Deep learning-based algorithm accurately classifies sleep stages in preadolescent children with sleep-disordered breathing symptoms and age-matched controls.

Introduction: Visual sleep scoring has several shortcomings, including inter-scorer inconsistency, which may adversely affect diagnostic decision-making. Although automatic sleep staging in adults has been extensively studied, it is uncertain whether such sophisticated algorithms generalize well to different pediatric age groups due to distinctive EEG characteristics. The preadolescent age group (10-13-year-olds) is relatively understudied, and thus, we aimed to develop an automatic deep learning-based sleep stage classifier specifically targeting this cohort. Methods: A dataset (n = 115) containing polysomnographic recordings of Icelandic preadolescent children with sleep-disordered breathing (SDB) symptoms, and age and sex-matched controls was utilized. We developed a combined convolutional and long short-term memory neural network architecture relying on electroencephalography (F4-M1), electrooculography (E1-M2), and chin electromyography signals. Performance relative to human scoring was further evaluated by analyzing intra- and inter-rater agreements in a subset (n = 10) of data with repeat scoring from two manual scorers. Results: The deep learning-based model achieved an overall cross-validated accuracy of 84.1% (Cohen's kappa κ = 0.78). There was no meaningful performance difference between SDB-symptomatic (n = 53) and control subgroups (n = 52) [83.9% (κ = 0.78) vs. 84.2% (κ = 0.78)]. The inter-rater reliability between manual scorers was 84.6% (κ = 0.78), and the automatic method reached similar agreements with scorers, 83.4% (κ = 0.76) and 82.7% (κ = 0.75). Conclusion: The developed algorithm achieved high classification accuracy and substantial agreements with two manual scorers; the performance metrics compared favorably with typical inter-rater reliability between manual scorers and performance reported in previous studies. These suggest that our algorithm may facilitate less labor-intensive and reliable automatic sleep scoring in preadolescent children.

[Autoimmune/inflammatory syndrome induced by aduvants].

For decades, breast implants have been available for breast reconstructions and breast augmentations to improve the patients' health-related quality of life. Silicone implants (SI) have been used since the middle of the last century for breast reconstruction, for example after breast cancer, for birth defects, gender confirmation procedures, or for breast augmentation. Every year, several hundred SI are performed in Iceland for these purposes, but no central register is maintained. It can be estimated that at least 1000 - 3000 women have SI in Iceland and that around 300 Icelandic patients get SI every year. This informal review article discusses the so-called ASIA syndrome, the immunological effects of silicone and the possible relationship of SI to autoimmune diseases, symptoms, and diagnosis. In the methodology, this paper does not rely on the strict conditions of systematic reviews, but the authors relied only on peer-reviewed sources through PubMed, UpToDate and Scopus. The keywords used are silicon, silicon implant, silicon particles, immune response, autoimmunity, autoinflammation, Autoimmune/inflammatory syndrome induced by aduvants, ASIA, ASIA syndrome, breast implant illness. The paper reviews known facts about the disease, its characteristics, and statistical aspects.

Meals, Microbiota and Mental Health in Children and Adolescents (MMM-Study): A protocol for an observational longitudinal case-control study.

Recent studies indicate that the interplay between diet, intestinal microbiota composition, and intestinal permeability can impact mental health. More than 10% of children and adolescents in Iceland suffer from mental disorders, and rates of psychotropics use are very high. The aim of this novel observational longitudinal case-control study, "Meals, Microbiota and Mental Health in Children and Adolescents (MMM-Study)" is to contribute to the promotion of treatment options for children and adolescents diagnosed with mental disorders through identification of patterns that may affect the symptoms. All children and adolescents, 5-15 years referred to the outpatient clinic of the Child and Adolescent Psychiatry Department at The National University Hospital in Reykjavik, Iceland, for one year (n≈150) will be invited to participate. There are two control groups, i.e., sex-matched children from the same postal area (n≈150) and same parent siblings (full siblings) in the same household close in age +/- 3 years (n<150). A three-day food diary, rating scales for mental health, and multiple questionnaires will be completed. Biosamples (fecal-, urine-, saliva-, blood samples, and buccal swab) will be collected and used for 16S rRNA gene amplicon sequencing of the oral and gut microbiome, measurements of serum factors, quantification of urine metabolites and host genotype, respectively. For longitudinal follow-up, data collection will be repeated after three years in the same groups. Integrative analysis of diet, gut microbiota, intestinal permeability, serum metabolites, and mental health will be conducted applying bioinformatics and systems biology approaches. Extensive population-based data of this quality has not been collected before, with collection repeated in three years' time, contributing to the high scientific value. The MMM-study follows the "Strengthening the Reporting of Observational Studies in Epidemiology" (STROBE) guidelines. Approval has been obtained from the Icelandic National Bioethics Committee, and the study is registered with Clinicaltrials.gov. The study will contribute to an improved understanding of the links between diet, gut microbiota and mental health in children through good quality study design by collecting information on multiple components, and a longitudinal approach. Furthermore, the study creates knowledge on possibilities for targeted and more personalized dietary and lifestyle interventions in subgroups. Trial registration numbers: VSN-19-225 & NCT04330703.

Social network and the risk for developing mild cognitive impairment and dementia among older adults.

BACKGROUND: This study aimed to investigate the longitudinal associations between social network (SN) and the risk of lower cognitive function, mild cognitive impairment (MCI), and dementia among cognitively normal individuals 65 years and older. METHODS: Data from the Age, Gene/Environment Susceptibility (AGES) Reykjavik Study on 2816 participants (aged 65 to 96 years) were used to examine the associations using multiple logistic and linear regression models. SN included questions on frequency of contact with family and friends as well as information on marital status, resulting in a score ranging from 0 (poor social network) to 3 (good social network). Cognitive function outcomes included the speed of processing (SP), executive function (EF) and memory function (MF). MCI and dementia were diagnosed using a detailed assessment according to international guidelines. RESULTS: At baseline 0.5, 7.0, 41.7 and 50.8% reported a score of 0, 1, 2 and 3, respectively. During a mean follow-up time of 5.2 years, 7.1% (n = 188) of cognitively intact participants developed MCI and 3.0% (n = 79) developed dementia. Longitudinal analyses demonstrated that participants who had low SN were significantly more likely to have declines in MF (ß = - 0.533, P = 0.014) compared to high SN. Social networks were not independently associated with the decline of SP and EF during follow-up. According to fully adjusted models using logistic regression, SN was significantly associated with incidence risk of MCI (OR = 2.030, P = 0.014 and OR = 1.847 P = 0.001). These associations were largely independent of other lifestyle factors, depression and genetic disposition. CONCLUSIONS: Community-dwelling older adults who have poor social networks have a higher risk of declining memory function as well as a higher risk of mild cognitive impairment than older adults who have a higher social network. This study included numbers of relevant covariates in the study analysis, thereby significantly contributing to the literature on cognitive aging.

Older adult psychopathology: international comparisons of self-reports, collateral reports, and cross-informant agreement.

OBJECTIVES: To conduct international comparisons of self-reports, collateral reports, and cross-informant agreement regarding older adult psychopathology. PARTICIPANTS: We compared self-ratings of problems (e.g. I cry a lot) and personal strengths (e.g. I like to help others) for 10,686 adults aged 60-102 years from 19 societies and collateral ratings for 7,065 of these adults from 12 societies. MEASUREMENTS: Data were obtained via the Older Adult Self-Report (OASR) and the Older Adult Behavior Checklist (OABCL; Achenbach et al., ). RESULTS: Cronbach's alphas were .76 (OASR) and .80 (OABCL) averaged across societies. Across societies, 27 of the 30 problem items with the highest mean ratings and 28 of the 30 items with the lowest mean ratings were the same on the OASR and the OABCL. Q correlations between the means of the 0-1-2 ratings for the 113 problem items averaged across all pairs of societies yielded means of .77 (OASR) and .78 (OABCL). For the OASR and OABCL, respectively, analyses of variance (ANOVAs) yielded effect sizes (ESs) for society of 15% and 18% for Total Problems and 42% and 31% for Personal Strengths, respectively. For 5,584 cross-informant dyads in 12 societies, cross-informant correlations averaged across societies were .68 for Total Problems and .58 for Personal Strengths. Mixed-model ANOVAs yielded large effects for society on both Total Problems (ES = 17%) and Personal Strengths (ES = 36%). CONCLUSIONS: The OASR and OABCL are efficient, low-cost, easily administered mental health assessments that can be used internationally to screen for many problems and strengths.

The generalizability of empirically derived syndromes of collateral-reported elder psychopathology across 11 societies.

The purpose of this study was to test whether a syndrome model of elder psychopathology derived from collateral ratings, such as from spouses and adult children, in the United States would be generalizable in 11 other societies. Societies represented South America, Asia, and Europe. The Older Adult Behavior Checklist (OABCL) was completed by collateral informants for 6141 60- to 102-year-olds. The tested model comprised syndromes designated as Anxious/Depressed, Worries, Somatic Complaints, Functional Impairment, Memory/Cognition Problems, Thought Problems, and Irritable/Disinhibited. The model was tested using confirmatory factor analyses in each society separately. The primary model fit index showed a good fit for all societies, while the secondary model fit indices showed acceptable to a good fit for all societies. The items loaded strongly on their respective factors, with a median item loading of 0.69 across the 11 societies. By syndrome, the overall median item loadings ranged from 0.47 for Worries to 0.77 for Functional Impairment. The OABCL syndrome structure was thus generalizable across the tested societies. The OABCL can be used for broad assessment of psychopathology for elders of diverse backgrounds in nursing services and research.

Detailed Multiplex Analysis of SARS-CoV-2 Specific Antibodies in COVID-19 Disease.

A detailed understanding of the antibody response against SARS-CoV-2 is of high importance, especially with the emergence of novel vaccines. A multiplex-based assay, analyzing IgG, IgM, and IgA antibodies against the receptor binding domain (RBD), spike 1 (S1), and nucleocapsid proteins of the SARS-CoV-2 virus was set up. The multiplex-based analysis was calibrated against the Elecsys® Anti-SARS-CoV-2 assay on a Roche Cobas® instrument, using positive and negative samples. The calibration of the multiplex based assay yielded a sensitivity of 100% and a specificity of 97.7%. SARS-CoV-2 specific antibody levels were analyzed by multiplex in 251 samples from 221 patients. A significant increase in all antibody types (IgM, IgG, and IgA) against RBD was observed between the first and the third weeks of disease. Additionally, the S1 IgG antibody response increased significantly between weeks 1, 2, and 3 of disease. Class switching appeared to occur earlier for IgA than for IgG. Patients requiring hospital admission and intensive care had higher levels of SARS-CoV-2 specific IgA levels than outpatients. These findings describe the initial antibody response during the first weeks of disease and demonstrate the importance of analyzing different antibody isotypes against multiple antigens and include IgA when examining the immunological response to COVID-19.

Prevalence and early-life risk factors of school-age allergic multimorbidity: The EuroPrevall-iFAAM birth cohort.

BACKGROUND: Coexistence of childhood asthma, eczema and allergic rhinitis is higher than can be expected by chance, suggesting a common mechanism. Data on allergic multimorbidity from a pan-European, population-based birth cohort study have been lacking. This study compares the prevalence and early-life risk factors of these diseases in European primary school children. METHODS: In the prospective multicentre observational EuroPrevall-iFAAM birth cohort study, we used standardized questionnaires on sociodemographics, medical history, parental allergies and lifestyle, and environmental exposures at birth, 12 and 24 months. At primary school age, parents answered ISAAC-based questions on current asthma, rhinitis and eczema. Allergic multimorbidity was defined as the coexistence of at least two of these. RESULTS: From 10,563 children recruited at birth in 8 study centres, we included data from 5,572 children (mean age 8.2 years; 51.8% boys). Prevalence estimates were as follows: asthma, 8.1%; allergic rhinitis, 13.3%; and eczema, 12.0%. Allergic multimorbidity was seen in 7.0% of the whole cohort, ranging from 1.2% (Athens, Greece) to 10.9% (Madrid, Spain). Risk factors for allergic multimorbidity, identified with AICc, included family-allergy-score, odds ratio (OR) 1.50 (95% CI 1.32-1.70) per standard deviation; early-life allergy symptoms, OR 2.72 (2.34-3.16) for each symptom; and caesarean birth, OR 1.35 (1.04-1.76). Female gender, OR 0.72 (0.58-0.90); older siblings, OR 0.79 (0.63-0.99); and day care, OR 0.81 (0.63-1.06) were protective factors. CONCLUSION: Allergic multimorbidity should be regarded as an important chronic childhood disease in Europe. Some of the associated early-life factors are modifiable and may be considered for prevention strategies.

Frequency of food allergy in school-aged children in eight European countries-The EuroPrevall-iFAAM birth cohort.

BACKGROUND: The prevalence of food allergy (FA) among European school children is poorly defined. Estimates have commonly been based on parent-reported symptoms. We aimed to estimate the frequency of FA and sensitization against food allergens in primary school children in eight European countries. METHODS: A follow-up assessment at age 6-10 years of a multicentre European birth cohort based was undertaken using an online parental questionnaire, clinical visits including structured interviews and skin prick tests (SPT). Children with suspected FA were scheduled for double-blind, placebo-controlled oral food challenges (DBPCFC). RESULTS: A total of 6105 children participated in this school-age follow-up (57.8% of 10 563 recruited at birth). For 982 of 6069 children (16.2%), parents reported adverse reactions after food consumption in the online questionnaire. Of 2288 children with parental face-to-face interviews and/or skin prick testing, 238 (10.4%) were eligible for a DBPCFC. Sixty-three foods were challenge-tested in 46 children. Twenty food challenges were positive in 17 children, including seven to hazelnut and three to peanut. Another seventy-one children were estimated to suffer FA among those who were eligible but refused DBPCFC. This yielded prevalence estimates for FA in school age between 1.4% (88 related to all 6105 participants of this follow-up) and 3.8% (88 related to 2289 with completed eligibility assessment). INTERPRETATION: In primary school children in eight European countries, the prevalence of FA was lower than expected even though parents of this cohort have become especially aware of allergic reactions to food. There was moderate variation between centres hampering valid regional comparisons.

The generalizability of Older Adult Self-Report (OASR) syndromes of psychopathology across 20 societies.

OBJECTIVES: As the world population ages, psychiatrists will increasingly need instruments for measuring constructs of psychopathology that are generalizable to diverse elders. The study tested whether syndromes of co-occurring problems derived from self-ratings of psychopathology by US elders would fit self-ratings by elders in 19 other societies. METHODS/DESIGN: The Older Adult Self-Report (OASR) was completed by 12 826 adults who were 60 to 102 years old in 19 societies from North and South America, Asia, and Eastern, Northern, Southern, and Western Europe, plus the United States. Individual and multigroup confirmatory factor analyses (CFAs) tested the fit of the seven-syndrome OASR model, consisting of the Anxious/Depressed, Worries, Somatic Complaints, Functional Impairment, Memory/Cognition Problems, Thought Problems, and Irritable/Disinhibited syndromes. RESULTS: In individual CFAs, the primary model fit index showed good fit for all societies, while the secondary model fit indices showed acceptable to good fit. The items loaded strongly on their respective factors, with a median item loading of .63 across 20 societies, and 98.7% of the loadings were statistically significant. In multigroup CFAs, 98% of items demonstrated approximate or full metric invariance. Fifteen percent of items demonstrated approximate or full scalar invariance, and another 59% demonstrated scalar invariance across more than half of societies. CONCLUSIONS: The findings supported the generalizability of OASR syndromes across societies. The seven syndromes offer empirically based clinical constructs that are relevant for elders of different backgrounds. They can be used to assess diverse elders and as a taxonomic framework to facilitate communication, services, research, and training in geriatric psychiatry.

Risk Factors for Hen's Egg Allergy in Europe: EuroPrevall Birth Cohort.

BACKGROUND: Hen's egg is one of the commonest causes of food allergy, but there are little data on its risk factors. OBJECTIVE: To assess the risk factors, particularly eczema, for hen's egg allergy in the EuroPrevall birth cohort. METHODS: In the pan-European EuroPrevall birth cohort, questionnaires were undertaken at 12 and 24 months or when parents reported symptoms. Children with suspected egg allergy were invited for skin prick testing, specific IgE assessment, and double-blind, placebo-controlled food challenge (DBPCFC) as indicated. Each egg allergy case (positive DBPCFC or egg-induced anaphylaxis) was allocated up to 2 age- and country-matched controls. RESULTS: A total of 12,049 infants were recruited into the EuroPrevall birth cohort, and 9,336 (77.5%) were followed until 2 years. A total of 86 infants had egg allergy (84 by DBPCFC) and were matched with 140 controls. Independently associated with egg allergy were past/current eczema (adjusted odds ratio, 9.21; 95% CI, 2.65-32.04), Scoring Atopic Dermatitis (1.54 per 5 units; 1.28-1.86), antibiotics in the first week of life (6.17; 1.42-26.89), and current rhinitis (3.02; 1.04-8.78). Increasing eczema severity was associated with an increasing likelihood of egg allergy. Eczema was reported to have started 3.6 (SE, 0.5) months before egg allergy. Age of introduction of egg into the diet was not associated with egg allergy. CONCLUSIONS: Similar to peanut allergy, eczema was strongly associated with egg allergy development and the association increased with increasing eczema severity. The age of introduction of dietary egg was not a risk factor. The potential role of antibiotics in early life as a risk factor for egg allergy needs further examination.

Infant Feeding, Vitamin D and IgE Sensitization to Food Allergens at 6 Years in a Longitudinal Icelandic Cohort.

Nordic Nutrition Recommendations (NNR) recommend exclusive breastfeeding until 6 months, partial breastfeeding until 1 year or longer and irrespective of breastfeeding, avoiding solid foods before 4 months. Strong evidence was found for benefits of breastfeeding regarding growth and infections but limited/inconclusive evidence regarding atopic disease and asthma. Vitamin D is of special interest in the Nordic diet. The aim of this prospective study was to compare infant feeding and vitamin D between immunoglobulin E (IgE) sensitized (n = 14) and non-sensitized (n = 130) children at 6 years. Information on diet and vitamin D supplement use were collected with dietary recall (<5 months), 1-d food records (5 and 6 months) and 3-d weighed food records (12 months and 6 years). Serum-specific IgE-antibodies against milk, egg, cod, wheat, soy and peanut (cut-off specific IgE ≥ 0.35 kUA/L) were measured at 6 years and serum 25-hydroxyvitamin D at 12 months and 6 years. At 4 months, 57% of IgE sensitized vs. 23% of non-sensitized children (p < 0.01) had received solid food. At 12 months, IgE sensitized children had a lower intake of vitamin D (median (25th, 75th percentiles): 3.9 µg/d (3.2, 7.2) vs. 8.1 µg/d (4.4, 12.3), p = 0.03) and at 6 years, fewer used vitamin D supplements regularly (23% vs. 56%, p = 0.03). Introduction of solid foods prior to 4 months increased the odds of IgE-sensitization, OR = 4.9 (95%, CI = 1.4-16.6) and vitamin D supplement at 6 years decreased the odds of IgE-sensitization, OR = 0.2 (95%, CI = 0.1-0.98), adjusting for maternal smoking. These observations support the NNR in their recommendation against introducing complementary solid foods before the age of 4 months. Furthermore, they support encouraging vitamin D intake for young children at northern latitudes.

Ara h 1 and Ara h 6 Sensitization Causes Clinical Peanut Allergy in Ara h 2-Negative Individuals.

BACKGROUND: Of the major peanut allergens, sensitivity to Ara h 2 has the highest prediction for clinical allergy. In this study, we evaluated sensitization to peanut components in Iceland and related Ara h 2-negative sensitization to clinical allergy. METHODS: Ara h 1, Ara h 2, Ara h 3, Ara h 8, and Bet v 1 IgEs were measured (ImmunoCAP) in 220 peanut IgE (Pn-IgE)-positive serum samples. Ara h 2 IgE-negative individuals were invited to an open peanut challenge and evaluated for Ara h 6 and 9 sensitization (ISAC microarray). RESULTS: The Ara h 2 IgE-negative group (52.3%, 115/220) was older (p = 0.04) and more likely to have a history of pollen allergy than the Ara h 2-positive group (p < 0.001). Of the Ara h 2-negative participants, 24.3% were already consuming peanuts and 38.3% were unavailable. Of the 43 who underwent an open peanut challenge, 79% were negative, 14% were positive, and 7% were inconclusive. Those who reacted to peanuts had a higher Ara h 1 IgE than that of the tolerant participants, and 3 were positive to Ara h 6 IgE, and 2 of those subjects were monosensitized. Ara h 8 may have caused a positive reaction, while Ara h 9 did not. CONCLUSIONS: Half of the peanut-sensitized individuals in Iceland were not sensitized to the major allergen Ara h 2. Ara h 1, Ara h 3, and Ara h 6 sensitizations resulted in a positive open peanut challenge and they are therefore clinically important for individuals with a peanut allergy in Iceland.

Early Introduction of Egg and the Development of Egg Allergy in Children: A Systematic Review and Meta-Analysis.

BACKGROUND: The timing of the introduction of egg to an infant's diet is of current interest, as new evidence raises questions regarding the benefit of delaying egg introduction. The objective of this study was to systematically review the existing literature regarding the effect of the early introduction of egg on the development of egg allergy. METHODS: Literature searches were conducted in MEDLINE, EMBASE, and CENTRAL, and trial protocols were searched in Meta Register and OpenGREY. Only randomized controlled trials (RCTs) comparing early (between 3 and 6 months of age) egg introduction to no early introduction were included. The primary outcome was the development of egg allergy. RESULTS: Of the 416 articles identified and screened, 6 RCTs met the eligibility criteria for data extraction. Allergic outcomes were evaluated in a total of 3,032 participants. A low to moderate level of evidence showed a benefit of the early introduction of egg (relative risk, RR 0.60, 95% CI 0.44-0.82, p = 0.002, mild heterogeneity, I2 = 23%). The absolute risk reduction for a population with an incidence of egg allergy of 9.3% was 37 fewer cases (95% CI 17-52) per 1,000 people. Consumption of < 4,000 mg/week of egg protein had a greater preventive effect than a higher dose. CONCLUSION: This systematic review and meta-analysis showed an association between the early introduction of egg and a lower risk of egg allergy. Furthermore, the nature and dose of egg protein exposure may play a role. These findings should be addressed in the context of primary studies.

Prevalence estimates and risk factors for early childhood wheeze across Europe: the EuroPrevall birth cohort.

BACKGROUND: Preschool wheeze is an important problem worldwide. No comparative population-based studies covering different countries have previously been undertaken. OBJECTIVE: To assess the prevalence of early childhood wheeze across Europe and evaluate risk factors focusing on food allergy, breast feeding and smoke exposure. METHODS: Infants from nine countries were recruited into the EuroPrevall birth cohort. At 12 and 24 months, data on wheeze, allergic signs/symptoms, feeding, smoke exposure, infections and day care attendance were collected using questionnaires. Poisson regression was used to assess risk factors for wheeze. RESULTS: 12 049 infants were recruited. Data from the second year of life were available in 8805 (73.1%). The prevalence of wheeze in the second year of life ranged from <2% in Lodz (Poland) and Vilnius (Lithuania) to 13.1% (95% CI 10.7% to 15.5%) in Southampton (UK) and 17.2% (95% CI 15.0% 19.5%) in Reykjavik (Iceland). In multivariable analysis, frequent lower respiratory tract infections in the first and second years of life (incidence rate ratio (IRR) 1.9 (95% CI 1.3 to 2.6) and 2.5 (95% CI 1.9 to3.4), respectively), postnatal maternal smoking (IRR 1.6, 95% CI 1.1 to 2.4), day care attendance (IRR 1.6, 95% CI 1.1 to 2.5) and male gender (IRR 1.3, 95% CI 1.0 to 1.7) were associated with wheeze. The strength of their association with wheeze differed between countries. Food allergy and breast feeding were not independently associated with wheeze. CONCLUSION: The prevalence of early childhood wheeze varied considerably across Europe. Lower respiratory tract infections, day care attendance, postnatal smoke exposure and male gender are important risk factors. Further research is needed to identify additional modifiable risk factors that may differ between countries.

Physician's appraisal vs documented signs and symptoms in the interpretation of food challenge tests: The EuroPrevall birth cohort.

BACKGROUND: Blinded food challenges are considered the current gold standard for the diagnosis of food allergies. We used data from a pan-European multicenter project to assess differences between study centers, aiming to identify the impact of subjective aspects for the interpretation of oral food challenges. METHODS: Nine study centers of the EuroPrevall birth cohort study about food allergy recruited 12 049 newborns and followed them for up to 30 months in regular intervals. Intensive training was conducted and every center visited to ensure similar handling of the protocols. Suspected food allergy was clinically evaluated by double-blind, placebo-controlled food challenges using a nine dose escalation protocol. The primary challenge outcomes based on physician's appraisal were compared to documented signs and symptoms. RESULTS: Of 839 challenges conducted, study centers confirmed food allergy in 15.6% to 53.6% of locally conducted challenges. Centers reported 0 to 16 positive placebo challenges. Worsening of eczema was the most common sign when challenged with placebo. Agreement between documented objective signs and the challenge outcome assigned by the physician was heterogeneous, with Cohen's kappa spanning from 0.42 to 0.84. CONCLUSIONS: These differences suggest that the comparison of food challenge outcomes between centers is difficult despite common protocols and training. We recommend detailed symptom assessment and documentation as well as objective sign-based challenge outcome algorithms to assure accuracy and comparability of blinded food challenges. Training and supervision of staff conducting food challenges is a mandatory component of reliable outcome data.

Development of a hypoallergenic recombinant parvalbumin for first-in-man subcutaneous immunotherapy of fish allergy.

BACKGROUND: The FAST (food allergy-specific immunotherapy) project aims at developing safe and effective subcutaneous immunotherapy for fish allergy, using recombinant hypoallergenic carp parvalbumin, Cyp c 1. OBJECTIVES: Preclinical characterization and good manufacturing practice (GMP) production of mutant Cyp (mCyp) c 1. METHODS: Escherichia coli-produced mCyp c 1 was purified using standard chromatographic techniques. Physicochemical properties were investigated by gel electrophoresis, size exclusion chromatography, circular dichroism spectroscopy, reverse-phase high-performance liquid chromatography and mass spectrometry. Allergenicity was assessed by ImmunoCAP inhibition and basophil histamine release assay, immunogenicity by immunization of laboratory animals and stimulation of patients' peripheral blood mononuclear cells (PBMCs). Reference molecules were purified wild-type Cyp c 1 (natural and/or recombinant). GMP-compliant alum-adsorbed mCyp c 1 was tested for acute toxicity in mice and rabbits and for repeated-dose toxicity in mice. Accelerated and real-time protocols were used to evaluate stability of mCyp c 1 as drug substance and drug product. RESULTS: Purified mCyp c 1 behaves as a folded and stable molecule. Using sera of 26 double-blind placebo-controlled food-challenge-proven fish-allergic patients, reduction in allergenic activity ranged from 10- to 5,000-fold (1,000-fold on average), but with retained immunogenicity (immunization in mice/rabbits) and potency to stimulate human PBMCs. Toxicity studies revealed no toxic effects and real-time stability studies on the Al(OH)3-adsorbed drug product demonstrated at least 20 months of stability. CONCLUSION: The GMP drug product developed for treatment of fish allergy has the characteristics targeted for in FAST: i.e. hypoallergenicity with retained immunogenicity. These results have warranted first-in-man immunotherapy studies to evaluate the safety of this innovative vaccine.

Epidemiology of Primary Immunodeficiency in Iceland.

PURPOSE: Primary immunodeficiencies (PID) are rare heterogeneous diseases. Little is known about the prevalence of PID in Iceland and no national registry exists. The aim of the study was to describe the epidemiology of PID in Iceland. METHODS: Using The European Society's for Immunodeficiencies (ESID) criteria for PID, information about individuals with a known PID between 1990 and 2010 in Iceland were collected from inpatient registries of the National University Hospital of Iceland, the Department of Immunology and from clinical immunologists. Selective IgA deficiency, mannan binding lectin deficiency and secondary immunodeficiencies were excluded RESULTS: Sixty six individuals met the study criteria, 35 of them (53%) were females. Four patients died during the study period from PID- or treatment related complications and two moved abroad. In the beginning of 2011 there were 60 individuals living in Iceland with a known PID diagnosis meeting ESID's criteria. Estimated prevalence for PID in the Icelandic population of 318.452 habitants was 18.8 for 100.000 inhabitants. Predominantly antibody disorders comprised the largest category of PID in Iceland. CONCLUSIONS: The prevalence of PID is high in Iceland compared to reports from other nations. Our patient data are easily accessible and a central laboratory measures the immune parameters. This high prevalence may indicate that PID is more common than generally recognized.