Rostrum Multiple-allergen and single-allergen immunotherapy strategies in polysensitized patients: Looking at the published evidence Moises A. Calderon, MD, PhD,a Linda Cox, MD,b Thomas B. Casale, MD,c Philippe Moingeon, PhD,d and Pascal Demoly, MD, PhDe London, United Kingdom, Davie, Fla, Omaha, Neb, and Antony and Montpellier, France In allergen immunotherapy there is debate as to whether immunotherapy protocols elicit distinct immune responses in polysensitized patients are best treated with many allergens monosensitized and polysensitized patients. Sublingual and simultaneously (chosen according to the sensitization profile, a subcutaneous multiallergen immunotherapy in polysensitized predominantly North American approach) or a single allergen patients requires more supporting data to validate its efficacy in (chosen according to the most clinically problematic allergy, a practice. (J Allergy Clin Immunol 2012;129:929-34.) predominantly European approach). In patients seeking Key words: treatment for moderate-to-severe respiratory allergies, Allergy, allergen immunotherapy, polysensitization, polysensitization is more prevalent (range, 50% to 80%) than monosensitization, polyallergic, subcutaneous immunotherapy, sub- monosensitization in both the United States and Europe. Safe, lingual immunotherapy, safety, efficacy effective, single-allergen preparations will most likely have been tested in polysensitized patients. In robust, large-scale clinical In the field of allergen immunotherapy, there is much debate as trials of grass pollen sublingual tablets, polysensitized patients to whether polysensitized patients are best treated with several benefited at least as much from allergen immunotherapy as allergens (chosen according to the individual’s sensitization pro- monosensitized patients. A recent review of multiallergen file)1 or a single allergen (corresponding to the most clinically immunotherapy concluded that simultaneous delivery of problematic allergy).2 We looked at the evidence for the efficacy multiple unrelated allergens can be clinically effective but that and safety of these 2 approaches in polysensitized patients. We there was a need for additional investigation of therapy with consider here that single-allergen immunotherapy includes the more than 2 allergen extracts (particularly in sublingual use of extracts containing several closely related allergens (eg, allergen immunotherapy). More work is also required to a 5-grass-pollen extract). Conversely, we consider that multialler- determine whether single-allergen and multiallergen gen immunotherapy refers to mixtures with little or no cross- reactivity (eg, grass pollen, tree pollen, weed pollen, house dust a From the Section of Allergy and Clinical Immunology, Imperial College–National Heart mite [HDM], and animal dander). & Lung Institute, Royal Brompton Hospital, London; bthe Department of Medicine, Nova Southeastern University, Davie; cthe Division of Allergy and Immunology, Department of Medicine, Creighton University, Omaha; dthe Research & Develop- ment Department, Stallergenes SA, Antony; and ethe Allergy Division, Pneumology POLYSENSITIZATION IS MORE PREVALENT THAN Department, INSERM U657, Hopital^ Arnaud de Villeneuve, University Hospital of MONOSENSITIZATION Montpellier. Disclosure of potential conflict of interest: M. A. Calderon receives honoraria for Data from 11,355 participants in the first European Community consulting and lectures from ALK-Abello and Stallergenes, receives honoraria for Respiratory Health Survey (median age, 34 years) tested with a lectures from Merck, and is the Chair of the Immunotherapy Group for the European panel of 4 to 9 skin prick tests, 4 to 5 serum allergen-specific IgE Academy of Allergy and Clinical Immunology (EAACI). L. Cox has consultant measurements, or both showed that, depending on the center and arrangements with Stallergenes, Genentech/Novartis, and ISTA; is on the speaker’s the test methods, 57.0% to 67.8% of European populations were bureau for Phadia; receives research support from Stallergenes and Novartis; is secre- tary/treasurer for the American Academy of Allergy, Asthma & Immunology not sensitized to any of the test allergens, 16.2% to 19.6% were 3 (AAAAI); is on the board of directors for the American Board of Allergy and Immu- monosensitized, and 12.8% to 25.3% were polysensitized. nology (ABAI); and is a member of the Joint Task Force on Practice Parameters. T. B. Skin sensitization to common indoor and outdoor allergens in Casale is on the advisory board for Stallergenes, receives research support from Stal- the US general population aged 6 to 59 years was investigated in lergenes and Merck/Schering-Plough, and is executive vice president of the AAAAI. P. Moingeon is an employee of Stallergenes SA. P. Demoly is on advisory boards for Stal- the second and third National Health and Nutrition Examination lergenes and ALK-Abello; is on the speaker’s bureau for Stallergenes, ALK-Abello, Surveys (NHANES II [1976-1980] and NHANES III [1988- Merck/Schering-Plough, AstraZeneca, and GlaxoSmithKline; has consultant arrange- 1994]). In NHANES III 10,863 patients participated in skin ments with Therabel and Crucell; receives research support from Stallergenes and testing: 45.7% were not sensitized to any of the test allergens, ALK-Abello; and is Vice President of the EAACI. 15.5% were monosensitized, and 38.8% were polysensitized.4 Received for publication July 14, 2011; revised November 9, 2011; accepted for publi- 5 cation November 17, 2011. Baatenburg de Jong et al tested allergen sensitization in 9044 Available online January 11, 2012. children referred to a regional clinical laboratory in The Nether- Corresponding author: Moises A. Calderon, MD, PhD, Section of Allergy and Clinical Im- lands: 60.1% were found not to be sensitized to any of the 13 munology, Imperial College–National Heart & Lung Institute, Royal Brompton Hospi- food and inhalant allergens tested, 12.4% were monosensitized, tal, Dovehouse St, London, United Kingdom. E-mail: [email protected]. 0091-6749/$36.00 18.9% were sensitized to 2 to 4 allergens, and 8.6% were sensi- Ó 2012 American Academy of Allergy, Asthma & Immunology tized to 5 or more allergens. Hence polysensitization is more doi:10.1016/j.jaci.2011.11.019 prevalent than monosensitization in the general population. 929 930 CALDERON ET AL J ALLERGY CLIN IMMUNOL APRIL 2012 include a sensitization screening panel of single-allergen extracts. Abbreviations used Malling et al9 performed a post hoc analysis of a recent multina- DBPC: Double-blind, placebo-controlled tional, well-powered, DBPC clinical trial of a once-daily 5-grass- HDM: House dust mite pollen sublingual tablet formulation (Table I).13 The Average NHANES: National Health and Nutrition Examination Survey Rhinoconjunctivitis Total Symptom Score during the pollen SCIT: Subcutaneous allergen immunotherapy season in the placebo group and 2 treatment groups did not differ SLIT: Sublingual allergen immunotherapy significantly according to sensitization status. Malling et al9 con- cluded that sensitization status was not a significant baseline co- variate and that ‘‘the risk-benefit ratio validates the use of 300 IR Polysensitization is much more prevalent in patients consulting [five-grass pollen] tablets in clinical practice in all of these patient allergists. In the French Odissee study, 62% of 4227 patients subgroups, regardless of . sensitization status.’’ However, the 6 registered by 264 physicians were polysensitized. In a US study trial in question featured a somewhat narrow definition of poly- of 1338 patients with objectively diagnosed mild-to-moderate sensitization/polyallergy; patients sensitized to allergens other 7 asthma, Craig et al reported that only 5% were not sensitized than grass pollen were included in the study only if the said aller- and that 81% of the sensitized patients reacted to 3 or more aller- gens did not induce potentially confounding symptoms during the gens. The use of component-based diagnostic tests with purified grass pollen season. Hence a common clinical situation for which natural or recombinant allergens has revealed that a significant multiallergen immunotherapy is often considered (ie, >_1 seasonal minority of polysensitized patients have IgE against highly allergies with a concomitant allergy to >_1 perennial allergens, cross-reactive panallergens (ranging from 10% for calcium- such as animal dander or HDM) was not taken into account by 8 binding proteins to around 40% for profilin). Similarly, the ma- the latter study. jority of participants in recent allergen immunotherapy clinical The results of a similar post hoc analysis of the first year of a 9,10 trials were polysensitized. 3-year DBPC trial14 evaluating the efficacy of sublingual allergen immunotherapy (SLIT) with a once-daily Phleum pratense tablet were reported in abstract format by Emminger et al.10 Three sen- STRATEGIES FOR ALLERGEN IMMUNOTHERAPY sitization groups were constituted (Table I): grass pollen mono- IN POLYSENSITIZED PATIENTS sensitization, polysensitization to grass pollen and tree pollen Meta-analyses of double-blind, placebo-controlled (DBPC) (and possibly other allergens), and polysensitization to grass trials and recent, large, well-designed, well-powered studies pollen and at least 1 other allergen (but not tree pollen). A narrow using standardized allergen preparations have generated high definition of polysensitization/polyallergy was again applied: pa- levels of evidence in favor of the efficacy of