Trajectory and determinants of agreement between parental and physicians' reports of childhood atopic dermatitis.

BACKGROUND: Parent self-administered reports are commonly used in studies on childhood atopic dermatitis (AD) but data on its validity are sparse. We aimed to examine the agreement between parent- and physician-reported measures of childhood AD throughout early life and identify the determinants. METHODS: In this prospective cohort study, we used data of 449 infants and their mothers recruited in the Ulm SPATZ Health Study in Germany. Longitudinal data of parental and children's caring physicians' reports were used to assess the point and cumulative agreement of parent- and physician-reported AD diagnoses, AD onset age, and trend of agreement at child ages between 1 and 6 years overall and by child and parent demographics and health conditions. A Generalized Estimating Equation model was fitted to identify factors associated with the sensitivity of parent reports. RESULTS: The point agreement between parent- and physician-reported AD was substantial at the age of 1 (kappa = 0.63, 95% CI: 0.51-0.75) but declined with age and became fair after the age of 3 (kappa < 0.40). The cumulative agreement remained moderate at the age of 6 (kappa = 0.51, 95% CI: 0.43-0.60). Parents had a bias towards delayed reporting of the AD onset age. The AD severity was the only strong determinant for the agreement of AD diagnoses and largely explained the variance of the sensitivity of parent reports. CONCLUSION: The disagreement between parent- and physician-reported AD increases with child age, likely due to the change of AD severity. Using parent-reported data might miss a substantial portion of mild childhood AD cases.

Osteopontin attenuates aging-associated phenotypes of hematopoietic stem cells.

Upon aging, hematopoietic stem cells (HSCs) undergo changes in function and structure, including skewing to myeloid lineages, lower reconstitution potential and loss of protein polarity. While stem cell intrinsic mechanisms are known to contribute to HSC aging, little is known on whether age-related changes in the bone marrow niche regulate HSC aging. Upon aging, the expression of osteopontin (OPN) in the murine bone marrow stroma is reduced. Exposure of young HSCs to an OPN knockout niche results in a decrease in engraftment, an increase in long-term HSC frequency and loss of stem cell polarity. Exposure of aged HSCs to thrombin-cleaved OPN attenuates aging of old HSCs, resulting in increased engraftment, decreased HSC frequency, increased stem cell polarity and a restored balance of lymphoid and myeloid cells in peripheral blood. Thus, our data suggest a critical role for reduced stroma-derived OPN for HSC aging and identify thrombin-cleaved OPN as a novel niche informed therapeutic approach for ameliorating HSC phenotypes associated with aging.

Soluble CD14 concentration in human breast milk and its potential role in child atopic dermatitis: Results of the Ulm Birth Cohort Studies.

BACKGROUND: Soluble CD14 (sCD14) is one of many factors in human breast milk which may influence programming of the immune response in the breastfed child. Although previous studies have mostly found little association between sCD14 concentration in breast milk and atopic outcomes, recent evidence continues to support a role of sCD14 in immune-related disease. OBJECTIVE: We aimed to clarify whether an association exists between sCD14 concentration in human breast milk (m-sCD14) and child atopic dermatitis (AD) diagnosis by age 3 years within the context of two large birth cohorts. METHODS: Data were obtained from the Ulm Birth Cohort Study (UBCS) and the Ulm SPATZ Health Study, methodologically similar birth cohort studies, each consisting of approximately 1000 newborns and their mothers recruited from the general population shortly after delivery in Ulm, Southern Germany, respectively, from 11/2000 to 11/2001 and 04/2012 to 05/2013. sCD14 concentrations were measured by different ELISAs (UBCS: IBL, SPATZ: R&D) in breast milk samples collected at 6 weeks post-delivery in both studies and additionally at 6 months and 1 year in SPATZ. Children's AD diagnosis was assessed using parent and paediatrician reports at 1, 2 and 3 years of age. RESULTS: Complete exposure and outcome data were available for 659 UBCS and 489 SPATZ children. In both cohorts, sCD14 concentration was significantly associated with breastfeeding frequency (P < 0.01). We observed no association between m-sCD14 concentration and child AD diagnosis in either study. CONCLUSIONS: Our results do not support an association between sCD14 concentration in mature breast milk and AD among breastfed children.

9-cis-Retinoic acid induces a distinct regulatory dendritic cell phenotype that modulates murine delayed-type allergy.

BACKGROUND: Hand eczema, which is frequently caused by delayed-type allergy, is treated with 9-cis-retinoic acid (9cisRA). However, knowledge on how 9cisRA modulates skin immunity is sparse. OBJECTIVE: As dendritic cells (DCs) are central in the pathogenesis of contact allergy, we investigated 9cisRA modulation of DC function in murine contact hypersensitivity (CHS). METHODS: 9cisRA-differentiated DCs (9cisRA-DCs) were analysed for phenotype and function. In vivo 9cisRA-DCs were tested in the CHS model. RESULTS: 9cisRA induces the differentiation of a distinct CD103- CD207- regulatory DC phenotype. CD11c+ DCs differentiated with 9cisRA have lower expression of major histocompatibility complex-II and costimulatory molecules, but conversely have higher expression of the inhibitory coreceptor PD1-L. 9cisRA-DC culture does not induce the expression of proinflammatory cytokines, but strongly enhances osteopontin (OPN) secretion. 9cisRA-DCs are compromised in the induction of T cell proliferation in vitro, but efficiently convert naive T cells into regulatory T cells (Tregs). Notably, OPN-deficient 9cisRA-DCs show a loss of Treg-inducing function, which is re-established by substituting OPN. In vivo, in allergic mice, allergen-primed 9cisRA-DCs suppress allergic inflammation and induce Treg accumulation in skin draining lymph nodes. CONCLUSIONS: This study describes 9cisRA-mediated differentiation of a distinct DC phenotype that relies on OPN for Treg transformation and suppresses established CHS through Treg induction.

Maternal prenatal stress and child atopic dermatitis up to age 2 years: The Ulm SPATZ health study.

BACKGROUND: Evidence linking maternal psychosocial stress during pregnancy to subsequent child atopic dermatitis (AD) is growing, but the definition of AD is diverse and results are inconsistent. We aimed to analyze the relationship between stress and AD using alternative measurements of stress and AD. METHODS: In the Ulm SPATZ Health Study, chronic stress and symptoms of anxiety and depression were assessed by standardized self-reported questionnaires in 934 mothers of singletons following delivery in Ulm, Germany, from 04/2012-05/2013. Maternal hair cortisol concentrations (HCCs, n = 626) at childbirth and the cumulative incidences of parent-reported child AD symptoms, parent-, and pediatrician-reported AD diagnoses were assessed until age 2 years (n = 787). Overall, 205 dermatologic examinations were performed in 167 children showing AD symptoms. Crude and adjusted risk ratios (RR, aRR) with 95% confidence intervals were estimated. RESULTS: Maternal stress and anxiety were associated with child AD symptoms by trend (RR and aRR: 1.5 (1.0,2.3) for the highest vs. the lowest quarter of chronic stress; aRR: 1.4 (1.0,2.0) for possible anxiety symptoms vs. no symptoms). No relationship was found between stress or related constructs and AD diagnoses nor could we show consistent associations between maternal HCC and child AD. However, a higher RR of child AD was evident in families not yet affected by AD in siblings given maternal depressive symptoms, examined in the crude model. CONCLUSIONS: Stress measurements or related constructs are linked to AD symptoms, but association with AD diagnoses is limited. The reason for this divergence still needs further research.

Osteopontin deficiency affects imiquimod-induced psoriasis-like murine skin inflammation and lymphocyte distribution in skin, draining lymph nodes and spleen.

Osteopontin (OPN) that enhances autoimmunity is expressed in psoriasis lesions; however, its functions in psoriatic inflammation are unknown. We investigated the role of OPN in OPN deficient mice (OPN-/-) by inducing psoriasis-like inflammation through skin application of imiquimod (IMQ). OPN-/- mice treated with IMQ showed delayed onset ear swelling and attracted less inflammatory cells to the skin. IMQ-induced lymph node swelling was reduced in the absence of OPN, and IMQ-mediated expansion of B cells was inhibited. Further, reduction of CD4(+) T-cell numbers by IMQ in lymph nodes was suppressed in OPN-/- mice, with an increase in the CD4/CD8 ratio. A comparable pattern was found in spleen. Importantly, IMQ-induced IL-17 and IL-4 expression by CD4(+) lymph node T cells was reduced in OPN-/- mice. In conclusion, OPN may modulate psoriasis-like inflammation through altering lymphocyte distribution in skin and draining lymph nodes and by inducing IL-17 expression of inflammatory T cells.

Keratinocytes determine Th1 immunity during early experimental leishmaniasis.

Experimental leishmaniasis is an excellent model system for analyzing Th1/Th2 differentiation. Resistance to Leishmania (L.) major depends on the development of a L. major specific Th1 response, while Th2 differentiation results in susceptibility. There is growing evidence that the microenvironment of the early affected tissue delivers the initial triggers for Th-cell differentiation. To analyze this we studied differential gene expression in infected skin of resistant and susceptible mice 16h after parasite inoculation. Employing microarray technology, bioinformatics, laser-microdissection and in-situ-hybridization we found that the epidermis was the major source of immunomodulatory mediators. This epidermal gene induction was significantly stronger in resistant mice especially for several genes known to promote Th1 differentiation (IL-12, IL-1beta, osteopontin, IL-4) and for IL-6. Expression of these cytokines was temporally restricted to the crucial time of Th1/2 differentiation. Moreover, we revealed a stronger epidermal up-regulation of IL-6 in the epidermis of resistant mice. Accordingly, early local neutralization of IL-4 in resistant mice resulted in a Th2 switch and mice with a selective IL-6 deficiency in non-hematopoietic cells showed a Th2 switch and dramatic deterioration of disease. Thus, our data indicate for the first time that epidermal cytokine expression is a decisive factor in the generation of protective Th1 immunity and contributes to the outcome of infection with this important human pathogen.

TGF-beta-dependent suppressive function of Tregs requires wild-type levels of CD18 in a mouse model of psoriasis.

Dysfunctional Tregs have been identified in individuals with psoriasis. However, their role in the pathogenesis of the disease remains unclear. Here we explored the effect of diminished CD18 (beta2 integrin) expression on the function of CD4+CD25+CD127(-) Tregs using the Cd18 hypomorphic (Cd18hypo) PL/J mouse model of psoriasis that closely resembles the human disease. We found that reduced CD18 expression impaired cell-cell contact between Tregs and DCs. This led to dysfunctional Tregs, which both failed to suppress the pathogenic T cells and promoted the onset and severity of the disease. This failure was TGF-beta-dependent, as Tregs derived from Cd18hypo PL/J mice had diminished TGF-beta1 expression. Adoptive transfer of Tregs expressing wild-type levels of CD18 into affected Cd18hypo PL/J mice resulted in a substantial improvement of the psoriasiform skin disease, which did not occur upon coinjection of the cells with TGF-beta-specific neutralizing antibody. Our data indicate a primary dysfunction of Cd18hypo Tregs, allowing subsequent hyperproliferation of pathogenic T cells in the Cd18hypo PL/J mouse model of psoriasis. This study may provide a step forward in our understanding of the unique role of CD18 expression levels in avoiding autoimmunity.

Antigen-specific induction of osteopontin contributes to the chronification of allergic contact dermatitis.

Allergic contact dermatitis is a T cell-mediated immune response, which in its relapsing chronic form is of high socioeconomic impact. The phosphoglycoprotein osteopontin (OPN) has chemotactic and Th1 cytokine functions and in various models is essential for robust T cell-mediated immunity. Here we demonstrate that OPN is abundantly expressed by both effector T cells and keratinocytes in allergic contact dermatitis lesions. T cells from nickel-allergic donors secrete high levels of OPN following antigen-specific stimulation. OPN may substitute for missing IFN-gamma secretion in T effector cells because low IFN-gamma-producing T cell clones secrete high levels of OPN, and OPN down-modulates their interleukin-4 expression. Furthermore, interferon-gamma from T effector cells augments OPN in allergic contact dermatitis by inducing OPN in keratinocytes, which in turn polarizes dendritic cells and attracts inflammatory cells. In the murine contact hypersensitivity (CHS) model for allergic contact dermatitis, OPN is strongly induced in antigen-specific proliferating T cells, and OPN null mice display a reduced chronic CHS inflammatory response due to a decreased influx of effector T cells. Importantly, because of its function for chronic allergic contact dermatitis, OPN may well be a therapeutic target, because anti-OPN antibody treatment in part suppresses established chronic CHS.

Targeting NF-kappa B with a natural triterpenoid alleviates skin inflammation in a mouse model of psoriasis.

Psoriasis vulgaris is a common chronic inflammatory skin disease involving cytokines and an activated cellular immune system. At variance to skin from patients with atopic dermatitis or from healthy subjects, human psoriatic skin lesions exhibit strong activation of transcription factor NF-kappaB that is mainly confined to dermal macrophages, whereas only a few dendritic cells but no CD3+ lymphocytes show activated NF-kappaB. Since NF-kappaB signaling is required for the induction and/or function of many cytokines and aberrant cytokine expression has been proposed as an underlying cause of psoriasis, we investigated whether NF-kappaB targeting would affect the course of the disease in the CD18 hypomorphic (CD18(hypo)) mouse model of psoriasis. When mice with severe psoriasiform lesions were treated systemically or locally with the IkappaB kinase inhibitor acetyl-11-keto-beta-boswellic acid (AKbetaBA), NF-kappaB signaling and the subsequent NF-kappaB-dependent cytokine production as shown by the TNF-alpha production of macrophages were profoundly suppressed. Additionally, application of the compound counteracted the intradermal MCP-1, IL-12, and IL-23 expression in previously lesional skin areas, led to resolution of the abundant immune cell infiltrates, and significantly reduced the increased proliferation of the keratinocytes. Overall, the AKbetaBA treatment was accompanied by a profound improvement of the psoriasis disease activity score in the CD18(hypo) mice with reconstitution of a nearly normal phenotype within the chosen observation period. Our data demonstrate that NF-kappaB signaling is pivotal for the pathogenesis in the CD18(hypo) mouse model of psoriasis. Therefore, targeting NF-kappaB might provide an effective strategy for the treatment of psoriasis.

Essential role of osteopontin in smoking-related interstitial lung diseases.

Smoking-related interstitial lung diseases are characterized by the accumulation of macrophages and Langerhans cells, and fibrotic remodeling, which are linked to osteopontin (OPN) expression. Therefore, OPN levels were investigated in bronchoalveolar lavage (BAL) cells in 11 patients with pulmonary Langerhans cell histiocytosis (PLCH), 15 patients with desquamative interstitial pneumonitis (DIP), 10 patients with idiopathic pulmonary fibrosis, 5 patients with sarcoidosis, 13 otherwise healthy smokers, and 19 non-smoking controls. Furthermore, OPN overexpression was examined in rat lungs using adenoviral gene transfer. We found that BAL cells from patients with either PLCH or DIP spontaneously produced abundant amounts of OPN. BAL cells from healthy smokers produced 15-fold less OPN, and those cells from non-smoking healthy volunteers produced no OPN. BAL cells from patients with either idiopathic pulmonary fibrosis or sarcoidosis produced significantly less OPN, as compared with patients with PLCH. These data were confirmed by immunochemistry. Nicotine stimulation increased production of both OPN and granulocyte-macrophage colony stimulating factor by alveolar macrophages from smokers. Nicotinic acetylcholine receptor expression resembled the pattern of spontaneous OPN production and was dramatically increased in both PLCH and DIP. OPN overexpression in rat lungs induced lesions similar to PLCH with marked alveolar and interstitial accumulation of Langerhans cells. Our findings suggest a pathogenetic role of increased OPN production in both PLCH and DIP by promoting the accumulation of macrophages and Langerhans cells.

Myiasis after study trip to French Guiana.

Cutaneous myiasis is usually a harmless tropical disease caused by infestation with larvae from a variety of flies. Because of its rare occurrence in Europe, it is often misdiagnosed. Increased travel to tropical regions has correspondingly increased the number of cases observed in Europe. The furuncular type of cutaneous myiasis in a 31-year-old biology student was diagnosed upon his return from French Guiana. The student cultured one of the larvae to obtain a botfly. This case is discussed in the light of the current literature on pathogenesis, incidence and therapy of cutaneous myiasis.

Osteopontin and the skin: multiple emerging roles in cutaneous biology and pathology.

Osteopontin (OPN) is a glycoprotein expressed by various tissues and cells. The existence of variant forms of OPN as a secreted (sOPN) and intracellular (iOPN) protein and its modification through post-translational modification and proteolytic cleavage explain its broad range of functions. There is increasing knowledge which receptors OPN isoforms can bind to and which signaling pathways are activated to mediate different OPN functions. sOPN interacts with integrins and CD44, mediates cell adhesion, migration and tumor invasion, and has T helper 1 (Th1) cytokine functions and anti-apoptotic effects. iOPN has been described to regulate macrophage migration and interferon-alpha secretion in plasmacytoid dendritic cells. Both sOPN and iOPN, through complex functions for different dendritic cell subsets, participate in the regulation of Th cell lineages, among them Th17 cells. For skin disease, OPN from immune cells and tumor cells is of pathophysiological relevance. OPN is secreted in autoimmune diseases such as lupus erythematosus, and influences inflammation of immediate and delayed type allergies and granuloma formation. We describe that OPN is overexpressed in psoriasis and propose a model to study OPN function in psoriatic inflammation. Through cytokine functions, OPN supports immune responses against Mycobacteria and viruses such as herpes simplex virus. OPN is also implicated in skin tumor progression. Overexpression of OPN influences invasion and metastasis of melanoma and squamous cell carcinoma cells, and OPN expression in melanoma is a possible prognostic marker. As OPN protein preparations and anti-OPN antibodies may be available in the near future, in-depth knowledge of OPN functions may open new therapeutic approaches for skin diseases.

Fetal growth and incidence of atopic dermatitis in early childhood: Results of the Ulm SPATZ Health Study.

Fetal growth may be a precursory factor in observed association between birthweight and atopic dermatitis (AD), however, recent studies utilizing fetal ultrasound-based data have reported contradictory results. This study aims to clarify previous findings through comprehensive investigation of association between several trimester-specific ultrasound-based anthropometric measures with AD diagnosis by age 3 years. Measurements of 386 newborns in the Ulm SPATZ Health Study were converted into adjusted z-scores categorized as "low" (≤1 SD below mean), "normal," or "high" (≥1 SD above mean). AD cases were defined using parent- or pediatrician-report of physician-diagnosis or clinical diagnosis. Adjusted risk ratios (RR) with 95% confidence intervals (95% CI) were calculated using modified Poisson regression. Compared to normal, both low and high 2nd trimester abdominal circumference [RR 1.51, (95% CI 1.01; 2.24) and 1.83 (1.21; 2.76)], high 2nd trimester head- abdominal circumference ratio [1.69 (1.16; 2.48)], and faltering 2nd to 3rd trimester [1.59 (1.04; 2.43)] head circumference were associated with greater AD risk. High 3rd trimester femur length [0.54 (0.31; 0.94)] was associated with lower risk. Using more inclusive exposure cut-points (0.8 SD), lower 1st trimester crown-rump length was also associated with greater AD risk. Our data suggest several different patterns of fetal growth may be differentially associated with AD.

Solitary cutaneous dendritic cell tumor in a child: role of dendritic cell markers for the diagnosis of skin Langerhans cell histiocytosis.

We describe a child with a solitary dendritic cell (DC) tumor positive for S-100 protein, CD1a, and HLA-DR with the clinical and histopathologic features of a so-called solitary variant of congenital self-healing Hashimoto-Pritzker reticulohistiocytosis (CSHRH). CSHRH is a spontaneously regressing, benign form of Langerhans cell histiocytosis (LCH) and was thought to be a histiocytosis consisting of precursor Langerhans cells. In our study the tumor cells did not express CD68, indicating that they represent mature DCs. Because of the negative finding for Langerin, it cannot be assessed whether the tumor consists of terminally mature Langerhans cells that have lost Langerin expression upon maturation or of mature dermal DCs. This case demonstrates that the progress in DC biology necessitates reevaluation of our knowledge of LCH to better understand the different variants of the disease. Therefore the literature on CSHRH is reviewed in light of present knowledge on cutaneous DC immunology.