2017 Molecular Profiles Of IgE To Timothy Grass Allergens In Patients Screened For Grass Tablet Immunotherapy

Saturday, 14 December 2013
Michigan Ballroom (Westin - Michigan Avenue)

Maria Nolte, BSc , Montana State University, Bozeman, MT

Jennifer Maloney, MD , Merck, Whitehouse Station, NJ

Hendrik Nolte, MD, PhD , Merck, Whitehouse Station, NJ

Background: Serum specific IgE levels to individual allergen components may vary depending on pollen exposure and allergen cross-reactivity. Regional differences in allergen exposure may induce different sensitization patterns. The objective of this post hoc analysis was to describe the IgE sensitization pattern in a SPT-positive patient population reporting Timothy grass allergy screened in 6 regions of North America. Specific IgE levels to a panel of 113 different allergens were measured using a microarray specific IgE method.

Methods: 1922 subject sera from the P08067 (NCT01385371) study were collected in Canada and 5 regions of the USA (Mid-Atlantic [MA], North Central [NC], Northeast [NE], South [S], West [W]). Serum specific IgE was measured using the Phadia ISAC microchip method in grass-pollen−allergic patients who consented to the analysis. Approval was obtained from appropriate IRBs.

Results: Most subjects were multi-sensitized with detectable (≥0.35 kU/L) serum specific IgE to grass and other common allergens, including tree (56%), weed (44%), animal dander (43%), mites (26%), foods (23%), and mold (22%). Out of 1922 subjects with a positive skin test to Timothy grass and history of grass pollen allergy, 1584 (82%) had measurable specific IgE to at least one of several Timothy grass allergen components (Phl p). Most subjects were sensitized to Phl p 1 (73%) and Phl p 5 (50%). The highest proportions of Phl p 1- and Phl p 5-positive subjects were found in Canada and the western part of the USA. The highest mean IgE levels against Phl p 1 and Phl p 5 occurred in sera from subjects in Canada  and the West.

Conclusions: Most subjects were sensitized to Phl p 1 (73%) and Phl p 5 (50%). The highest mean IgE levels and proportion of Phl p 1- and Phl p 5-positive subjects were found in Canada and the western part of the USA, corresponding to regions where Timothy grass (Phleum pratense) is most prevalent.
Allergen Canada MA NC NE S W Grand Mean (kU/L)
Phl p 1 14.41 9.37 11.21 4.83 9.19 20.91 14.32
Phl p 5 10.24 6.42 6.25 1.40 6.26 15.96 10.01
Phl p 2 4.26 2.26 2.80 0.92 2.05 7.86 4.52
Phl p 4 2.02 1.27 0.84 0.22 0.93 3.23 1.89
Phl p 6 4.19 2.32 2.02 0.24 0.66 5.31 3.38
Phl p 7 0.15 0.11 0.04 0.00 0.06 0.46 0.21
Phl p 11 1.75 0.63 0.77 0.44 1.31 3.13 1.72
Phl p 12 0.43 0.56 0.42 0.10 0.16 0.38 0.41