Components in soy allergy diagnostics: Gly m 2S albumin has the best diagnostic value in adults

BackgroundThus far, four soy allergens have been characterized. Their diagnostic value was assessed only using a case-control design with controls not suspected of soy allergy or in a soy-allergic population without controls. Our objective was to analyze the diagnostic value of specific immunoglobulin E (sIgE) to Gly m 2S albumin, Gly m 4, 5, and 6, and their possible relation with severity or culprit soy product. MethodsAdult patients suspected of soy allergy were included (n=46). Allergy was confirmed by challenge (n=19) or history (n=16) and excluded by challenge in 11 patients. Soy components were analyzed by ImmunoCAP. Diagnostic value was assessed in the challenged patient group by an area under receiver operating characteristic (ROC) curve (AUC). ResultsSpecific immunoglobulin E to Gly m 2S albumin had the highest AUC (0.79), comparable to skin prick test (SPT) and sIgE to soy extract (0.76 and 0.77, respectively). All patients were sensitized to either soy extract or Gly m 4 (sIgE0.35kU/l). sIgE to soy extract, Gly m 5, and Gly m 6 was significantly higher in patients with mild symptoms (P=0.04, 0.02 and 0.02, respectively). Patients only reacting to soy milk had higher sIgE levels to Gly m 4 (median 9.8 vs 1.1 kU/l, P=0.01). ConclusionSpecific immunoglobulin E to Gly m 2S albumin had the best accuracy in diagnosing soy allergy. Gly m 5 and 6 were related to mild symptoms. Higher levels of Gly m 4 were related to allergy to soy milk

Threshold Dose Distribution in Walnut Allergy

BACKGROUND: In food allergy, eliciting doses (EDs) of foods on a population level can improve risk management and labeling strategies for the food industry and regulatory authorities. Previously, data available for walnut were unsuitable to determine EDs. OBJECTIVE: The objective of this study was to determine EDs for walnut allergic adults and to compare with previously established threshold data for peanut and tree nuts. METHODS: Prospectively, adult subjects with a suspected walnut allergy underwent a low-dose double-blind, placebo-controlled food challenge. Individual no observed and lowest observed adverse effect levels were determined and log-normal, log-logistic, and Weibull models were fit to the data. Estimated ED values were calculated for the ED5, ED10, and ED50, the dose respectively predicted to provoke an allergic reaction in 5%, 10%, and 50% of the walnut allergic population. RESULTS: Fifty-seven subjects were challenged and 33 subjects were confirmed to be walnut allergic. Objective symptoms occurred in 20 of the positive challenges (61%). The cumulative EDs in the distribution models ranged from 3.1 to 4.1 mg for the ED05, from 10.6 to 14.6 mg walnut protein for the ED10, and from 590 to 625 mg of walnut protein for the ED50. CONCLUSIONS: Our data indicate that population EDs for walnut are slightly higher compared with those for peanut and hazelnut allergy. Currently available data indicate that the ED values for hazelnut could be used as a conservative temporary placeholder when implementing risk management strategies for other tree nuts where little or no food challenge data are available

Threshold Dose Distribution in Walnut Allergy

BACKGROUND: In food allergy, eliciting doses (EDs) of foods on a population level can improve risk management and labeling strategies for the food industry and regulatory authorities. Previously, data available for walnut were unsuitable to determine EDs. OBJECTIVE: The objective of this study was to determine EDs for walnut allergic adults and to compare with previously established threshold data for peanut and tree nuts. METHODS: Prospectively, adult subjects with a suspected walnut allergy underwent a low-dose double-blind, placebo-controlled food challenge. Individual no observed and lowest observed adverse effect levels were determined and log-normal, log-logistic, and Weibull models were fit to the data. Estimated ED values were calculated for the ED5, ED10, and ED50, the dose respectively predicted to provoke an allergic reaction in 5%, 10%, and 50% of the walnut allergic population. RESULTS: Fifty-seven subjects were challenged and 33 subjects were confirmed to be walnut allergic. Objective symptoms occurred in 20 of the positive challenges (61%). The cumulative EDs in the distribution models ranged from 3.1 to 4.1 mg for the ED05, from 10.6 to 14.6 mg walnut protein for the ED10, and from 590 to 625 mg of walnut protein for the ED50. CONCLUSIONS: Our data indicate that population EDs for walnut are slightly higher compared with those for peanut and hazelnut allergy. Currently available data indicate that the ED values for hazelnut could be used as a conservative temporary placeholder when implementing risk management strategies for other tree nuts where little or no food challenge data are available

Objective eliciting doses of peanut-allergic adults and children can be combined for risk assessment purposes

BACKGROUND: To improve food labelling strategies, information regarding eliciting doses (EDs) and the effect of patient characteristics on these EDs is necessary. OBJECTIVE: To establish EDs for objective and subjective symptoms and analyse the effect of sensitization levels and other patient characteristics on threshold distribution curves (TDCs). METHODS: Threshold data from 100 adults and 262 children with a positive food challenge were analysed with interval-censoring survival analysis (ICSA) and fitted to a TDC from which EDs could be extracted. Possible influencing factors were analysed as covariates by ICSA. A hazard ratio (HR) was calculated in case of a significant effect. RESULTS: TDCs for both objective and subjective symptoms were significantly different between adults and children (P < 0.001). Objective ED05 values, however, were comparable (2.86 mg peanut protein in adults and 6.38 mg in children). Higher levels of sIgE to Ara h 2 and peanut extract were associated with a larger proportion of patient groups reacting to a dose increase with objective symptoms (adults and children) or subjective symptoms (adults, in children a trend). Age had a similar effect in children (HR 1.05 for objective symptoms and 1.09 for subjective symptoms). Gender had no effect on TDCs. CONCLUSION AND CLINICAL RELEVANCE: Subjective and objective TDCs were different between adults and children, but objective ED05 values were comparable, meaning that threshold data from children and adults can be combined for elaboration of reference doses for risk assessment. Higher sIgE levels to Ara h 2 and peanut extract were associated with a larger proportion of both patient groups to react to a certain dose increase

Objective eliciting doses of peanut-allergic adults and children can be combined for risk assessment purposes

BACKGROUND: To improve food labelling strategies, information regarding eliciting doses (EDs) and the effect of patient characteristics on these EDs is necessary. OBJECTIVE: To establish EDs for objective and subjective symptoms and analyse the effect of sensitization levels and other patient characteristics on threshold distribution curves (TDCs). METHODS: Threshold data from 100 adults and 262 children with a positive food challenge were analysed with interval-censoring survival analysis (ICSA) and fitted to a TDC from which EDs could be extracted. Possible influencing factors were analysed as covariates by ICSA. A hazard ratio (HR) was calculated in case of a significant effect. RESULTS: TDCs for both objective and subjective symptoms were significantly different between adults and children (P < 0.001). Objective ED05 values, however, were comparable (2.86 mg peanut protein in adults and 6.38 mg in children). Higher levels of sIgE to Ara h 2 and peanut extract were associated with a larger proportion of patient groups reacting to a dose increase with objective symptoms (adults and children) or subjective symptoms (adults, in children a trend). Age had a similar effect in children (HR 1.05 for objective symptoms and 1.09 for subjective symptoms). Gender had no effect on TDCs. CONCLUSION AND CLINICAL RELEVANCE: Subjective and objective TDCs were different between adults and children, but objective ED05 values were comparable, meaning that threshold data from children and adults can be combined for elaboration of reference doses for risk assessment. Higher sIgE levels to Ara h 2 and peanut extract were associated with a larger proportion of both patient groups to react to a certain dose increase