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Heart rate variability during oral food challenge
AB126 Abstracts
396
Heart rate variability during oral food challenge
SUNDAY
Katsuhito Iikura, MD, PhD1, and Hiroshi Tachimoto, MD, PhD2; 1Tokyo Jikei University Hospital, Tokyo, Japan, 2Tokyo Jikei Hospital, Tokyo, Japan. RATIONALE: Oral food challenge (OFC) is the standard methods to diagnose food allergy. In early stage of OFC, it is difficult to detect severe reaction such as anaphylaxis. To detect the severe reaction before objective symptom, we examined the change of HR values during OFC. METHODS: We performed 45 OFC and analyzed the recorded HR values during OFC. Changes of HR from values at start were calculated, and we analyzed the root mean square (RMS) of those change rates during OFC. Subjects were divided to three groups, such as anaphylaxis group, mild symptom group, and tolerant group. We compared the HR change from start of OFC between those three groups and evaluated whether an occurrence of anaphylactic reaction was detected by RMS of HR change. RESULTS: ata from 45 children were analyzed (anaphylaxis group, n517, mild symptom group, n515, tolerant group, n513). It included eggwhite (n513), cow’s milk (n515), wheat (n58), peanut (n56), sesame (n51), almond (n51), and buckwheat (n51) test. RMS of HR change had significantly increased in anaphylaxis group (8.2 6 0.2%) more than mild symptom group (5.6 6 0.2%) and tolerant group (5.8 6 0.2%). RMS of HR change detected in anaphylaxis group achieved an ROC-AUC of .89. A cut-off 7.17% achieved a sensitivity of 90.5% and a specificity of 79.4%. CONCLUSIONS: Change of RMS was seen before the visible severe reactions. Change of HR values may be useful tool as the objective marker when we perform OFC safely.
397
Clinical Sensitivity, Reproducibly Defined by DoubleBlind Placebo-Controlled Food Challenge, is Associated with Peanut Specific Skin Testing and Peanut IgE
Lauren E. Tracy; Massachusetts General Hospital, Boston, MA; Food Allergy Center, Massachusetts General Hospital, Boston, MA. RATIONALE: During screening for a peanut oral immunotherapy trial (PNOIT), we identified a cohort of peanut-allergic patients who met all eligibility criteria (history, +PST, +Arah2-specific IgE and peanut-specific IgE > 5kU/L), but passed the low dose pre-randomization double-blind placebo-controlled food challenge (DBPCFC). We hypothesized that these patients, while truly allergic, were clinically less sensitive and assessed if baseline characteristics were associated with reactivity to peanut. METHODS: For participation in PNOIT, we screened peanut-allergic subjects ages 7-55, using peanut skin test and serology (Arah2, peanut IgE), followed by a DBPCFC of up to 443 mg of peanut. Subjects who met all other screening criteria but passed the entry DBPCFC, were invited to return for a DBPCFC challenge up to 7443mg. Statistical analyses were performed by Student’s T test. RESULTS: Ninety-eight subjects were screened for participation in PNOIT and 62 met initial screening criteria. Of these, 21 (34%) passed the entry challenge. Six of these subjects elected to repeat DBPCFC, and all reacted at eliciting doses > 443 mg. The high ED subjects had significantly smaller skin prick tests (8.8 vs 12.2 mm, p50.02), and a significantly lower IgE (34 vs 56, p50.05). CONCLUSIONS: Skin prick test wheal size and peanut IgE were significantly smaller in the cohort of subjects who met initial study eligibility criteria but passed the DBPCFC up to 443mg. Among all subjects who returned for the additional DBPCFC, all reacted to peanut, potentially identifying a sub-population of high-threshold peanut-allergic individuals, characterized by higher levels of allergic sensitization.
398
Peanut Allergy testing correlates with clinical symptoms and outcomes suggesting peanut allergy phenotypes.
Efren L. Rael, MD, FAAAAI; Stanford University, Sean N. Parker Center for Allergy and Asthma Research, Stanford, CA. RATIONALE: Allergic phenotypes exist in asthma. It is unclear if allergic phenotypes exist in peanut allergy (PA). Subject reported PA symptoms,
J ALLERGY CLIN IMMUNOL FEBRUARY 2017
treatments, emergency room related food reactions (ERFR), and hospitalizations were reviewed in relation to peanut wheal size (PWS) and peanut specific IgE components (PSIC). METHODS: Subjects with PA concern, completed a standardized questionnaire. Symptoms were reviewed in relation to PWS (in 121 subjects) and PSIC Ara_h1, 2, 3, 8, and 9 (in 47 subjects). RESULTS: PWS correlated with skin, upper/lower airway anaphylactic symptoms of throat/chest tightness (CT), shortness of breath (SOB), tongue/lip swelling, and urticaria but not gastrointestinal symptoms of stomach pain, diarrhea, vomiting, regurgitation or the Modified Aceves questionnaire score (MAQ). ERFR and mechanical ventilation also correlated. Ara_h1 and 2 correlated with intubations, retching, and nausea. Ara_h1,2, and 3 correlated with bitter acid taste, the ACQ6 score, throat tightness, and stomach pains. Ara_h1,2, and 9 correlated with nausea. Ara_h2 correlated with hives and SOB, and PA persistence. Ara_h2 and 9 correlated with abdominal bloating. Ara_h1 and 3 correlated with total respiratory symptom scores. Ara_h1,2, and 8 correlated with ERFR, and age. Ara_h1,3, and 9 correlated with vomit, the MAQ. Ara_h8 correlated with prednisone treatments, and birch pollen IgE and wheal size. Ara_h9 correlated with angioedema, diarrhea, excessive satiety, antibiotic treatment for sinusitis, tongue, throat/lip swelling, heartburn, lower/upper abdominal discomfort, breast milk intolerance, and CT. CONCLUSIONS: Symptoms and outcomes may relate to PA skin testing to predict skin, upper and lower respiratory symptoms; whilst PSIC might predict respiratory and gastrointestinal symptoms.
399
Predictive Accuracy Of Peanut Components In The Diagnosis Of Peanut Allergy: A Systematic Literature Review And Meta-Analysis
Malin Berthold, PhD1, Barbara Mascialino, PhD1, Donna Fountain2, Kevin Cadwell2, Chrysanthi Papageorgakopoulou2, Sigrid Sjolander, PhD1, and Robert G. Hamilton, PhD, DABMLI3; 1ImmunoDiagnostics, Thermo Fisher Scientific, Uppsala, Sweden, 2PHMR, Berkeley Works, Berkley Grove, London, United Kingdom, 3Johns Hopkins Asthma and Allergy Center, Baltimore, MD. RATIONALE: Oral food challenge is the gold standard for diagnosing peanut allergy, however peanut allergen components are also used as risk markers for clinical reactivity. The objective was to investigate the predictive accuracy of allergen components in the diagnosis of peanut allergy. METHODS: A systematic literature review was conducted to identify studies providing objective information on the performance of peanut allergens in diagnosing children suspected of peanut allergy. Food challenge was used as the reference standard. Methodological quality of included studies was assessed using the QUADAS-2 tool. A random effects meta-regression was performed, and pooled estimates for each index test were calculated (sensitivity, specificity, likelihood ratios (LR)). RESULTS: Twenty-three studies met the inclusion criteria. Computed diagnostic performance of Ara-h 1, Ara-h 2 and Ara-h 3 tests at 0.35 kUA/L cut-off level displayed sensitivities of 57 - 84 %, and specificities of 84 - 87%. Corresponding values for peanut extract were 93 % and 32 %, respectively. Positive LRs of Ara-h 2 and Ara-h 1 were 6.7 and 4.4, respectively, significantly higher than for the other tests, while peanut sIgE and Ara-h 2 both had negative LRs of 0.2, significantly lower than Ara-h 8 ( 1.0). CONCLUSIONS: Ara-h 2 and Ara-h 1 tests had the highest specificity for diagnosing peanut allergy, while peanut extract was the most sensitive test. These results suggest that a combination of peanut extract and storage protein tests would give the highest accuracy for identifying peanut allergic individuals.
396
Heart rate variability during oral food challenge
SUNDAY
Katsuhito Iikura, MD, PhD1, and Hiroshi Tachimoto, MD, PhD2; 1Tokyo Jikei University Hospital, Tokyo, Japan, 2Tokyo Jikei Hospital, Tokyo, Japan. RATIONALE: Oral food challenge (OFC) is the standard methods to diagnose food allergy. In early stage of OFC, it is difficult to detect severe reaction such as anaphylaxis. To detect the severe reaction before objective symptom, we examined the change of HR values during OFC. METHODS: We performed 45 OFC and analyzed the recorded HR values during OFC. Changes of HR from values at start were calculated, and we analyzed the root mean square (RMS) of those change rates during OFC. Subjects were divided to three groups, such as anaphylaxis group, mild symptom group, and tolerant group. We compared the HR change from start of OFC between those three groups and evaluated whether an occurrence of anaphylactic reaction was detected by RMS of HR change. RESULTS: ata from 45 children were analyzed (anaphylaxis group, n517, mild symptom group, n515, tolerant group, n513). It included eggwhite (n513), cow’s milk (n515), wheat (n58), peanut (n56), sesame (n51), almond (n51), and buckwheat (n51) test. RMS of HR change had significantly increased in anaphylaxis group (8.2 6 0.2%) more than mild symptom group (5.6 6 0.2%) and tolerant group (5.8 6 0.2%). RMS of HR change detected in anaphylaxis group achieved an ROC-AUC of .89. A cut-off 7.17% achieved a sensitivity of 90.5% and a specificity of 79.4%. CONCLUSIONS: Change of RMS was seen before the visible severe reactions. Change of HR values may be useful tool as the objective marker when we perform OFC safely.
397
Clinical Sensitivity, Reproducibly Defined by DoubleBlind Placebo-Controlled Food Challenge, is Associated with Peanut Specific Skin Testing and Peanut IgE
Lauren E. Tracy; Massachusetts General Hospital, Boston, MA; Food Allergy Center, Massachusetts General Hospital, Boston, MA. RATIONALE: During screening for a peanut oral immunotherapy trial (PNOIT), we identified a cohort of peanut-allergic patients who met all eligibility criteria (history, +PST, +Arah2-specific IgE and peanut-specific IgE > 5kU/L), but passed the low dose pre-randomization double-blind placebo-controlled food challenge (DBPCFC). We hypothesized that these patients, while truly allergic, were clinically less sensitive and assessed if baseline characteristics were associated with reactivity to peanut. METHODS: For participation in PNOIT, we screened peanut-allergic subjects ages 7-55, using peanut skin test and serology (Arah2, peanut IgE), followed by a DBPCFC of up to 443 mg of peanut. Subjects who met all other screening criteria but passed the entry DBPCFC, were invited to return for a DBPCFC challenge up to 7443mg. Statistical analyses were performed by Student’s T test. RESULTS: Ninety-eight subjects were screened for participation in PNOIT and 62 met initial screening criteria. Of these, 21 (34%) passed the entry challenge. Six of these subjects elected to repeat DBPCFC, and all reacted at eliciting doses > 443 mg. The high ED subjects had significantly smaller skin prick tests (8.8 vs 12.2 mm, p50.02), and a significantly lower IgE (34 vs 56, p50.05). CONCLUSIONS: Skin prick test wheal size and peanut IgE were significantly smaller in the cohort of subjects who met initial study eligibility criteria but passed the DBPCFC up to 443mg. Among all subjects who returned for the additional DBPCFC, all reacted to peanut, potentially identifying a sub-population of high-threshold peanut-allergic individuals, characterized by higher levels of allergic sensitization.
398
Peanut Allergy testing correlates with clinical symptoms and outcomes suggesting peanut allergy phenotypes.
Efren L. Rael, MD, FAAAAI; Stanford University, Sean N. Parker Center for Allergy and Asthma Research, Stanford, CA. RATIONALE: Allergic phenotypes exist in asthma. It is unclear if allergic phenotypes exist in peanut allergy (PA). Subject reported PA symptoms,
J ALLERGY CLIN IMMUNOL FEBRUARY 2017
treatments, emergency room related food reactions (ERFR), and hospitalizations were reviewed in relation to peanut wheal size (PWS) and peanut specific IgE components (PSIC). METHODS: Subjects with PA concern, completed a standardized questionnaire. Symptoms were reviewed in relation to PWS (in 121 subjects) and PSIC Ara_h1, 2, 3, 8, and 9 (in 47 subjects). RESULTS: PWS correlated with skin, upper/lower airway anaphylactic symptoms of throat/chest tightness (CT), shortness of breath (SOB), tongue/lip swelling, and urticaria but not gastrointestinal symptoms of stomach pain, diarrhea, vomiting, regurgitation or the Modified Aceves questionnaire score (MAQ). ERFR and mechanical ventilation also correlated. Ara_h1 and 2 correlated with intubations, retching, and nausea. Ara_h1,2, and 3 correlated with bitter acid taste, the ACQ6 score, throat tightness, and stomach pains. Ara_h1,2, and 9 correlated with nausea. Ara_h2 correlated with hives and SOB, and PA persistence. Ara_h2 and 9 correlated with abdominal bloating. Ara_h1 and 3 correlated with total respiratory symptom scores. Ara_h1,2, and 8 correlated with ERFR, and age. Ara_h1,3, and 9 correlated with vomit, the MAQ. Ara_h8 correlated with prednisone treatments, and birch pollen IgE and wheal size. Ara_h9 correlated with angioedema, diarrhea, excessive satiety, antibiotic treatment for sinusitis, tongue, throat/lip swelling, heartburn, lower/upper abdominal discomfort, breast milk intolerance, and CT. CONCLUSIONS: Symptoms and outcomes may relate to PA skin testing to predict skin, upper and lower respiratory symptoms; whilst PSIC might predict respiratory and gastrointestinal symptoms.
399
Predictive Accuracy Of Peanut Components In The Diagnosis Of Peanut Allergy: A Systematic Literature Review And Meta-Analysis
Malin Berthold, PhD1, Barbara Mascialino, PhD1, Donna Fountain2, Kevin Cadwell2, Chrysanthi Papageorgakopoulou2, Sigrid Sjolander, PhD1, and Robert G. Hamilton, PhD, DABMLI3; 1ImmunoDiagnostics, Thermo Fisher Scientific, Uppsala, Sweden, 2PHMR, Berkeley Works, Berkley Grove, London, United Kingdom, 3Johns Hopkins Asthma and Allergy Center, Baltimore, MD. RATIONALE: Oral food challenge is the gold standard for diagnosing peanut allergy, however peanut allergen components are also used as risk markers for clinical reactivity. The objective was to investigate the predictive accuracy of allergen components in the diagnosis of peanut allergy. METHODS: A systematic literature review was conducted to identify studies providing objective information on the performance of peanut allergens in diagnosing children suspected of peanut allergy. Food challenge was used as the reference standard. Methodological quality of included studies was assessed using the QUADAS-2 tool. A random effects meta-regression was performed, and pooled estimates for each index test were calculated (sensitivity, specificity, likelihood ratios (LR)). RESULTS: Twenty-three studies met the inclusion criteria. Computed diagnostic performance of Ara-h 1, Ara-h 2 and Ara-h 3 tests at 0.35 kUA/L cut-off level displayed sensitivities of 57 - 84 %, and specificities of 84 - 87%. Corresponding values for peanut extract were 93 % and 32 %, respectively. Positive LRs of Ara-h 2 and Ara-h 1 were 6.7 and 4.4, respectively, significantly higher than for the other tests, while peanut sIgE and Ara-h 2 both had negative LRs of 0.2, significantly lower than Ara-h 8 ( 1.0). CONCLUSIONS: Ara-h 2 and Ara-h 1 tests had the highest specificity for diagnosing peanut allergy, while peanut extract was the most sensitive test. These results suggest that a combination of peanut extract and storage protein tests would give the highest accuracy for identifying peanut allergic individuals.