[Primary cutaneous cryptococcosis : Pigeons can carry more than letters !] / Primär kutane Kryptokokkose : Tauben können mehr als Briefe transportieren !

In the event of non-specific epidermal lesions, the importance of a comprehensive anamnesis becomes especially apparent. In the following, we report on a patient case in which only a focused anamnesis was able to bring light into the darkness of numerous differential diagnoses - and to produce the diagnosis of a rare but in this collective common illness: primary cutaneous cryptococcosis.

Selective recognition of rat follicular dendritic cells (dendritic reticulum cells) by a new monoclonal antibody Ki-M4R in vitro and in vivo.

Using unstimulated rat peritoneal cells as immunogen a new monoclonal antibody Ki-M4R was produced. Ki-M4R recognizes follicular dendritic cells (dendritic reticulum cells) in germinal centers of lymphoid follicles in lymphatic tissue. In addition, sinus lining cells, endothelia of postcapillary venules, as well as mesangial cells of the renal glomerula immunoreact with Ki-M4R in vitro as well as in vivo. This antibody might be useful for studying the interaction of follicular dendritic cells and B-cell immune response.

CD4+ cutaneous T-cell lymphomas show the phenotype of helper/inducer T cells (CD45RA-, CDw29+).

CD4+ T cells are heterogenous and include at least two subsets that differ in their influence to immunoglobin synthesis, cytokine secretion pattern and immunophenotype. Among others these subsets have been designated as suppressor/inducer or naive T cells (CD45RA+, CDw29-) and helper/inducer or memory T cells (CD45RA-, CDw29+). Current theories suggest that these CD4+ T-cell subsets either reflect sequential stages of maturation before and after activation (antigen contact) or represent distinct lineages. In this study, we systematically analyzed the participation of both suppressor/inducer (CD45RA+) and helper/inducer (CDw29+) T cells in the dermal lymphohistiocytic infiltrate of various CD4+ cutaneous T-cell lymphomas. Although in peripheral blood both subsets are equally distributed, we present evidence that all CD4+ cutaneous T-cell lymphomas are of the helper/inducer T cell phenotype. These findings are of importance both for pathogenetic and clinical considerations: the presence of plasma cells in dermal infiltrates and the elevation of serum immunoglobulins in patients of mycosis fungoides may be the consequence of interleukin-4 secretion of the neoplastic CD4+ helper/inducer cells. The exclusive memory T cell phenotype of cutaneous T-cell lymphomas may be due to a general predominance of this subset in the skin, or be the consequence of cellular activation during malignant transformation.

Cell trafficking in positive and negative patch-test reactions: demonstration of a stereotypic migration pathway.

The cellular and molecular events taking place during epidermal antigen exposure in sensitized individuals are principally well understood. Epidermal Langerhans cells (LC) are supposed to take up, process, and express a given foreign substance on their cell surface. The antigen is then recognized by T cells bearing the appropriate T-cell receptor (TCR). Because LC do not bear variable antigen (Ag)-specific binding sites, one could postulate that the epidermal exposure of any substance should activate LC and other cells of the skin immune system. To test this hypothesis, we analyzed immunophenotypically the cellular trafficking events in positive (n = 5) and negative epicutaneous patch-test reactions (n = 10), using a panel of monoclonal antibodies against CD1a, CD11c (Ki-M1, LeuM5), CD68 (Ki-M6), Ki-M8, and CD3 (Leu4). We can demonstrate that irrespective of whether or not an antigen will be responded to by the immune system (i.e., positive or negative test reaction), epidermal antigen exposure causes a decrease of LC density in the epidermis and simultaneously causes an increase of LC in the dermis. Moreover, monocytes and T cells immigrate into the dermis both in positive and negative patch-test reactions. As is to be expected, the degree of this cellular traffic is more pronounced in positive test reactions, which may be due to amplification mechanisms caused by antigen recognition of sensitized T cells. This finding demonstrates that human skin contains cell migration programs that ensure that any foreign substance will be accessible to the skin immune and phagocytic system.

Upper keratinocytes of psoriatic skin lesions express high levels of NAP-1/IL-8 mRNA in situ.

In order to better understand the factors regulating disease promotion and activity in psoriasis (PS), we searched for the in situ expression of mRNA for various cytokines in long-standing PS skin lesions. Specific hybridization with a NAP-1/IL-8 anti-sense RNA probe was keratinocyte associated and yielded strong and specific signals exclusively in the upper layers of the lesional epidermis, but not in uninvolved skin from psoriatic patients or normal skin from non-psoriatics. Interestingly, NAP-1/IL-8 transcripts were focally clustered in a spotty pattern predominantly between the tips of elongated papillae, but were absent in the lower epidermal region and the dermal compartment. We consistently failed to detect appreciable numbers of TNF-alpha and/or IL-6 mRNA-containing cells in psoriatic lesions. These results support the notion that IL-8, rather than IL-6, is an important disease-promoting cytokine in PS. In view of the known in vitro and in vivo effects of IL-8, it is conceivable that this substance greatly contributes to the major pathologic changes seen in psoriatic skin, i.e., keratinocyte hyperproliferation and leucocyte infiltration. In this case, local pharmacologic down-regulation of NAP-1/IL-8 activity could be a promising therapeutic strategy in PS.

Infiltration of both T cells and neutrophils in the skin is accompanied by the expression of endothelial leukocyte adhesion molecule-1 (ELAM-1): an immunohistochemical and ultrastructural study.

Various inducible adhesion molecules on human endothelial cells like the endothelial leukocyte adhesion molecule-1 (ELAM-1) seem to be the basis of mechanisms that allow peripheral blood leukocytes to enter precisely areas of inflamed tissue. Because in vitro data had shown that ELAM-1 plays a central role in neutrophil as well as memory T-cell endothelium interactions, we analyzed in vivo at the light and electron microscopic level its expression in various benign and malignant skin diseases, which differ in the composition of the cellular infiltrates. The expression of ELAM-1 on endothelial cells at different anatomical sites could be demonstrated independently from the cell type (neutrophils/memory T cells) infiltrating the surrounding tissue. On the ultrastructural level we demonstrate that the expression of ELAM-1 is restricted to certain segments of post-capillary venules exhibiting distinctive morphologic features. The ELAM-1-positive endothelia are identical to those vessels that are currently described to be the preferred sites of lymphocyte trafficking in diseased skin.

Expression of the B7/BB1 activation antigen and its ligand CD28 in T-cell-mediated skin diseases.

Interactions of CD28 (on T cells) with its recently identified ligand B7/BB1 (on antigen-presenting cells) have been shown to activate T cells via a major histocompatibility complex/Ag-independent "alternative" pathway, leading to an amplification of T-cell-mediated immune responses. The in vivo relevance of these molecules for cutaneous immunity is presently unknown. These findings prompted us to study the expression of B7/BB1 and CD28 in normal human skin and in selected T-cell-mediated inflammatory skin diseases. Biopsies were obtained from lesional skin of patients with allergic contact dermatitis, lichen planus, and, as control, from basal cell carcinoma and from healthy controls. Serial cryostat sections were stained with a panel of MoAbs directed against CD28, B7/BB1, CD3, CD1a, and KiM8 using immunohistochemistry (ABC technique). CD28 expression was observed in the majority of dermal and epidermal CD3+ T cells in contact dermatitis and lichen planus. In normal skin and basal cell carcinoma, CD28 was expressed only occasionally by perivascular T cells. In allergic contact dermatitis and lichen planus, B7/BB1-expression was found on dermal dendritic cells, on dermal macrophages, on Langerhans cells, focally on keratinocytes, and occasionally on dermal T cells. No B7/BB1 immunoreactivity was detected in normal skin and basal cell carcinoma. These findings indicate that T-cell-mediated skin diseases are accompanied by an influx of CD28+ T cells and an upregulation of B7/BB1 on cutaneous antigen-presenting cells, keratinocytes, and on some T cells. We speculate that "alternative" T cell-activation via the B7/CD28 pathway may contribute to the pathogenesis of these skin diseases.

Localized and disseminated pagetoid reticulosis. Diagnostic immunophenotypical findings.

Pagetoid reticulosis (PaRet) is a rare skin disease with an intraepidermal infiltrate of atypical lymphocytes. We performed phenotypic studies on two patients with classic localized PaRet (Woringer-Kolopp disease) and one patient with the disseminated type (Ketron-Goodman disease) and compared these with all published reports of cases; both variants show intraepidermal, highly activated, proliferating T cells with variable loss of pan-T-cell antigens, contrasting with nonactivated dermal reactive T cells. This pattern is unique among cutaneous lymphomas and can be used for diagnosis. Despite the fact that localized PaRet does not show a malignant course, recent genotypic analysis of one patient showed monoclonality. Comparable constellations are found in other diseases like lymphomatoid papulosis, which also represent monoclonal disorders of activated T cells with a benign course. To unify these seeming discrepancies, we introduce the concept of "benign cutaneous lymphomas."

Systemic treatment for cutaneous lymphomas.

Primary malignant T cell lymphomas of the skin form a heterogenous group. Relevant classifications were recently made to separate different entities by various criteria. This is of great importance, because one should only rely on those therapeutical trials in which patients were included according such classifications. In this paper, we will mainly focus on therapeutic modalities for mycosis fungoides, which is the most frequent cutaneous T cell lymphoma and which may serve as a model disease. In principle, local (e.g., psoralens and ultraviolet A, PUVA) and systemic therapies (e.g., interferon-alpha 2a) can be applied. Very recently, we were able to demonstrate that even in initial stages of mycosis fungoides, the T cell clone is not restricted to the skin, but rather is present in low amounts in the peripheral blood. Therefore, systemic therapeutic modalities alone or in combination with local strategies (interferon-alpha 2a and acitretin/PUVA and interferon-alpha 2a) should be more effective, which will be proven by currently running clinical trials.

Adhesion molecule mapping in normal human skin.

Adhesion molecules are a rapidly growing group of cell surface receptors providing cell-cell and cell-matrix interactions. Their physiological role in tissue homeostasis as well as cellular migration and differentiation is increasingly appreciated. In the present study we have analyzed the expression pattern of most adhesion molecules of the integrin family as well as of adhesion molecules belonging to the immunoglobulin superfamily in normal human skin. We provide evidence that expression of adhesion molecules in the various cutaneous cell systems follows a constant distribution. Moreover, the physiological mononuclear infiltrate of the skin also expresses a variety of adhesion molecules enabeling these cells to migrate or to reside within the skin. Furthermore, our results indicate that intercellular adhesion molecule-1 is not a prerequisite for lymphocyte epidermotropism as frequently stated. Our data provide a rational basis to analyze changing adhesion molecule expression in inflammatory and neoplastic skin diseases.

Clonal disease in early cutaneous T-cell lymphoma.

Our experience with 185 cases of T-cell dominated skin infiltrates demonstrates that the PCR-based method for detection of TCR gamma chain gene rearrangement in combination with temperature gradient electrophoresis can routinely be used for the demonstration of clonal T cells in formalin-fixed and paraffin-embedded biopsies of lesional skin. In contrast to Southern blot analysis, the amplification by PCR is nonradioactive, is not time consuming (approximately 3 days), can be performed using frozen or paraffin-embedded tissue, and allows additional molecular biologic analyses, such as sequencing. Furthermore, it offers the possibility to design patient-specific primers for monitoring of the disease activity. It also has to be concluded from our study that all available clinical, histologic, cytologic, immunophenotypical, and rearrangement studies have to be considered in order to establish the correct diagnosis.

HTLV-1-negative pleomorphic T-cell lymphoma of the skin: the clinicopathological correlations and natural history of 15 patients.

The peripheral T-cell lymphomas represent a heterogeneous group and include, besides mycosis fungoides and Sézary syndrome, large-cell anaplastic lymphoma. We report 15 cases from our files that fulfil the histological criteria of pleomorphic T-cell lymphoma with primary skin involvement. Most of the cases were elderly with a male-to-female ratio of 1.5:1. The HTLV-1 serology was negative. The clinical features of these patients differed from those with mycosis fungoides and Sézary syndrome, in that eczematous and precursor lesions such as parapsoriasis en plaque were lacking apart from one exception. All the patients with small-cell pleomorphic T-cell lymphomas were alive, although three of the nine patients with medium-to-large tumour cells have died. Pleomorphic T-cell lymphoma should be regarded as a distinct entity among the lymphoproliferative disorders of the skin.

CD4+ memory T cells in peripheral blood are not decreased in patients with atopic dermatitis.

Atopic dermatitis (AD) is a severe and chronic eczematous skin disease, to which increased IgE levels and imbalances of CD4+ T cells are related. CD4+ T cells, however, are heterogeneous and include at least two subpopulations being designated as CD4+ naive and memory T cells. They represent sequential maturational stages (naive into memory) in CD4+ T cell development differing in function and phenotype. Of these two subpopulations the CD4+ memory T cell compartment is a potent producer of gamma-interferon which suppresses IgE synthesis in B cells. Therefore, we speculated whether an inborn maturation defect of CD4+ memory T cells causes the increased IgE production in AD. In patients with AD and age- and sex-matched controls (both n = 10) we analyzed the distribution of both subpopulations in peripheral blood by two-color flow cytometry using monoclonal antibodies against the CD4, CD45RA and CD29 antigen. We provide evidence that the numerical values of CD4+ memory T cells and CD4+ naive T cells are equivalent in both groups. This supports the view that functional disturbances of lymphocytes or lymphocyte subsets are responsible for IgE excess and the pathogenesis of AD.

[Parakertosis variegata after pityriasis lichenoides et varioliformis acuta]. / Parakeratosis variegata nach Pityriasis lichenoides et varioliformis acuta.

We report on a 34-year-old male patient who developed generalized parakeratosis variegata lesions 4 years after suffering from pityriasis lichenoides et varioliformis acuta. For further investigation of a possible interrelationship between these two diseases of the parapsoriasis group and their relationship to the T-cell type of cutaneous non-Hodgkin-lymphoma, histological, immunohistological and molecular-biological techniques were applied. We were able to demonstrate typical morphological features common to both diseases, and a polyclonal T-cell infiltrate in both. It is concluded that pityriasis lichenoides et varioliformis acuta and parakeratosis variegata are separate entities without monoclonal rearrangement or signs of malignancy.

[Reticular elastolytic giant cell granuloma. A variant of the annular elastolytic giant cell granuloma]. / Retikuläres elastolytisches Riesenzellgranulom. Eine Variante des anulären elastolytischen Riesenzellgranuloms.

The case report presented describes a new variant of annular elastolytic giant cell granuloma. Over a period of 10 years, a 40-year-old woman had developed reticular, brown to livid, partly atrophic skin lesions on the shoulders and decolletée. The patient had no subjective symptoms. Histology revealed a patchy lymphohistiocytic infiltrate in the dermis, with many giant cells. Elastic fibres were less frequently found in these infiltrates; in a few of the giant cells and macrophages fragments of elastic fibres were demonstrated within the cytoplasm. There were no deposits of mucin. For this new variant we propose the term "reticular elastolytic giant cell granuloma."

Cellular and molecular composition of human skin in long-term xenografts on SCID mice.

We report on the immunophenotypical characterization of adult human skin transplanted onto severe combined immunodeficient (SCID) mice. Thirty animals were followed for up to 12 months after receiving split-thickness xenografts, of which 28 were tolerated for the whole test period. Antigen mapping revealed an almost complete preservation of human cellular and extracellular tissue components in long-term transplants including skin immune cells (Langerhans-cells, macrophages, lymphocytes) and also parts of the engrafted endothelium. Hence, xenografts on SCID mice offer a versatile experimental tool for the in vivo study of both human skin immune cell function and endothelial cell-mediated interactions in an environment completely devoid of interferences by adoptive host immune response.

Predominant usage of distinct T-cell receptor V beta regions by epidermotropic T cells in psoriasis.

To investigate the role of T cells in psoriasis, we analyzed the T-cell receptor (TCR) repertoire in peripheral blood lymphocytes (PBLs) and in skin lesions of 9 patients with chronic plaque-stage psoriasis by means of immunohistochemistry. An extended panel of monoclonal antibodies detecting 11 different V beta families was employed in this study. In the peripheral blood, no predominant TCR V beta expression was detected and interindividual differences were small. Skin-infiltrating T cells showed only marginal differences in the TCR V beta usage when compared with PBLs. However, in 3 patients the intraepidermal infiltrate comprised up to 40% of T cells expressing a TCR V beta region which was virtually absent in the peripheral blood and the dermal infiltrate. Thus, although the TCR V beta usage of skin-infiltrating T cells showed little difference compared to PBLs, several cases exhibited a significant increase of epidermotrophic T cells using one particular V beta region.

["Granulomatous slack skin"--cutaneous elastolytic lymphoma]. / "Granulomatous slack skin"--kutanes elastolytisches Lymphom.

The term "granulomatous slack skin" (GSS) was introduced by Ackerman for a disease first described by Convit et al. in 1973. GSS represents a rare cutaneous lymphoma characterized by localized elastolytic lesions with a granulomatous infiltrate. We recently observed two male patients with the characteristic features of this disease. Both patients responded well to therapy with interferon-alpha 2b. In one patient clinical remission was stable under long-term treatment with clofazimine. We report on common features of these two patients and give a review of the cases published in the literature.

Neutrophil-activating peptide 1/interleukin 8 mRNA expression and protein secretion by human monocytes: effect of cyclosporin A.

Neutrophil-activating peptide 1/interleukin 8 (NAP-1/IL-8) is a recently described cytokine with potent chemotactic activity for human neutrophil granulocytes (PMN) and T cells. In psoriasis, a chronic hyperproliferative and inflammatory skin disorder, PMN and T cells are found as prominent cells in the inflammatory infiltrate of the lesions; however, monocytes were shown to be the first cells invading a newly formed plaque. NAP-1/IL-8 was found to be present in high amounts in the skin and in scale material of psoriatic patients. Psoriasis responds well to systemic treatment with cyclosporin A (CsA), an immunosuppressive peptide. Therefore, we addressed the question of whether the clinical improvement of psoriatic patients during CsA therapy may be due to an inhibition of NAP-1/IL-8 production and secretion from monocytes. Purified human monocytes were stimulated by lipopolysaccharide in the presence or absence of various concentrations of CsA. Production of NAP-1/IL-8 was determined as expression of specific mRNA by fluorescent in situ hybridization. Secreted peptide was measured by bioassay (PMN chemotaxis) and enzyme-linked immunosorbent assay (ELISA) using specific monoclonal antibodies. The results show that CsA neither inhibited mRNA expression for NAP-1/IL-8 nor secretion of the peptide. These findings support the hypothesis that the pharmacological effect of CsA may be restricted to the inhibition of T-cell activation and proliferation.

Role of beta 1-integrins in epidermotropism of malignant T cells.

To better understand the molecular mechanisms of epidermotropism, we immunohistochemically analyzed the expression pattern of adhesion molecules belonging to the integrin and immunoglobulin superfamilies in cases of mycosis fungoides (MF) (n = 15), pleomorphic T cell lymphoma (n = 10), and high-grade T cell lymphoma (n = 7). The cutaneous T cell lymphomas (CTCLs) investigated were categorized into cases with or without epidermotropism. Focal neoexpression of ICAM-1 on keratinocytes was restricted to epidermotropic lymphomas. Both LFA-1 and LFA-3 were expressed on infiltrating cells in all cases investigated. In contrast, beta 1-integrins showed differential expression, most prominent in the case of VLA-1 and VLA-6: These molecules were present on infiltrating cells in most cases with epidermotropic MF and absent in most other CTCLs. We conclude that the phenomenon of epidermotropism might involve different sets of adhesion molecules in different entities of CTCL, with VLA-1 being the most influential beta 1-integrin in the case of MF.