc.

[Initial visceral involvement with diffuse systemic scleroderma]. / Initialer viszeraler Befall bei diffuser systemischer Sklerodermie.

Progressive systemic sclerosis (PSS) is characterized in most patients by initially unspecific symptoms like acrocyanosis. Raynaud's phenomenon, general malaise or acral paresthesia. Clinical manifestations appear with an edematous-inflammatory stage of disease leading to a chronic-progressive phase with increasing fibrosclerosis of the skin and internal organs. Dermal involvement and the demonstration of immunopathological abnormalities in the peripheral blood precede visceral fibrosis in most cases. We report on an unusual case of diffuse PSS with preceding involvement of internal organs. Early visceral fibrosis is demonstrated by histomorphological results and is correlated with laboratory findings. Serum antinuclear antibodies could not be obtained until 4 months ante finem and the liver was also involved in the fibrotic process.

[Snake bite by a poisonous snake. Report of an unusual case]. / Bissverletzung durch eine Giftschlange. Bericht über einen ungewöhnlichen Fall.

We report on a 31-year-old white woman, who was bitten in her right calf by a "spitting cobra" (Neia nigricollis) during a safari in Tansania. Minor initial systemic symptoms such as nausea and vomiting were followed by severe oedematous swelling of the extremity after 2-3 h and demarcation of a 2.75 x 2.75 in. area of necrotic skin. The patient returned to her home country, where 8 days after the snake-bite necrosectomy was performed. Antibiotics, anti-inflammatory agents and local therapy with hydrocolloidal wound dressings were administered. With this therapy the lesion healed completely with minor scarring within 5 months. A new Salmonella strain was isolated from the ground of the ulcer.

Effects of cytokine application on glucocorticoid secretion in an animal model for systemic scleroderma.

We previously reported on an altered immune-endocrine feedback loop via the hypothalamo-pituitary-adrenal (HPA) axis in Obese strain (OS) chickens afflicted with spontaneous autoimmune thyroiditis. These animals are deficient in plasma corticosterone increase after antigenic challenge or application of cytokine-containing conditioned medium of mitogen-stimulated spleen cells (CM). To investigate whether the impaired ability to respond to cytokines with glucocorticoid-increasing factor (GIF) activity, e.g. interleukin 1 (IL 1), is restricted to OS chickens as a model for an organ-specific autoimmune disease, we extended our experiments to another autoimmune-prone animal strain, the chickens of the University of California at Davis line 200 (UCD-200). These animals develop an inherited inflammatory fibrotic disease that closely resembles human progressive systemic sclerosis (scleroderma). Application of GIF-containing CM to UCD-200 chickens leads to a transient increase in glucocorticoid serum levels within 1-2 hours comparable to that of controls. But, while corticosterone levels in the latter returned to normal baseline levels after 4 hours, they were still elevated in autoimmune chickens. Although the peak of the glucocorticoid hormone serum concentrations was equal to that of controls, UCD-200 had to secrete twice as much adrenocorticotropic hormone to achieve this corticosterone serum level due to an apparent hyporesponsiveness of the adrenal gland to this secretagogue. The altered cytokine-induced glucocorticoid secretion is found in early as well as in chronic, sclerotic stages of the disease. Cellular alterations in the peripheral blood of UCD-200 chickens during the prolonged elevated corticosterone section, i.e. between 2-4 hours after CM application, are characterized by a significant decrease in the percentage of CD4+ and CD8+ cells. Furthermore, a significant increase in B cells up to 24 hours with a maximum after 1 hour was found. The proliferative response to the mitogen concanavalin A of peripheral mononuclear cells was inversely correlated to the serum corticosterone level, showing a permanent decrease of 80-90% after 1-4 hours in autoimmune animals. This functional alteration in UCD-200 was accompanied by an 80% decrease in serum interleukin 2 (sIL 2) activity 4 hours after CM application. Twenty-four hours later an eight-fold increase in sIL 2 rebound activity was found, indicating that the inhibitory effect of corticosterone in UCD-200 chickens is not long-lasting.

Microcirculatory functions in systemic sclerosis: additional parameters for therapeutic concepts?

To study the functional reactivity of the cutaneous microcirculation in progressive systemic sclerosis (PSS), hyperemic responses after arterial occlusion (3 min) and during local heating (42 degrees C) were investigated with simultaneous measurements of red blood cell flux and cutaneous oxygen tension (pcuO2) of the skin in female patients (n = 19) with PSS and in healthy female controls (n = 15). Additionally, serum levels of 6-keto-prostaglandin 1 alpha (PGF1 alpha), a stable metabolite of prostacyclin, were compared to the microcirculatory data, and both were used to evaluate further a standardized therapy with 10-d intravenous calcitonin (100 IU/d) infusion in six PSS patients. In PSS, the initial mean pcuO2 value was significantly reduced and was inversely proportional to flux and to PGF1 alpha levels, whereas the flux and pcuO2 responses to the above hyperemic stimuli showed significant reductions, revealing a pattern of "hyperemic hypoxia" probably due to exhausted functional reserves of cutaneous perfusion. During calcitonin infusion significant rises in pcuO2 and temporarily in PGF1 alpha and flux were found. After 10 d of therapy, increased pcuO2 was associated significantly with decreased flux, indicating a shifting of blood from deeper regulatory vessels to the subepidermal capillaries. Both clinical improvement and the results of microcirculatory measurements demonstrate a beneficial effect of calcitonin on the cutaneous microcirculation in PSS patients, possibly due in part to a short-term increase in release of endogenous prostacyclin from the vascular endothelium during the infusion. The disturbed reactivity of the dermal vessels in PSS is important for the evaluation of therapeutic concepts and stresses, together with the elevated PGF1 alpha plasma levels, vascular factors in the pathogenesis of PSS.

Effects of interferon-alpha-2b on the clinical course, inflammatory skin infiltrates and peripheral blood lymphocytes in patients with severe atopic eczema.

Increased serum IgE and enhanced susceptibility to viral infections, decreased levels of interferons, lymphocytic skin infiltrates and IgE-bearing epidermal Langerhans cells are striking features in patients with atopic eczema (AE). Since the hyper-IgE syndrome is known to improve under alpha-interferon (alpha-IFN) therapy, we treated 7 patients with severe AE and high serum IgE exclusively with 3 x 10(6) units IFN alpha 2b thrice weekly for 3 months. Before treatment the skin infiltrates mainly consisted of CD3+/CD4+/TcR alpha/beta + lymphocytes, whereas the CD3+/CD8+ phenotype was limited to about 10% of cells. After 6 weeks of therapy, epidermal inflammation with CD4+ and CD8+ cells was reduced but dense infiltrates remained in papillary perivascular areas. Expression of TcR gamma/delta, HLA-DR and CD25 showed no significant changes. Initially high serum IgE and soluble CD23 as well as cell-bound IgE dropped under therapy, whereas a short-term elevation in serum IL-2 receptor was observed. On peripheral blood lymphocytes slightly reduced expression of HLA-DR, LFA-1, CD23 and ICAM-1 was seen after 100 days. LFA-3 expression became reduced in 4 patients, the CD4/CD8 ratio decreased in all cases. After an initial therapeutic response of all patients, significant longer-lasting improvement of the skin lesions could only be observed in 2 of 7 patients. The data of our long-term study suggest that systemic IFN alpha 2b treatment leads to a remarkable reduction in epidermal inflammation but does not significantly influence cutaneous cell subsets. Immunomodulatory effects became obvious by reduced peripheral cell subsets expressing TcR alpha/beta, MHC class II and adhesion molecules.

Antinuclear antibody profile in UCD line 200 chickens: a model for progressive systemic sclerosis.

The fully blown disease of human progressive systemic sclerosis (PSS, scleroderma) is serologically associated with the emergence of several types of autoantibodies, some of them regarded as more specific for scleroderma (e.g. Scl-70, anti-centromere) and some common also to other connective tissue diseases (e.g. anti-ssDNA). Since most patients suffering from PSS are not under medical control until clinical manifestations are fully established, only scarce data are available on the dynamics and clinical significance of autoantibodies in the very early stages of this systemic fibrotic disease. The University of California at Davis line 200 (UCD 200) of chickens spontaneously develop a PSS-like disorder with an acute inflammatory stage around 60 days after hatching, leading to fibrosis with fast progression. In order to address a possible correlation between the occurrence and titer of autoantibodies and the initial disease activity, we have chronologically investigated the presence and titer of autoantibodies directed against several human nuclear antigens in this animal strain. In UCD-200 chickens, we found a progressive increase in autoantibodies to histones, to ssDNA and--to a lesser degree--dsDNA with peaks at the age of 60 and 120 days, to poly(I) and poly(G) with a peak at 120 days and an elevation in anti-cardiolipin antibodies. Total immunoglobulin concentrations, anti-Ro, anti-La and anti-Sm showed no significant differences as compared to negative results in healthy normal controls. Our data reveal parallels in the antinuclear antibody (ANA) spectrum between UCD-200 chickens and human autoimmune collagen diseases, but do not reflect the typical ANA spectrum found in the foudroyant form of diffuse scleroderma.(ABSTRACT TRUNCATED AT 250 WORDS)

Investigation of ACTH responses of chickens with autoimmune disease.

An altered immunoendocrine feedback regulation within the hypothalamo-pituitary-adrenal axis may modulate the pathogenesis of an avian autoimmune disease. To date studies have been hampered by a lack of reliable, specific, and sensitive methods for determining adrenocorticotropic hormone (ACTH) in chickens. The present study describes the determination of ACTH in plasma of chickens with a commercial radioimmunoassay, the antibody of which binds to the midregion of human ACTH 1-39. The chickens, kept on a 12-hr day and 12-hr night shift with artificial light, showed changes in plasma ACTH concentrations during the light phase with maximum values 8 hr after the light was turned on. ACTH was not measurable after treatment with dexamethasone. Intravenous administration of supernatants from concanavalin A-stimulated spleen cells increased basal plasma ACTH concentrations more than 20-fold within 1 hr. This increase in plasma ACTH was higher and longer lasting in UCD 200 chickens, an animal model for scleroderma, compared with outbred and inbred normal White Leghorn chickens.

Expression of adhesion proteins involved in cell-cell and cell-matrix interactions in the skin of patients with progressive systemic sclerosis.

BACKGROUND: Lymphocytic infiltration and activation of connective tissue metabolism in the early phase of progressive systemic sclerosis (PSS, scleroderma) may be critically influenced by cellular adhesion molecules (CAMs), which mediate cell-cell and cell-extracellular matrix interactions. OBJECTIVE: The tissue distribution might demonstrate a pathogenetic role of these adhesion molecules in early edematous and chronic fibrotic scleroderma. METHODS: We investigated by immunohistochemical techniques the in situ expression and distribution of beta 1 and beta 2 integrins, selectins, and CAMs of the immunoglobulin superfamily in patients with scleroderma. RESULTS: In the early disease stage a moderate percentage of perivascular CD3+/CD4+/TCR alpha/beta + lymphocytes showed expression of the alpha 3, alpha 5, and beta 1 chains and, to a lesser degree, of the alpha 1, alpha 2, alpha 4 and alpha 6 subunits. In contrast to chronic PSS, LFA-1 alpha, LFA-1 beta and ICAM-1 expression on mononuclear infiltrating cells was seen more frequently in acute scleroderma. Different percentages of fibroblasts expressed alpha 1-, alpha 3-, alpha 5- and beta 1-integrin chains. In acute PSS ICAM-1 was expressed especially by fibroblasts located around perivascular inflammatory infiltrates as well as by endothelial cells (ECs). A few ECs expressed alpha 2 beta 1 integrins. CONCLUSION: Our observations suggest that CAMs are intimately involved in early pathogenetic events in scleroderma, mediating cellular interactions between lymphocytes, ECs, and fibroblasts, as well as homing and tissue targeting of mononuclear infiltrating cells.