title: Systemic reactions to inhalant immunotherapy using 1:1 target dosing.
abstract: BACKGROUND
  The 2007 immunotherapy practice parameters advocate maintenance dosing at 1:1 (1:20 maintenance concentrate). There is limited literature exploring the effect of 1:1 dosing on the rate of systemic reactions to subcutaneous immunotherapy (SRITs).
  
  
  OBJECTIVE
  To investigate the effects of 1:1 dosing on SRITs in a large, academic practice.
  
  
  METHODS
  We conducted a retrospective cohort study of all nonvenom and noncluster SRITs that occurred between 2005 and 2011. SRITs that occurred from August 2008 through December 2011, postparameter dosing (post-PD) was initiated, were compared to SRITs that occurred from January 2005 to July 2008 with preparameter dosing (pre-PD) using 1:50 as a maintenance concentrate.
  
  
  RESULTS
  A total of 269 SRITs occurred in a 7-year period. Significantly more post-PD SRITs (131 of 38,548 injections) occurred than pre-PD SRITs (132 of 52,833 injections) (0.34% vs 0.25%, P = .01). However, when excluding 44 SRITs that occurred in established pre-PD patients transitioned to post-PD, there was no significant difference in SRIT rate (0.25% vs 0.22%), World Allergy Organization (WAO) grade, or SRIT time to onset. Nonred (non-1:1) vials accounted for a significantly larger proportion of all post-PD SRITs compared with all pre-PD SRITs (50.7% vs 31.1%, adjusted P = .009). Prior SRITs were reported less frequently among persons with post-PD SRITs (29.2% vs 70.8%, adjusted P = .009). In an adjusted logistic regression model, male sex (odds ratio, 7.9; 95% CI, 2.4-26) and longer time to reaction onset (odds ratio, 0.94; 95% CI, 0.89-0.99) were associated with higher WAO severity grade reactions.
  
  
  CONCLUSIONS
  Pre-PD vs post-PD SRIT rates were not significantly different, adjusting for patients transitioned from established pre-PD to post-PD. This finding suggests that post-PD is as safe as pre-PD. Male sex and faster time to reaction onset were associated with higher WAO grade reactions.
authors.affiliation: Department of Internal Medicine, Division of Allergy and Clinical Immunology, The University of Michigan Medical School and the University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: Christine L
authors.initials: CL
authors.lastname: Holland
authors.affiliation: Department of Internal Medicine, Division of Allergy and Clinical Immunology, The University of Michigan Medical School and the University of Michigan Health System, Ann Arbor, Michigan; School of Pharmacy, University of Michigan, Ann Arbor, Michigan.
authors.forename: Kiela M
authors.initials: KM
authors.lastname: Samuels
authors.affiliation: Department of Internal Medicine, Division of Allergy and Clinical Immunology, The University of Michigan Medical School and the University of Michigan Health System, Ann Arbor, Michigan.
authors.forename: James L
authors.initials: JL
authors.lastname: Baldwin
authors.affiliation: Department of Internal Medicine, Division of Allergy and Clinical Immunology, The University of Michigan Medical School and the University of Michigan Health System, Ann Arbor, Michigan. Electronic address: mgreenha@med.umich.edu.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Greenhawt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000008:administration & dosage* / Q000276:immunology*; D001249:Asthma / Q000276:immunology / Q000628:therapy*; D015331:Cohort Studies; D003888:Desensitization, Immunologic / Q000009:adverse effects* / Q000379:methods*; D005260:Female; D006801:Humans; D001239:Inhalation; D007279:Injections, Subcutaneous / Q000009:adverse effects / Q000379:methods; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012737:Sex Factors; D055815:Young Adult
chemical_list: D000485:Allergens