Relationship Between Nasal Symptom Scores, IgE Class and Skin Prick Test (SPT) Size in the Environmental Exposure Unit (EEU) Relevance of IgE Class and Spt Diameter.
Monday, March 7, 2016
South Exhibit Hall H (Convention Center)
Dan Adams, Mena Soliman, MBChB, MSc (candidate), Lisa M. Steacy, BSc, Terry J Walker, BA, Barnaby Hobsbawn, Jenny Thiele, MSc, Anne K. Ellis, MD MSc FAAAAI
Rationale: The requirement for minimum allergen-specific IgE(sIgE) levels in clinical trials involving novel allergy therapeutics has been increasing in both EEU type studies and traditional field trials. The impact of sIgE Class(traditionally divided into 6 classes) and/or SPT wheal size on Total Nasal Symptom Score(TNSS) when exposed to allergen in the EEU are not fully characterized.

Methods:  Participants with grass-induced allergic rhinitis(AR) and a SPT wheal to rye grass ≥3mm than negative control were included. Four consecutive daily 3HR rye grass pollen exposures in the EEU generated AR symptoms. Different classes of sIgE and SPT wheal sizes were compared to TNSS over time. sIgE testing was performed by Phadia. Data were analyzed via GraphPad Prism 6.0.

Results:  On average, participants with higher sIgE or larger SPT wheals achieved a higher TNSS. Significant differences were seen in mean TNSS scores between certain classes of sIgE or wheal diameters (e.g. TNSS by sIgE Class 0 vs. Class 3 days 2,3,4 respectively; p<0.05)(Day 2 TNSS by wheals 3-5mm vs. 8-9mm,10-12mm,13mm+ respectively; p<0.05). TNSS did not correlate with sIgE or SPT directly, however. Correlation was noted between sIgE and SPT(r<0.61;p<<0.0001). On the 3rd EEU challenge, however, there were no significant differences between the TNSS scores of the various classes of sIgE (two-way ANOVA with Bonferroni correction).

Conclusions:  Statistically significant differences in TNSS are shown between different classes of sIgE or SPT wheal size after 1,2 or 3 consecutive exposure days in the EEU. Most significant differences, however, are lost after a 3rd consecutive exposure.