Browsing by Author "Vitalpur, Girish"

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    Designer covalent heterobivalent inhibitors prevent IgE-dependent responses to peanut allergen
    (National Academy of Sciences, 2019-04-30) Deak, Peter E.; Kim, Baksun; Qayum, Amina Abdul; Shin, Jaeho; Vitalpur, Girish; Kloepfer, Kirsten M.; Turner, Matthew J.; Smith, Neal; Shreffler, Wayne G.; Kiziltepe, Tanyel; Kaplan, Mark H.; Bilgicer, Basar; Pediatrics, School of Medicine
    Allergies are a result of allergen proteins cross-linking allergen-specific IgE (sIgE) on the surface of mast cells and basophils. The diversity and complexity of allergen epitopes, and high-affinity of the sIgE-allergen interaction have impaired the development of allergen-specific inhibitors of allergic responses. This study presents a design of food allergen-specific sIgE inhibitors named covalent heterobivalent inhibitors (cHBIs) that selectively form covalent bonds to only sIgEs, thereby permanently inhibiting them. Using screening reagents termed nanoallergens, we identified two immunodominant epitopes in peanuts that were common in a population of 16 allergic patients. Two cHBIs designed to inhibit only these two epitopes completely abrogated the allergic response in 14 of the 16 patients in an in vitro assay and inhibited basophil activation in an allergic patient ex vivo analysis. The efficacy of the cHBI design has valuable clinical implications for many allergen-specific responses and more broadly for any antibody-based disease.
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    Multicenter prevalence of anaphylaxis in clinic-based oral food challenges
    (Elsevier, 2017-10-01) Akuete, Kwei; Guffey, Danielle; Israelsen, Ryan B.; Broyles, John M.; Higgins, Lori Jo; Green, Todd D.; Naimi, David R.; MacGinnitie, Andrew J.; Vitalpur, Girish; Minard, Charles G.; Davis, Carla M.; Pediatrics, School of Medicine
    Background Although previous single-center studies report the rate of anaphylaxis for oral food challenges (OFCs) as 9% to 11%, little is known regarding the epidemiology of clinical OFCs across multiple centers in the United States. Objective To examine the epidemiology, symptoms, and treatment of clinical low-risk OFCs in the nonresearch setting. Methods Data were obtained from 2008 to 2013 through a physician survey in 5 food allergy centers geographically distributed across the United States. Allergic reaction rates and the association of reaction rates with year, hospital, and demographics were determined using a linear mixed model. Meta-analysis was used to pool the proportion of reactions and anaphylaxis with inverse-variance weights using a random-effects model with exact confidence intervals (CIs). Results A total of 6,377 OFCs were performed, and the pooled estimate of anaphylaxis was 2% (95% CI, 1%-3%). The rate of allergic reactions was 14% (95% CI, 13%-16%) and was consistent during the study period (P = .40). Reaction rates ranged from 13% to 33%. Males reacted 16% more frequently than females (95% CI, 4%-37.5%; P = .04). Foods challenged in 2013 varied geographically, with peanut as the most challenged food in the Northeast, Midwest, and West and egg as the most challenged in the South. Conclusion As the largest national survey of allergic reactions of clinical open OFCs in a nonresearch setting in the United States, this study found that performing clinical nonresearch open low-risk OFCs results in few allergic reactions, with 86% of challenges resulting in no reactions and 98% without anaphylaxis.
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    Multisystem reactions during egg oral food challenges may be associated with less severe reactions on initial presentation
    (Springer (Biomed Central Ltd.), 2016) Vitalpur, Girish; Esquivel, Ann; Kloepfer, Kirsten M.; Slaven, James E.; Leickly, Frederick E.; Department of Pediatrics, IU School of Medicine
    In this study, we assessed whether multisystem reactions to egg and extensively-heated (EH) egg during OFCs were associated with a history of multisystem reactions. Records of children, who underwent OFC to egg or EH egg over a five-year period were reviewed. Of the 120 challenges, 26 (21.67 %) failed, with 38.4 % (10/26) having multisystem reactions. Of the 13 who had multisystem reactions on initial presentation, only two (15.4 %) had a similar OFC outcome. Eighty percent (8/10) of those who had a multisystem OFC reaction had a less severe initial presentation. Initial and OFC multisystem reactions were not associated with each other.
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    Oral Food Challenge Failures Among Foods Restricted Due to Atopic Dermatitis
    (Elsevier, 2018) Eapen, A. A.; Kloepfer, Kirsten M.; Leickly, Frederick E.; Slaven, James E.; Vitalpur, Girish; Pediatrics, School of Medicine
    BACKGROUND Recent studies have suggested that removing foods from the diet to manage atopic dermatitis (AD), based on positive allergy tests, may lead to immediate allergic reactions on reintroduction of that food. OBJECTIVE The purpose of this study was to examine the frequency of oral food challenge (OFC) failures among foods removed from the diet as suspected AD triggers, focusing on the five major food allergens in the US. METHODS OFCs to egg, milk, peanut, soy, and wheat, performed from 2008-14, at a children's hospital's allergy clinics, were reviewed. OFCs were offered based on history and laboratory values. Reasons for food avoidance were classified as food allergy (IgE-mediated reaction occurring within two hours); sensitization only (lack of introduction due to positive test results); and removal due to test results during AD evaluation. RESULTS There were 442 OFCs performed, with 89 failures (20.1%). Reasons for OFCs included a history of food allergy (320/442; 72.4%); food sensitization without any introduction (77/442; 17.4%); and AD (45/442; 10.2%). OFC failures among those who had food allergy (70/320; 21.9%); sensitization only (13/77; 16.9%); and suspected AD trigger (6/45; 13.3%) did not significantly differ (p=0.63). Wheat was more likely to be avoided than the other four foods for AD concerns (p<0.0001). CONCLUSION The frequency of OFC failure among those who removed foods suspected as AD triggers was 13.3%, indicating a loss of tolerance. Restriction of foods to manage AD must be done with caution and close monitoring.
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    Variations in pollen counts between Indianapolis, IN, and Dayton, OH, in spring 2013 and 2014
    (Elsevier, 2016-09) Vitalpur, Girish; Padgett, Shaylar; Kloepfer, Kirsten M.; Slaven, James; Leickly, Frederick E.; Department of Pediatrics, IU School of Medicine
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    Weed Pollen Season Trends In Relation To Atmospheric Co2 Changes In Indiana And Ohio
    (Elsevier, 2019-09) Vitalpur, Girish; Ahmad, Hassan A.; Slaven, James E.; Pediatrics, School of Medicine