Response to Nasal Challenge Correlates with Seasonal Outcomes during Grass Pollen Immunotherapy with Either Subcutaneous or Sublingual Immunotherapy

A randomised, double-blind, double-placebo, controlled-trial of subcutaneous (Alutard SQ® Phleum Pratense ALK, Denmark) and sublingual (GRAZAX® ALK) grass pollen immunotherapy (105 patients,randomized 1:1:1). We previously reported the results of 2-years treatment and 1-year follow-up (year 3) using the total nasal symptom score (TNSS) at 0-10 hours after nasal allergen challenge as the primary outcome (Scadding G et al. Allergy 2016: 71, S102;3). Here we evaluate the relationship between the response to nasal allergen challenge and seasonal clinical outcomes. Post-hoc correlation of response to out of season nasal allergen challenge TNSS and seasonal outcomes including weekly visual analogue score (VAS), rhinitis quality of life (miniRQLQ), and end of season global evaluation of hay fever severity at baseline, years 1, 2 and 3. Positive correlations were seen between response to nasal challenge and each of VAS, miniRQLQ and global evaluation at year-1 of treatment (r=0.22, p=0.02; r=0.25, p=0.01 and r=0.24, p=0.01, respectively), becoming stronger at year 2(r=0.32, p=0.002; r=0.33, p=0.002 and r=0.31, p=0.002). Correlations persisted at year 3, off treatment, for all three outcomes(r=0.22, p=0.04; r=0.25, p=0.01 and r=0.42, p<0.001). No significant correlations were observed at baseline, possibly because overall spread of nasal challenge results was constrained by initial dose titration to achieve a minimum entry criterion of TNSS ≥7/12 for study inclusion. Total nasal symptom score following nasal allergen challenge out of season correlated with seasonal outcomes during allergen immunotherapy. These data support the use of nasal allergen challenge as a useful clinical surrogate in immunotherapy trials.