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Biomedical subjects

K Rappersberger

Publications and source records attributed to K Rappersberger.

At least 19 recordsLinked to original sources
PubMed2006

[Infections with herpes simplex and varicella-zoster viruses during pregnancy].

Primary infections with herpes simplex virus (HSV) and varicella-zoster virus (VZV) may lead to severe illness in pregnancy. Both diseases may be associated with transplacental virus transmission and fetal infection. Such infections can lead to intrauterine death, severe malformations and premature birth; the fetal/congenital varicella syndrome is well-defined. Herpes genitalis and varicella at the time of labor may lead to life threatening neonatal-herpes or varicella of the newborn. Currently neither active immunization nor neutralizing immunoglobulin is available for HSV infections. VZV-seronegative women in child-bearing age can be vaccinated and pregnant women exposed to VZV can be given specific immunoglobulins. While an infection is rarely blocked, the severity is generally reduced. For severe disease antiviral treatment is necessary, with valacyclovir and acyclovir represents the drugs of choice. Primary or recurrent overt disease of the genital tract at the time of delivery an indication for caesarean section. Suppression of recurrent genital herpes during the last weeks of pregnancy with valacyclovir and acyclovir reduces the need for surgical intervention. Neonates exposed to VZV should receive specific immunoglobulin. If neonates show signs of either infection, immediate treatment with acyclovir must be initiated.

Cesarean Section↗
PubMed2005

Enzyme-linked immunosorbent assay for detection of peptide-specific human antidesmoplakin autoantibodies.

BACKGROUND: Autoantibodies directed against desmoplakin (Dp) I and II have recently been characterized in a subset of patients with severe erythema multiforme (EM), a recurrent inflammatory skin disease with a broad spectrum of clinical manifestations. These autoantibodies recognize a peptide epitope localized within the extreme end of the carboxy terminal domain of Dp responsible for the assembly of keratin filaments to the desmosomal plaque. Using dot blot analysis with overlapping synthetic peptides, the binding epitope YSYSYS has been identified. OBJECTIVES: To establish an enzyme-linked immunosorbent assay (ELISA) for detection of peptide-specific anti-Dp autoantibodies in sera of patients with EM. METHODS: A synthetic peptide containing the respective amino acid sequence was used as matrix for ELISA plates. Serum samples from patients with known EM and peptide-specific anti-Dp autoantibodies verified by immunoblotting, immunoprecipitation and epitope mapping were used. RESULTS: Establishing an index value of 42.0, 25 of 25 serum samples from five patients with peptide-specific anti-Dp autoantibodies were positive in the ELISA. From control sera, none of 31 bullous disease sera and only one (1.2%) of 83 normal human sera were positive. CONCLUSIONS: These data show that the ELISA presented in this study represents a sensitive and highly specific tool for the detection of peptide-specific anti-Dp autoantibodies in patients with EM.

Autoantibodies↗
PubMed2003

[New immunosuppressive agents for treating psoriasis].

Accumulative evidence suggests that psoriasis may be a genetically determined immunologenic inflammatory disorder based on an ongoing autoreactive Th-1 response. Various cytokines (e.g. IL-2, interferon-gamma etc.) are released and exert proliferative signals on to keratinocytes, which start proliferation that finally results in an incomplete differentiation. During this pathobiological process keratinocytes themselves express receptors that make them sensitive for growth inducing stimulation and also start the production of a set of cytokines that contribute to and maintain inflammation. Immunosuppressive agents, mostly by affecting T-cells may interfere with or even disrupt by rather unspecific mechanisms, this complex process of mutual stimulation of leucocytes and keratinocytes. In this manuscript we show mode of action, efficacy and side effects of Methotrexate, Ciclosporin A, Tacrolimus and Pimecrolimus, and discuss therapeutic options with mycophenolate mofetil and fumaric acid esters.

Autoantibodies↗
PubMed2003

Evidence for altered mast cell proliferation and apoptosis in cutaneous mastocytosis.

BACKGROUND: Mastocytosis presents as a focal or generalized increase of mast cells, particularly in the skin, but also in other organs. Activating mutations of KIT (formerly c-kit), the receptor of the mast cell growth factor stem cell factor (SCF), appear to play a key role in the pathogenesis of sporadic adult onset mastocytosis. However, these mutations are not present in childhood-onset and familial mastocytosis and also fail to explain the heterogeneity of adult-onset disease. Other factors such as prolonged survival of mast cells may therefore participate in causing and modulating the pathological increase of mast cells in mastocytosis. OBJECTIVES: To examine the expression of proliferation and apoptosis markers in the mast cells of cutaneous mastocytosis lesions in order to gain further insight into the pathogenesis of mastocytosis. METHODS: Lesional cutaneous biopsies from eight infants with solitary mastocytomas, five children with multiple mastocytomas, 11 children with generalized urticaria pigmentosa, 12 adults with urticaria pigmentosa, and skin from seven normal controls were used in this study. Serial sections were stained with toluidine blue to quantify mast cell numbers and with antibodies against the proliferation marker Ki67 protein, the tumour suppressor protein p53, and the inhibitor of cyclins and cyclin-dependent kinases p21WAF1/CIP1, using the alkaline phosphatase antialkaline phosphatase technique. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) method was used to assess apoptosis. RESULTS: Cutaneous mast cell counts were significantly increased in all patient sections, particularly in childhood lesions, and similarly, a small but significant increase of proliferation was found in the lesional mast cells of all patients. Enhanced mast cell numbers and proliferation was associated with a significant decrease of TUNEL staining, particularly in mastocytomas. p53 expression was highly variable, with an overall significant increase in all patient skin mast cells, whereas p21 expression was barely observed at all. CONCLUSIONS: These findings further support the concept that an imbalance of mast cell proliferation and apoptosis is prevalent in mastocytosis lesions that may account in part for the increased focal mast cell accumulation in this condition.

Adolescent↗
PubMed2002

Hereditary, focal, transgressive palmoplantar keratoderma with associated clinical findings: a new entity?

We report on a 24-year-old male originating from Yugoslavia with a focal, transgressive palmoplantar keratoderma presumably inherited as an autosomal recessive trait. Associated clinical findings were hyperkeratotic lichenoid papules on the knees and elbows, psoriasis-like lesions in the groins and on the scalp, a spotty or reticulate hyperpigmentation of the face, trunk and extremities and a partial alopecia of the left eyebrow and eyelashes. The patient's sister was affected by similar but less pronounced cutaneous changes. Although our case shares some similarities with other hereditary palmoplantar keratodermas there remain substantial differences. We therefore believe this case to represent a new entity.

Adult↗
PubMed2001

Pathogenesis of the permeability barrier abnormality in epidermolytic hyperkeratosis.

Epidermolytic hyperkeratosis is a dominantly inherited ichthyosis, frequently associated with mutations in keratin 1 or 10 that result in disruption of the keratin filament cytoskeleton leading to keratinocyte fragility. In addition to blistering and a severe disorder of cornification, patients typically display an abnormality in permeability barrier function. The nature and pathogenesis of the barrier abnormality in epidermolytic hyperkeratosis are unknown, however. We assessed here, first, baseline transepidermal water loss and barrier recovery kinetics in patients with epidermolytic hyperkeratosis. Whereas baseline transepidermal water loss rates were elevated by approximately 3-fold, recovery rates were faster in epidermolytic hyperkeratosis than in age-matched controls. Electron microscopy showed no defect in either the cornified envelope or the adjacent cornified-bound lipid envelope, i.e., a corneocyte scaffold abnormality does not explain the barrier abnormality. Using the water-soluble tracer, colloidal lanthanum, there was no evidence of tracer accumulation in corneocytes, despite the fragility of nucleated keratinocytes. Instead, tracer, which was excluded in normal skin, moved through the extracellular stratum corneum domains. Increasing intercellular permeability correlated with decreased quantities and defective organization of extracellular lamellar bilayers. The decreased lamellar material, in turn, could be attributed to incompletely secreted lamellar bodies within granular cells, demonstrable not only by several morphologic findings, but also by decreased delivery of a lamellar body content marker, acid lipase, to the stratum corneum interstices. Yet, after acute barrier disruption a rapid release of preformed lamellar body contents was observed together with increased organelle contents in the extracellular spaces, accounting for the accelerated recovery kinetics in epidermolytic hyperkeratosis. Accelerated recovery, in turn, correlated with a restoration in calcium in outer stratum granulosum cells in epidermolytic hyperkeratosis after barrier disruption. Thus, the baseline permeability barrier abnormality in epidermolytic hyperkeratosis can be attributed to abnormal lamellar body secretion, rather than to corneocyte fragility or an abnormal cornified envelope/cornified-bound lipid envelope scaffold, a defect that can be overcome by external applications of stimuli for barrier repair.

Adolescent↗
PubMed2001

A localized variant of paraneoplastic pemphigus: acantholysis associated with malignant melanoma.

We report a 72-year-old male patient with a nodular malignant melanoma that was associated with focal suprabasal acantholysis (FSA). This phenomenon, which is regarded as an incidental finding by dermatopathologists, may be associated with inflammatory and also neoplastic skin diseases. Haematoxylin and eosin stained sections from an erythematous plaque surrounding the patient's tumour showed FSA, direct immunofluorescence (DIF) and indirect immunofluorescence (IIF) on normal human skin, monkey oesophagus and rat urinary bladder were negative. On electron microscopy few desmosomes could be detected in the basal cell layer of the acantholytic areas and there was a nearly complete loss of these structures in the spinous cell layer. Only remnants of cytoplasmic plaques and keratin filaments could be observed in those areas. In contrast, adherens junctions appeared to be well preserved. An enzyme-linked immunosorbent assay (ELISA) using recombinant fusion proteins as antigens did not show circulating autoantibodies against desmoglein 1 (Dsg1) or desmoglein 3 (Dsg3). In contrast, immunoblotting revealed autoantibodies directed against keratinocyte antigens with a molecular weight of 85 kDa and 250 kDa, the first band corresponding to the molecular weight of comigrating plakoglobin. Immunoprecipitation with patient serum also revealed a 85-kDa band. We conclude that these autoantibodies, probably in conjunction with cofactors produced by the tumour, could play a part in the pathogenesis of this variant of FSA, for which we propose the term 'localized paraneoplastic pemphigus.'

Acantholysis↗
PubMed2000

Functional involvement of E-cadherin in TGF-beta 1-induced cell cluster formation of in vitro developing human Langerhans-type dendritic cells.

Epithelial Langerhans cells (LC) represent immature dendritic cells that require TGF-beta 1 stimulation for their development. Little is known about the mechanisms regulating LC generation from their precursor cells. We demonstrate here that LC development from human CD34+ hemopoietic progenitor cells in response to TGF-beta 1 costimulation (basic cytokine combination GM-CSF plus TNF-alpha, stem cell factor, and Flt3 ligand) is associated with pronounced cell cluster formation of developing LC precursor cells. This cell-clustering phenomenon requires hemopoietic progenitor cell differentiation, since it is first seen on day 4 after culture initiation of CD34+ cells. Cell cluster formation morphologically indicates progenitor cell development along the LC pathway, because parallel cultures set up in the absence of exogenous TGF-beta 1 fail to form cell clusters and predominantly give rise to monocyte, but not LC, development (CD1a-, lysozyme+, CD14+). TGF-beta 1 costimulation of CD34+ cells induces neoexpression of the homophilic adhesion molecule E-cadherin in the absence of the E-cadherin heteroligand CD103. Addition of anti-E-cadherin mAb or mAbs to any of the constitutively expressed adhesion molecule (CD99, CD31, LFA-1, or CD18) to TGF-beta 1-supplemented progenitor cell cultures inhibits LC precursor cell cluster formation, and this effect is, with the exception of anti-E-cadherin mAb, associated with inhibition of LC generation. Addition of anti-E-cadherin mAb to the culture allows cell cluster-independent generation of LC from CD34+ cells. Thus, functional E-cadherin expression and homotypic cell cluster formation represent a regular response of LC precursor cells to TGF-beta 1 stimulation, and cytoadhesive interactions may modulate LC differentiation from hemopoietic progenitor cells.

12E7 Antigen↗
PubMed1999

CD34+ cell-derived CD14+ precursor cells develop into Langerhans cells in a TGF-beta 1-dependent manner.

Langerhans cells (LC) are CD1a+E-cadherin (E-cad)+Birbeck granule+ but CD11b-CD36-factor XIIIa (FXIIIa)- members of the dendritic cell (DC) family. Evidence holds that LC originate from CD1a+CD14- rather than CD14+CD1a- progenitors, both of which arise from GM-CSF/TNF-alpha-stimulated CD34+ stem cells. The CD14+CD1a- progenitors, on the other hand, can give rise to a separate DC type characterized by its CD1a+CD11b+CD36+FXIIIa+E-cad-BG- phenotype (non-LC DC). Although GM-CSF/TNF-alpha are important for both LC and non-LC DC differentiation, TGF-beta 1 is thought to preferentially promote LC development in vitro and in vivo. However, the hemopoietic biology of this process and the nature of TGF-beta 1-responsive LC precursors (LCp) are not well understood. Here we show that CD14+ precursors in the presence, but not in the absence, of TGF-beta 1 give rise to a progeny that fulfills all major criteria of LC. In contrast, LC development from CD1a+ progenitors was TGF-beta 1 independent. Further studies revealed that CD14+ precursors contain a CD11b+ and a CD11b- subpopulation. When either subset was stimulated with GM-CSF/TNF-alpha and TGF-beta 1, only CD14+CD11b- cells differentiated into LC. The CD11b+ cells, on the other hand, acquired non-LC DC features only. The higher doubling rates of cells entering the CD14+ LCp rather than the CD1a+ LCp pathway add to the importance of TGF-beta 1 for LC development. Because CD14+CD11b- precursors are multipotent cells that can enter LC or macrophage differentiation, it is suggested that these cells, if present at the tissue level, endow a given organ with the property to generate diverse cell types in response to the local cytokine milieu.

Adult↗
PubMed1999

Survival, maturation, and function of CD11c- and CD11c+ peripheral blood dendritic cells are differentially regulated by cytokines.

Two types of dendritic cells (DC) are circulating in human blood and can be identified by their differential expression of the myeloid Ag CD11c. In this study, we show that CD11c- peripheral blood (PB)-DC correspond to plasmacytoid DC of lymphoid tissue not only by their surface Ag expression profile but, more impressively, by their peculiar ultramorphology. We also demonstrate that CD11c- and CD11c+ DC differ in the quality of their response to and in their requirement for certain cytokines. Freshly isolated CD11c- cells depend on IL-3 for survival and use autocrine or exogenous TNF-alpha as maturation signal, leading to the appearance of a highly dendritic phenotype, the up-regulation and redistribution of MHC class II from lysosomal compartments to the plasma membrane, the increased expression of costimulatory molecules, and the switch from a high Ag-processing to a low Ag-processing/potent accessory cell mode. Surprisingly, IL-4 efficiently killed freshly isolated CD11c- PB-DC, but did not impair the viability of CD11c+ PB-DC and, together with GM-CSF, induced maturation of these cells. A direct functional comparison revealed that neo-Ag-modified and subsequently matured CD11c- but to a lesser extent CD11c+ DC were able to prime naive Ag-specific CD4+ T cells. Our findings show that two diverse DC types respond to certain T cell-derived cytokines in a differential manner and, thus, suggest that suppression or activation of functionally diverse DC types may be a novel mechanism for the regulation of the quantity and quality of immune responses.

Animals↗
PubMed1999

[Prenatal diagnosis of recessive hereditary dystrophic epidermolysis bullosa with haplotype analysis of the type VII collagen gene].

DNA-based prenatal testing of the fetal genotype was performed in a family at risk for recurrence of recessive dystrophic epidermolysis bullosa (RDEB). DNA from cultured fibroblasts and leukocytes from the peripheral blood of the previously affected offspring, DNA from parental leukocytes and DNA from fetal tissue obtained by chorionic villus biopsy was analysed by direct PCR amplification of known polymorphic regions within or flanking the type VII collagen gene, the candidate gene in RDEB. One flanking marker (D3S2/Mspl) as well as two intragenic polymorphisms (C7/Mspl, C7/Eco01091) in exons 30 and 84 were informative in this family. Thus, based on the haplotype analysis and the lack of evidence for locus heterogeneity in RDEB, a phenotypically healthy child was predicted. This prediction was confirmed by the birth of a healthy female infant. The study reports successful determination of the fetal genotype by PCR-based prenatal diagnosis in a family at risk for recurrence of severe RDEB.

Adult↗
PubMed1999

[Infections with herpes simplex and varicella zoster virus in pregnancy: clinical manifestations in mother, fetus and newborn--therapeutic options].

Infections with herpes simplex virus (HSV) type I and type II and varicella/zoster-virus (VZV) are lifelong. The life cycle of the virus - primary infection-latency-endogenous reactivation - determines the clinical features of the diseases, i. e. primary infection and recurrences. During pregnancy, infections with HSV and VZV may induce severe maternal illness that occasionally runs a lethal course. With viremia placental transmission of the virus may occur infecting the fetus and possibly causing spontaneous abortion, stillbirth and congenital malformations. The occurrence of such malformations is best documented for the "fetal varicella syndrome". Maternal varicella and genital herpes simplex within the perinatal period represent a tremendous risk for the newborn to be infected during delivery; such infection may cause life threatening diseases that have a lethal outcome in more than 50% of affected children. We describe the life cycle of HSV/VZV in infected individuals and the peculiar clinical features of maternal infections during pregnancy. The epidemiological and clinical characteristics of the infected fetus and newborn are highlighted and prophylactic and therapeutic possibilities are discussed.

Animals↗
PubMed1999

Paraneoplastic pemphigus with fatal pulmonary involvement in a woman with a mesenteric Castleman tumour.

A 42-year-old woman presented with oral and labial erosions, conjunctivitis, facial rash and lichenoid erythematous papules on the trunk. Paraneoplastic pemphigus (PNP) was suspected, and a search for a neoplasm revealed an intra-abdominal Castleman tumour sized 7 x 5 x 6 cm. After removal of the Castleman tumour, the skin and mucosal inflammation gradually subsided over the next 12 months. However, due to irreversible pulmonary involvement the patient died of intractable respiratory distress 2 years after the onset of the disease. Systemic corticosteroids, azathioprine, cyclophosphamide, high-dose intravenous immunoglobulins and thalidomide were ineffective. The diagnosis of PNP was confirmed by keratinocyte antigen immunoprecipitation with the patient's serum.

Adult↗
PubMed1999

Ultrastructural changes in PAM cells after photodynamic treatment with delta-aminolevulinic acid-induced porphyrins or photosan.

Photodynamic therapy (PDT) is the combination of a photosensitizing drug (Ps) with light in the presence of oxygen leading to the generation of reactive molecular species and destruction of cancer cells. In this study we compared PDT with two Ps, the hematoporphyrin derivative Photosan (Ph) and delta-aminolevulinic acid (ALA)-induced endogenous protoporphyrin IX, with respect to mitochondrial function and ultrastructural alterations. The effects of PDT were investigated in PAM 212 cells after different Ps incubation times, light doses, and post-treatment periods. Both Ps induced a light dose-dependent impairment of the mitochondrial function with the dose-response curve being steep for ALA and flat for Ph. The prolongation of the incubation time from 4 to 20 h resulted in an increased reduction of mitochondrial activity after ALA PDT but not after Ph PDT. Treatment with an irradiation dose that decreased mitochondrial activity by 50% (IC50) led to early and profound changes of mitochondrial morphology in ALA photosensitized cells, whereas photosensitization with Ph resulted in more pronounced alterations of lysosomes. We conclude that at bioequivalent sublethal PDT exposures of PAM 212 cells, ALA-induced damage is primarily restricted to mitochondria, whereas Ph-induced cytotoxicity is mediated by damage of the lysosomal system.

Aminolevulinic Acid↗
PubMed1998

Neutrophil granulocyte-committed cells can be driven to acquire dendritic cell characteristics.

Polymorphonuclear granulocytes (PMNs) are thought to fulfill their role in host defense primarily via phagocytosis and release of cytotoxic compounds and to be inefficient in antigen presentation and stimulation of specific T cells. Dendritic cells (DCs), in contrast, are potent antigen-presenting cells with the unique capacity to initiate primary immune responses. We demonstrate here that highly purified lactoferrin-positive immediate precursors of end-stage neutrophilic PMN (PMNp) can be reverted in their functional maturation program and driven to acquire characteristic DC features. Upon culture with the cytokine combination granulocyte/macrophage colony-stimulating factor plus interleukin 4 plus tumor necrosis factor alpha, they develop DC morphology and acquire molecular features characteristic for DCs. These molecular changes include neo-expression of the DC-associated surface molecules cluster of differentiation (CD)1a, CD1b, CD1c, human leukocyte antigen (HLA)-DR, HLA-DQ, CD80, CD86, CD40, CD54, and CD5, and downregulation of CD15 and CD65s. Additional stimulation with CD40 ligand induces also expression of CD83 and upregulates CD80, CD86, and HLA-DR. The neutrophil-derived DCs are potent T cell stimulators in allogeneic, as well as autologous, mixed lymphocyte reactions (MLRs), whereas freshly isolated neutrophils are completely unable to do so. In addition, neutrophil-derived DCs are at least 10,000 times more efficient in presenting soluble antigen to autologous T cells when compared to freshly isolated monocytes. Also, in functional terms, these neutrophil-derived DCs thus closely resemble "classical" DC populations.

Antigen Presentation↗
PubMed1998

Immunoapheresis in paraneoplastic pemphigus.

BACKGROUND: Paraneoplastic pemphigus was first described in 1990 in 5 patients with extensive mucocutaneous erosions, a distinct set of autoantibodies, and underlying neoplasia. Since then, patients described have been middle-aged, have suffered from prognostically unfavorable malignant neoplasms, and have responded poorly to immunosuppressive agents. OBSERVATION: A 16-year-old boy was examined with extensive oral erosions, halitosis that interfered with his quality of life, and rapid weight loss. The suspected clinical diagnosis of paraneoplastic pemphigus was confirmed by histopathological, immunofluorescence, and biochemical (eg, immunoblotting and immunoprecipitation) findings as well as by the demonstration of an inflammatory myofibroblastic tumor of the left retroclavicular region. Despite administration of corticosteroids, followed by excision of the neoplasm, clinical symptoms improved only slightly, and autoantibody titers decreased only marginally. We therefore initiated an immunoapheresis regimen with the use of sheep anti-human-IgG bead-formed agarose gel (Sepharose; Pharmacia Biotech Comp, Vienna, Austria), which led to the disappearance of circulating autoantibodies and the patient's recovery. CONCLUSION: Immunoapheresis may represent a novel therapeutic option for patients with paraneoplastic pemphigus who show little improvement after curative treatment of their neoplasms.

Adolescent↗
PubMed1998

Erythema multiforme associated human autoantibodies against desmoplakin I and II: biochemical characterization and passive transfer studies into newborn mice.

The demonstration of circulating autoantibodies directed against the constitutive desmosomal plaque proteins desmoplakin (dp) I and II in mucocutaneous lesions in a subset of patients with erythema multiforme major, suggests that humoral immune mechanisms may play a role in the pathogenesis of this severe skin disease. In this study we identified a specific peptide sequence--YSYSYS--representing an antigenic binding site for the human autoantibodies. This epitope is localized at the extreme carboxy terminal domain of dp thought to be responsible for the assembly of keratin filaments with desmosomes. To test the possibility whether these antibodies may exert any pathologic effects in vivo, human autoantibodies were affinity purified on a corresponding synthetic peptide matrix and peptide-specific antibodies were raised in rabbits. After repeated subcutaneous injections into newborn mice, affinity-purified human autoantibodies and anti-peptide rabbit IgG were detected on desmosomal plaques of keratinocytes overlying the injection site. Histologic and electron microscopic examinations showed hydropic degeneration of basal and suprabasal keratinocytes, dyskeratosis, signs of suprabasal acantholysis, and keratin filaments detached from the desmosomal plaques clumping around the nucleus. We demonstrate that autoantibodies are directed to an epitope within a dp domain crucial for the interaction of keratin filaments with desmosomes, and, when injected subcutaneously into newborn mice, produce pathologic changes. These findings imply that autoantibodies to dp could impair the function of desmosome-keratin filament complexes suggesting a pathogenic role in vivo.

Animals↗