Predictive value of peanut skin prick test, specific IgE in peanut-sensitized children in Singapore.
BACKGROUND: The predictive decision points for both peanut skin prick test (SPT) wheal size and serum IgE concentrations, in peanut-sensitized children, have not been evaluated in Singapore. OBJECTIVE: We aim to derive clinically useful predictive decision points to be used for risk stratification of oral food challenge (OFC) in peanut-sensitized patients. METHODS: Patients with a positive SPT to peanut, performed during a 4-year period between 2012 and 2016, were included in a retrospective chart review. The patients were assessed for their peanut allergy status based on a convincing clinical history. Their first SPT and serum IgE results done at presentation to our centre were used. RESULTS: There were 269 patients with a clinical diagnosis of peanut allergy based on recent immediate reaction to peanut and 59 patients whom were tolerating peanuts regularly. There were 251 patients sensitized to peanut, without prior known peanut exposure. A wheal size of ≥8 mm and a peanut-specific IgE of ≥6 kU/L each provided for a 95% positive predictive value of clinical reaction to peanuts; the larger the wheal size on SPT, the higher the probability. CONCLUSION: The cutoff values derived in this study can help clinicians in the risk assessment of OFC in peanut-sensitized patients. Prospective studies using OFCs for the diagnosis of peanut allergy are needed to confirm the diagnostic performance of these tests in predicting OFC outcomes.
Allergen components in diagnosing childhood hazelnut allergy: systematic literature review and meta‐analysis
BACKGROUND: Hazelnut-specific IgE antibodies (sIgE) in serum support the diagnosis of hazelnut allergy, but extract-based tests have low diagnostic specificity, commonly leading to over-diagnosis. Measuring sensitization to individual allergen components may enhance the diagnosis of hazelnut allergy. We systematically examined data on diagnostic accuracy of sIgE to commercially available hazelnut components to compare their individual contributions in diagnosing hazelnut allergy. METHODS: Seven databases were searched for diagnostic studies on patients suspected of having hazelnut allergy. Studies employing component-specific IgE testing on patients whose final diagnosis was determined by oral food challenges were included in the meta-analysis. Study quality was assessed as recommended by Cochrane. RESULTS: Seven cross-sectional studies and one case-control study were identified, seven presenting data on children (N=635), and one on a mixed age population. Overall, the diagnostic accuracies of sIgE to both Cor a 9 and Cor a 14 were significantly higher than for Cor a 1-sIgE (p<0.05). In children, the specificity of Cor a 14-sIgE at 0.35 kUA /L cut-off was 81.7% [95% CI 77.1, 85.6], 67.3% [60.3, 73.6] for Cor a 9-sIgE. The specificities for Cor a 1-sIgE and hazelnut-sIgE were 22.5% [7.4, 51.2] and 10.8% [3.4, 29.8], respectively. The sensitivity of Cor a 1-sIgE (60.2% [46.9, 72.2]) was lower than for hazelnut extract-sIgE (95.7% [88.7, 98.5]), while their specificities did not differ significantly. CONCLUSION: sIgE to Cor a 14 and Cor a 9 hazelnut storage proteins increase diagnostic specificity in assessing hazelnut allergy in children. Combined use of hazelnut extract and hazelnut storage proteins may improve diagnostic value.
Almond (Prunus dulcis) allergen Pru du 8, the first member of a new family of food allergens.
An almond allergen with 2 known short peptide sequences was reported as the almond 2S albumin but was later suspected to be almond vicilin. However, this allergen was designated by WHO/IUIS. This study aimed to determine the true identity of this elusive almond allergen. cDNAs were synthesized from total RNA of the Nonpareil almond. The complete sequence of the previously reported almond allergen was determined from its coding sequence. The deduced protein was produced recombinantly, and it was confirmed to be a food allergen by testing with 18 almond-allergic sera. The allergen is a potential cysteine-rich antimicrobial protein with characteristic C[X]3C-[X]10-12-C[X]3C motifs of the hairpinin antimicrobial protein. This first member of a novel family of food allergens was named Pru du 8. The signature motif of the hairpinin antimicrobial protein can be found in the N-terminal region of some vicilin allergens (e.g., Ara h 1). It can also be found in the signal peptide of other vicilin allergens (e.g., Car i 2). In many species, however, vicilins do not contain such a motif, indicating that the presence of the signature motifs of the hairpinin antimicrobial protein in vicilins might be a result of translocation during evolution.
SPT predictive values for the outcome of cashew challenges in children.
BACKGROUND: Cashew is a common cause of tree nut allergy in children. To date there have been few studies of diagnostic tests for cashew allergy, and positive predictive values (PPVs) for cashew as well as other tree nuts are largely extrapolated from studies of peanut allergy. How relevant these cut-offs are for cashew has not been formally explored. OBJECTIVE: We aimed to establish skin prick test (SPT) wheal sizes that correlated to 95% PPV for a positive food challenge for cashew. METHODS: We included all cashew oral food challenges (OFC) conducted as part of the HealthNuts (n=108, age 4-6 years) and SchoolNuts (n=37, age 10-14 years) studies, both recruited from the community (Population cohort). A second cohort of all cashew OFCs conducted at the Royal Children's Hospital (RCH) allergy centre (n=343) (2011-2016) and a private allergy clinic based at RCH (n=43) was included via electronic medical record review (Clinic cohort). 95% PPV for cashew SPT was calculated for both cohorts. RESULTS: Among the population cohort (n=145), 62% of cashew OFC were positive compared to 20% of the clinic cohort (n=386). The SPT cut-off for 95% PPV derived from the population cohort was 10mm (95%CI 7.5-12.0). For the clinic cohort the 95% PPV was 14mm (95%CI 9.5-unknown). A SPT wheal size of 8mm had a PPV of 89% (95%CI 79-95) in the population cohort and 62% (95%CI 45-78) in the clinic cohort. CONCLUSION: A higher SPT wheal size may be more appropriate than the commonly used 8mm cut-off to guide clinical decisions around when to perform OFC for cashew.
Pistachio and cashew nut allergy in childhood: Predictive factors towards development of a decision tree.
BACKGROUND: Pistachio and cashew nut, which belong to the same botanical family, are tree nuts that induce serious allergic reactions. OBJECTIVE: We aimed to determine the predictive factors for pistachio and cashew nut reactivity during oral food challenge (OFC). METHODS: A total of 112 pistachio and/or cashew nut sensitized children, aged 58.45 (IQR:40.38-88.32) months, were included. Cutoff values and probability curves for skin prick test (SPT), sIgE, sIgE/Total IgE that predict reactivity were determined for pistachio and cashew nut. Additionally, a diagram was created that can be useful while making a decision for OFC based on SPT and sIgE values. RESULTS: A total of 73 patients underwent OFC with pistachio and/or cashew nut. Twelve children with current anaphylaxis history were not challenged and accepted as allergic. SPT was the only predictive factor for positive pistachio/ cashew nut OFC. According to area under curve (AUC) analysis, SPT was more predictive than sIgE and sIgE/Total IgE both for pistachio and cashew nut. Optimal cutoff values according to "Youden index" for pistachio SPT, sIgE, and sIgE/ Total IgE were 7.25 mm, 4.14 kUA/L, and 1.32%, respectively. And those values for cashew nut SPT, sIgE, and sIgE/Total IgE were 6.25 mm, 1.125 kUA/L, and 3.30%, respectively. The diagram showed that SPT predicted the reactivity together with sIgE better than only the SPT values. CONCLUSION: SPT was the best predictor for reactivity both for pistachio and cashew nut. Combined use of SPT and sIgE may improve the prediction of reactivity at pistachio and cashew nut OFCs in children.
Funding Opportunities for Research and Dissemination 2020
The INC also runs the “Nutfruit Power” dissemination campaign, which is aimed at promoting the idea of eating nuts and dried fruits for breakfast or as a morning snack to gain power to face the challenges of the day ahead.
2019 Grant Awardees
Research Grant Recipients:
- Project: “Effects of long-term mixed nut consumption on brain health in elderly: focus on underlying mechanisms”. Principal Investigator: Prof. Ronald Mensink, Maastricht University, Netherlands.
- Project: “Associations between nut intake, cognitive function and non-alcoholic fatty liver disease in older adults”. PI: Dr. Sze-Yen Tan, Deakin University, Australia.
Dissemination Grant Recipients:
- Nucis Italia. Project: “Nuts and nutrition system”.
- Toronto 3D Knowledge Synthesis and Clinical Trials foundation. Project: “37th International Symposium on Diabetes and Nutrition: Dried Fruits & Diabetes Symposium and Presentation”.
By year end, the INC will have provided over 3.5 million euros of funding for research and dissemination projects over the last seven years.
WorldFood Instanbul 2019
Attending the exhibition means you get to see the innovations in the global industry, source tens of thousands of new products and services, and meet local and international suppliers and manufacturers of food and drink products.
Biofach India
The 11th edition of BIOFACH INDIA, the only organic platform in India to connect and network with your target audience is scheduled to be held from 7 – 9 November, 2019 at India Expo Centre, IEML, Greater Noida, Delhi-NCR.
Organic is more than a label or certification: organic stands for quality and conviction – for theresponsible use of nature’s resources. BIOFACH INDIA is the meeting place in India whereanyone and everyone who is connected to organic converge annually to share their passionate interest for organic products, network at a common platform and educate themselves about thelatest developments in the organic sector.
New Study Reveals an Inverse Association between Nut Consumption and CVD
A systematic search, limited to human studies, was conducted in the PubMed and Cochrane databases. In total, 19 prospective studies were included in this systematic review and meta-analysis.
A 13% reduction in the risk of CVD incidence was observed up to a consumption of 10 g/day, compared to no consumption. For CVD mortality and CHD mortality, a 29% and 32% lower risk was observed, respectively, at approximately 15-20 g/day. Similarly, for stroke mortality, a 16% reduction in the risk was observed up to a consumption of 5 g/day.
In conclusion, a beneficial role of total nut consumption was observed in reducing the incidence of, and mortality from, different CVD outcomes.
[1] World Health Organization. WHO Cardiovascular diseases (CVDs). 2017: https://www.who.int/en/news-room/fact-sheets/detail/cardiovascular-diseases-(cvds). Accessed July 12, 2019.
[2] Becerra-Tomás, N., Paz-Graniel, I., Kendall, C.W.C., Kahleova, H., Rahelić, D., Sievenpiper, J.L., Salas-Salvadó, J. (2019). Nut consumption and incidence of cardiovascular diseases and cardiovascular disease mortality: a meta-analysis of prospective cohort studies. Nutrition Reviews, doi: 10.1093/nutrit/nuz042.