Rare variant analysis in eczema identifies exonic variants in DUSP1, NOTCH4 and SLC9A4

Previous genome-wide association studies revealed multiple common variants involved in eczema but the role of rare variants remains to be elucidated. Here, we investigate the role of rare variants in eczema susceptibility. We meta-analyze 21 study populations including 20,016 eczema cases and 380,433 controls. Rare variants are imputed with high accuracy using large population-based reference panels. We identify rare exonic variants in DUSP1, NOTCH4, and SLC9A4 to be associated with eczema. In DUSP1 and NOTCH4 missense variants are predicted to impact conserved functional domains. In addition, five novel common variants at SATB1-AS1/KCNH8, TRIB1/LINC00861, ZBTB1, TBX21/OSBPL7, and CSF2RB are discovered. While genes prioritized based on rare variants are significantly up-regulated in the skin, common variants point to immune cell function. Over 20% of the single nucleotide variant-based heritability is attributable to rare and low-frequency variants. The identified rare/low-frequency variants located in functional protein domains point to promising targets for novel therapeutic approaches to eczema.

Genetic studies of eczema to date have mostly explored common genetic variation. Here, the authors perform a large meta-analysis for common and rare variants and discover 8 loci associated with eczema. Over 20% of the heritability of the condition is attributable to rare variants.

Trans-ancestry analysis reveals genetic and nongenetic associations with COVID-19 susceptibility and severity

COVID-19 presents with a wide range of severity, from asymptomatic in some individuals to fatal in others. Based on a study of 1,051,032 23andMe research participants, we report genetic and nongenetic associations with testing positive for SARS-CoV-2, respiratory symptoms and hospitalization. Using trans-ancestry genome-wide association studies, we identified a strong association between blood type and COVID-19 diagnosis, as well as a gene-rich locus on chromosome 3p21.31 that is more strongly associated with outcome severity. Hospitalization risk factors include advancing age, male sex, obesity, lower socioeconomic status, non-European ancestry and preexisting cardiometabolic conditions. While non-European ancestry was a significant risk factor for hospitalization after adjusting for sociodemographics and preexisting health conditions, we did not find evidence that these two primary genetic associations explain risk differences between populations for severe COVID-19 outcomes.

Chromatin activity at GWAS loci identifies T cell states driving complex immune diseases

Immune-disease-associated variants are enriched in active chromatin regions of T cells and macrophages. However, whether these variants function in specific cell states is unknown. Here we stimulated T cells and macrophages in the presence of 13 cytokines and profiled active and open chromatin regions. T cell activation induced major chromatin remodeling, while the presence of cytokines fine-tuned the magnitude of changes. We developed a statistical method that accounts for subtle changes in the chromatin landscape to identify SNP enrichment across cell states. Our results point towards the role of immune-disease-associated variants in early rather than late activation of memory CD4+ T cells, with modest differences across cytokines. Furthermore, variants associated with inflammatory bowel disease are enriched in type 1 T helper (TH1) cells, whereas variants associated with Alzheimer's disease are enriched in different macrophage cell states. Our results represent an in-depth analysis of immune-disease-associated variants across a comprehensive panel of activation states of T cells and macrophages.

Identification of new therapeutic targets for osteoarthritis through genome-wide analyses of UK Biobank data

Osteoarthritis is the most common musculoskeletal disease and the leading cause of disability globally. Here, we perform a genome-wide association study for osteoarthritis (77,052 cases and 378,169 controls), analysing 4 phenotypes: knee osteoarthritis, hip osteoarthritis, knee and/or hip osteoarthritis, and any osteoarthritis. We discover 64 signals, 52 of them novel, more than doubling the number of established disease loci. Six signals fine map to a single variant. We identify putative effector genes by integrating eQTL colocalization, fine-mapping, human rare disease, animal model, and osteoarthritis tissue expression data. We find enrichment for genes underlying monogenic forms of bone development diseases, and for the collagen formation and extracellular matrix organisation biological pathways. Ten of the likely effector genes, including TGFB1, FGF18, CTSK and IL11 have therapeutics approved or in clinical trials, with mechanisms of action supportive of evaluation for efficacy in osteoarthritis.

4th Pediatric Allergy and Asthma Meeting (PAAM)

WORKSHOP 4: Challenging clinical scenarios (CS01–CS06)

CS01 Bullous lesions in two children: solitary mastocytoma

S. Tolga Yavuz, Ozan Koc, Ali Gungor, Faysal Gok

CS02 Multi-System Allergy (MSA) of cystic fibrosis: our institutional experience

Jessica Hawley, Christopher O’Brien, Matthew Thomas, Malcolm Brodlie, Louise Michaelis

CS03 Cold urticaria in pediatric age: an invisible cause for severe reactions

Inês Mota, Ângela Gaspar, Susana Piedade, Graça Sampaio, José Geraldo Dias, Miguel Paiva, Mário Morais-Almeida

CS04 Angioedema with C1 inhibitor deficiency in a girl: a challenge diagnosis

Cristina Madureira, Tânia Lopes, Susana Lopes, Filipa Almeida, Alexandra Sequeira, Fernanda Carvalho, José Oliveira

CS05 A child with unusual multiple organ allergy disease: what is the primer?

Fabienne Gay-Crosier

CS06 A case of uncontrolled asthma in a 6-year-old patient

Ioana-Valentina Nenciu, Andreia Florina Nita, Alexandru Ulmeanu, Dumitru Oraseanu, Carmen Zapucioiu

ORAL ABSTRACT SESSION 1: Food allergy (OP01–OP06)

OP01 Food protein-induced enterocolitis syndrome: oral food challenge outcomes for tolerance evaluation in a Pediatric Hospital

Adrianna Machinena, Olga Domínguez Sánchez, Montserrat Alvaro Lozano, Rosa Jimenez Feijoo, Jaime Lozano Blasco, Mònica Piquer Gibert, Mª Teresa Giner Muñoz, Marcia Dias da Costa, Ana Maria Plaza Martín

OP02 Characteristics of infants with food protein-induced enterocolitis syndrome and allergic proctocolitis

Ebru Arik Yilmaz, Özlem Cavkaytar, Betul Buyuktiryaki, Ozge Soyer, Cansin Sackesen

OP03 The clinical and immunological outcomes after consumption of baked egg by 1–5 year old egg allergic children: results of a randomised controlled trial

MerrynNetting, Adaweyah El-Merhibi, Michael Gold, PatrickQuinn, IrmeliPenttila, Maria Makrides

OP04 Oral immunotherapy for treatment of egg allergy using low allergenic, hydrolysed egg

Stavroula Giavi, Antonella Muraro, Roger Lauener, Annick Mercenier, Eugen Bersuch, Isabella M. Montagner, Maria Passioti, Nicolò Celegato, Selina Summermatter, Sophie Nutten, Tristan Bourdeau, Yvonne M. Vissers, Nikolaos G. Papadopoulos

OP05 Chemical modification of a peanut extract results in an increased safety profile while maintaining efficacy

Hanneke van der Kleij, Hans Warmenhoven, Ronald van Ree, Raymond Pieters, Dirk Jan Opstelten, Hans van Schijndel, Joost Smit

OP06 Administration of the yellow fever vaccine in egg allergic children

Roisin Fitzsimons, Victoria Timms, George Du Toit

ORAL ABSTRACT SESSION 2: Asthma (OP07–OP12)

OP07 Previous exacerbation is the most important risk factor for future exacerbations in school-age children with asthma

S. Tolga Yavuz, Guven Kaya, Mustafa Gulec, Mehmet Saldir, Osman Sener, Faysal Gok

OP08 Comparative study of degree of severity and laboratory changes between asthmatic children using different acupuncture modalities

Nagwa Hassan, Hala Shaaban, Hazem El-Hariri, Ahmed Kamel Inas E. Mahfouz

OP09 The concentration of exhaled carbon monoxide in asthmatic children with different controlled stadium

Papp Gabor, Biro Gabor, Kovacs Csaba

OP10 Effect of vitamin D3 supplementation during pregnancy on risk of persistent wheeze in the offspring: a randomised clinical trial

Bo Chawes, Klaus Bønnelykke, Jakob Stokholm, Lene Heickendorff, Susanne Brix, Morten Rasmussen, Hans Bisgaard

OP11 Lung function development in childhood

Henrik Wegener Hallas, Bo Chawes, Lambang Arianto, Hans Bisgaard

OP12 Is the effect of maternal and paternal asthma different in female and male children before puberty?

Maike Pincus, Thomas Keil, Andreas Reich, Ulrich Wahn, Susanne Lau, Linus Grabenhenrich

ORAL ABSTRACT SESSION 3: Epidemiology—genetics (OP13–OP18)

OP13 Lifestyle is associated with incidence and category of allergen sensitisation: the ALADDIN birth cohort

Sara Fagerstedt, Helena Marell Hesla, Emelie Johansson, Helen Rosenlund, Axel Mie, Annika Scheynius, Johan Alm

OP15 Maternal filaggrin mutations increase the risk of atopic dermatitis in children: an effect independent of mutation inheritance

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

OP16 Allergic multimorbidity of asthma, rhinitis and eczema in the first 2 decades of the German MAS birth cohort

Thomas Keil, Hannah Gough, Linus Grabenhenrich, Dirk Schramm, Andreas Reich, John Beschorner, Antje Schuster, Carl-Peter Bauer, Johannes Forster, Fred Zepp, Young-Ae Lee, Renate Bergmann, Karl Bergmann, Ulrich Wahn, Susanne Lau

OP17 Childhood anaphylaxis: a growing concern

Filipe Benito Garcia, Inês Mota, Susana Piedade, Ângela Gaspar, Natacha Santos, Helena Pité, Mário Morais-Almeida

OP18 Indoor exposure to molds and dampness in infancy and its association to persistent atopic dermatitis in school age. Results from the Greek ISAAC II study

Athina Papadopoulou, Despina Mermiri, Elpida Xatziagorou, Ioannis Tsanakas, Stavroula Lampidi, Kostas Priftis

ORAL ABSTRACT SESSION 4: Pediatric rhinitis—immunotherapy (OP19–OP24)

OP19 Associations between residential greenness and childhood allergic rhinitis and aeroallergen sensitisation in seven birth cohorts

Elaine Fuertes, Iana Markevych, Gayan Bowatte, Olena Gruzieva, Ulrike Gehring, Allan Becker, Dietrich Berdel, Michael Brauer, Chris Carlsten, Barbara Hoffmann, Anita Kozyrskyj, Caroline Lodge, Göran Pershagen, Alet Wijga, Heinrich Joachim

OP20 Full symptom control in pediatric patients with allergic rhinitis and asthma: results of a 2-year sublingual allergen immunotherapy study

Zorica Zivkovic, Ivana Djuric-Filipovic, Jasmina Jocić-Stevanovic, Snežana Zivanovic

OP21 Nasal epithelium of different ages of atopic subjects present increased levels of oxidative stress and increased cell cytotoxicity upon rhinovirus infection

Styliani Taka, Dimitra Kokkinou, Aliki Papakonstantinou, Panagiota Stefanopoulou, Anastasia Georgountzou, Paraskevi Maggina, Sofia Stamataki, Vassiliki Papaevanggelou, Evangelos Andreakos, Nikolaos G. Papadopoulos

OP22 Cluster subcutaneous immunotherapy schedule: tolerability profile in children

Monica Piquer Gibert, Montserrat Alvaro Lozano, Jaime Lozano Blasco, Olga Domínguez Sánchez, Rosa Jiménez Feijoo, Marcia Dias da Costa, Mª Teresa Giner Muñoz, Adriana Machinena Spera, Ana Maria Plaza Martín

OP23 Rhinitis as a risk factor for asthma severity in 11-year old children: population-based cohort study

Matea Deliu, Danielle Belgrave, Angela Simpson, Adnan Custovic

OP24 The Global Lung Function Initiative equations in airway obstruction evaluation of asthmatic children

João Gaspar Marques, Pedro Carreiro-Martins, Joana Belo, Sara Serranho, Isabel Peralta, Nuno Neuparth, Paula Leiria-Pinto

POSTER DISCUSSION SESSION 1: Food allergy (PD01–PD05)

PD01 Allergen-specific humoral and cellular responses in children who fail egg oral immunotherapy due to allergic reactions

Marta Vazquez-Ortiz, Mariona Pascal, Ana Maria Plaza, Manel Juan

PD02 FoxP3 epigenetic features in children with cow milk allergy

Lorella Paparo, Rita Nocerino, Rosita Aitoro, Ilaria Langella, Antonio Amoroso, Alessia Amoroso, Carmen Di Scala, Roberto Berni Canani

PD04 Combined milk and egg allergy in early childhood: let them eat cake?

Santanu Maity, Giuseppina Rotiroti, Minal Gandhi

PD05 Introduction of complementary foods in relation to allergy and gut microbiota in farm and non-farm children

Karin Jonsson, Annika Ljung, Bill Hesselmar, Ingegerd Adlerbert, Hilde Brekke, Susanne Johansen, Agnes Wold, Ann-Sofie Sandberg

POSTER DISCUSSION SESSION 2: Asthma and wheeze (PD06–PD16)

PD06 The association between asthma and exhaled nitric oxide is influenced by genetics and sensitisation

Björn Nordlund, Cecilia Lundholm, Villhelmina Ullemar, Marianne van Hage, Anne Örtqvist, Catarina Almqvist

PD09 Prevalence patterns of infant wheeze across Europe

Anna Selby, Kate Grimshaw, Thomas Keil, Linus Grabenhenrich, Michael Clausen, Ruta Dubakiene, Alessandro Fiocchi, Marek Kowalski, Nikos Papadopoulos, Marta Reche, Sigurveig Sigurdardottir, Aline Sprikkleman, Paraskevi Xepapadaki, Clare Mills, Kirsten Beyer, Graham Roberts

PD10 Epidemiologic changes in recurrent wheezing infants

Herberto Jose Chong Neto, Gustavo Falbo Wandalsen, Ana Carolina Dela Bianca, Carolina Aranda, Nelson Augusto Rosário, Dirceu Solé, Javier Mallol, Luis García Marcos

PD13 A single nucleotide polymorphism in the GLCCI1 gene is associated with response to asthma treatment in children

IvanaBanic, Matija Rijavec, Davor Plavec, Peter Korosec, Mirjana Turkalj

PD14 Pollen induced asthma: Could small molecules in pollen exacerbate the protein-mediated allergic response?

Alen Bozicevic, Maria De Mieri, Matthias Hamburger

PD15 A qualitative study to understand how we can empower teenagers to better self-manage their asthma

Simone Holley, Ruth Morris, Frances Mitchell, Rebecca Knibb, Susan Latter, Christina Liossi, Graham Roberts

PD16 Polymorphism of endothelial nitric oxide synthase (eNOS) gene among Egyptian children with bronchial asthma

Mostafa M. M. Hassan

POSTER DISCUSSION SESSION 3: Mechanisms—Epidemiology (PD17–PD21)

PD17 Pregnancy outcomes in relation to development of allergy in a Swedish birth cohort

Malin Barman, Anna Sandin, Agnes Wold, Ann-Sofie Sandberg

PD18 Evolution of the IgE response to house dust mite molecules in childhood

Daniela Posa, Serena Perna, Carl-Peter Bauer, Ute Hoffmann, Johannes Forster, Fred Zepp, Antje Schuster, Ulrich Wahn, Thomas Keil, Susanne Lau, Kuan-Wei Chen, Yvonne Resch, Susanne Vrtala, Rudolf Valenta, Paolo Maria Matricardi

PD19 Antibody recognition of nsLTP-molecules as antigens but not as allergens in the German-MAS birth cohort

Olympia Tsilochristou, Alexander Rohrbach, Antonio Cappella, Stephanie Hofmaier, Laura Hatzler, Carl-Peter Bauer, Ute Hoffmann, Johannes Forster, Fred Zepp, Antje Schuster, RaffaeleD’Amelio, Ulrich Wahn, Thomas Keil, Susanne Lau, Paolo Maria Matricardi

PD20 Early life colonization with Lactobacilli and Staphylococcus aureus oppositely associates with the maturation and activation of FOXP3+ CD4 T-cells

Sophia Björkander, Maria A. Johansson, Gintare Lasaviciute, Eva Sverremark-Ekström

PD21 Genome-wide meta-analysis identifies 7 susceptibility loci involved in the atopic march

Ingo Marenholz, Jorge Esparza-Gordillo, Franz Rüschendorf, Anja Bauerfeind, David P. Strachan, Ben D. Spycher, Hansjörg Baurecht, Patricia Margaritte-Jeannin, Annika Sääf, Marjan Kerkhof, Markus Ege, Svetlana Baltic, Melanie C Matheson, Jin Li, Sven Michel, Wei Q. Ang, Wendy McArdle, Andreas Arnold, Georg Homuth, Florence Demenais, Emmanuelle Bouzigon, Cilla Söderhäll, Göran Pershagen, Johan C. de Jongste, Dirkje S Postma, Charlotte Braun-Fahrländer, Elisabeth Horak, Ludmila M. Ogorodova, Valery P. Puzyrev, Elena Yu Bragina, Thomas J Hudson, Charles Morin, David L Duffy, Guy B Marks, Colin F Robertson, Grant W Montgomery, Bill Musk, Philip J Thompson, Nicholas G. Martin, Alan James, Patrick Sleiman, Elina Toskala, Elke Rodriguez, Regina Fölster-Holst, Andre Franke, Wolfgang Lieb, Christian Gieger, Andrea Heinzmann, Ernst Rietschel, Thomas Keil, Sven Cichon, Markus M Nöthen, Craig E Pennell, Peter D Sly, Carsten O Schmidt, Anja Matanovic, Valentin Schneider, Matthias Heinig, Norbert Hübner, Patrick G. Holt, Susanne Lau, Michael Kabesch, Stefan Weidinger, Hakon Hakonarson, Manuel AR Ferreira, Catherine Laprise, Maxim B. Freidin, Jon Genuneit, Gerard H Koppelman, Erik Melén, Marie-Hélène Dizier, A. John Henderson, Young Ae Lee

POSTER DISCUSSION SESSION 4: Food allergy—Anaphylaxis (PD22–PD26)

PD22 Atopy patch test in food protein induced enterocolitis caused by solid food

Purificacion González-Delgado, Esther Caparrós, Fernando Clemente, Begoña Cueva, Victoria M. Moreno, Jose Luis Carretero, Javier Fernández

PD23 Watermelon allergy: a novel presentation

Kate Swan, George Du Toit

PD24 A pilot study evaluating the usefulness of a guideline template for managing milk allergy in primary care

Mudiyur Gopi, Tim Smith, Edara Ramesh, Arun Sadasivam

PD26 Efficacy and safety of cow’s milk oral immunotherapy protocol

Inês Mota, Filipe Benito Garcia, Susana Piedade, Angela Gaspar, Graça Sampaio, Cristina Arêde, Luís Miguel Borrego, Graça Pires, Cristina Santa-Marta, Mário Morais-Almeida

POSTER DISCUSSION SESSION 5: Prevention and treatment—Allergy (PD27–PD36)

PD27 Allergy-protection by the lactic acid bacterium Lactococcus lactis G121: mode-of-action as revealed in a murine model of experimental allergy

Stephanie Brand, Karina Stein, Holger Heine, Marion Kauth

PD29 The relationship between quality of life and morning salivary cortisol after acute bronchiolitis in infancy

Leif Bjarte Rolfsjord, Egil Bakkeheim, Johan Alm, Håvard Ove Skjerven, Kai-Håkon Carlsen, Jon Olav Hunderi, Teresa Løvold Berents, Petter Mowinckel, Karin C. Lødrup Carlsen

PD30 Randomised trial of the efficacy of MP29-02* compared with fluticasone propionate nasal spray in children aged ≥6 years to <12 years with allergic rhinitis

Ulrich Wahn, Ullrich Munzel, William Berger

PD31 10 mg of oral bilastine in 2 to 11 years old children has similar exposure to the adult therapeutic dose (20 mg)

Ulrich Wahn, Román Valiente, Valvanera Vozmediano, John C. Lukas, Mónica Rodríguez

PD33 Daily symptoms, nocturnal symptoms, activity limitations and reliever therapies during the three steps of IOEASMA programme: a comparison

Sebastiano Guarnaccia, Luigi Vitale, Ada Pluda, Emanuele D’Agata, Denise Colombo, Stefano Felici, Valeria Gretter, Susanna Facchetti, Gaia Pecorelli, Cristina Quecchia

PD34 Sensitisation to an inert aeroallergen in weaning rats and longstanding disease, in a sensitisation-tolerant and easily tolerisable rodent strain

George Guibas, Evangelia Spandou, Spyridon Megremis, Peter West, Nikolaos Papadopoulos

PD35 Bacterial and fungi exposure in school and allergic sensitisation in children

João Cavaleiro Rufo, Joana Madureira, Inês Paciência, Lívia Aguiar, Patrícia Padrão, Mariana Pinto, Luís Delgado, Pedro Moreira, João Paulo Teixeira, Eduardo Oliveira Fernandes, André Moreira

PD36 Comparative study of allergy rhinitis between two populations: children vs. adults

Adriana Izquierdo Dominguez, Antonio Valero, Joaquim Mullol, Alfonso Del Cuvillo, Javier Montoro, Ignacio Jauregui, Joan Bartra, Ignacio Davila, Marta Ferrer, Joaquin Sastre

POSTER VIEWING SESSION 1: Inflammation—Genetics—Immunology—Dermatology (PP01–PP09)

PP01 Immune profile in late pregnancy: immunological markers in atopic asthmaticwomen as risk factors for atopy in the progeny

Catarina Martins, Jorge Lima, Maria José Leandro, Glória Nunes, Jorge Cunha Branco, Hélder Trindade, Luis Miguel Borrego

PP02 The impact of neonatal sepsis on development of allergic diseases

Secil Conkar, Mehtap Kilic, Canan Aygun, Recep Sancak

PP03 Clinical overview of selective IgE deficiency in childhood

Athina Papadopoulou, Eleni Tagalaki, Lambros Banos, Anna Vlachou, Fotini Giannoula, Despina Mermiri

PP04 Inverse relationship between serum 25(ΟΗ) vitamin D3 and total IgE in children and adolescence

Athina Papadopoulou, Stavroula Lampidi, Marina Pavlakou, Maria Kryoni, Kostas Makris

PP05

PP06

PP07 Asthma control questionnaire and specific IgE in children

Snezhina Lazova, Guergana Petrova, Dimitrinka Miteva, Penka Perenovska

PP08 Features of chronic urticaria of adolescents

Aliya Klyucharova, Olesya Skorohodkina

PP09 Cutaneous mastocytosis in children: a clinical analysis of 8 cases in Greece

Dimitra Koumaki, Alkisti Manousaki, Maria Agrapidi, Lida Iatridou, Omima Eruk, Konstantinos Myridakis, Emmanouil Manousakis, Vasiliki Koumaki

POSTER VIEWING SESSION 2: Food allergy—Anaphylaxis (PP10–PP47)

PP10 Prognostic factors in egg allergy

Maria Dimou, Maria Ingemansson, Gunilla Hedlin

PP11 Evaluation of the efficacy of an amino acid-based formula in infants who are intolerant to extensively hydrolysed protein formula

Nitida Pastor, Delphine de Boissieu, Jon Vanderhoof, Nancy Moore, Kaitlin Maditz

PP12 Anaphylaxis and epinephrine auto-injector use: a survey of pediatric trainees

Adeli Mehdi, Shaza Elhassan, Carolin Beck, Ahmed Al-Hammadi

PP13 Anaphylaxis in children: acute management in the Emergency Department

Ioana Maris, Ronan O’Sullivan, Jonathan Hourihane,

PP14 Understanding Cumbrian schools preparedness in managing children at risk of anaphylaxis in order to provide training and support which will create healthy and safe environments for children with allergies

George Raptis, Louise Michaelis

PP15 A new valid and reliable parent and child questionnaire to measure the impact of food protein enterocolitis syndrome on children: the FPIES Quality of Life Questionnaire (FPIESQL), Parent and Child Short Form

Audrey DunnGalvin, Matthew Greenhawt, Carina Venter, Jonathan Hourihane

PP16 An in-depth case study investigation of the experiences of teenagers and young adults in growing up and living with food allergy with emphasis on coping, management and risk, support, and social and self-identity

Evelyn O’Regan, Duncan Cronin, Jonathan Hourihane, Anna O’Reilly, Audrey DunnGalvin

PP17 Cow’s milk protein allergy in Constantine. A retrospective study of 62 cases between 1996 and 2013

Foued Abdelaziz, Dounia Khelifi-Touhami, Nihad Selim, Tahar Khelifi-Touhami

PP18

PP19 Cow’s milk and egg oral immunotherapy in children older than 5 years

Pablo Merida, Ana Mª Plaza, Juan Heber Castellanos, Adrianna Machinena, Montserrat Alvaro Lozano, Jaime Lozano, Olga Dominguez, Monica Piquer, Rosa Jimenez, Mª Teresa Giner

PP20 Professionals’ awareness of management of Cow’s Milk Protein Allergy (CMPA) in North Wales Hospitals

Konstantinos Kakleas, Manohar Joishy, Wendmu Maskele, Huw R. Jenkins

PP21

PP22 Anaphylaxis: the great unknown for teachers. Presentation of a protocol for schools

Mercedes Escarrer, Agustín Madroñero, Maria Teresa Guerra, Juan Carlos Julia, Juan Carlos Cerda, Javier Contreras, Eulalia Tauler, Maria Jesus Vidorreta, Ana Rojo, Silvia Del Valle

PP23 Challenges facing children with food allergies and their parents in out of school activity sectors

Niamh Flynn

PP24 A review of food challenges at a Regional Irish Centre

Gary Foley, Carol Harmon, John Fitzsimons

PP25 The use of epinephrine in infants with anaphylaxis

Krasimira Baynova, Ávila Maria Del Robledo, Labella Marina

PP26

PP27

PP28 Mother’s psychological state predicts the expression of symptoms in food allergic children

Aaron Cortes, Alicia Sciaraffia, Angela Castillo

PP29 The correlation between sIgE towards tree nuts and birch pollen in a Danish Pediatric Allergy Clinic

Nanna Juel-Berg, Kirsten Skamstrup Hansen, Lars Kærgaard Poulsen

PP30 Food allergy in children: evaluation of parents’ use of online social media

Andreia Florina Nita, Ioana Valentina Nenciu, Adina Lazar, Dumitru Oraseanu

PP31 The impact of food allergy on quality of life: FAQLQ questionnaire

Rita Aguiar, Anabela Lopes, Maria J. Paes, Amélia S. Santos, M. A. Pereira-Barbosa

PP32 An unexpected cause of anaphylaxis: potato

Hatice Eke Gungor, Salih Uytun, Umit Murat Sahiner, Yasemin Altuner Torun

PP33 Is it clinical phenotype of allergic diseases determined by sensitisation to food?

Mirjana Zivanovic, Marina Atanasković-Marković

PP34

PP35 Prescribing adrenaline auto-injectors in children in 2014: the data from regional pediatricians

Tina Vesel, Mihaela Nahtigal, Andreja Obermayer-Temlin, Eva Šoster Križnik, Mirjana Maslar, Ruben Bizjak, Marjeta Tomšič-Matic, Sonja Posega-Devetak, Maja Skerbinjek-Kavalar, Mateja Predalič, Tadej Avčin

PP36 Who should have an adrenaline autoinjector? Adherence to the European and French guidelines among 121 allergists from the Allergy Vigilance Network

Guillaume Pouessel, Etienne Beaudouin, Anne M. Moneret-Vautrin, Antoine Deschildre, Allergy Vigilance Network

PP37 Anaphylaxis by Anacardium Occidentale

Marta Viñas, Bartolomé Borja, Nora Hernández, Mª José Castillo, Adriana Izquierdo, Marcel Ibero

PP38 Anaphylaxis with honey in a child

S. Tolga Yavuz, Ali Gungor, Betul Buyuktiryaki, Ozan Koc, Can Naci Kocabas, Faysal Gok

PP39 Evaluation of courses adopted to children on prevention, recognition and management of anaphylaxis

Tina Vesel, Mihaela Nahtigal

PP40 Symptomatic dust mites and shrimp allergy: three pediatric case reports

Filipa Almeida, Susana Lopes, Cristina Madureira, Tânia Lopes, Fernanda Carvalho

PP41 Poor identification rates of nuts by high risk individuals: a call for improved education and support for families

Camille Heming, Emily Garrett, Adam Blackstock, Santanu Maity, Rahul Chodhari

PP42 DAFALL: database of food allergies in the Czech Republic

Simona Belohlavkova, Eliska Kopelentova, Petr Visek, Ivana Setinova, Ivana Svarcova

PP43 Serological cross-reactivity between grass and wheat is not only caused by profilins and CCDs

Sigrid Sjölander, Nora Nilsson, Malin Berthold, Helena Ekoff, Gunilla Hedlin, Magnus Borres, Caroline Nilsson

PP44 Oil body associated proteins in children with nuts allergy. Allergens to consider in IgE-mediated nuts allergy

Loreto González Domínguez, Cristina Muñoz Archidona, Ana Moreira Jorge, Sergio Quevedo Teruel, Teresa Bracamonte Bermejo, Miriam Castillo Fernández, Fernando Pineda de la Losa, Luis Ángel Echeverría Zudaire

PP45

PP46 Protective effect of helicobacter pylori infection against food allergy in children

Olga Vrani, Antigone Mavroudi, Maria Fotoulaki, Maria Emporiadou, Kleomenis Spiroglou, Ioannis Xinias

PP47 Anaphylaxis pathway: A road tryp-tase to success?

Helyeh A. Sadreddini, Mia Warnes, Donna Traves

POSTER VIEWING SESSION 3: Miscellaneous (PP48–PP58)

PP48 Surveillance study on safety of SLIT in pediatric population

Ivana Djuric-Filipovic, Zorica Zivkovic, Snežana Zivanovic, Gordana Kostić, Đorđe Filipovic

PP49 Efficacy and safety of mixed mite subcutaneous immunotherapy among allergic rhinitis patients in the Northeastern Thailand

Sawapon Sittisomwong, Siripong Sittisomwong

PP50 Effect of inhaled beclomethasone or placebo on brain stem activity in a patient chronically treated with steroids: preliminary report

Zygmunt Podolec, Marcin Hartel, Daria Panek, Magdalena Podolec-Rubiś, Tomasz Banasik

PP51 Sensitisation to aeroallergens in patients with allergic rhinitis, asthma and atopic dermatitis in Shiraz, Southwestern Iran

Elham Abbasi, Mozhgan Moghtaderi

PP52 Referring a child for allergy test: how appropriate are we?

Phani Sanneerappa, Alina Deliu, Moosa Kutty, Nagabathula Ramesh

PP53 EBV lymphoproliferative disease and cardiac lymphoma in a STK4 deficient patient

Roya Sherkat, Mohammad Reza Sabri, Bahar Dehghan, Hamid Bigdelian, Nahid Raeesi, Mino Afshar, Hamid Rahimi, Christoph Klein

PP54 A case study: the effect of massive honeybees attack on various body parameters atopic girl including allergy

Mohemid Al-Jebouri

PP55 The role of TLR9, NLRP3 and proIL-1β in activation of antiviral innate immunity

Oxana A. Svitich, Daria O. Zubacheva, Dmitrii A. Potemkin, Ludmila V. Gankovskaya, Vitalii V. Zverev

PP56 Overnight pulse oximetry, as a screening tool to diagnose obstructive sleep apnoea. How effective is it?

Phani Sanneerappa, Elaine OB Doyle, Paul Gallagher, Nagabathula Ramesh

PP57 The presentation and management of acute urticaria and allergic reactions in children in a multi-ethnic, inner city Emergency Department (ED)

Sherine Dewlett, Kin Man, Minal Gandhi, James Pocock, Anna Gerrardhughes

PP58 Food allergens responsible for delayed-type sensitisation in atopy patch test in children diagnosed with autism spectrum disorder

Jolanta Wasilewska, Maciej Kaczmarski, Dariusz Lebensztejn

POSTER VIEWING SESSION 4: Asthma—Rhinitis (PP59–PP87)

PP59 Systematic review of incense as a trigger factor for asthma

Chandramani Thuraisingham, Davendralingam Sinniah

PP60 Increased risks of mood and anxiety disorders in children with asthma

Yue Chen, Xiaomei Mei

PP61

PP62 Asthma Control Test (ACT) and Pediatric Asthma Quality of Life Questionnaire (PAQLQ) association in children

Sebnem Ozdogan, Pinar Karadeniz, Durdugul Ayyildiz-Emecen, Ummuhan Oncul

PP63 Seasonal and gender variations in vitamin D levels in children with asthma and its association with pulmonary function tests

Sebnem Ozdogan, Gizem Sari, Sabanur Cavdar

PP64 Defining treatment response in childhood asthma: rationale and design of the Pharmacogenomics in the Childhood Asthma (PiCA) consortium

Niloufar Farzan, Susanne J. Vijverberg, Colin J. Palmer, Kelan G. Tantisira, Anke-Hilseon Maitland-van der Zee behalf of the PiCA consortium

PP65 Prevalence of asthma and allergic disease in patients with inflammatory disease compared to celiac disease

Fatma Yavuzyilmaz, Sebnem Ozdogan, Nafiye Urganci, Merve Usta

PP66 A severe case with cystic fibrosis (CF) asthma

Mehmet Hoxha, Maksim Basho

PP67 Severe asthma exacerbation complicated with pneumothorax in a child with uncontrolled asthma due to poor treatment compliance

Ioana Valentina Nenciu, Andreia Florina Nita, Adina Lazar, Alexandru Ulmeanu, Carmen Zapucioiu, Dumitru Oraseanu

PP68 Evaluation of the Pediatric Quality of Life inventory (PedsQL) asthma module among low income asthmatic children and adolescents in Sao Paolo, Brazil

Gustavo F. Wandalsen, Fernanda Monteiro, Dirceu Solé

PP69 Early initiation of specific immunotherapy in asthma patients leads to higher benefits

Blerta Lame, Eris Mesonjesi, Arjeta Sherri

PP70 Treatment resistant asthma and rhinosinusitis with recurrent pulmonary infections. Is it primary ciliary dyskinesia?

Alkerta Ibranji, Laert Gjati, Gjustina Loloci, Ardii Bardhi

PP71 The comparison of sensitisation to animal allergens in children- and adult- onset patients with asthma

Behnam Moghtaderi, Shirin Farjadian, Dorna Eghtedari

PP72 Characterisation of children less than five years with wheezing episodes in Cali, Colombia

Manuela Olaya, Laura Del Mar Vasquez, Luis Fernando Ramirez, Carlos Daniel Serrano

PP73 Evaluation of the patients with recurrent croup

Belgin Usta Guc, Suna Asilsoy, Fulya Ozer

PP74 Obesity in adolescence compromising the asthma control

Guergana Petrova, Sylvia Shopova, Vera Papochieva, Snezhina Lazova, Dimitrinka Miteva, Penka Perenovska

PP75 Sleep behavior in children with persistent allergic rhinitis

Gustavo F. Wandalsen, Jessica Loekmanwidjaja, Márcia Mallozi, Dirceu Solé

PP76 Randomised trial of the safety of MP29-02* compared with fluticasone propionate nasal spray in children aged ≥4 years to <12 years with allergic rhinitis

William Berger, Ulrich Wahn, Paul Ratner, Daniel Soteres

PP77 Safety and tolerability evaluation of bilastine 10 mg in children from 2 to 11 years of age with allergic rhinoconjunctivitis or urticaria

Zoltán Novák, Anahí Yáñez, Kiss Ildikó, Piotr Kuna, Miguel Tortajada, Román Valiente, the Bilastine Pediatric Safety Study Group

PP78 Sensitisation to Alternaria alternata: Is it a risk factor for severe rhinitis?

Susana Lopes, Filipa Almeida, Tânia Lopes, Cristina Madureira, José Oliveira, Fernanda Carvalho

PP79 Validation of the Patient Benefit Index (PBI) for the assessment of patient-related outcomes in allergic rhinitis in children

Julia Feuerhahn, Christine Blome, Meike Hadler, Efstrathios Karagiannis, Anna Langenbruch, Matthias Augustin

PP80 Efficacy of sublingual tablet of house dust mite allergen extracts in adolescents with house dust mite-associated allergic rhinitis

Michel Roux, Shinji Kakudo, Efstrathios Karagiannis, Robert K. Zeldin

PP81 Lung function improvement in a child treated with omalizumab for bronchial asthma

Anna Sokolova, Tiago Milheiro Silva

PP82 How to treat a child suffering from asthma, allergic rhinitis, allergy to peanuts and diabetes at the same time?

Snezana S. Zivanovic, Vesna Cvetkovic, Ivana Nikolic, Sonja J. Zivanovic

PP83 Nitric oxide in exhaled air in the relationship of the degree of sensitisation to aeroallergens

Snezana S. Zivanovic, Ljiljana Saranac, Ivana Nikolic, Sonja J. Zivanovic, Zorica Zivkovic

PP84 Clinical basis of diagnostic errors in pediatric asthma

Zoia Nesterenko

PP85

PP86 Childhood asthma control in Serbia and organised Asthma Educational Intervention (AEI)

Snezana Radic, Branislava Milenkovic, Spomenka Smiljanic, Milka Micic-Stanijevic, Olivera Calovic

PP87 Experience from a group of adolescents with severe allergic asthma treated with Omalizumab

Anne Marie Bro Hofbauer, Lone Agertoft

THEMATIC POSTER SESSION 1: Prevention and Treatment—Epidemiology (TP01–TP18)

TP01 A cost effective primary school asthma education program: pilot study from inner London schools

Lucy Everson, Jessica Kearney, Jonny Coppel, Simon Braithwaite, Rahul Chodhari

TP02 The prevalence of allergic diseases among 14–15 years old adolescents in two Danish birth cohorts 14 years apart

Elisabeth S. Christiansen, Henrik Fomsgaard Kjaer, Esben Eller, Charlotte G. Mørtz, Susanne Halken

TP03 Does pattern of sensitisation to phleum pratense change with age? Is it different in children with allergic rhinitis or asthma?

Cristina Román India, Ana Moreira Jorge, Loreto González Domínguez, Cristina Muñoz Archidona, Sergio Quevedo Teruel, Teresa Bracamonte Bermejo, Juana Jiménez Jiménez, Luis Echeverría Zudaire

TP04 Practicalities of prevention of peanut allergy: modelling a national response to LEAP

Cathal O’Connor, Jonathan Hourihane

TP05 Comparison of the influence of sunflower seed oil and skin care lotion on the skin barrier function of newborns: a randomised controlled trial

Varvara Kanti, Lena Lünnemann, Günther Malise, Laine Ludriksone, Andrea Stroux, Wolfgang Henrich, Michael Abu-Dakn, Ulrike Blume-Peytavi, Natalie Garcia Bartels

TP06 The effect of daily skin care on skin barrier properties in infants with dry skin and risk for atopic dermatitis

Varvara Kanti, Lena Lünnemann, Laine Ludriksone, Marianne Schario, Andrea Stroux, Ulrike Blume-Peytavi, Natalie Garcia Bartels

TP07 Change in sum total aeroallergen skin prick test wheal diameters at 6 months predicts which children will respond to subcutaneous immunotherapy by three years

Thorsten Stanley, Nicolien Brandenbarg

TP08 Are mobile apps regarding adrenaline auto-injectors accessed by adolescents for support and education in the community?

Alia Boardman, Gary McGreevy, Emily Rodger, Katherine Knight, Victoria Timms, Trisha Taylor, Gemma Scanlan, Roisin Fitzsimons

TP09

TP10 Prevention of early atopic dermatitis among low-atopy-risk infants by immunoactive prebiotics is not sustained after the first year of life

Grüber Christoph, Ulrich Wahn, Margriet van Stuivenberg, Fabio Mosca, Guido Moro, Gaetano Chirico, Christian P. Braegger, Joseph Riedler, Yalcin Yavuz, Günther Boehm

TP11

TP12

TP13 Treatment with Omalizumab in a 16-year-old Caucasian girl with refractory solar urticaria

Stefania Arasi, Giuseppe Crisafulli, Lucia Caminiti, Federica Porcaro, Giovanni Battista Pajno

TP14 Ultra-pure soft water ameliorates skin conditions of adult and child patients with atopic dermatitis

Akane Tanaka, Yaei Togawa, Kumiko Oida, Naotomo Kambe, Peter Arkwright, Yosuke Amagai, Naoki Shimojo, Yasunori Sato, Hiroyuki Mochizuki, Hyosun Jang, Saori Ishizaka, Hiroshi Matsuda

TP15 Potential adjuvant effect of immunomodulator to improve specific immunotherapy in asthmatic child

Wisnu Barlianto, Ery Olivianto, H. M. S. Chandra Kusuma

TP16 How can Component Resolved Diagnosis (CRD) influence in Specific Immunotherapy (SIT) prescription, in a Spanish children population

Ana Moreira Jorge, Cristina Román India, Loreto González Domínguez, Cristina Muñoz Archidona, Juana Jiménez Jiménez, Teresa Bracamonte Bermejo, Sergio Quevedo Teruel, Luis Echeverría Zudaire

TP17 Mitochondrial dysfunction in food allergy: effects of L. rhamnosus GG in a mice model of peanut allergy

Rosita Aitoro, Mariapia Mollica, Roberto Berni Canani, Giovanna Trinchese, Elena Alfano, Antonio Amoroso, Lorella Paparo, Francesco Amato, Claudio Pirozzi, Antonio Calignano, Rosaria Meli

TP18 Prediction of atopic diseases in childhood: elevated blood eosinophils in infancy in a high risk birth cohort

Siri Rossberg, Kerstin Gerhold, Kurt Zimmermann, Mohammad Zaino, Thomas Geske, Eckard Hamelmann, Susanne Lau

THEMATIC POSTER SESSION 2: Food allergy—Anaphylaxis (TP19–TP38)

TP19

TP20

TP21 Double-blind provocation tests in non-IgE mediated cow’s milk allergy and the occurrence of placebo reactions

Sarah Bogovic, Jochem van den Berg, Chantal Janssen

TP22 Gradual introduction of baked egg (BE) in egg allergic patients under 2 years old

Angela Claver

TP23 Randomised controlled trial of SOTI with raw hen’s egg in children with persistent egg allergy I: safety and efficacy of daily vs. weekly protocols of induction

Mª Flor Martin-Muñoz, C. Martorell, M. T. Belver, E. Alonso Lebrero, L. Zapatero, V. Fuentes, M. Piqué, A. Plaza, C. Muñoz, A. Martorell, Cristina Blasco, B. Villa, C. Gómez, S. Nevot, J. M. García, L. Echeverria

TP24 Randomised controlled trial of SOTI with raw hen’s egg in children with persistent egg allergy II: a randomised controlled trial to study a safer, more effective and easy to perform maintenance (daily vs. every two days) pattern of egg SOTI

Mª Flor Martin-Muñoz, C. Martorell, M. T. Belver, E. Alonso Lebrero, L. Zapatero, V. Fuentes, M. Piqué, A. Plaza, C. Muñoz, A. Martorell, Cristina Blasco, B. Villa, C. Gómez, S. Nevot, J. M. García, L. Echeverria

TP25 Determining the safety of baked egg home reintroduction for children with mild egg allergy

Brenda DeWitt, Judith Holloway, Donald Hodge

TP26 Demographics, investigations and patterns of sensitisation in children with oral allergy syndrome in a London Teaching Hospital

Sian Ludman, Merhdad Jafari-Mamaghani, Rosemary Ebling, Adam T. Fox, Gideon Lack, George Du Toit

TP27 Airborne peanut challenge in children: allergic reactions are rare

Sofia Lovén Björkman, Caroline Nilsson, Natalia Ballardini

TP28 The nutty question on Pediatric Wards: to be or “nut” to be?

Supriyo Basu, Jenny Hallet, Jyothi Srinivas

TP29

TP30

TP31 Allergy education in nursery schools

Hazel Stringer, Nicola Jay

TP32 Food allergy in the first year of life

Tânia Lopes, Cristina Madureira, Filipa Almeida, Susana Lopes, Paula Fonseca, Clara Vieira, Fernanda Carvalho

TP33 Prevalence and geographic distribution of oral allergy syndrome in Italian children: a multicenter study

Carla Mastrorilli, Carlo Caffarelli, Riccardo Asero, Salvatore Tripodi, Arianna Dondi, Gianpaolo Ricci, Carlotta Povesi Dascola, Elisabetta Calamelli, Francesca Cipriani, Andrea Di Rienzo Businco, Annamaria Bianchi, Paolo Candelotti, Tullio Frediani, Carmen Verga, Paolo Maria Matricardi

TP34 Are common standardised allergen extracts used in skin test enough in the diagnosis of nuts allergy?

Cristina Muñoz Archidona, Loreto González Domínguez, Ana Moreira Jorge, Sergio Quevedo Teruel, Teresa Bracamonte Bermejo, Miriam Castillo Fernández, Fernando Pineda de la Losa, Luis Ángel Echeverría Zudaire

TP35 Evaluation of IgE sensitisation in children with allergic proctocolitis and its relationship to atopic dermatitis

Despina Mermiri, Paraskevi Korovessi, Skevi Tiliakou, Evaggelia Tavoulari, Kalliopi-Maria Moraiti, Fotini Giannoula, Athina Papadopoulou

TP36 Food allergy in children: are we managing them appropriately in the Emergency Department?

Wan Jean Tee, Samir Deiratany, Raymond Seedhoo, Roisin McNamara, Ike Okafor

TP37 Importance of oil body associated allergenic proteins in nuts suspected allergy children

Loreto González Domínguez, Ana Moreira Jorge, Cristina Muñoz Archidona, Teresa Bracamonte Bermejo, Sergio Quevedo Teruel, Fernando Pineda de la Losa, Miriam Castillo Fernández, Luis Ángel Echeverría Zudaire

TP38 Practical application of basophil activation test in children with food allergy

Ekaterina Khaleva, Gennady Novic, Natalia Bychkova

THEMATIC POSTER SESSION 3: Asthma (TP39–TP57)

TP39 Effect of corticosteroid therapy upon serum magnesium level in chronic asthmatic children

Amany Abd Al-Aziz, Amany Fatouh, Ayat Motawie, Eman El Bostany, Amr Ibrahim

TP40 ADAM33 in Bulgarian children with asthma

Guergana Petrova, Dimitrinka Miteva, Snezhina Lazova, Penka Perenovska, Sylvia Andonova, Alexey Savov

TP41

TP42 The impact of vitamin D serum levels in asthma and allergic rhinitis

Maria Zoto, Marialena Kyriakakou, Paraskevi Xepapadaki, Nikolaos G. Papadopoulos

TP43 Life-threatening, first reported, paradoxical bronchospasm after nebulised Salbutamol in a 10 year old child

Paraskevi Korovessi, Mariza Vassilopoulou, Athina Balaska, Lambros Banos, Stavroula Kostaridou, Despina Mermiri

TP44

TP45 Asthma symptoms in children with treatment for allergic rhinoconjunctivitis

Jorien Wartna, Arthur M. Bohnen, Gijs Elshout, David H. J. Pols, Patrick J. E. Bindels

Erasmus MC, Rotterdam, The Netherlands

TP46 Atopy increased the risk of developing exercise-induced bronchoconstriction in young athletes

Sven F. Seys; Ellen Dilissen, Sarah Van der Eycken, An-Sofie Schelpe, Gudrun Marijsse, Thierry Troosters, Vincent Vanbelle, Sven Aertgeerts, Jan L. Ceuppens, Lieven J. Dupont, Koen Peers, Dominique M. Bullens

TP47 The effect of higher BMI on risk for asthma and treatment outcome in overweight and obese children

Ivana Banic, Sandra Bulat Lokas, Jelena Zivkovic, Boro Nogalo, Iva Mrkic Kobal, Davor Plavec, Mirjana Turkalj

TP48

TP49

TP50

TP51

TP52 The impact of a multidisciplinary project intended to change the culture of nebulisers towards pressurised metered dose inhalers

Georgeta Oliveira, Katharine Pike, Alda Melo, Tomás Amélia, José Carlos Cidrais Rodrigues, Cristina Serrano, José Manuel Lopes dos Santos, Carla Lopes

TP53

TP54

TP55

TP56 Increased asthma control in patients with severe persistent allergic asthma after 12 month of nightly temperature controlled laminar airflow (TLA)

Eckard Hamelmann, Uwe Schauer, Karl-Christian Bergmann

TP57

THEMATIC POSTER SESSION 4: Drug allergy—Dermatology (TP58–TP77)

TP58 Should we proceed directly to provocation challenges to diagnose drug allergy? Our experience says yes

Luis Moral, Teresa Toral, Nuria Marco, Beléns García Avilés, Mª Jesús Fuentes, Jesús Garde, Cristina Montahud, Javier Perona, Mª José Forniés

TP59 Anaphylaxis to 13-valent pneumococcal vaccine

Esozia Arroabarren, Marta Anda, Maria Luisa Sanz, Maria Teresa Lizaso, Candida Arregui

TP60 Intrapartum antibiotic exposure for treatment of group B streptococcus was not associated with the development of penicillin allergy in children

Sara May, Martha Hartz, Avni Joshi, Miguel A. Park

TP61 Evaluation of suspected drug hypersensitivity reactions in 169 children referred to the General Hospital

Sonja Posega Devetak, Tina Vesel, Anja Koren Jeverica, Tadej Avčin

TP62 Drug provocation testing: experience of a tertiary hospital

Leonor Castro, Carolina Gouveia, Ana Carvalho Marques, Antonio Jorge Cabral

TP63 Perioperative anaphylaxis: a growing concern in pediatric population

Luis Amaral, Fabrícia Carolino, Eunice Castro, Madalena Passos, Josefina R. Cernadas

TP64 Raising awareness of hypersensitivity to non-steroidal anti-inflammatory drugs in the pediatric age

Fabrícia Carolino, Luís Amaral, Eunice Dias de Castro, Josefina R. Cernadas

TP65 Perioperative anaphylaxis in young children: how to confirm the suspicion

Josefina R. Cernadas, Fabrícia Carolino, Luís Amaral, Fernando Pineda, Armanda Gomes

TP66 A case study of a child suspected to be penicillin allergic-digging deeper

Katherine Knight, Roisin Fitzsimons, Helen Brough

TP67 Prevalence, characteristics and risk factors of hypersensitivity reactions to antibiotics in patients with cystic fibrosis

Jobst Röhmel, Carsten Schwarz, Anne Mehl, Philippe Stock, Doris Staab

TP68 Antibiotic drug hypersensitivity in cystic fibrosis: A pilot study using cellular allergy tests for diagnostics

Jobst Röhmel, Carsten Schwarz, Christine Seib, Doris Staab, Philippe Stock

TP69 Oral antibiotics challenges in children

Anita Critchlow, Alyson Barber, Nicola Jay

TP70 Hypersensitivity reaction to vancomycin: a new successful desensitization protocol

Belen Delavalle, Teresa Garriga, Blanca Vilá, Cristina Blasco

TP71

TP72 Clinical phenotypes according to FLG gene loss of function mutations in children with atopic dermatitis

Francesca Cipriani, Annalisa Astolfi, Costanza Di Chiara, Elisabetta Calamelli, Iria Neri, Annalisa Patrizi, Gianpaolo Ricci

TP73

TP74 Urticaria in children: clinical and epidemiological features

Katerina Neskorodova, Asya Kudryavtseva

TP75

TP76 Acute urticaria at the Pediatrics Emergency Department: is it allergy?

Esozia Arroabarren, Jorge Alvarez, Marta Anda, Miriam Palacios, Marta Martinez-Merino, Ibone Vaquero

TP77

The genetics of the skin barrier in eczema and other allergic disorders

PURPOSE OF REVIEW

We summarize current knowledge on the genetic determinants of skin barrier deficiency in relation to eczema and disease progression to other allergic manifestations.

RECENT FINDINGS

There is increasing evidence that impairment of epidermal barrier function is not only a risk factor for the development of eczema but also for disease progression to allergic airway disease and food allergy. Support comes from recent association studies linking genetic variants in epidermal genes with eczema and food allergy, from monogenic diseases with severe skin barrier defects which display multiple allergic manifestations, and from mouse models providing a mechanism from skin inflammation to allergic reactions in the lung and intestine.

SUMMARY

The key role of the skin barrier defect in the development of eczema and eczema-associated allergic diseases may have important implications for prevention and treatment strategies. Initial clinical trials with moisturizing creams revealed promising results for the prevention of eczema in early infancy. Their long-term effects will be critical to demonstrate the potential benefit of barrier repair therapy in allergic disease prevention.

DNA methylation within melatonin receptor 1A (MTNR1A) mediates paternally transmitted genetic variant effect on asthma plus rhinitis

BACKGROUND

Asthma and allergic rhinitis (AR) are common allergic comorbidities with a strong genetic component in which epigenetic mechanisms might be involved.

OBJECTIVE

We aimed to identify novel risk loci for asthma and AR while accounting for parent-of-origin effect.

METHODS

We performed a series of genetic analyses, taking into account the parent-of-origin effect in families ascertained through asthma: (1) genome-wide linkage scan of asthma and AR in 615 European families, (2) association analysis with 1233 single nucleotide polymorphisms (SNPs) covering the significant linkage region in 162 French Epidemiological Study on the Genetics and Environment of Asthma families with replication in 154 Canadian Saguenay-Lac-Saint-Jean asthma study families, and (3) association analysis of disease and significant SNPs with DNA methylation (DNAm) at CpG sites in 40 Saguenay-Lac-Saint-Jean asthma study families.

RESULTS

We detected a significant paternal linkage of the 4q35 region to asthma and allergic rhinitis comorbidity (AAR; P = 7.2 × 10(-5)). Association analysis in this region showed strong evidence for the effect of the paternally inherited G allele of rs10009104 on AAR (P = 1.1 × 10(-5), reaching the multiple-testing corrected threshold). This paternally inherited allele was also significantly associated with DNAm levels at the cg02303933 site (P = 1.7 × 10(-4)). Differential DNAm at this site was found to mediate the identified SNP-AAR association.

CONCLUSION

By integrating genetic and epigenetic data, we identified that a differentially methylated CpG site within the melatonin receptor 1A (MTNR1A) gene mediates the effect of a paternally transmitted genetic variant on the comorbidity of asthma and AR. This study provides a novel insight into the role of epigenetic mechanisms in patients with allergic respiratory diseases.

Multi-ancestry genome-wide association study of 21,000 cases and 95,000 controls identifies new risk loci for atopic dermatitis

Genetic association studies have identified 21 loci associated with atopic dermatitis risk predominantly in populations of European ancestry. To identify further susceptibility loci for this common complex skin disease, we performed a meta-analysis of >15 million genetic variants in 21,399 cases and 95,464 controls from populations of European, African, Japanese and Latino ancestry, followed by replication in 32,059 cases and 228,628 controls from 18 studies. We identified 10 novel risk loci, bringing the total number of known atopic dermatitis risk loci to 31 (with novel secondary signals at 4 of these). Notably, the new loci include candidate genes with roles in regulation of innate host defenses and T-cell function, underscoring the important contribution of (auto-)immune mechanisms to atopic dermatitis pathogenesis.

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

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 genome's 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 (R1_{meta-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, P_{meta-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.

Most human diseases are caused by a combination of multiple environmental and genetic influences. The widely used case/control approach aims to identify disease risk genes by comparing the genetic constitution of affected and healthy individuals. Although successful, this approach ignores additional mechanisms influencing disease risk. Here, we studied mutations in the filaggrin gene (FLG), which are strong risk factors for atopic dermatitis (AD) and allergies, in a large number of families with AD. We found that FLG mutations in the mother, not the father, increased the AD risk of the children, even if the child did not inherit the mutation. Thus, our study revealed, for the first time, a direct influence of a maternal mutation on the child’s risk for a common disease. The maternal FLG effect was only found when the mothers were allergic, and was absent in families of non-allergic mothers. This finding suggests that FLG-induced changes in the maternal immune response shape the child’s immune system during pregnancy and increase the child’s risk for AD. Our study indicates that maternal FLG mutations act as strong environmental risk factors for the child and highlights the potential of family-based studies in uncovering novel disease mechanisms in medical genetics.

Genome-wide comparative analysis of atopic dermatitis and psoriasis gives insight into opposing genetic mechanisms

Atopic dermatitis and psoriasis are the two most common immune-mediated inflammatory disorders affecting the skin. Genome-wide studies demonstrate a high degree of genetic overlap, but these diseases have mutually exclusive clinical phenotypes and opposing immune mechanisms. Despite their prevalence, atopic dermatitis and psoriasis very rarely co-occur within one individual. By utilizing genome-wide association study and ImmunoChip data from >19,000 individuals and methodologies developed from meta-analysis, we have identified opposing risk alleles at shared loci as well as independent disease-specific loci within the epidermal differentiation complex (chromosome 1q21.3), the Th2 locus control region (chromosome 5q31.1), and the major histocompatibility complex (chromosome 6p21-22). We further identified previously unreported pleiotropic alleles with opposing effects on atopic dermatitis and psoriasis risk in PRKRA and ANXA6/TNIP1. In contrast, there was no evidence for shared loci with effects operating in the same direction on both diseases. Our results show that atopic dermatitis and psoriasis have distinct genetic mechanisms with opposing effects in shared pathways influencing epidermal differentiation and immune response. The statistical analysis methods developed in the conduct of this study have produced additional insight from previously published data sets. The approach is likely to be applicable to the investigation of the genetic basis of other complex traits with overlapping and distinct clinical features.

Genome-wide association study of body mass index in 23 000 individuals with and without asthma

BACKGROUND

Both asthma and obesity are complex disorders that are influenced by environmental and genetic factors. Shared genetic factors between asthma and obesity have been proposed to partly explain epidemiological findings of co-morbidity between these conditions.

OBJECTIVE

To identify genetic variants that are associated with body mass index (BMI) in asthmatic children and adults, and to evaluate if there are differences between the genetics of BMI in asthmatics and healthy individuals.

METHODS

In total, 19 studies contributed with genome-wide analysis study (GWAS) data from more than 23 000 individuals with predominantly European descent, of whom 8165 are asthmatics.

RESULTS

We report associations between several DENND1B variants (P = 2.2 × 10(-7) for rs4915551) on chromosome 1q31 and BMI from a meta-analysis of GWAS data using 2691 asthmatic children (screening data). The top DENND1B single nucleotide polymorphisms(SNPs) were next evaluated in seven independent replication data sets comprising 2014 asthmatics, and rs4915551 was nominally replicated (P < 0.05) in two of the seven studies and of borderline significance in one (P = 0.059). However, strong evidence of effect heterogeneity was observed and overall, the association between rs4915551 and BMI was not significant in the total replication data set, P = 0.71. Using a random effects model, BMI was overall estimated to increase by 0.30 kg/m(2) (P = 0.01 for combined screening and replication data sets, N = 4705) per additional G allele of this DENND1BSNP. FTO was confirmed as an important gene for adult and childhood BMI regardless of asthma status.

CONCLUSIONS AND CLINICAL RELEVANCE

DENND1B was recently identified as an asthma susceptibility gene in a GWAS on children, and here, we find evidence that DENND1B variants may also be associated with BMI in asthmatic children. However, the association was overall not replicated in the independent data sets and the heterogeneous effect of DENND1B points to complex associations with the studied diseases that deserve further study.

Multi-locus stepwise regression: a haplotype-based algorithm for finding genetic associations applied to atopic dermatitis

Background

Genome-wide association studies (GWAS) provide an increasing number of single nucleotide polymorphisms (SNPs) associated with diseases. Our aim is to exploit those closely spaced SNPs in candidate regions for a deeper analysis of association beyond single SNP analysis, combining the classical stepwise regression approach with haplotype analysis to identify risk haplotypes for complex diseases.

Methods

Our proposed multi-locus stepwise regression starts with an evaluation of all pair-wise SNP combinations and then extends each SNP combination stepwise by one SNP from the region, carrying out haplotype regression in each step. The best associated haplotype patterns are kept for the next step and must be corrected for multiple testing at the end. These haplotypes should also be replicated in an independent data set. We applied the method to a region of 259 SNPs from the epidermal differentiation complex (EDC) on chromosome 1q21 of a German GWAS using a case control set (1,914 individuals) and to 268 families with at least two affected children as replication.

Results

A 4-SNP haplotype pattern with high statistical significance in the case control set (p = 4.13 × 10^-7 after Bonferroni correction) could be identified which remained significant in the family set after Bonferroni correction (p = 0.0398). Further analysis revealed that this pattern reflects mainly the effect of the well-known FLG gene; however, a FLG-independent haplotype in case control set (OR = 1.71, 95% CI: 1.32-2.23, p = 5.6 × 10^-5) and family set (OR = 1.68, 95% CI: 1.18-2.38, p = 2.19 × 10^-3) could be found in addition.

Conclusion

Our approach is a useful tool for finding allele combinations associated with diseases beyond single SNP analysis in chromosomal candidate regions.

The eczema risk variant on chromosome 11q13 (rs7927894) in the population-based ALSPAC cohort: a novel susceptibility factor for asthma and hay fever

In a genome-wide association study, a common variant on chromosome 11q13.5 (rs7927894[T]) has been identified as a susceptibility locus for eczema. We aimed to analyze the effect of this risk variant on asthma and hay fever and to determine its impact on the general population level in over 9300 individuals of the prospectively evaluated Avon Longitudinal Study of Parents and Children birth cohort. We demonstrate an association of rs7927894[T] with atopic asthma and with hay fever. The largest effect sizes were found in patients with the combined phenotype atopic asthma plus eczema [odds ratio (OR) = 1.50; 95% confidence interval (CI) 1.20-1.88; P = 3.7 × 10(-4)] and hay fever plus eczema (OR = 1.37; 95% CI 1.15-1.62; P = 3.8 × 10(-4)). We replicated the effects of rs7927894[T] on eczema-associated asthma and hay fever independently in the German GENUFAD (GEnetic studies in NUclear Families with Atopic Dermatitis) study and show that they are significantly larger than the effect observed in eczema. The estimated population attributable risk fractions for eczema, eczema-associated atopic asthma or hay fever were 9.3, 24.9 and 23.5%, respectively. Finally in eczema, we found a synergistic interaction of rs7927894[T] with filaggrin gene (FLG) mutations, which are a major cause of epidermal barrier dysfunction, and replicated the interaction in the German Multicenter Allergy Study birth cohort. The synergistic effect of rs7927894[T] and FLG mutations on eczema risk as well as the association of both variants with eczema-associated atopic asthma and hay fever point to an involvement of rs7927894[T] in a functional pathway that is linked to the barrier defect.

Variants in a novel epidermal collagen gene (COL29A1) are associated with atopic dermatitis

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder and a major manifestation of allergic disease. AD typically presents in early childhood often preceding the onset of an allergic airway disease, such as asthma or hay fever. We previously mapped a susceptibility locus for AD on Chromosome 3q21. To identify the underlying disease gene, we used a dense map of microsatellite markers and single nucleotide polymorphisms, and we detected association with AD. In concordance with the linkage results, we found a maternal transmission pattern. Furthermore, we demonstrated that the same families contribute to linkage and association. We replicated the association and the maternal effect in a large independent family cohort. A common haplotype showed strong association with AD (p = 0.000059). The associated region contained a single gene, COL29A1, which encodes a novel epidermal collagen. COL29A1 shows a specific gene expression pattern with the highest transcript levels in skin, lung, and the gastrointestinal tract, which are the major sites of allergic disease manifestation. Lack of COL29A1 expression in the outer epidermis of AD patients points to a role of collagen XXIX in epidermal integrity and function, the breakdown of which is a clinical hallmark of AD.

Atopic dermatitis (AD, eczema) is a common chronic inflammatory skin disorder and a major manifestation of allergic disease. Typically, AD first occurs in early childhood, often preceding the onset of allergic airways disease, such as asthma and hay fever. A family history of allergic disorders is the single strongest predictor for AD, showing that genetic factors play a major role in the disease development. We have previously mapped a disease locus for AD on Chromosome 3q21, Now we have used a dense map of microsatellite markers and single nucleotide polymorphisms (SNPs) to find the underlying disease gene. We identified genetic markers in a subregion that showed association with AD, and replicated this finding in a large independent family cohort. The associated region contained a single gene, COL29A1, which encodes a novel collagen. We demonstrate that AD patients lack COL29A1 expression in the outer epidermis, implicating collagen XXIX in epidermal integrity and function. The gene expression pattern of COL29A1 in other organs, including the lung and the gut, suggests that this gene could have a role in a wider spectrum of allergic diseases and may provide a molecular link between AD and respiratory airways disease and food allergies.

The gene underlying atopic dermatitis susceptibility has been identified by gene mapping as expressing a novel collagen, whose expression is lacking in the outer epidermis of atopic dermatitis patients.

A common haplotype of the IL-31 gene influencing gene expression is associated with nonatopic eczema

BACKGROUND

IL-31 is a novel cytokine that, when overexpressed in transgenic mice, induces severe itching dermatitis resembling human eczema.

OBJECTIVE

We aimed to evaluate the importance of polymorphisms in the human IL-31 gene (IL31) in the genetic susceptibility to eczema.

METHODS

We sequenced the entire IL-31 gene, including the promoter region, and determined the haplotype structure. Single nucleotide polymorphisms tagging the main haplotypes were genotyped in 3 independent European populations comprising 690 affected families. An association analysis of IL31 gene variants with atopic and nonatopic eczema was performed.

RESULTS

We found significant association of a common IL31 haplotype with the nonatopic type of eczema in all 3 study populations (combined P = 4.5 x 10(-5)). Analysis of PBMCs in healthy individuals revealed a strong induction IL31 mRNA expression on stimulation with anti-CD3 and anti-CD28 that was 3.8-fold higher in individuals homozygous for the risk haplotype (AA) in contrast to non-A haplotype carriers, suggesting that altered regulation of IL-31 gene expression is the disease-causing factor.

CONCLUSION

Our results lend strong support to an important role of IL-31 in the pathogenesis of nonatopic eczema.

CLINICAL IMPLICATIONS

This study presents the first genetic risk factor for the nonatopic type of eczema and indicates a primary role of IL-31-induced pruritus in the initiation of this disease, thus proposing a new target for the prevention and therapy of eczema.

Gain-of-function mutations in complement factor B are associated with atypical hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) is an important cause of acute renal failure in children. Mutations in one or more genes encoding complement-regulatory proteins have been reported in approximately one-third of nondiarrheal, atypical HUS (aHUS) patients, suggesting a defect in the protection of cell surfaces against complement activation in susceptible individuals. Here, we identified a subgroup of aHUS patients showing persistent activation of the complement alternative pathway and found within this subgroup two families with mutations in the gene encoding factor B (BF), a zymogen that carries the catalytic site of the complement alternative pathway convertase (C3bBb). Functional analyses demonstrated that F286L and K323E aHUS-associated BF mutations are gain-of-function mutations that result in enhanced formation of the C3bBb convertase or increased resistance to inactivation by complement regulators. These data expand our understanding of the genetic factors conferring predisposition to aHUS, demonstrate the critical role of the alternative complement pathway in the pathogenesis of aHUS, and provide support for the use of complement-inhibition therapies to prevent or reduce tissue damage caused by dysregulated complement activation.

Filaggrin loss-of-function mutations predispose to phenotypes involved in the atopic march

BACKGROUND

Childhood eczema often precedes the development of asthma and allergic rhinitis in the so-called atopic march. Recently, 2 loss-of-function mutations in the gene encoding the epidermal barrier protein filaggrin were reported to be predisposing factors for eczema and concomitant asthma, suggesting a possible role in disease transition.

OBJECTIVE

We aimed to assess the importance of filaggrin loss-of-function mutations in the susceptibility to eczema and associated clinical phenotypes.

METHODS

The filaggrin mutations were genotyped and tested for association with allergic disorders in 2 large European populations including 1092 children with eczema.

RESULTS

Highly significant association of the filaggrin null mutations with eczema and concomitant asthma was replicated. Moreover, we found that these mutations predispose to asthma, allergic rhinitis, and allergic sensitization only in the presence of eczema. We show that the presence of 2 filaggrin null alleles is an independent risk factor for asthma in children with eczema, and that the 2 investigated mutations account for about 11% of eczema cases in the German population.

CONCLUSION

These results lend strong support to the role of filaggrin in the pathogenesis of eczema and in the subsequent progression along the atopic march. The fact that previous expression of eczema is a prerequisite for the manifestation of allergic airways disease and specific sensitization highlights the importance of the epidermal barrier in the pathogenesis of these disorders.

CLINICAL IMPLICATIONS

Our results suggest that the maintenance and repair of the epidermal barrier in infants with eczema may prevent the subsequent development of allergic airways disease.

De novo gene conversion in the RCA gene cluster (1q32) causes mutations in complement factor H associated with atypical hemolytic uremic syndrome

Many of the complement regulatory genes within the RCA cluster (1q32) have arisen through genomic duplication and the resulting high degree of sequence identity is likely to predispose to gene conversion events. The highest degree of identity is between the genes for factor H (CFH) and five factor H-related proteins--CFHL1, CFHL2, CFHL3, CFHL4, and CFHL5. CFH mutations are associated with atypical hemolytic uremic syndrome (aHUS). In the Newcastle cohort of 157 aHUS patients we have identified CFH mutations in 25 families or individuals. Eleven of these 25 independent mutations are either c.3226C>G,Q1076E; c.3572C>T,S1191L; c.3590T>C,V1197A or combined c.3572C>T,S1191L/c.3590T>C,V1197A. Sequence analysis shows that all four of these changes could have arisen as a result of gene conversion between CFH and CFHL1. Analysis of parental samples in two patients with S1191L/V1197A has shown that the changes are de novo thus providing conclusive evidence that gene conversion is the mutational mechanism in these two cases. To confirm that S1191L and V1197A are disease predisposing we examined their functional significance in three ways - analysis of the C3b/C3d binding characteristics of recombinant mutant S1191L/V1197A protein, heparin affinity chromatography and haemolytic assays of serum samples from aHUS patients carrying these changes. The results showed that these changes resulted in impaired C3b binding and a defective capacity to control complement activation on cellular surfaces. We, therefore, provide conclusive evidence that gene conversion is responsible for functionally significant CFH mutations in aHUS.

Expression of the peptide C4b-binding protein beta in the arthritic joint

BACKGROUND

C4b-binding protein (C4BP) is a plasma oligomeric glycoprotein that participates in the regulation of complement and haemostasis. Complement-regulatory activity depends on the C4BPalpha-polypeptide, whereas the C4BPbeta-polypeptide inactivates protein S, interfering with the anti-coagulatory protein C-dependent pathway.

OBJECTIVE

To investigate the expression of C4BPbeta in the rheumatoid joint.

METHODS

Expression of C4BP was studied in synovial explants from patients with rheumatoid arthritis, osteoarthritis and healthy controls, using immunohistochemistry and in situ hybridisation. C4BP isoforms and free C4BPbeta were studied in synovial effusions from patients with rheumatoid arthritis, osteoarthritis and microcrystalline arthritis (MCA) by immunoblotting; total and free protein S levels were studied by enzyme immunoassay.

RESULTS

C4BPbeta was overexpressed in the synovial membranes of patients with rheumatoid arthritis, in close association with the severity of synovitis and the extension of interstitial fibrin deposits. As many as 85% fluids from patients with rheumatoid arthritis contained free C4BPbeta, whereas this unusual polypeptide was present in 50% fluids from patients with MCA and 40% fluids from patients with osteoarthritis. Free protein S at the effusions was pathologically reduced in patients with rheumatoid arthritis and MCA, and remained normal in patients with osteoarthritis.

CONCLUSION

C4BPbeta is expressed by the inflamed synovial tissue, where it can participate in processes of tissue remodelling associated with invasive growth.

Insights into hemolytic uremic syndrome: segregation of three independent predisposition factors in a large, multiple affected pedigree

Mutations in the complement regulators factor H, membrane cofactor protein (MCP), and factor I are associated with atypical hemolytic uremic syndrome (aHUS, MIM 235400), suggesting that the disease develops as a consequence of the inefficient protection of the renal endothelium from damage by the complement system. Incomplete penetrance of the disease in individuals carrying these mutations is, however, relatively frequent. Here, we report the identification of a large, multiple affected aHUS pedigree in which there is independent segregation of three different aHUS risk factors: a MCP missense mutation (c.-598C>T; Pro165Ser) that decreases MCP expression on the cell surface, a dinucleotide insertion in the coding sequence of factor I (c.-1610insAT) that introduces a premature stop codon in the factor I protein, and the MCPggaac SNP haplotype block that was previously shown to decrease the transcription activity from the MCP promoter. Interestingly, individuals affected by aHUS in the pedigree are only those who have inherited the three aHUS risk factors. These data show an additive effect for mutations in MCP and factor I and provide definitive support to the conclusion that aHUS results from a defective protection of cellular surfaces from complement activation. Furthermore, they help to explain the incomplete penetrance of the disease, illustrating that concurrence of multiple hits in complement regulatory proteins may be necessary to significantly impair host tissue protection and to confer susceptibility to aHUS.

Predisposition to atypical hemolytic uremic syndrome involves the concurrence of different susceptibility alleles in the regulators of complement activation gene cluster in 1q32

The efficiency of the complement system as an innate immune defense mechanism depends on a fine control that restricts its action to pathogens and prevents non-specific damage to host tissues. Genetic and functional analyses have shown that this critical control of complement activation may be impaired in atypical hemolytic uremic syndrome (aHUS) patients. Mutations in HF1, MCP or FI have been found in aHUS patients, but incomplete penetrance of the disease in individuals carrying these mutations is relatively frequent and no genetic defect has yet been found in a majority of aHUS patients. We report here the identification of a specific SNP haplotype block, spanning the MCP gene in the regulators of complement activation gene cluster, which is over-represented in aHUS patients and strongly associates with the severity of the disease. Linkage disequilibrium analyses suggest that this SNP haplotype also includes the CR1, DAF and C4BP genes. Initial studies identified two SNPs in the haplotype that influence the transcription activity of the MCP promoter in transient transfection experiments. Notably, the SNP haplotype block was found to be particularly frequent among patients who carry mutations in HF1, MCP or FI. These findings and the identification of aHUS patients carrying mutations in two complement regulatory genes provide an important insight into the etiology of aHUS. Together, they suggest that complement regulatory molecules act as a protein network and that multiple hits, involving plasma- and membrane-associated complement regulatory proteins, are necessary to impair protection to host tissues and to confer significant predisposition to aHUS.

The human complement factor H: functional roles, genetic variations and disease associations

Factor H is an essential regulatory protein that plays a critical role in the homeostasis of the complement system in plasma and in the protection of bystander host cells and tissues from damage by complement activation. Genetic and structural data generated during recent years have been instrumental to delineate the functional domains responsible for these regulatory activities in factor H, which is helping to understand the molecular basis underlying the different pathologies associated to factor H. This review summarises our current knowledge of the role of factor H in health and disease.

Genetic and environmental factors influencing the human factor�H plasma levels

Factor H is a plasma protein that plays a critical role in the regulation of complement activation in fluid phase and on cellular surfaces. Over the years numerous reports have illustrated the association of factor H deficiencies with chronic renal and infectious diseases. Plasma levels of factor H show a five-fold range of variation in humans (116-562 microg/ml), which may also be relevant to disease susceptibility. To quantify the effects of the genetic and environmental factors responsible for the variation in the factor H plasma levels, we have applied variance-component methods to a family-based sample. Factor H plasma levels show an age-dependent increase ( P<0.0001) and are decreased in smokers ( P<0.0001). Interestingly, the heritability of the factor H trait is very high ( h(2)=0.62+/-0.07; P<0.0001), indicating that 62% of the factor H phenotypic variance is due to the additive effects of genes. On this premise, we conducted a genome-wide linkage screen in order to identify genes regulating the factor H trait. Three genomic regions (1q32, 2p21-24 and 15q22-24) provided suggestive evidence of linkage (LOD scores 2.03, 2.15 and 2.00, respectively) with the plasma levels of factor H.

Functional analysis of MCCA and MCCB mutations causing methylcrotonylglycinuria

Methylcrotonylglycinuria (MCG; MIM 210200) is an autosomal recessive inherited human disorder caused by the deficiency of 3-methylcrotonyl-CoA carboxylase (MCC, E.C.6.4.1.4), involved in leucine catabolism. This mitochondrial enzyme is one of the four biotin-dependent carboxylases known in humans. MCC is composed of two different types of subunits, alpha and beta, encoded by the nuclear genes MCCA and MCCB, respectively, recently cloned and characterized. Several mutations have been identified, in both genes, the majority are missense mutations along with splicing mutations and small insertions/deletions. We have expressed four missense mutations, two MCCA and two MCCB mapping to highly evolutionarily conserved residues, by transient transfection of SV40-transformed deficient fibroblasts in order to confirm their pathogenic effect. All the missense mutations expressed resulted in null or severely diminished MCC activity providing direct evidence that they are disease-causing ones. The MCCA mutations have been analysed in the context of three-dimensional structural information modelling the changes in the crystallized biotin carboxylase subunit of the Escherichia coli acetyl-CoA carboxylase. The apparent severity of all the MCC mutations contrasts with the variety of the clinical phenotypes suggesting that there are other cellular and metabolic unknown factors that affect the resulting phenotype.

Genetic determinants of variation in the plasma levels of the C4b-binding protein (C4BP) in Spanish families

The C4b-binding protein (C4BP) is a plasma glycoprotein implicated in the homeostasis of the complement and coagulation systems. It is composed of two polypeptides (alpha and beta), which form three plasma oligomers with different subunit compositions (alpha(7)beta(1), alpha(7)beta(0), and alpha(6)beta(1)). The beta chain-containing C4BP isoforms (C4BPbeta(+)isoforms) bind and inactivate protein S (PS), downregulating the activated protein C (APC)-dependent anticoagulatory pathway. Because PS deficiency is associated with recurrent thrombosis, it has been suggested that increased levels of C4BPbeta(+)isoforms might diminish the free PS plasma level, affecting the risk of developing thromboembolism. Previous work has tested this hypothesis, but no definitive conclusions were reached, mostly because nothing is known about the factors influencing the high variability in C4BP plasma levels in humans. As a part of the GAIT project, using variance component analysis, this work provides the first estimation of the relative contributions of genetic and environmental influences on the plasma levels of total C4BP and C4BPbeta(+)isoforms. Plasma levels of total C4BP and C4BPbeta(+)isoforms showed strong evidence of genetic regulation (heritability 37.7% and 42.5%, respectively). They were also affected by age, smoking, and exogenous sex hormones. Our results constitute the first step in localizing and evaluating potential quantitative trait loci that affect the plasma levels of C4BP and C4BPbeta(+). Furthermore, analysis of phenotypic and genetic correlations between C4BPbeta(+)plasma levels and the components of the APC anticoagulatory pathway (total PS, free PS, functional PS, and functional PC) suggests a genetic co-regulation of the proteins. These observations might have important implications in the individual susceptibility to thrombotic disease.

The molecular basis of 3-methylcrotonylglycinuria, a disorder of leucine catabolism

3-Methylcrotonylglycinuria is an inborn error of leucine catabolism and has a recessive pattern of inheritance that results from the deficiency of 3-methylcrotonyl-CoA carboxylase (MCC). The introduction of tandem mass spectrometry in newborn screening has revealed an unexpectedly high incidence of this disorder, which, in certain areas, appears to be the most frequent organic aciduria. MCC, an heteromeric enzyme consisting of alpha (biotin-containing) and beta subunits, is the only one of the four biotin-dependent carboxylases known in humans that has genes that have not yet been characterized, precluding molecular studies of this disease. Here we report the characterization, at the genomic level and at the cDNA level, of both the MCCA gene and the MCCB gene, encoding the MCC alpha and MCC beta subunits, respectively. The 19-exon MCCA gene maps to 3q25-27 and encodes a 725-residue protein with a biotin attachment site; the 17-exon MCCB gene maps to 5q12-q13 and encodes a 563-residue polypeptide. We show that disease-causing mutations can be classified into two complementation groups, denoted "CGA" and "CGB." We detected two MCCA missense mutations in CGA patients, one of which leads to absence of biotinylated MCC alpha. Two MCCB missense mutations and one splicing defect mutation leading to early MCC beta truncation were found in CGB patients. A fourth MCCB mutation also leading to early MCC beta truncation was found in two nonclassified patients. A fungal model carrying an mccA null allele has been constructed and was used to demonstrate, in vivo, the involvement of MCC in leucine catabolism. These results establish that 3-methylcrotonylglycinuria results from loss-of-function mutations in the genes encoding the alpha and beta subunits of MCC and complete the genetic characterization of the four human biotin-dependent carboxylases.