Longitudinal peanut and Ara h 2 specific-IgE, -IgG4, and -IgG4/-IgE ratios are associated with the natural resolution of peanut allergy in childhood.

BACKGROUND: There are no studies of longitudinal immunoglobulin measurements in a population-based cohort alongside challenge-confirmed peanut allergy outcomes. Little is known about biomarkers for identifying naturally resolving peanut allergy during childhood. OBJECTIVES: To measure longitudinal trends in whole peanut and component Ara h 2 sIgE and sIgG4 in the first 10 years of life, in a population cohort of children with challenge-confirmed peanut allergy, and to determine whether peanut-specific immunoglobulin levels or trends are associated with peanut allergy persistence or resolution by 10 years of age. METHODS: One-year-old infants with challenge-confirmed peanut allergy (n = 156) from the HealthNuts study (n = 5276) were prospectively followed at ages 4, 6, and 10 years with questionnaires, skin prick tests, oral food challenges, and plasma total-IgE, sIgE and sIgG4 to peanut and Ara h 2. RESULTS: Peanut allergy resolved in 33.9% (95% CI = 25.3%, 43.3%) of children by 10 years old with most resolving (97.4%, 95% CI = 86.5%, 99.9%) by 6 years old. Decreasing Ara h 2 sIgE (p = .01) and increasing peanut sIgG4 (p < .001), Ara h 2 sIgG4 (p = .01), peanut sIgG4/sIgE (p < .001) and Ara h 2 sIgG4/sIgE (p < .001) from 1 to 10 years of age were associated with peanut allergy resolution. Peanut sIgE measured at 1 year old had the greatest prognostic value (AUC = 0.75 [95% CI = 0.66, 0.82]); however, no single threshold produced both high sensitivity and specificity. CONCLUSION: One third of infant peanut allergy resolved by 10 years of age. Decreasing sIgE and sIgG4 to peanut and Ara h 2 over time were associated with natural resolution of peanut allergy. However, biomarker levels at diagnosis were not strongly associated with the natural history of peanut allergy.

Assessment of Evidence About Common Infant Symptoms and Cow's Milk Allergy.

Importance: Sales of specialized formula for managing cow's milk allergy (CMA) have increased, triggering concern that attribution of common infant symptoms, such as crying, vomiting, and rashes, to CMA may be leading to overdiagnosis, which could undermine breastfeeding. Objective: To understand whether CMA guideline recommendations might promote CMA overdiagnosis or undermine breastfeeding. Evidence Review: We reviewed recommendations made in CMA guidelines and critically appraised 2 key recommendations. First, we reviewed relevant literature summarizing whether maternal or infant dietary exclusion of cow's milk is effective for managing common infant symptoms. Second, we reviewed published data on breastmilk composition and thresholds of reactivity in CMA to estimate the probability that cow's milk protein in human breastmilk can trigger symptoms in infants with CMA. We also documented the level of commercial involvement in CMA guidelines. Findings: We reviewed 9 CMA guidelines published from 2012 to 2019. Seven suggest considering CMA as a cause of common infant symptoms. Seven recommend strict maternal cow's milk exclusion for managing common symptoms in breastfed infants. We found CMA proven by food challenge affects approximately 1% of infants, while troublesome crying, vomiting, or rashes are each reported in 15% to 20% of infants. We found clinical trials do not provide consistent support for using maternal or infant cow's milk exclusion to manage common symptoms in infants without proven CMA. We estimated that for more than 99% infants with proven CMA, the breastmilk of a cow's milk-consuming woman contains insufficient milk allergen to trigger an allergic reaction. Three CMA guidelines were directly supported by formula manufacturers or marketing consultants, and 81% of all guideline authors reported a conflict of interest with formula manufacturers. Conclusions and Relevance: Recommendations to manage common infant symptoms as CMA are not evidence based, especially in breastfed infants who are not directly consuming cow's milk. Such recommendations may cause harm by undermining confidence in breastfeeding.

Study protocol for the Melbourne Infant Study: BCG for Allergy and Infection Reduction (MIS BAIR), a randomised controlled trial to determine the non-specific effects of neonatal BCG vaccination in a low-mortality setting.

INTRODUCTION: BCG vaccination reduces all-cause infant mortality in high-mortality settings by more than can be attributed to protection against tuberculosis. This is proposed to result from non-specific protection against non-vaccine targeted ('off-target') infections. There is also evidence that BCG protects against allergic diseases. METHODS AND ANALYSIS: The Melbourne Infant Study: BCG for Allergy and Infection Reduction is a phase III multicentre, single-blinded, randomised controlled trial. A total of 1438 healthy neonates will be randomised to receive either BCG vaccination or no BCG vaccination in the first 10 days of life. Measures of allergy, eczema, infection and asthma will be obtained from parent-completed questionnaires 3 monthly in the first year and 6 monthly from 1 to 5 years of age, and clinical assessments at 1 and 5 years of age. Biological samples will also be collected for future immunological studies. ANALYSIS PRIMARY OUTCOME: The proportion of participants with measures of allergy and infection (atopic sensitisation, eczema, lower respiratory tract infection) at 1 and 5 years of age, and asthma at 5 years of age. SECONDARY OUTCOMES: (1) the proportion of participants with additional measures of allergy, eczema, asthma and infections; (2) medication use for eczema and asthma; (3) the severity and age of onset of eczema and asthma; (4) the number of episodes of infection; (5) hospitalisations for infections and (6) laboratory measures of immune responses. ETHICS AND DISSEMINATION: This trial has ethical and governance approval from Mercy Health Human Research Ethics Committee (HREC, No. R12-28) and Royal Children's Hospital HREC (No. 33025) with additional governance approval from Barwon Health and St John of God, Geelong, Victoria. Results of this trial will be published in peer-reviewed journals and presented at scientific conferences. TRIAL REGISTRATION NUMBER: NCT01906853.

Why do people choose not to have screening for hemochromatosis?

AIM: Hemochromatosis is a common disorder of iron overload most commonly due to homozogosity for the HFE C282Y substitution. A workplace-screening program was conducted in which over 11,000 individuals were screened for this mutation. A substudy of this project was to ascertain why people chose not to attend information and screening sessions offered in their workplace. METHOD: Staff were recruited by email, questionnaires in common areas, and direct approach. A purpose-designed questionnaire sought the reasons for not attending information and screening sessions. RESULTS: The nonattender questionnaire was distributed at 24 workplaces and completed by 872 individuals. The most common reason for not attending sessions, accounting for 70.1%, was practical (e.g., unaware of session, too busy, or unavailable). Other relatively common reasons were that the individual had low iron levels or were a blood donor (14.9%), or that hemochromatosis was considered unimportant (12.2%). Insurance concerns were very rarely cited as the reason for nonattendance (1.0%). CONCLUSION: The nonattender data presented here indicate that concerns about insurance, anxiety, and use of genetic information are not major factors for why people did not attend workplace information and screening sessions for hereditary hemochromatosis. Practical barriers were the major reasons identified. This highlights that when implementing screening programs, as many practical barriers as possible need to be overcome, so that a maximum number of people who would like to be informed about screening are given the opportunity to do so.

Phenotypic and genotypic analysis of Flavobacterium psychrophilum isolates from Ontario salmonids with bacterial coldwater disease.

Flavobacterium psychrophilum is the causative agent of bacterial coldwater disease (BCWD) and rainbow trout fry syndrome. BCWD has a considerable economic impact on aquaculture operations in Ontario, Canada, and our limited understanding of the population structure and epidemiology of F. psychrophilum isolates is an impediment to the development of improved management strategies. Seventy-five 16S rRNA gene and gyr polymerase chain reaction positive isolates of F. psychrophilum that had been collected over a 16-year period from farmed salmonids with tail rot, necrotic myositis, and osteochondrosis were characterized morphologically, biochemically, and genotypically. Although the isolates were homogeneous by preliminary biochemical and phenotypic characterization, two distinct biovars were found by API ZYM testing. As well, four restriction pattern types were detected by 16S rRNA polymerase chain reaction -- restriction fragment length polymorphism analysis and there was a significant (P < 0.001) correlation between biovar I and digestion with MaeIII and between biovar II and digestion with MnlI or no site (P < 0.05). Further heterogenity was detected by sequence analysis of a 194 bp stem loop 3 region of rRNA. Nine sequence types were identified; 40/46 biovar I isolates were sequence type "a", while 21/32 biovar II isolates belonged to either sequence type "c" or "d". More than one biovar and genotype was identified among the strains recovered from separate fish sampled from three groups of rainbow trout (Oncorhynchus mykiss) experiencing BCWD mortality events. No association was found between genotype or biovar and type of disease. Taken together, these data suggest that F. psychrophilum from Ontario can be grouped into two major lineages based on biovar and 16S rRNA polymorphisms, and although three major strain types were most frequently isolated in this study, it appears that the population of F. psychrophilum with pathogenic potential is quite heterogeneous.