Search PubMed⌕ Search

Biomedical subjects

U Wahn

Publications and source records attributed to U Wahn.

At least 73 records · Page 4Linked to original sources
PubMed2000

Early exposure to house-dust mite and cat allergens and development of childhood asthma: a cohort study. Multicentre Allergy Study Group.

BACKGROUND: In a prospective birth-cohort study, we assessed the relevance of mite and cat allergen exposure for the development of childhood asthma up to age 7 years. METHODS: Of 1314 newborn infants enrolled in five German cities in 1990, follow-up data at age 7 years were available for 939 children. Assessments included repeated measurement of specific IgE to food and inhalant allergens, measurement of indoor allergen exposure at 6 months, 18 months, and 3 years of age, and yearly interviews by a paediatrician. At age 7 years, pulmonary function was tested and bronchial hyper-responsiveness was measured in 645 children. FINDINGS: At age 7, the prevalence of wheezing in the past 12 months was 10.0% (94 of 938), and 6.1% (57 of 939) parents reported a doctor's diagnosis of asthma in their children. Sensitisation to indoor allergens was associated with asthma, wheeze, and increased bronchial responsiveness. However, no relation between early indoor allergen exposure and the prevalence of asthma, wheeze, and bronchial hyper-responsiveness was seen. INTERPRETATION: Our data do not support the hypothesis that exposure to environmental allergens causes asthma in childhood, but rather that the induction of specific IgE responses and the development of childhood asthma are determined by independent factors.

Air Pollution, Indoor↗
PubMed2000

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.

Alleles↗
PubMed2000

Does allergy in parents depend on allergy in their children? Recall bias in parental questioning of atopic diseases. Multicenter Allergy Study Group.

BACKGROUND: A positive atopic family history has proved to be one important risk factor for the development of atopic diseases in offspring. However, many epidemiologists are concerned about the accuracy and reliability of data because responses to questionnaires can be biased for many reasons. OBJECTIVE: The study investigated whether responses of parents questioned about their atopic diseases change depending on the development of atopic symptoms in their children. METHODS: During a prospective birth cohort study on atopy in children (the Multicenter Allergy Study) parents filled out questionnaires twice within 2 years about their atopic diseases. Differences between the 2 responses were examined by log-linear and logistic regression models depending on the diagnosed atopy status of the study children. RESULTS: Mothers tended to report more atopic diseases in the second questioning than in the first, indicating a nondifferential misclassification. Fathers were influenced by the development of atopic diseases in their children: they reported significantly more atopic diseases if the child developed atopic illness with atopic dermatitis. CONCLUSION: In parental questioning about atopic diseases, a recall bias must be considered for the association of atopic family history and atopy in children. Especially in case-control and cross-sectional studies, such misclassifications can result in biased estimates of prognosis and risk factors.

Child, Preschool↗
PubMed2000

Structured parent education in the management of childhood atopic dermatitis: the Berlin model.

Childhood atopic dermatitis (AD) is a common disease with the prevalence rates increasing. Its chronic course with frequent relapses puts a special burden on both children and their parents. To maximise positive long-term outcome in the management of AD it is important to support parents in dealing with the chronic condition of their child in addition to treating symptoms. In the present article, we describe in detail the goals, structure, and content of the Berlin education program for parents of children with AD. The program aims to contribute towards a comprehensive, family-oriented management of childhood AD. Its objective is to improve parent's self-management skills with regard to their child's disease and to positively impact the course of the disease as well as the family's quality of life. Medical, nutritional and psychological issues are covered in six group sessions which are conducted by a multiprofessional team of paediatricians, psychologists and dieticians. Preliminary data show that the program has a desirable effect on aspects of quality of life and coping.

Adult↗
PubMed2000

Is there a role for immunoblots in the diagnosis of latex allergy? Intermethod comparison of in vitro and in vivo IgE assays in spina bifida patients.

BACKGROUND: The best diagnostic method for latex allergy is still controversial. This investigation was designed to evaluate the diagnostic efficiency of immunoblotting in comparison with established in vitro and in vivo test systems. METHODS: A total of 108 spina bifida patients were investigated by questionnaire and skin prick test (SPT). Specific serum IgE to latex was analyzed by the Pharmacia CAP FEIA immunoassay, DPC AlaSTAT microplate immunoassay, and DPC AlaBLOT immunoblot. Patients were regarded as latex allergic if they reacted positively to challenge by the latex glove wearing test. RESULTS: Thirty-four patients reacted positively to challenge. The sensitivity rates were 97% (SPT), 94% (immunoblot, CAP), 74% (AlaSTAT), and 35% (clinical history). The specificity rates were 92% (clinical history), 88% (AlaSTAT), 77% (SPT), 76% (CAP), and 69% (immunoblot). If two methods were combined, efficiency rates were highest for SPT combined with CAP (sensitivity 94%, specificity 82%), with AlaSTAT (sensitivity 74%, specificity 92%), or with immunoblot (sensitivity 91%, specificity 84%). The sera of challenge-positive patients recognized more immunoblot bands than challenge-negative patients, and the severity of symptoms correlated with the number of recognized bands. CONCLUSIONS The diagnostic efficiency of immunoblotting is not superior to that of SPT. However, immunoblotting may serve as an additional tool to increase slightly the specificity of SPT and specific serum IgE tests.

Adolescent↗
PubMed2000

The atopy patch test (APT)-- a useful tool for the diagnosis of food allergy in children with atopic dermatitis.

BACKGROUND: While immediate-type clinical reactions to food can quite easily be identified by history or measurement of specific IgE in combination with positive oral food challenges, the evaluation of food allergy in the absence of immediate clinical reactions still presents diagnostic difficulties--particularly in children with atopic dermatitis. The objective of this study was to evaluate the diagnostic value of the atopy patch test (APT) with regard to late-phase reactions observed in double-blind, placebo-controlled food challenges with cow's milk, hen's egg, wheat, and soybean. METHODS: We investigated 75 children (median age 2.1 years) with suspected food allergy by double-blind, placebo-controlled food challenges, specific IgE in serum, skin prick test, and APT. Of the subjects, 69/75 suffered from atopic dermatitis. RESULTS: Of 209 oral challenges, 133 were performed with allergen and 76 with placebo. We assessed 77/133 allergen and 2/76 placebo challenges as positive. In 66 of 77 (86%) positive oral challenges, specific IgE in serum to the corresponding allergen was positive; in 64/77 (83%) the skin prick test, and in 42/77 (55%) the APT was positive. While immediate-type reactions were associated with positive skin prick test and proof of specific IgE in serum, late-phase clinical reactions were associated with a positive APT (sensitivity 76%, specificity 95%). CONCLUSIONS: The APT seems to be a valuable additional tool in the diagnostic work-up of food allergy in children with atopic dermatitis - especially with regard to late-phase clinical reactions. The APT may help to prevent unnecessary restrictive diets which may be the consequence of misjudging late reactions by clinical assessment alone.

Animals↗
PubMed2000

What safety measures need to be taken in oral food challenges in children?

BACKGROUND: Food allergens are often accused of causing numerous ailments. This is particularly true for the pediatric population, where the incidence of food allergy is four times as high as in adults. As food challenges may provoke life-threatening reactions, intensive safety measures need to be taken during provocation, and prompt medical intervention may become necessary. METHODS: We retrospectively evaluated 349 oral challenges in 204 children with atopic dermatitis, looking for criteria to help the physician decide which patients need medical intervention. RESULTS: A total of 178 (51%) oral food challenges with the four allergens (cow's milk [CM], hen's egg [HE], wheat, and soy) showed a positive clinical reaction. Of these, 120 (67%) needed medical intervention. In 42 (35%) cases, intervention was parenteral, and oral medication was given in 78 (65%) cases. There was a strong positive correlation (90%) between the level of specific IgE and the need for medical intervention (> or = 17.50 kU/l for CM, wheat, and soy; > or = 3.50 kU/l for HE). Patient history of food allergy was an indicator of the need for medical intervention (P = 0.01). A positive patient history and a high level of specific IgE were significantly (P=0.003) associated with parenteral medication in HE. CONCLUSIONS: Patient history of food allergy is a reliable indicator of the need for medical intervention in the cases of CM, wheat, and soy regardless of the level of specific IgE. With HE, a positive patient history plus a high level of specific IgE significantly indicates the need for parenteral medication. On the basis of our results, we recommend establishing intravenous access in children with a level of specific IgE of > or = 17.50 kU/l (CAP class 4) to CM and wheat, or with specific IgE of > or =3.50 kU/l (CAP class 3) to HE.

Administration, Oral↗
PubMed2000

Ventricular shunts and the prevalence of sensitization and clinically relevant allergy to latex in patients with spina bifida.

Patients with spina bifida represent the highest-risk group for developing hypersensitivity to latex. Recognized risk factors for these patients are repeated surgery and an atopic disposition. Our aim was to study the influence of a ventricular shunt as an independent risk factor. One hundred and sixty-one patients with spina bifida (median age 10 years) were investigated for the presence of a shunting device and the number, type and date of previous surgical interventions. Additionally, skin-prick tests and provocation tests were performed in order to classify sensitized and symptomatic latex-allergic individuals. Eighty-eight patients (54.7%) were sensitized; 55 (34.2%) were provocation-positive. Patients with a shunt system had undergone a significantly higher number of surgical procedures (p < 0.0001) and showed significantly higher levels of immunoglobulin E (IgE)-antibodies to latex (p < 0.0001) than patients without a shunting device. The total number of operations correlated significantly with the level of IgE-antibodies to latex in serum (p < 0.0001), whereas the number of shunt operations in patients with a ventricular shunt did not significantly correlate with the degree of sensitization. In conclusion, patients with spina bifida who have a ventricular shunt are at particularly high risk because they undergo a significantly higher number of operations than patients without a ventricular shunt. However, the ventricular shunt does not seem to be an independent risk factor. Furthermore, this study emphasizes that individuals at high risk, such as patients with spina bifida, should be handled latex-free from the very beginning of life.

Adolescent↗
PubMed2000

A major susceptibility locus for atopic dermatitis maps to chromosome 3q21.

Atopic dermatitis (eczema) is a chronic inflammatory skin disease with onset mainly in early childhood It is commonly the initial clinical manifestation of allergic disease, often preceding the onset of respiratory allergies. Along with asthma and allergic rhinitis, atopic dermatitis is an important manifestation of atopy that is characterized by the formation of allergy antibodies (IgE) to environmental allergens. In the developed countries, the prevalence of atopic dermatitis is approximately 15%, with a steady increase over the past decades. Genetic and environmental factors interact to determine disease susceptibility and expression, and twin studies indicate that the genetic contribution is substantial. To identify susceptibility loci for atopic dermatitis, we ascertained 199 families with at least two affected siblings based on established diagnostic criteria. A genome-wide linkage study revealed highly significant evidence for linkage on chromosome 3q21 (Zall=4.31, P= 8.42 10(-6)). Moreover, this locus provided significant evidence for linkage of allergic sensitization under the assumption of paternal imprinting (hlod=3.71,alpha=44%), further supporting the presence of an atopy gene in this region. Our findings indicate that distinct genetic factors contribute to susceptibility to atopic dermatitis and that the study of this disease opens new avenues to dissect the genetics of atopy.

Adolescent↗
PubMed2000

Socioeconomic status is a risk factor for allergy in parents but not in their children.

BACKGROUND: Allergic diseases are more prevalent in affluent countries, which has been attributed to life-style factors. Life-style habits may also differ between socioeconomic (SES) classes. The objective of this paper therefore was to evaluate if SES had an impact on the development of atopic disorders. METHODS: A total of 1314 German children were followed-up in an observational birth cohort study to 6 years of age. Parents filled in questionnaires, and had multi-allergen screening tests for sensitization. Indoor allergen concentrations were determined by ELISA. Children were examined regularly up to 6 years, specific serum IgE values were determined by CAP-Rast-Feia. RESULTS: The risk of aeroallergen sensitization (odds ratio 1.76; 95% CI 1.30-2.37), and the lifetime prevalence of hay fever (2.36; 1.76-3.17), and asthma (1.74; 1.08-2.80), but not of atopic dermatitis (AD: 0.90; 0. 54-1.51) was elevated in parents of high compared to low SES. With high SES the risk of smoking in pregnancy (0.35; 0.23-0.51), in the home (0.31; 0.21-0.46), pet ownership (0.37; 0.26-0.55), high mite (0.42; 0.25-0.74), and high cat (0.38; 0.18-0.82) allergen concentration in house dust was reduced, but elevated for breastfeeding over more than 6 months (4.67; 2.9-7.48). In children, even after controlling for other risk factors, only the risk of AD from 3 to 6 years (2.42; 1.42-4.14) was elevated in families with high SES, but not of AD in infancy or of any other atopic disorder. CONCLUSIONS: While parents of high SES have a higher prevalence of inhalative allergies, their favourable life-style prevents the development of atopic disorders in their children, except for AD beyond infancy.

Adult↗
PubMed2000

Association and linkage of atopic dermatitis with chromosome 13q12-14 and 5q31-33 markers.

Atopic dermatitis is a chronic inflammatory skin disease that affects 10-20% of the population. Linkage of atopy, asthma, allergic rhinitis, and total serum IgE levels to several different chromosomal regions have been described extensively, but little is known about the genetic control of atopic dermatitis. We tested for the association and linkage between atopic dermatitis and five chromosomal regions: 5q31-33, 6p21.3, 12q15-24.1, 13q12-31, and 14q11.2/14q32.1-32.3. Marker analysis was performed in two Caucasian populations: (i) 192 unrelated German children with atopic dermatitis and 59 non-atopic children from a German birth cohort study (MAS'90), parental DNA was tested in 77 of 192 children with atopic dermatitis; (ii) 40 Swedish families with at least one family member with atopic dermatitis selected from the International Study of Asthma and Allergy in Children. Evidence for linkage and allelic association for atopic dermatitis was observed for markers on chromosome 13q12-14 and 5q31-33.

Child↗
PubMed2000

Evidence for a disease-promoting effect of Staphylococcus aureus-derived exotoxins in atopic dermatitis.

BACKGROUND: The skin of patients with atopic dermatitis (AD) exhibits a striking susceptibility to colonization with Staphylococcus aureus. Some strains of S aureus secrete exotoxins with T-cell superantigen activity (toxigenic strains), and abnormal T-cell functions are known to play a critical role in AD. OBJECTIVE: Our purpose was to examine the impact of superantigen production by skin-colonizing S aureus on disease severity. METHODS: In a cross-sectional study of 74 children with AD, the presence and density of toxigenic and nontoxigenic strains of S aureus was correlated with disease severity. In a subgroup of patients the T-cell receptor Vbeta repertoire of peripheral blood and lesional T cells was investigated and correlated with individual superantigen activity of skin-colonizing S aureus. RESULTS: Fifty-three percent of children with AD were colonized with toxigenic strains of S aureus producing staphylococcal enterotoxin C, staphylococcal enterotoxin A, toxic shock syndrome toxin-1, staphylococcal enterotoxin B, and staphylococcal enterotoxin D in decreasing frequency. Children colonized with toxigenic S aureus strains had higher disease severity compared with the nontoxigenic and S aureus-negative groups. Patients colonized with toxigenic S aureus exhibited shifts in the intradermal T-cell receptor Vbeta repertoire that correspond to the respective superantigen-responsive T-cell subsets. CONCLUSION: The data demonstrate that S aureus-released exotoxins can modulate disease severity and dermal T-cell infiltration.

Adolescent↗
PubMed2000

An IL13 coding region variant is associated with a high total serum IgE level and atopic dermatitis in the German multicenter atopy study (MAS-90).

BACKGROUND: Allergic diseases are one of the major causes of morbidity in the developed countries today, and the prevalence of these diseases is increasing steadily. Study of total serum gE level is important in understanding the genetics of allergic iseases because IgE levels are considered to be a crucial pathogenic component. IL-13 plays an important role in the induction of IgE synthesis and in the pathogenesis of allergic diseases. OBJECTIVE: We sought to examine potential variation at the IL13 gene and estimate its effect on elevated IgE level and atopic dermatitis (AD). METHODS: We conducted mutational analyses of the IL13 gene by using single-stranded conformation polymorphism and DNA sequencing. Case control studies for high-IgE phenotype and AD were performed by using subjects from the German MAS-90 cohort. RESULTS: A novel IL13 coding region variant at 4257 bp (G to A, fourth exon) was identified. Case control studies of a German sample from the MAS-90 cohort showed significant associations between the presence of the A allele and two atopic phenotypes: high IgE (odds ratio, 2.38; 95% confidence interval, 1.35-4.21; P =.0026) and AD (odds ratio, 1.77; 95% confidence interval, 1.06-2.96; P =.03). CONCLUSION: This IL13 coding region variant may be involved in the pathogenesis of AD and high total serum IgE level in a study population of white subjects.

Chromosomes, Human, Pair 5↗