We and others(16, 35) also have suggested that IgE to Ara h 2 shows higher discriminative accuracy than IgE to whole peanut extract in the prediction of PA. Low IgG4 levels have been generally proposed as a reflection of low dietary exposure to allergens. anaphylaxis) had significantly higher IgE reactivity to Ara h 1C3 (peanut allergens) and Gly m 5C6 (soy allergens) than asymptomatically-sensitized children (p 0.00001). Similar but more modest relationships were found for IgG4 to Ara MK-4305 (Suvorexant) h 2 (p 0.01). IgE to Ara h 2 was the major contributor to accurate discrimination between PA and asymptomatic sensitization. With an optimal cutoff point of 0.65 ISU-E, it conferred 99.1% sensitivity, 98.3% specificity, and a 1.2% misclassification rate in the prediction of PA, which represented a higher discriminative accuracy than IgE to whole peanut extract (p=0.008). However, none of the IgE and/or IgG4 tests could significantly differentiate peanut anaphylaxis from non-anaphylactic PA. Conclusions IgE to Ara h 2 can efficiently differentiate clinical PA from asymptomatic peanut sensitization, which may represent a major step forward in the diagnosis of PA. and em D. farinae /em ], cat hair, dog epithelia, cockroach mix, and em Alternaria Rabbit Polyclonal to MCM3 (phospho-Thr722) tenius /em ) was performed with histamine and saline serving as positive and negative controls, respectively. SPT is considered valid when the mean wheal diameter (MWD) for histamine is 3mm, the MWD for saline is 3mm, and their difference is 3mm. Specific IgE (sIgE) to these 14 extracts and total IgE (tIgE) were measured by the Clinical Immunology Laboratory of CMH using Phadia ImmunoCAP (Phadia AB, Uppsala, Sweden). The calibration range for tIgE and sIgE was 2.0C5000 kU/L and 0.1 C100 kUA/L, respectively. Percent peanut sIgE was calculated as peanut sIgE/tIgE 100%. Definition of Phenotypes Sensitization was defined as SPT MWD 3 mm compared to the negative control and/or sIgE 0.1kUA/L to any of the 14 measured extracts. Non-atopic controls were defined if a child had no sensitization to any of these extracts and had no history of any MK-4305 (Suvorexant) physician-diagnosed allergic diseases. Asymptomatic PS children were defined if a child was sensitized to peanut (SPT MWD 3 mm to peanut compared to the negative control and/or peanut sIgE 0.1kUA/L) but reported no clinical symptoms on peanut ingestion. PA cases were defined if a child met both of the following criteria: 1) peanut sIgE 14 kUA/L and/or peanut SPT MWD 8 mm; 2) a convincing clinical reaction within 2 hours of peanut ingestion consisting of any of the following: oral cavity symptoms (lip or tongue swelling); skin-mucosal symptoms (hives, swollen face/extremities, swollen eyes); throat symptoms (itching, tightness, hoarseness/change of voice, or choking/difficulty swallowing); respiratory tract symptoms (shortness of breath, repetitive coughing, wheezing, chest tightness); cardiovascular symptoms (dizziness, lightheadedness, fainting, decreased level of consciousness); and gastrointestinal symptoms (vomiting). Peanut anaphylaxis was defined according to the previous report by Sampson et al.(30). CRD-based IgE and IgG4 measurement IgE reactivity to 103 allergens (including four peanut allergens: Ara h 1C3 and 8) was simultaneously tested using ImmunoCAP ISAC IgE chips by Phadia Immunology Reference Laboratory (Portage, Michigan) according to the manufacturers instructions. Information on these allergens can be found elsewhere(31). This technique is a semi-quantitative test, and results are reported in ISAC Standardized Units (ISU-E) where ISU-E corresponds to IgE antibody levels in the ng/mL range. Similarly, ImmunoCAP ISAC IgG4 chips were applied to measure IgG4 reactivity to the same 103 allergens where ISU-G4 corresponds to IgG4 antibody levels in the mg/mL range. The detection limit for IgE and IgG4 was 0.3 ISU-E and 0.1 ISU-G4, respectively. Positive IgE and IgG4 reactivity was defined if their value was above detection limit, respectively. Statistical Analyses IgE and IgG4 reactivity to the 103 allergens were analyzed as both continuous (IgE or IgG4 levels) and categorical MK-4305 (Suvorexant) variables (the frequency of positive reactivity). The non-parametric Wilcoxon Rank Sums tests and Fishers exact tests were applied to compare the distribution of continuous variables and categorical variables, respectively, among different study groups as well as between 108 PA cases and 58 asymptomatic PS children. The statistical significance cutoff level was a two-sided p-value 0.01. These analyses were conducted using SAS software version 9.3 (SAS Institute, Cary, North Carolina, USA). If IgE and/or IgG4 reactivity profiles clearly.