Incidence and risk factors for food hypersensitivity in UK infants: results from a birth cohort study.

BACKGROUND: The prevalence of food hypersensitivity in the UK is still largely open to debate. Additionally its pathogenesis is also unclear although it is known that there are differing phenotypes. Determining its prevalence, along with identifying those factors associated with its development will help to assess its clinical importance within the national setting and also add to the debate on appropriate prevention strategies. METHODS: A population based birth cohort study conducted in Hampshire, UK as part of the EuroPrevall birth cohort study. 1140 infants were recruited with 823 being followed up until 2 years of age. Infants with suspected food reactions were assessed including specific IgE measurement and skin prick testing. Diagnosis of food hypersensitivity was by positive double-blind, placebo-controlled food challenge (DBPCFC) where symptoms up to 48 h after the end of the food challenge were considered indicative of a food hypersensitivity. Factors associated with food hypersensitivity and its two phenotypes of IgE-mediated and non-IgE-mediated disease were modelled in a multivariable logistic regression analysis. RESULTS: Cumulative incidence of food hypersensitivity by 2 years of age was 5.0 %. The cumulative incidence for individual food allergens were hens' egg 2.7 % (1.6-3.8); cows' milk 2.4 % (1.4-3.5); peanut 0.7 % (0.1-1.3); soy 0.4 % (0.0-0.8); wheat 0.2 % (0.0-0.5) and 0.1 % (0.0-0.32) for fish. The cumulative incidence of IgE-mediated food allergy was 2.6 % with 2.1 % reacting to hens' egg. For non-IgE-mediated food allergy the cumulative incidence was 2.4 % (cows' milk 1.7 %). Predictors for any food hypersensitivity were wheeze, maternal atopy, increasing gestational age, age at first solid food introduction and mean healthy dietary pattern score. Predictors for IgE mediated allergy were eczema, rhinitis and healthy dietary pattern score whereas for non-IgE-mediated food allergy the predictors were dog in the home, healthy dietary pattern score, maternal consumption of probiotics during breastfeeding and age at first solid food introduction. CONCLUSIONS: Just under half the infants with confirmed food hypersensitivity had no demonstrable IgE. In an exploratory analysis, risk factors for this phenotype of food hypersensitivity differed from those for IgE-mediated food allergy except for a healthy infant diet which was associated with less risk for both phenotypes.

Using statistical models to identify factors that have a role in defining the abundance of ions produced by tandem MS.

A database of 5448 peptide tandem mass spectra acquired in a quadrupole time-of-flight mass spectrometer was generated for peptides derived from proteins digested with trypsin. Peptides were identified from their mass spectra by the Mascot algorithm. Statistical models were then used to investigate factors influencing the abundance of ions formed. Separate models were formulated for b and y ions as it was thought that different factors may influence the formation of each type of ion. Several factors were found to have a highly significant influence on the abundance of ions formed. These include the actual mass of the ion formed after fragmentation as well as the location of the cleavage. The composition of the fragmenting peptide was also found to be important, and amino acids either side of the fragmentation site influenced the abundance of ions produced. To increase understanding of fragmentation mechanisms, the effect of several physicochemical properties of these residues was also investigated in a separate model. In conclusion, the models formulated for b and y ions provide useful characterization of the abundance of ions formed, and this information could be used to develop improved algorithms for peptide identification.

Ultramolecular homeopathy has no observable clinical effects. A randomized, double-blind, placebo-controlled proving trial of Belladonna 30C.

AIMS: To investigate if ultramolecular homeopathy has any clinical effects. This was assessed using the proving of the homeopathic remedy Belladonna given at an ultramolecular dose (30C), as a model. A proving states that when a homeopathic remedy is given to a healthy person, they will experience symptomatic effects specific to that remedy. If ultramolecular doses are clinically active, the Belladonna 30C group should experience more true Belladonna proving symptoms than the placebo group. METHODS: Healthy subjects (n = 253), aged 18-30 years, took part in this double-blind, randomized placebo-controlled study. Total study duration was 4 weeks. Subjects were randomized before 1 week placebo run-in. They received 2 weeks of treatment intervention (Belladonna 30C or placebo) and were followed up for 1 week. Subjects recorded any symptoms experienced during the total study period on a daily basis using a structured questionnaire. Symptom diaries were analysed blind to determine if each subject had proved or not (based on predefined criteria). The main outcome was the proportion of subjects who had proved in each treatment group. RESULTS: No significant group differences in proving rates were observed [Belladonna provers N = 14 (13.9%); placebo provers N = 15 (14.3%); mean difference -0.4%, 95% confidence interval -9.3, 10.1] based on intention to treat analysis. Primary outcome was not affected by seasonality or the individual's attitude to complementary medicine. CONCLUSION: Ultramolecular homeopathy had no observable clinical effects.