Basophil activation test with progressively less heated forms of egg distinguishes egg allergic from tolerant children.

BACKGROUND AND OBJECTIVE: Diagnosis of egg allergy through basophil activation testing (BAT) has been mainly performed with an egg white extract or individual egg allergens rather than clinically more representative whole-egg extracts. Impact of heating on whole-egg extract allergenicity remains unassessed.Validating BAT with gradually less heated whole-egg extracts in egg allergy diagnosis and as tolerance marker. METHODS: CD63-based BAT was performed with five progressively less heated extracts from cake, hard-boiled egg, omelet, soft-boiled, and raw egg in 10 egg allergic (EA), 10 complete egg tolerant (ET) and 12 non-egg-sensitized non-allergic (NEA) children. Cutoffs and diagnostic accuracy measures were established through ROC analysis. Changes in basophil response were assessed in 12 baked egg tolerant children undergoing an 8-month gradual egg reintroduction protocol with BAT and oral food challenges prior to each reintroduction step. RESULTS: Basophil responses to all egg extracts were increased in EA, but not in ET and NEA children. Responses decreased progressively with more heated egg extracts. Compared to ET children, EA children showed higher basophil sensitivity for all egg extracts. Negative BAT responses predicted clinical tolerance with a 90-100% sensitivity, 100% specificity, and false positive rate of 2.78%. In comparison, egg sIgE's (<0.35 kUA/L) had a lower specificity of 50-78% with a false positive rate of 40%. Basophil reactivity and sensitivity tended to decrease in baked egg tolerant children undergoing gradual egg reintroduction, concurrent with tolerance development. CONCLUSION: BAT with progressively less heated egg preparations is a sensitive and highly specific tool to discriminate EA from ET children.

The clinical and immunological basis of early food introduction in food allergy prevention.

IgE-mediated food allergy has an estimated prevalence of 6%-10% in developed countries. Allergen avoidance has long been the main focus in the prevention of food allergy and late solid food introduction after 6-12 months of age was recommended in high-risk infants. However, the rising prevalence of food allergy despite delayed exposure to allergens and the observations that IgE-mediated sensitization to food products could even occur before the introduction of solid foods resulted in a shift towards early solid food introduction as an attempt to prevent IgE-mediated food allergy. Since then, many trials focused on the clinical outcome of early allergen introduction and overall seem to point to a protective effect on the development of IgE-mediated food allergies. For non-IgE-mediated diseases of food allergy, evidence of early food introduction seems less clear. Moreover, data on the underlying immunological processes in early food introduction is lacking. The goal of this review is to summarize the available data of immunological changes in early food introduction to prevent IgE and non-IgE mediated food allergy.

Multicentre study to establish interpretive criteria for clofazimine drug susceptibility testing.

To conduct a multicentre study to establish the critical concentration (CC) for clofazimine (CFZ) for drug susceptibility testing (DST) of Mycobacterium tuberculosis on the MGIT™960™ system using the distribution of minimum inhibitory concentrations (MIC) and genotypic analyses of Rv0678 mutations. In phase I of the study, the MIC distribution of laboratory strains (H37Rv and in vitro-selected Rv0678 mutants) and clinical pan-susceptible isolates were determined (n = 70). In phase II, a tentative CC for CFZ (n = 55) was proposed. In phase III, the proposed CC was validated using clinical drug-resistant tuberculosis (DR-TB) isolates stratified by Rv0678 mutation (n = 85). The MIC distribution of CFZ for laboratory and clinical pan-susceptible strains ranged between 0.125 µg/ml and 0.5 µg/ml. As the MIC values of DR-TB isolates used for phase II ranged between 0.25 µg/ml and 1 µg/ml, a CC of 1 µg/ml was proposed. Validation of the CC in phase III showed that probably susceptible and probably resistant Rv0678 mutants overlapped at 1 µg/ml. We therefore recommend a CC of 1 µg/ml, with additional testing at 0.5 µg/ml to define an intermediate category. This was the first comprehensive study to establish a CC for routine phenotypic DST of CFZ using the MGIT960 system to guide therapeutic decisions. .

Practices in prescribing protein substitutes for PKU in Europe: No uniformity of approach.

BACKGROUND: There appears little consensus concerning protein requirements in phenylketonuria (PKU). METHODS: A questionnaire completed by 63 European and Turkish IMD centres from 18 countries collected data on prescribed total protein intake (natural/intact protein and phenylalanine-free protein substitute [PS]) by age, administration frequency and method, monitoring, and type of protein substitute. Data were analysed by European region using descriptive statistics. RESULTS: The amount of total protein (from PS and natural/intact protein) varied according to the European region. Higher median amounts of total protein were prescribed in infants and children in Northern Europe (n=24 centres) (infants <1 year, >2-3g/kg/day; 1-3 years of age, >2-3 g/kg/day; 4-10 years of age, >1.5-2.5 g/kg/day) and Southern Europe (n=10 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, 2 g/kg/day; 4-10 years of age, 1.5-2 g/kg/day), than by Eastern Europe (n=4 centres) (infants <1 year, 2.5 g/kg/day, 1-3 years of age, >2-2.5 g/kg/day; 4-10 years of age, >1.5-2 g/kg/day) and with Western Europe (n=25 centres) giving the least (infants <1 year, >2-2.5 g/kg/day, 1-3 years of age, 1.5-2 g/kg/day; 4-10 years of age, 1-1.5 g/kg/day). Total protein prescription was similar in patients aged >10 years (1-1.5 g/kg/day) and maternal patients (1-1.5 g/kg/day). CONCLUSIONS: The amounts of total protein prescribed varied between European countries and appeared to be influenced by geographical region. In PKU, all gave higher than the recommended 2007 WHO/FAO/UNU safe levels of protein intake for the general population.

How strict is galactose restriction in adults with galactosaemia? International practice.

Dietary management of 418 adult patients with galactosaemia (from 39 centres/12 countries) was compared. All centres advised lactose restriction, 6 restricted galactose from galactosides ± fruits and vegetables and 12 offal. 38% (n=15) relaxed diet by: 1) allowing traces of lactose in manufactured foods (n=13) or 2) giving fruits, vegetables and galactosides (n=2). Only 15% (n=6) calculated dietary galactose. 32% of patients were lost to dietetic follow-up. In adult galactosaemia, there is limited diet relaxation.