J ALLERGY CLIN IMMUNOL

VOLUME 133, NUMBER 2

Abstracts AB223

MONDAY

770 Ex-Vivo Allergen Stimulation In Whole Blood: A NovelApproach For Evaluating Mechanisms Of Action OfSynthetic Peptide Immuno-Regulatory Epitopes

Dr. Pascal LC. Hickey, BPharm PhD1, Dr. Mark Larch�e, PhD2, Dr. Rod

Hafner, PhD3, Ms. Kristen Armstrong, MSc4, Ms. Eileen Lee, BA

(Hons)5, Dr. Elaine Lee, PhD5, Dr. Stephen A. Kilfeather, PhD5; 1Adiga

Life Sciences, Hamilton, Canada, 2McMaster University, Hamilton, ON,

Canada, 3Circassia Ltd, Oxford, United Kingdom, 4Adiga Life Sciences

Inc., Hamilton, ON, Canada, 5Aeirtec Limited, Newcastle upon Tyne,

United Kingdom.

RATIONALE: Novel immunotherapies such asSynthetic Peptide Immuno-

Regulatory Epitopes (SPIREs) act on a very small subset of the immune cell

population to produce immune tolerance. The biochemical signature of these

effects is extremely difficult to detect in readily sampled tissues. Ex-vivo

allergen stimulation of whole blood, coupled with modern analytical tech-

niques and computational tools may overcome these challenges.

METHODS: A subgroup of 13 ragweed-allergic subjects from a phase II

clinical study of Ragweed-SPIRE provided heparinised blood samples for

biomarker research prior to, during and up to 3 months following

treatment. An ex-vivo allergen challenge involving incubation with

ragweed allergen or vehicle control for 1, 6 and 24 hours at 37oC was per-

formed. Concentrations of 45 immune/inflammatory markers were deter-

mined using a customised LuminexTM multiplex immunoassay.

RESULTS: The following markers demonstrated a significant ex-vivo

elevation in response to ragweed allergen (>100% of control; p<0.05):

TNFa, MIP-1b and IL-5 at 1 to 6 hours; IL-1b, MCP-1, MIP-1a, MIP-

1b, IL-5 and IL-8 at 6 to 24 hours; TARC, IP-10, osteopontin, eotaxins 2

and 3 at 24 hours only. Furthermore, changes in baseline cytokine concen-

trations were also observed over the course of the study.

CONCLUSIONS: This study identified clear, allergen-induced changes

in the plasma concentrations of a range of cytokines during ex-vivo allergenchallenge in blood samples from clinical trial subjects. These responses

could relate to mechanisms underlying in-vivo early and late phase re-

sponses to allergens and may provide a tool for the assessment of mecha-

nism of action of novel immunotherapies such as SPIREs.

771 Efficacy Of 300IR 5-Grass Pollen Sublingual Tablets In GrassPollen-Induced Allergic Rhinoconjunctivitis: Pooled AnalysisBy Age

Dr. Robert K. Zeldin, MD1, Prof. Ulrich Wahn, Prof Dr Med2,

Prof. Alain Didier, MD, PhD3, Mrs. Armelle Montagut1, Dr. Marie-Pierre

Furrer, PhD1; 1Stallergenes S.A., Antony, France, 2Charite, Berlin, Ger-

many, 3Larrey Hospital, CHU, Toulouse, France.

RATIONALE: The efficacy of 300IR 5-grass pollen sublingual tablet

administered 4 months pre-seasonally and co-seasonally has been demon-

strated. Here, we present the results of a pooled efficacy analysis by age group.

METHODS: Adults, adolescents and children (>5 years old) were enrolledin one of four double-blind, placebo-controlled, natural field studies and

randomized to receive placeboor 300IR5-grass pollen sublingual tablet daily

beginning 4 months (4M) prior to the grass pollen season and continuing for

its duration. The severity of each of six rhinoconjunctivitis symptoms (0-3

scale) and the use of rescue medication were recorded daily. Derived scores

were the rhinoconjunctivitis total symptom score (RTSS, scale 0-18) and the

rescue medication score (RMS, scale 0-3). In the pooled database, the daily

Combined Score [daily CS 5 (RTSS/6 + RMS)/2] was analyzed using a

repeated measures linear mixed model.

RESULTS: Data from 1,113 adults (placebo: n5581; 300IR (4M):

n5532) and 266 adolescents/children (placebo: n5135; 300IR (4M):

n5131) were analyzed. Significant differences in daily CS between the

300IR (4M) and placebo groups were observed in both age groups (point

estimate: -0.15 CI95% [-0.19; -0.11] in adults, p<_0.0005 and -0.19 CI95%[-0.29; -0.08] in adolescents/children). ThedailyCSrelativeLSmeandiffer-

ence vs. placebo was -30.1% in adolescents/children and -26.3% in adults.

CONCLUSIONS: Treatment with the 300IR 5-grass pollen extract

sublingual tablet was similarly effective in adults and adolescents/children

with grass pollen-induced allergic rhinoconjunctivitis.

772 Characterization Of Allergic Rhinitis SymptomotologyInduced By a Nasal Allergen Challenge (NAC) Titration In aDust Mite Sensitize Population

Mr. Paul Gomes1, Endri Angjeli2, Mr. Keith Lane2, Dr. Paul H. Ratner,

MD, FAAAAI3; 1ORA. Inc, Andover, MA, 2Ora, Inc, Andover, MA, 3Syl-

vana Research, San Antonio, TX.

RATIONALE: Allergic rhinitis signs and symptoms can be safely and

precisely evaluated using nasal allergen challenge (NAC) titration.

METHODS: Eligible skin test positive dust mite subjects underwent NAC

titration. Challenge titration began with bilateral instillation of 100uL of

saline. Increasingly concentrated doses of dust mite allergen were instilled

until a positive reaction was elicited. Primary endpoint was Total Nasal

Symptom Score (TNSS, 0 to 12 scale) the sum of nasal itching, congestion,

rhinorrhea, and sneezing (0 to 3 scales). A positive NAC was defined as

TNSS > 8 within 15 minutes of instillation. Secondary measures included

investigator evaluated inflammation (0 to 4 scale).

RESULTS: Twenty-one (21) subjects were screened and 13 successfully

completed NAC titration. Baseline TNSS scores were 0.38+0.87

increasing to 9.2+1.2 following the qualifying challenge. Individual

post-NAC scores were: itching, 2.060.8; congestion, 2.560.5; rhinorrhea,

2.460.5; and sneezing, 2.160.5. The post NAC Nasal Inflammation Score

(NIS) was 2.6+1.5. The dose of allergen needed for qualification varied

from 2 to 8 concentrations. Twenty-five percent of subjects demonstrated

negative correlation between signs and symptoms R5 -0.85.

CONCLUSIONS: NAC titration is a useful tool for characterizing the

rhinitis response of a study subject to a particular allergen. Additionally,

the NIS may be useful as an enrichment tool for clinical trials.

773 Atopic and Non-Atopic Individuals Manifest PartlyConcordant Clinical and Leukocyte Responses FollowingExposure To House Dust Mite In An Antigen ChallengeChamber (ACC)

Weijing He, MD1,2, Nathan Harper, BS1,2, Andrew Carrillo, BS1,2,

Charles Andrews, MD3, Cynthia Rather, CCRC3, Daniel Ramirez, MD3,

Robert L. Jacobs, MD3, Sunil K. Ahuja, MD1,2; 1Department of Medicine,

University of Texas Health Science Center, San Antonio, TX, 2Veterans

Administration Center for Personalized Medicine, South Texas Veterans

Health Care System, San Antonio, TX, 3Biogenics Research Chamber,

San Antonio, TX.

RATIONALE: While inter-subject differences in the responsiveness to

seasonal allergens in an ACC have been demonstrated much less is known

about heterogeneity in responses to perennial allergens such as house dust

mite.

METHODS: Twenty-three dust mite sensitive and 15 normal controls

were enrolled to undergo 3 hour chamber exposures on 4 consecutive days

to a milled, purified mite body preparation ofDermatophagoides pteronys-

sinus. Total symptom scores (TSS) were monitored at baseline and 30min-

ute intervals. Complete blood cell counts (CBC) were measured

immediately prior to and immediately after the exposures on the first and

fourth day.

RESULTS: 65% of the atopics develop TSS >_ 15 (out of 28) while the

majority of the non-atopics had TSS <_ 4. The increases in lymphocyte,

monocyte and eosinophil cell counts were concordant between atopics and

non-atopics, but eosinophilia was greater in the atopics compared with

non-atopics. Hierarchical clustering of TSS identified five clinical

endophenotypes in the atopics: 4 differed primarily with respect to severity

of TSS, with one group remaining non-responsive; the fifth endophenotype

was characterized by a progressive decrease in TSS with each ACC

exposure and a distinct CBC signature.

CONCLUSIONS: While atopics exhibit wide heterogeneity in severity of

symptom responses following dust mite exposure in an ACC, non-atopics

are non-responsive. Despite this, non-atopics and atopics share a partly

concordant leukocyte response. Identifying the basis for non-responsive-

ness despite leukocyte responses following exposure to dust mites in an

ACC could potentially uncover the basis for resistance to dust mite allergy.