@article{MuellerStoetterKalluvyaetal.2015, author = {Mueller, A. and Stoetter, L. and Kalluvya, S. and Stich, A. and Majinge, C. and Weissbrich, B. and Kasang, C.}, title = {Prevalence of hepatitis B virus infection among health care workers in a tertiary hospital in Tanzania}, series = {BMC Infectious Diseases}, volume = {15}, journal = {BMC Infectious Diseases}, number = {386}, doi = {10.1186/s12879-015-1129-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141786}, year = {2015}, abstract = {Background: Sub-Saharan Africa has a high prevalence of hepatitis B virus (HBV) infections. Health care workers (HCWs) are at high risk of contracting HBV infection through their occupation. Vaccination of HCWs against HBV is standard practice in many countries, but is often not implemented in resource-poor settings. We aimed with this cross-sectional study to determine HBV prevalence, HCW vaccination status, and the risk factors for HCWs contracting HBV infection in Tanzania. Methods: We enrolled 600 HCWs from a tertiary Tanzanian hospital. Their demographics, medical histories, HBV vaccination details and risk factors for contracting blood-borne infections were collected using a standardized questionnaire. Serum samples were tested for HBV and hepatitis C virus (HCV) markers by ELISA techniques, PCR and an anti-HBs rapid test. HCWs were divided in two subgroups: those at risk of contracting HBV (rHCW 79.2 \%) via exposure to potentially infectious materials, and those considered not at risk of contracting HBV (nrHCW, 20.8 \%). Results: The overall prevalence of chronic HBV infection (HBsAg+, anti-HBc+, anti-HBs-) was 7.0 \% (42/598). Chronic HBV infection was found in 7.4 \% of rHCW versus 5.6 \% of nrHCW(p-value = 0.484). HCWs susceptible to HBV (HBsAg-, anti-HBc-, anti-HBs-) comprised 31.3 \%. HBV immunity achieved either by healed HBV infection (HBsAg-, anti-HBc+, anti-HBs+) or by vaccination (HBsAg-, anti-HBc-, anti-HBs+) comprised 36.5 \% and 20.2 \%, respectively. 4.8 \% of participants had indeterminate results (HBsAg-, anti-HBc+, anti-HBc-IgM-, anti-HBs-). Only 77.1 \% of HCWs who received a full vaccination course had an anti-HBs titer > 10 ml/U. An anti-HBs point-of-care test was 80.7 \% sensitive and 96.9 \% specific. There was a significantly higher risk for contracting HBV (anti-HBc+) among those HCW at occupational risk (rHCW) of older age (odds ratios (OR) in rHCW 3.297, p < 0.0001 vs. nrHCW 1.385, p = 0.606) and among those HCW being employed more than 11 years (OR 2.51, p < 0.0001***). HCV prevalence was low (HCV antibodies 1.2 \% and HCV-RNA 0.3 \%). Conclusions: Chronic HBV infection is common among Tanzanian HCWs. One third of HCWs were susceptible to HBV infection, highlighting the need for vaccination. Due to high prevalence of naturally acquired immunity against HBV pre-testing might be a useful tool to identify susceptible individuals.}, language = {en} } @article{SchattonYangKleffeletal.2015, author = {Schatton, Tobias and Yang, Jun and Kleffel, Sonja and Uehara, Mayuko and Barthel, Steven R. and Schlapbach, Christoph and Zhan, Qian and Dudeney, Stephen and Mueller, Hansgeorg and Lee, Nayoung and de Vries, Juliane C. and Meier, Barbara and Beken, Seppe Vander and Kluth, Mark A. and Ganss, Christoph and Sharpe, Arlene H. and Waaga-Gasser, Ana Maria and Sayegh, Mohamed H. and Abdi, Reza and Scharffetter-Kochanek, Karin and Murphy, George F. and Kupper, Thomas S. and Frank, Natasha Y. and Frank, Markus H.}, title = {ABCB5 Identifies Immunoregulatory Dermal Cells}, series = {Cell Reports}, volume = {12}, journal = {Cell Reports}, doi = {10.1016/j.celrep.2015.08.010}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149989}, pages = {1564 -- 1574}, year = {2015}, abstract = {Cell-based strategies represent a new frontier in the treatment of immune-mediated disorders. However, the paucity of markers for isolation of molecularly defined immunomodulatory cell populations poses a barrier to this field. Here, we show that ATP-binding cassette member B5 (ABCB5) identifies dermal immunoregulatory cells (DIRCs) capable of exerting therapeutic immunoregulatory functions through engagement of programmed cell death 1 (PD-1). Purified Abcb5\(^+\) DIRCs suppressed T cell proliferation, evaded immune rejection, homed to recipient immune tissues, and induced Tregs in vivo. In fully major-histocompatibility-complex-mismatched cardiac allotransplantation models, allogeneic DIRCs significantly prolonged allograft survival. Blockade of DIRC-expressed PD-1 reversed the inhibitory effects of DIRCs on T cell activation, inhibited DIRC-dependent Treg induction, and attenuated DIRC-induced prolongation of cardiac allograft survival, indicating that DIRC immunoregulatory function is mediated, at least in part, through PD-1. Our results identify ABCB5\(^+\) DIRCs as a distinct immunoregulatory cell population and suggest promising roles of this expandable cell subset in cellular immunotherapy.}, language = {en} }