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Dive into the research topics where Katja Nemat is active.

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Featured researches published by Katja Nemat.


Pediatric Allergy and Immunology | 2011

Provoking allergens and treatment of anaphylaxis in children and adolescents--data from the anaphylaxis registry of German-speaking countries.

Stephanie Hompes; Alice Köhli; Katja Nemat; Kathrin Scherer; Lars Lange; Franziska Ruëff; Ernst Rietschel; Thomas Reese; Zsolt Szépfalusi; Nicolaus Schwerk; Kirsten Beyer; Thomas Hawranek; B. Niggemann; Margitta Worm

To cite this article: Hompes S, Köhli A, Nemat K, Scherer K, Lange L, Rueff F, Rietschel E, Reese T, Szepfalusi Z, Schwerk N, Beyer K, Hawranek T, Niggemann B, Worm M. Provoking allergens and treatment of anaphylaxis in children and adolescents – data from the anaphylaxis registry of German‐speaking countries. Pediatr Allergy Immunol 2011; 22: 568–574.


The Journal of Allergy and Clinical Immunology | 2016

Anaphylaxis in children and adolescents: The European Anaphylaxis Registry.

Linus Grabenhenrich; Sabine Dölle; Anne Moneret-Vautrin; Alice Köhli; Lars Lange; Thomas Spindler; Franziska Ruëff; Katja Nemat; Ioana Maris; Eirini Roumpedaki; Kathrin Scherer; Hagen Ott; Thomas Reese; Tihomir Mustakov; Roland Lang; Montserrat Fernandez-Rivas; Marek L. Kowalski; Maria Beatrice Bilò; Jonathan O'b Hourihane; Nikolaos G. Papadopoulos; Kirsten Beyer; Antonella Muraro; Margitta Worm

BACKGROUND Anaphylaxis in children and adolescents is a potentially life-threatening condition. Its heterogeneous clinical presentation and sudden occurrence in virtually any setting without warning have impeded a comprehensive description. OBJECTIVE We sought to characterize severe allergic reactions in terms of elicitors, symptoms, emergency treatment, and long-term management in European children and adolescents. METHODS The European Anaphylaxis Registry recorded details of anaphylaxis after referral for in-depth diagnosis and counseling to 1 of 90 tertiary allergy centers in 10 European countries, aiming to oversample the most severe reactions. Data were retrieved from medical records by using a multilanguage online form. RESULTS Between July 2007 and March 2015, anaphylaxis was identified in 1970 patients younger than 18 years. Most incidents occurred in private homes (46%) and outdoors (19%). One third of the patients had experienced anaphylaxis previously. Food items were the most frequent trigger (66%), followed by insect venom (19%). Cows milk and hens egg were prevalent elicitors in the first 2 years, hazelnut and cashew in preschool-aged children, and peanut at all ages. There was a continuous shift from food- to insect venom- and drug-induced anaphylaxis up to age 10 years, and there were few changes thereafter. Vomiting and cough were prevalent symptoms in the first decade of life, and subjective symptoms (nausea, throat tightness, and dizziness) were prevalent later in life. Thirty percent of cases were lay treated, of which 10% were treated with an epinephrine autoinjector. The fraction of intramuscular epinephrine in professional emergency treatment increased from 12% in 2011 to 25% in 2014. Twenty-six (1.3%) patients were either admitted to the intensive care unit or had grade IV/fatal reactions. CONCLUSIONS The European Anaphylaxis Registry confirmed food as the major elicitor of anaphylaxis in children, specifically hens egg, cows milk, and nuts. Reactions to insect venom were seen more in young adulthood. Intensive care unit admissions and grade IV/fatal reactions were rare. The registry will serve as a systematic foundation for a continuous description of this multiform condition.


Allergy | 2012

Symptom profile and risk factors of anaphylaxis in Central Europe

M. Worm; G. Edenharter; Franziska Ruëff; Kathrin Scherer; Claudia Pföhler; Vera Mahler; R. Treudler; Roland Lang; Katja Nemat; Alice Koehli; B. Niggemann; Stephanie Hompes

Anaphylaxis is the most severe manifestation of an IgE‐dependent allergy. Standardized acquired clinical data from large cohorts of well‐defined cases are not available. The aim of this study was to analyse the symptom profile and risk factors of anaphylaxis in a large Central European cohort.


Deutsches Arzteblatt International | 2014

Triggers and treatment of anaphylaxis: an analysis of 4,000 cases from Germany, Austria and Switzerland.

Margitta Worm; Oliver Eckermann; Sabine Dölle; Werner Aberer; Kirsten Beyer; Thomas Hawranek; Stephanie Hompes; Alice Koehli; Vera Mahler; Katja Nemat; Bodo Niggemann; Claudia Pföhler; Uta Rabe; Angelika Reissig; Ernst Th. Rietschel; Kathrin Scherer; R. Treudler; Franziska Ruëff

BACKGROUND Anaphylaxis is the most severe manifestation of a mast cell-dependent immediate reaction and may be fatal. According to data from the Berlin region, its incidence is 2-3 cases per 100 000 persons per year. METHOD We evaluated data from the anaphylaxis registry of the German-speaking countries for 2006-2013 and data from the protocols of the ADAC air rescue service for 2010-2011 to study the triggers, clinical manifestations, and treatment of anaphylaxis. RESULTS The registry contained data on 4141 patients, and the ADAC air rescue protocols concerned 1123 patients. In the registry, the most common triggers for anaphylaxis were insect venom (n = 2074; 50.1%), foods (n = 1039; 25.1%), and drugs (n = 627; 15.1%). Within these groups, the most common triggers were wasp (n = 1460) and bee stings (n = 412), legumes (n = 241), animal proteins (n = 225), and analgesic drugs (n = 277). Food anaphylaxis was most frequently induced by peanuts, cow milk, and hens egg in children and by wheat and shellfish in adults. An analysis of the medical emergency cases revealed that epinephrine was given for grade 3 or 4 anaphylaxis to 14.5% and 43.9% (respectively) of the patients in the anaphylaxis registry and to 19% and 78% of the patients in the air rescue protocols. CONCLUSION Wasp and bee venom, legumes, animal proteins, and analgesic drugs were the commonest triggers of anaphylaxis. Their relative frequency was age-dependent. Epinephrine was given too rarely, as it is recommended in the guidelines for all cases of grade 2 and above.


The Journal of Allergy and Clinical Immunology | 2014

Modified oral food challenge used with sensitization biomarkers provides more real-life clinical thresholds for peanut allergy

Katharina Blumchen; Alena Beder; John Beschorner; Frank Ahrens; Armin Gruebl; Eckard Hamelmann; Gesine Hansen; Andrea Heinzmann; Katja Nemat; Bodo Niggemann; Ulrich Wahn; Kirsten Beyer

BACKGROUND Threshold levels for peanut allergy determined by using oral challenges are important for the food industry with regard to allergen labeling. Moreover, the utility of biological markers in predicting threshold levels is uncertain. OBJECTIVE We sought to use a modified oral food challenge regimen that might determine threshold levels for peanut allergy mimicking a more real-life exposure and to correlate the eliciting dose (ED) and severity of clinical reaction in children with peanut allergy with B-cell, T-cell, and effector cell markers. METHODS A modified food challenge procedure with doses scheduled 2 hours apart was used in 63 children with peanut allergy. All children received a maximum of 8 semi-log increasing titration steps of roasted peanuts ranging from 3 to 4500 mg of peanut protein until objective allergic reactions occurred. Severity of symptoms was graded from I to V. Biological markers were measured before challenge. RESULTS Forty-five of 63 patients showed objective symptoms after greater than 30 minutes, with a median latency of clinical reaction of 55 minutes. By using a log-normal dose-distribution model, the ED5 was calculated to be 1.95 mg of peanut protein. The ED was significantly and inversely correlated with peanut- and Ara h 2-specific IgE levels, skin prick test responses, basophil activation, and TH2 cytokine production by PBMCs. Symptom severity did not correlate with any of the markers or the ED. CONCLUSION This modified food challenge procedure might better reflect threshold levels for peanut allergy than the standard procedure because most of the patients reacted at a time interval of greater than 30 minutes. By using this model, threshold levels, but not severity, could be correlated with biological markers.


Journal Der Deutschen Dermatologischen Gesellschaft | 2016

S2k-Leitlinie Neurodermitis [atopisches Ekzem; atopische Dermatitis] – Kurzversion

Thomas Werfel; Annice Heratizadeh; Werner Aberer; Frank Ahrens; Matthias Augustin; Tilo Biedermann; Thomas L. Diepgen; Regina Fölster-Holst; Uwe Gieler; Julia Kahle; Alexander Kapp; Alexander Nast; Katja Nemat; Hagen Ott; Bernhard Przybilla; Martin Roecken; Martin Schlaeger; Peter Schmid-Grendelmeier; Jochen Schmitt; Thomas Schwennesen; Doris Staab; Margitta Worm

Bei dem Krankheitsbild der Neurodermitis handelt es sich um eine chronische oder chronisch‐rezidivierende, nichtkontagiöse, entzündliche Hauterkrankung mit in der Regel starkem Juckreiz. Darüber hinaus besteht ein Risiko für komplizierte Verläufe mit bakteriellen oder viralen Superinfektionen. Sowohl die genetische Prädisposition als auch zahlreiche Auslösefaktoren spielen für die Erstmanifestation und das Auftreten der Erkrankungsschübe eine wichtige Rolle, so dass auch die Therapiekonzepte vielfältig sind. Bei zahlreichen für die Neurodermitis zur Verfügung stehenden Behandlungsoptionen gilt es, in Abstimmung mit den Patienten bzw. Eltern erkrankter Kinder fallorientiert einen optimalen Behandlungsplan aufzustellen, der im Verlauf ggf. erneut angepasst werden muss.


The Journal of Allergy and Clinical Immunology | 2013

A functional IL-6 receptor (IL6R) variant is a risk factor for persistent atopic dermatitis

Heidi Schaarschmidt; Liming Liang; William Cookson; Anja Bauerfeind; Min Ae Lee-Kirsch; Katja Nemat; John Henderson; Lavinia Paternoster; John I. Harper; Elisabeth Mangold; Markus M. Nöthen; Franz Rüschendorf; Tamara Kerscher; Ingo Marenholz; Anja Matanovic; Susanne Lau; Thomas Keil; Carl Peter Bauer; Michael Kurek; Andrzej Ciechanowicz; Milan Macek; Andre Franke; Michael Kabesch; Norbert Hubner; Gonçalo R. Abecasis; Stephan Weidinger; Miriam F. Moffatt; Young-Ae Lee

BACKGROUND Atopic dermatitis (AD) is a common inflammatory skin disease. Previous studies have revealed shared genetic determinants among different inflammatory disorders, suggesting that markers associated with immune-related traits might also play a role in AD. OBJECTIVE We sought to identify novel genetic risk factors for AD. METHODS We examined the results of all genome-wide association studies from a public repository and selected 318 genetic markers that were significantly associated with any inflammatory trait. These markers were considered candidates and tested for association with AD in a 3-step approach including 7 study populations with 7130 patients with AD and 9253 control subjects. RESULTS A functional amino acid change in the IL-6 receptor (IL-6R Asp358Ala; rs2228145) was significantly associated with AD (odds ratio [OR], 1.15; P = 5 × 10(-9)). Interestingly, investigation of 2 independent population-based birth cohorts showed that IL-6R 358Ala specifically predisposes to the persistent form of AD (ORpersistent AD = 1.22, P = .0008; ORtransient AD = 1.04, P = .54). This variant determines the balance between the classical membrane-bound versus soluble IL-6R signaling pathways. Carriers of 358Ala had increased serum levels of soluble IL-6R (P = 4 × 10(-14)), with homozygote carriers showing a 2-fold increase. Moreover, we demonstrate that soluble IL-6R levels were higher in patients with AD than in control subjects (46.0 vs 37.8 ng/mL, P = .001). Additional AD risk variants were identified in RAD50, RUNX3, and ERBB3. CONCLUSION Our study supports the importance of genetic variants influencing inflammation in the etiology of AD. Moreover, we identified a functional genetic variant in IL6R influencing disease prognosis and specifically predisposing to persistent AD.


Allergo journal international | 2016

S2k guideline on diagnosis and treatment of atopic dermatitis — short version

Thomas Werfel; Annice Heratizadeh; Werner Aberer; Frank Ahrens; Matthias Augustin; Tilo Biedermann; Thomas L. Diepgen; Regina Fölster-Holst; Uwe Gieler; Julia Kahle; Alexander Kapp; Alexander Nast; Katja Nemat; Hagen Ott; Bernhard Przybilla; Martin Roecken; Martin Schlaeger; Peter Schmid-Grendelmeier; Jochen Schmitt; Thomas Schwennesen; Doris Staab; Margitta Worm

SummaryAtopic dermatitis (AD) represents a pruritic, non-contagious, chronic or chronically relapsing, inflammatory skin disease. The course of the disease may be complicated by bacterial or viral superinfections. The first manifestation of the disease and further flare-ups are due to genetic predisposition and also to a variety of further trigger factors. The therapy regimen should be adapted to disease symptoms that are actually present and consider individual features of the disease as reported by the patients or their parents. This short version of the German guideline on AD provides an overview of evidence-based diagnostic and treatment options. All recommendations made here are the result of a consensus of the scientific medical societies, working groups and support groups based on scientific data published to date. Abstracts and details of the studies cited are provided in the long version of this guideline (see: www.awmf.org).


PLOS Genetics | 2015

Maternal filaggrin mutations increase the risk of atopic dermatitis in children: an effect independent of mutation inheritance

Anja Matanovic; Ingo Marenholz; Anja Bauerfeind; Klaus Rohde; Katja Nemat; Min-Ae Lee-Kirsch; Magnus Nordenskjöld; Mårten C. G. Winge; Thomas Keil; Renate Krüger; Susanne Lau; Kirsten Beyer; Birgit Kalb; Bodo Niggemann; Norbert Hubner; Heather J. Cordell; Maria Bradley; Young-Ae Lee

Epidemiological studies suggest that allergy risk is preferentially transmitted through mothers. This can be due to genomic imprinting, where the phenotype effect of an allele depends on its parental origin, or due to maternal effects reflecting the maternal genomes influence on the child during prenatal development. Loss-of-function mutations in the filaggrin gene (FLG) cause skin barrier deficiency and strongly predispose to atopic dermatitis (AD). We investigated the 4 most prevalent European FLG mutations (c.2282del4, p.R501X, p.R2447X, and p.S3247X) in two samples including 759 and 450 AD families. We used the multinomial and maximum-likelihood approach implemented in the PREMIM/EMIM tool to model parent-of-origin effects. Beyond the known role of FLG inheritance in AD (R1meta-analysis = 2.4, P = 1.0 x 10−36), we observed a strong maternal FLG genotype effect that was consistent in both independent family sets and for all 4 mutations analysed. Overall, children of FLG-carrier mothers had a 1.5-fold increased AD risk (S1 = 1.50, Pmeta-analysis = 8.4 x 10−8). Our data point to two independent and additive effects of FLG mutations: i) carrying a mutation and ii) having a mutation carrier mother. The maternal genotype effect was independent of mutation inheritance and can be seen as a non-genetic transmission of a genetic effect. The FLG maternal effect was observed only when mothers had allergic sensitization (elevated allergen-specific IgE antibody plasma levels), suggesting that FLG mutation-induced systemic immune responses in the mother may influence AD risk in the child. Notably, the maternal effect reported here was stronger than most common genetic risk factors for AD recently identified through genome-wide association studies (GWAS). Our study highlights the power of family-based studies in the identification of new etiological mechanisms and reveals, for the first time, a direct influence of the maternal genotype on the offspring’s susceptibility to a common human disease.


Allergy | 2018

Increased attention‐deficit/hyperactivity symptoms in atopic dermatitis are associated with history of antihistamine use

Jochen Schmitt; Angelika Buske-Kirschbaum; Falko Tesch; Katharina Trikojat; Victoria Stephan; Susanne Abraham; Andrea Bauer; Katja Nemat; Franziska Plessow; Veit Roessner

Epidemiologic evidence indicates a relevant association between atopic dermatitis (AD) and attention‐deficit/hyperactivity disorder (ADHD). Underlying mechanisms and ways to best identify subgroups of AD patients at risk for ADHD are poorly understood.

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Anja Bauerfeind

Max Delbrück Center for Molecular Medicine

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Norbert Hubner

Max Delbrück Center for Molecular Medicine

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