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Peanut and Arah2 Specific Immunoglobulin E Is Predictive of Sustained Unresponsiveness Following Peanut Oral Immunotherapy
Sunday, March 6, 2016: 4:45 PM
Concourse Foyer (Convention Center)
Alanna J. Hickey, B.S., Yamini Virkud, MD, MA, MPH, Cecilia Washburn, B.S., Neal Smith, B.S., Sarita U. Patil, MD, Wayne Shreffler, MD PhD FAAAAI
Rationale:  Although most patients develop clinical desensitization during peanut oral immunotherapy (OIT), many of them remain dependent on regular peanut exposure to maintain desensitization. A retrospective analysis was done to determine if any baseline clinical factors are associated with the development of sustained unresponsiveness (SU) for one month following OIT.

Methods:  Twenty-three peanut-allergic children ages 7-13 participated in an open-label peanut OIT trial.  Subjects received 14-20 months of therapy before undergoing an open food challenge (OFC) to verify desensitization to peanut (n=22).  After an avoidance period of one month, a double blind placebo controlled food challenge (DBPCFC) was done to determine if SU was achieved.  Fisher’s Exact Test and Wilcoxon Rank-Sum statistical analyses were used to determine which baseline characteristics (including demographics, skin prick tests and immunoglobulin levels) were associated with passing the DBPCFC.

Results:  Nine of the twenty-three subjects passed a DBPCFC after discontinuing therapy for one month.  Characteristics associated with SU included lower peanut IgE (p=0.006), lower IgE to Arah2 (p=0.007), lower peanut IgE:IgG4 ratio (p=0.016), and lower Arah2 IgE:IgG4 ratio (p=0.004). Age, gender, race, ethnicity, history of allergic rhinitis, history of atopic dermatitis, history of asthma, home location (i.e. urban vs. rural), peanut skin prick test, peanut IgG4, and Arah2 to IgG4 were not found to be associated with SU.

Conclusions:  Baseline peanut IgE, IgE to Arah2, IgE :IgG4 ratio, and IgE to Arah2:IgG4 to Arah2 ratio are associated with the development of SU following peanut OIT in children.