Claudia Sengler

EULAR/PRINTO/PRES criteria for Henoch–Schönlein purpura, childhood polyarteritis nodosa, childhood Wegener granulomatosis and childhood Takayasu arteritis: Ankara 2008. Part II: Final classification criteria

Objectives To validate the previously proposed classification criteria for Henoch–Schönlein purpura (HSP), childhood polyarteritis nodosa (c-PAN), c-Wegener granulomatosis (c-WG) and c-Takayasu arteritis (c-TA). Methods Step 1: retrospective/prospective web-data collection for children with HSP, c-PAN, c-WG and c-TA with age at diagnosis ≤18 years. Step 2: blinded classification by consensus panel of a representative sample of 280 cases. Step 3: statistical (sensitivity, specificity, area under the curve and κ-agreement) and nominal group technique consensus evaluations. Results 827 patients with HSP, 150 with c-PAN, 60 with c-WG, 87 with c-TA and 52 with c-other were compared with each other. A patient was classified as HSP in the presence of purpura or petechiae (mandatory) with lower limb predominance plus one of four criteria: (1) abdominal pain; (2) histopathology (IgA); (3) arthritis or arthralgia; (4) renal involvement. Classification of c-PAN required a systemic inflammatory disease with evidence of necrotising vasculitis OR angiographic abnormalities of medium-/small-sized arteries (mandatory criterion) plus one of five criteria: (1) skin involvement; (2) myalgia/muscle tenderness; (3) hypertension; (4) peripheral neuropathy; (5) renal involvement. Classification of c-WG required three of six criteria: (1) histopathological evidence of granulomatous inflammation; (2) upper airway involvement; (3) laryngo-tracheo-bronchial involvement; (4) pulmonary involvement (x-ray/CT); (5) antineutrophilic cytoplasmic antibody positivity; (6) renal involvement. Classification of c-TA required typical angiographic abnormalities of the aorta or its main branches and pulmonary arteries (mandatory criterion) plus one of five criteria: (1) pulse deficit or claudication; (2) blood pressure discrepancy in any limb; (3) bruits; (4) hypertension; (5) elevated acute phase reactant. Conclusion European League Against Rheumatism/Paediatric Rheumatology International Trials Organisation/Paediatric Rheumatology European Society propose validated classification criteria for HSP, c-PAN, c-WG and c-TA with high sensitivity/specificity.

Atopic Dermatitis Is Associated with a Functional Mutation in the Promoter of the C-C Chemokine RANTES

Up-regulation of C-C chemokine expression characterizes allergic inflammation and atopic diseases. A functional mutation in the proximal promoter of the RANTES gene has been identified, which results in a new consensus binding site for the GATA transcription factor family. A higher frequency of this allele was observed in individuals of African descent compared with Caucasian subjects (p < 0.00001). The mutant allele was associated with atopic dermatitis in children of the German Multicenter Allergy Study (MAS-90; p < 0.037), but not with asthma. Transient transfections of the human mast cell line HMC-1 and the T cell line Jurkat with reporter vectors driven by either the mutant or wild-type RANTES promoter showed an up to 8-fold higher constitutive transcriptional activity of the mutant promoter. This is the first report to our knowledge of a functional mutation in a chemokine gene promoter. Our findings suggest that the mutation contributes to the development of atopic dermatitis. Its potential role in other inflammatory and infectious disorders, particularly among individuals of African ancestry, remains to be determined.

Evaluation of the CD14 C-159 T polymorphism in the German Multicenter Allergy Study cohort

Background Multiple genetic studies have shown linkage of atopy‐related phenotypes to chromosome 5q31. In this region several candidate genes for atopy are localized such as the Th2 cytokines IL‐4, IL‐5 and IL‐13, but also CD14, a receptor for LPS. Recently, a functional CD14 promoter polymorphism was related to total and specific IgE responsiveness.

Interactions between genes and environmental factors in asthma and atopy: new developments

Asthma and associated phenotypes are complex traits most probably caused by an interaction of multiple disease susceptibility genes and environmental factors. Major achievements have occurred in identifying chromosomal regions and polymorphisms in candidate genes linked to or associated with asthma, atopic dermatitis, IgE levels and response to asthma therapy. The aims of this review are to explain the methodology of genetic studies of multifactorial diseases, to summarize chromosomal regions and polymorphisms in candidate genes linked to or associated with asthma and associated traits, to list genetic alterations that may alter response to asthma therapy, and to outline genetic factors that may render individuals more susceptible to asthma and atopy due to environmental changes.

Takayasu arteritis is characterised by disturbances of B cell homeostasis and responds to B cell depletion therapy with rituximab

Introduction Takayasu arteritis (TA) is a large vessel vasculitis involving the aorta and its major branches. T cell-mediated autoimmunity is thought to play a major role in its pathogenesis, while the role of B cells is still unclear. Methods B cell subsets in the peripheral blood of 17 patients with TA were analysed and compared with nine patients with active systemic lupus erythematosus (SLE) and nine healthy controls by flow cytometry. Based on these findings, three patients with active refractory TA were treated with B cell depletion therapy (BCDT) using monoclonal anti-CD20 antibodies (rituximab). Results The absolute number and frequency of peripheral blood CD19+/CD20−/CD27high antibody-secreting cells in patients with active TA was significantly higher than in healthy donors. As in active SLE, the majority of these cells are newly generated plasmablasts which significantly correlated with TA activity. Three patients with active refractory TA and expansion of plasmablasts were successfully treated with BCDT, which resulted in remission. Conclusion Disturbances of B cell homeostasis may be critical in TA. Circulating plasmablasts could be a useful biomarker of disease activity and a tool for selecting appropriate candidates for BCDT. B cells and plasmablasts/plasma cells may therefore represent novel targets for effective therapies for TA.

A longitudinal PRINTO study on growth and puberty in juvenile systemic lupus erythematosus

Objective To obtain longitudinal data on growth/puberty in a large-scale, multi-national prospective cohort of juvenile systemic lupus erythematosus (SLE). Methods Data from 331/557 (59.4%) patients ≤18 years old with juvenile SLE in active phase, with anthropometric data available at four follow-up visits, were studied. Results There was a significant reduction in parent-adjusted height z score with time in females and males (p<0.0001), with a significant gender difference (p<0.0001) and with male height being most affected. Median body mass index z score peaked at 6 months and was still significantly above baseline after 26 months (p<0.01), with no gender difference. Standardised height reduction was inversely related to age at onset. Females with onset age <12 years had a median parent-adjusted height z score of −0.87 with no catch-up growth. At the end of the study, growth failure was seen in 14.7% of the females and 24.5% of the males. Height deflection (less than −0.25/year) was found in 20.7% of the females and 45.5% of the males. Delayed pubertal onset was seen in 15.3% and 24% of the females and males, respectively, and delayed/absent menarche was seen in 21.9%, while 36.1% of the females and 44% of the males had some degree of delayed pubertal development. Growth failure baseline determinants were previous growth failure (OR: 56.6), age at first visit ≤13.4 years (OR: 4.2) and cumulative steroid dose >426 mg/kg (OR: 3.6). Conclusions The children at risk of having a negative effect on height and pubertal development are prepubertal and peripubertal children treated with >400 mg/kg cumulative dose of corticosteroids.

Association of Filaggrin loss‐of‐function‐mutations with atopic dermatitis and asthma in the Early Treatment of the Atopic Child (ETAC) population

Many candidate gene studies for atopic dermatitis (AD) and associated phenotypes have been conducted so far, but replication of significant results has been a major problem. Two loss of function polymorphisms FLG R501X‐ and 2282del4, in the Filaggrin (FLG) gene encoding for an epidermal barrier protein were recently identified. They were reported to be predisposing factors for AD and concomitant asthma. Several groups confirmed the initial results in independent populations. The aim of this study is to further investigate the importance of these FLG variants in the development of AD and subsequent asthma symptoms in pre‐school children, we investigated children and parents of the Early Treatment of the Atopic Child (ETAC)‐trial. We genotyped 496 children and 488 parents of the ETAC population for the two FLG variants, evaluating an association by family based analysis (transmission disequilibrium test). We found a highly significant association of the FLG null variants R501X‐ and 2282del4 with AD (combined genotype p < 0.0001) and asthma (combined genotype p < 0.0001). The replication and its statistical significance underlines the importance of the FLG polymorphisms and the importance of the skin barrier function in the development of AD and subsequent asthma.

No association of histamine‐ N‐methyltransferase polymorphism with asthma or bronchial hyperresponsiveness in two German pediatric populations

Histamine plays an important role in the allergic inflammation. Histamin N‐Methyltransferase (HNMT) catalyses the major pathway of histamine metabolism in the human lung. A common functional single nucleotide polymorphism (SNP) within the HNMT gene (C314T) was recently related to asthma. We tested this SNP for associations with asthma and asthma associated traits in two German pediatric populations (1. MAS‐cohort, n = 888, 85 children with asthma; 2. asthmatic children from Freiburg, n = 176). Non‐asthmatic (n = 515) and non‐atopic (n = 211) children from the MAS‐cohort were used as controls. For genotyping melting curve analyses (Light Cycler System) were applied. In contrast to a previous study, no association of the HNMT 314T allele with asthma, bronchial hyperresponsiveness (BHR) or other asthma related phenotypes could be observed in either study population. We conclude that this SNP might not play a major role in the pathogenesis of asthma or BHR in German children.

Association study of Glutathione S-transferase P1 (GSTP1) with asthma and bronchial hyper-responsiveness in two German pediatric populations

Glutathione S‐Transferase P1 (GSTP1) is an important enzyme in the detoxification of products of oxidative stress. Several studies have shown an association of the amino acid variant Ile105Val with bronchial asthma and the reaction of the lung to inhalant pollutants. The aim of this study was to test the two known amino acid variants in GSTP1 for association with bronchial asthma and airway hyper‐responsiveness in two German pediatric populations. We genotyped Ile105Val and Ala114Val in the Multicenter Allergy Study cohort (85 children with asthma, 123 controls) and asthmatic children from Freiburg (n = 178). We did not find association of either polymorphisms with bronchial asthma or airway hyper‐responsiveness. We conclude from our data that polymorphisms within GSTP1 do not play a major role in the development of bronchial asthma in German children.

IL13 variants are associated with total serum IgE and early sensitization to food allergens in children with atopic dermatitis

Increased total and specific serum immunoglobulin E (IgE) levels are common characteristics of atopic diseases and their basal production is proposed to be under strong genetic control. Interleukin 13 (IL13) variants have been consistently associated with total serum IgE levels in white populations with a strongest association in non‐atopics. The aim of this study was to test the IL13 p.R130Q and c.1‐1111C>T variants in children with atopic dermatitis (AD) for associations with total serum IgE and early sensitization to common food and inhalant allergens and with asthma. We included 453 children with AD [participants of the Early Treatment of the Atopic Child (ETAC) study] that were followed from the age of 12–24 months for 3 yr. Total and specific IgE were determined at four time points. We genotyped the IL13 p.R130Q and c.1‐1111C>T variants by melting curve analysis. In children up to 4 yr of age, the 130Q allele was related to slightly higher total IgE levels compared to heterozygotes and 130R homozygotes. More importantly, both IL13 variants were significantly associated with sensitization to food allergens, with most significant results for sensitization to egg (p = 0.0001). Although early sensitization to hen’s egg represents a strong risk factor for subsequent sensitization to inhalant allergens and asthma, the investigated IL13 variants were not associated with these phenotypes at the age of 48–60 months. In summary IL13 variants contribute to elevated levels of total serum IgE in young atopic children and are strongly associated with sensitization to food allergens, particularly to hen’s egg. These findings suggest that IL13 variants play a major role not only in non‐cognate but also in allergen specific IgE synthesis.