Distinct Expression and Function of FcεRII in Human B Cells and Monocytes.

FcεRII is a multifunctional low-affinity IgER that is involved in the pathogenesis of allergic, inflammatory, and neoplastic diseases. Although discrepancies in FcεRII-mediated functions are being increasingly recognized, the consequences of FcεRII activation are not completely understood. In this study, we evaluated the expression of FcεRII on human blood cells and found that it was primarily expressed on monocytes and B cells. Although IL-4 promoted expression of the FcεRIIb isoform on B cells and monocytes, the expression of the FcεRIIa isoform was not dependent on IL-4. Furthermore, FcεRII predominantly bound allergen-IgE complexes on B cells but not on monocytes. FcεRII-mediated allergen-IgE complex uptake by B cells directed Ags to MHC class II-rich compartments. FcεRII-bearing monocytes and B cells expressed high levels of the FcεRII sheddase a disintegrin and metalloproteinase 10, which implies that they are important sources of soluble FcεRII. Moreover, we identified that IgE immune complex stimulation of FcεRII activated intracellular tyrosine phosphorylation via Syk in B cells but not in monocytes. Importantly, FcεRII-mediated signaling by allergen-IgE immune complexes increased IFN-γ production in B cells of allergic patients during the build-up phase of allergen-specific immunotherapy. Together, our results demonstrate that FcεRII mediates cell type-dependent function in allergic reactions. In addition, the results identify a novel allergen-IgE complex/FcεRII/Syk/IFN-γ pathway in allergic responses and suggest that FcεRII may play a role in regulating allergic reactions via modulating IFN-γ production in B cells.

Pathophysiology of atopic dermatitis.

Only few diseases have been studied as extensively and on as many different levels in recent years as atopic dermatitis (AD). One of the reasons why AD is the focus of interest is that it is one of the most common chronic inflammatory skin diseases, affecting up to 30 % of children and 1-10 % of adults. Numerous complex alterations both on the genetic level as well as on the level of innate and adaptive immunity have been identified and form the basis for the characterization of different patient groups and the development of novel diagnostic and therapeutic approaches. Despite the complex pathophysiological and immunological differences, which are closely related to disease stage and severity, as well as the heterogeneity of individual trigger factors, treatment of AD - in particular that of moderate-to-severe AD - was long limited to merely symptomatic and relatively nonspecific immunosuppressive approaches. Since the approval of the first biologic for the treatment of moderate-to-severe adult AD (commercially available in Germany since late 2017), there has been some movement in the field of AD management. The present review highlights recent pathophysiologic insights. Advances in research allow for better characterization of certain patient subgroups and different disease manifestations. In addition, they form the basis of current and future developments in the field of precision medicine in AD.

[Skin diseases and fertility/hormone disorders]. / Hauterkrankungen und Fertilitäts­/Hormonstörungen.

Male fertility can be impaired by a multitude of factors. In addition to environmental and life style factors, such as stress, noise, smoking and overweight, diverse diseases can also have a negative effect on the ability to father a child and the hormone balance, particularly the testosterone level. In many diseases the currently available data do not go beyond observations of limited fertility. In this article the focus is on diseases in the treatment field of dermatology. Special attention is paid to chronic inflammatory and autoimmune skin diseases. Data from recent years show that the excessive inflammatory reaction that these diseases have in common, most probably also has an influence on fertility and interacts with the testosterone concentration in serum. In addition, the impact of hereditary skin diseases on male fertility is discussed, which can have a direct influence on the ability to father a child due to disruption of the hypothalamus-pituitary-gonad axis.

Occupational UV-Exposure is a Major Risk Factor for Basal Cell Carcinoma: Results of the Population-Based Case-Control Study FB-181.

OBJECTIVE: The aim of this study was to investigate the role of occupational and nonoccupational ultraviolet (UV)-exposure concerning the development of basal cell carcinoma (BCC). METHODS: We undertook a population-based multicenter case-control study. Patients with first incident BCC (n = 836) were propensity score matched by age and sex to controls without skin cancer (n = 836). Sociodemographic characteristics, clinical characteristics, and lifetime UV-exposure were assessed by trained investigators. The differential estimation of occupational and nonoccupational UV-exposure dosages was based on validated instruments and established reference values. Associations were assessed using multivariable-adjusted conditional logistic regression models. RESULTS: Individuals with high levels of occupational UV-exposure were at significantly increased BCC-risk compared with individuals with low [odds ratio (OR) 1.84; 95% confidence interval (95% CI) 1.19 to 2.83 and moderate (OR 1.97; 95% CI 1.20 to 3.22) occupational UV-exposure. Nonoccupational UV-exposure was not independently associated with BCC. CONCLUSION: Skin cancer prevention strategies should be expanded to the occupational setting.