title: Effect of confounding cofactors on responses to pollens during natural season versus pollen challenge chamber exposure.
abstract: BACKGROUND
  The severity of allergic rhinoconjunctivitis (AR) symptomatology elicited after exposure to pollen in the absence versus the presence of confounding cofactors, such as in a pollen challenge chamber (PCC) and the natural pollinating season, respectively, might differ.
  
  
  OBJECTIVE
  We sought to determine the correlation of AR severity in the natural season versus out-of-season PCC exposures.
  
  
  METHODS
  Twenty-four Virginia live oak (VLO)-positive, 14 VLO-negative, 16 mountain cedar (MC)-positive, 8 MC-negative, and 26 ragweed-positive participants recorded AR symptoms (total symptom score [TSS]) during the VLO, MC, and ragweed pollinating seasons and during 2 consecutive PCC exposures of 3 hours each to these pollens separately.
  
  
  RESULTS
  The TSSs recorded before the natural season were higher than the pre-PCC values. This prepriming was greater among VLO(+) than MC(+) participants, and it blunted further increases in TSSs during the VLO natural season. Nonatopic participants were nonreactive in the PCC. There was wide variation in the level of AR symptomatology after exposure to VLO, MC, or ragweed pollen in the PCC. Prepriming formed the basis for higher AR responses observed in the natural season than in the PCC, resulting in the identification of distinct PCC/natural season endophenotypes and a partial correlation between the TSSs recorded in the natural season versus those recorded in the PCC (r = 0.34, 0.54, and 0.65 for VLO(+), MC(+), and ragweed-positive participants, respectively).
  
  
  CONCLUSIONS
  Prepriming in the natural pollinating season might obscure the true correlation between AR severity in the natural season versus the PCC. By mitigating confounding cofactors, PCC exposures have utility for evaluation of novel AR therapeutics.
authors: Biogenics Research Chamber, San Antonio, Tex. Electronic address: robert.jacobs7025@sbcglobal.net.
authors: Robert L
authors: RL
authors: Jacobs
authors: Veterans Administration Center for Personalized Medicine, South Texas Veterans Health Care System, San Antonio, Tex; Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Tex.
authors: Nathan
authors: N
authors: Harper
authors: Veterans Administration Center for Personalized Medicine, South Texas Veterans Health Care System, San Antonio, Tex; Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Tex.
authors: Weijing
authors: W
authors: He
authors: Biogenics Research Chamber, San Antonio, Tex.
authors: Charles P
authors: CP
authors: Andrews
authors: Biogenics Research Chamber, San Antonio, Tex.
authors: Cynthia G
authors: CG
authors: Rather
authors: Biogenics Research Chamber, San Antonio, Tex.
authors: Daniel A
authors: DA
authors: Ramirez
authors: Veterans Administration Center for Personalized Medicine, South Texas Veterans Health Care System, San Antonio, Tex; Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Tex; Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, Tex; Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, Tex.
authors: Sunil K
authors: SK
authors: Ahuja
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D031164:Ambrosia; D003233:Conjunctivitis, Allergic / Q000276:immunology / Q000473:pathology / Q000628:therapy; D003888:Desensitization, Immunologic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011058:Pollen / Q000276:immunology*; D029963:Quercus; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology / Q000473:pathology / Q000628:therapy; D012621:Seasons; D013997:Time Factors
keywords: Allergy; challenge; confounding; pollen; season