Skip to main content

AIT (allergen immunotherapy): a model for the “precision medicine”


The interpretation of medical approaches, especially therapy, evolved rapidly in the last century. Starting from the simple description of symptoms, we moved to the pathophysiological descriptions, to the evidence-based medicine, until the so-called “precision medicine”. This latter can be defined as a structural model aimed at customizing healthcare, with medical decisions/products tailored on an individual patient at a highly detailed level. In this sense, allergen immunotherapy represents an optimal model of “precision medicine”, since we know and describe symptoms, function, aetiological agents at molecular level, and we have the possibility to intervene on the natural history of the disease. If considered under the point of view of pharmaco-economy, that is prescribing the optimal treatment to the right patient, allergen immunotherapy represents an almost-ideal model of precision medicine.

General aspects

The medical science slowly evolved, along centuries, from the Hippocratic “humours” [1] to a more pathophysiology-oriented interpretation of clinical phenomena [24], until the current “omic” sciences. Thus, it seems that a more and more potent magnifying lens has become available to study and understand diseases. In addition, it is clear that the clinical science, the mechanistic knowledge and the translational applications are becoming more and more strictly interconnected.

From the clinical point of view (essentially the therapeutic aspect), a “blockbuster” approach was applied in clinical practice during the last decades. This attitude was likely due to a superficial and incomplete knowledge of the underlying mechanisms of diseases. The advanced insights on the mechanisms and the specific features of patients’ groups leaded to the definition of phenotypes and endotypes [5, 6]. This “stratification” of groups, in turn, provided a more detailed definition of diagnosis and treatments, consequently resulting in more appropriate definition of the eligibility of patients to the different therapeutic tools. The “phenotype driven therapy” is now a real and urging need, especially when expensive drugs, such as biologicals/biosimilars have to be prescribed [7, 8]. This aspect is unavoidably linked to sustainability for HealthCare Systems, which will afford relevant economic burdens. These latter will grow dramatically targeting, for instance, 30 % of Gross Incoming Product in 2040 in the US [9]. According to those premises we have to face two major reasons for a more selective approach (phenotyping/endotyping) to the patients who are potentially candidates to an effective treatment:

  • medical/scientific aspects

  • pharmaco-economic aspects.

The “blockbuster approach” (i.e. one size fits all) cannot be currently used with many of the very expensive treatments available, where the best cost/effective treatment should be provided. This also implies a greater professional and responsible involvement of specialists in properly selecting patients. The “precision medicine” can be defined as a structural model aimed at customizing healthcare at best, with medical decisions, practices, and/or products tailored on an individual patient. The term of “personalized medicine” is also used interchangeably.

The major goals of “personalized medicine” are essentially:

  • to improve the clinical outcomes and their predictability;

  • to reduce the side effects caused by a possibly inappropriate treatment;

  • to increase the quality of life;

  • to encourage patients’ compliance due to a perceived clinical improvement;

  • to optimise the use of healthcare resources.

Hamburg and Collins [10], described the path to a personalized medicine as summarized in Fig. 1, highlighting the relevant economic investments to pursue this approach: cost/effective medicine. A pertinent example is the identification, in cystic fibrosis, of one of the molecular mechanisms that cause the disease: this is present in only 4 % of patients, but once they are identified, an effective treatment, although expensive, can be given with expected positive results [11]. Another explanatory example is the specific antagonism to IL-5 in eosinophilic-driven asthma. Also in this case, it is possible to reasonably identify a priori those candidate patients who will respond to the targeted biological treatment [12, 13].

Fig. 1
figure 1

The consequential process underlying personalized medicine

Personalized medicine is still a critical aspect in the most complex, prevalent and expensive chronic diseases, such as COPD [14] or asthma in general [15], where a targeted approach would heavily affect the management.

Allergen immunotherapy (AIT)

Allergen immunotherapy remains one of the best candidates to a personalized-medicine approach since we currently know: (a) the main immunological and molecular events underlying the allergic symptoms [16]; (b) which are the more specific and sensitive standard diagnostic tests to identify the IgE-mediated reactions; (c) the relevant molecules involved in allergic reactions [17, 18]; (d) purified and standardized documented products for effective and safe AIT.

Under a clinical point of view, AIT is well characterized by numerous clinical trials showing the effectiveness of the treatment [1921], and this is even more apparent for sublingual immunotherapy (SLIT), for which large trials involving hundreds of patients are nowadays available [21]. According to this, we can perform an optimized prescription (Fig. 2) [17].

Fig. 2
figure 2

The role of allergen immunotherapy (AIT) as a personalized or precision medicine

Allergen immunotherapy has a unique immunological rationale, tailored to the specific IgE spectrum of each individual. In addition, AIT can modify the immune response against the allergen for which the treatment is designed, thus allowing to modify the natural history of the disease itself [22], and this is a unique feature in treating allergies. In addition, the AIT long term effect remains a unique feature of great impact in the pharmaco-economic evaluation, since no other allergy treatment has this specific characteristic [23].

Nonetheless, we still need biomarkers which could be predictive of the expected efficacy and, consequently, the identification of the eligible patients, with a direct economic implication. We, would highlight other critical issues for a correct and effective AIT. Certainly we would need a more spread knowledge on molecular allergy, to be ourselves more adherent to the definition of personalized medicine. Moreover, a clear characterization and definition of commercial products for vaccination is also urgently needed. A precision medicine requires precision approaches, whereas nowadays, for many commercial products the characterization remains poor, and in some cases an experimental proof of efficacy is lacking [24]. This is the reason why, regulatory authorities are strenuously trying to provide clear rules for the marketing, and for AIT products commercial authorizations [25, 26].


According to the current knowledge of mechanistic aspects, to the detailed identification of aetiological agents, and the not negligible longstanding experience, AIT, in the context of the other available therapies for respiratory allergy, is the most “personalized” treatment [27] (Fig. 2). Possibly, in the past, the concept of AIT as Precision Treatment was not properly considered or emphasized, but AIT was and still is upfront in this context. We are aware that more precise information and markers will be provided by systems medicine [28] and networks projects [29, 30]: these will further improve AIT indication, patient selection for clinical trials, prescription and, consequently, effectiveness and cost/effectiveness.

The area of medical technology is evolving rapidly and monitoring data will be critical to many aspects of developing AIT as precision medicine: finding patients with the required biomarkers (Fig. 3) for trials, monitoring efficacy and safety of targeted therapies will be also needed for reaching a justified sustainability. Finally, also partnerships between allergy scientific community, manufacturers and all other stakeholders in the healthcare system should be promoted and encouraged to achieve significant changes in medicine reimbursement.

Fig. 3
figure 3

Allergen immunotherapy (AIT): the ideal pathway towards precision medicine


  1. Corpus Hyppocraticum (1839) Émile Littré: Oeuvres Completes (Traduction Nouvelle, avec le texte grec en regard), vol I. J.-B. Baillière, Paris

  2. Harvey W (1628) Exercitatio Anatomica de Motu Cordis et Sanguinis in animalibus. Sp Coll Hunterian Y.7.13, Frankfurt

  3. Virchow RK (1858) Die Cellularpathologie in ihrer Begründung auf physiologische und pathologische Gewebenlehre, Berlin

  4. Lister J (1967) Antiseptic principle in the practice of surgery. Br Med J 2(5543):9–12

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  5. Brasier AR (2013) Identification of innate immune response endotypes in asthma: implications for personalized medicine. Curr Allergy Asthma Rep 13:462–468

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Agache IO (2013) From phenotypes to endotypes to asthma treatment. Curr Opin Allergy Clin Immunol 13:249–256

    CAS  PubMed  Google Scholar 

  7. Bieber T (2013) Stratified medicine. Future Medicine Ltd. ISBN: 978-1-78084-318-6

  8. Braido F, Holgate S, Canonica GW (2012) From “Blockbusters” to “biosimilars”: an opportunity for patients, medical specialists and health care providers. Pulm Pharmacol Ther 25:483

    Article  CAS  PubMed  Google Scholar 

  9. Fuchs VR (2013) The gross domestic product and health care spending. N Engl J Med 369(2):107–109

    Article  CAS  PubMed  Google Scholar 

  10. Hamburg MA, Collins FS (2010) The path to personalized medicine. N Engl J Med 363:301–304

    Article  CAS  PubMed  Google Scholar 

  11. Rowe SM, Heltshe SL, Gonska T, Donaldson SH, Borowitz D, Gelfond D et al (2014) Clinical mechanism of the cystic fibrosis transmembrane conductance regulator potentiator ivacaftor in G551D-mediated cystic fibrosis. Am J Respir Crit Care Med 190:175–184

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Katz LE, Gleich GJ, Hartley BF, Yancey SW, Ortega HG (2014) Blood eosinophil count is a useful biomarker to identify patients with severe eosinophilic asthma. Ann Am Thorac Soc 11(4):531–536

    Article  PubMed  Google Scholar 

  13. Liu Y, Zhang S, Li DW, Jiang SJ (2013) Efficacy of anti-interleukin-5 therapy with mepolizumab in patients with asthma: a meta-analysis of randomized placebo-controlled trials. PLoS One 8(3):e59872. doi:10.1371/journal.pone.0059872 (Epub 2013 Mar 27)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Agusti A (2014) The path to personalised medicine in COPD. Thorax 69:857–864

    Article  PubMed  Google Scholar 

  15. Fajt ML, Wenzel SE (2015) Asthma phenotypes and the use of biologic medications in asthma and allergic disease: the next steps toward personalized care. J Allergy Clin Immunol 135:299–310

    Article  PubMed  Google Scholar 

  16. Akdis CA, Akdis M (2015) Mechanisms of allergen-specific immunotherapy and immune tolerance to allergens. World Allergy Organ J 8(1):17

    Article  PubMed  PubMed Central  Google Scholar 

  17. Canonica GW, Ansotegui IJ, Pawankar R, Schmid-Grendelmeier P, van Hage M, Baena-Cagnani CE et al (2013) A WAO-ARIA-GA2LEN consensus document on molecular-based allergy diagnostics. World Allergy Organ J. 6(1):17. doi:10.1186/1939-4551-6-17

    Article  PubMed  PubMed Central  Google Scholar 

  18. Sastre J (2013) Molecular diagnosis and immunotherapy. Curr Opin Allergy Clin Immunol 13:646–650

    Article  CAS  PubMed  Google Scholar 

  19. Burks AW, Calderon MA, Casale T, Cox L, Demoly P, Jutel M et al (2013) Update on allergy immunotherapy: American Academy of Allergy, Asthma & Immunology/European Academy of Allergy and Clinical Immunology/PRACTALL consensus report. J Allergy Clin Immunol. 131(5):1288–1296

    Article  PubMed  Google Scholar 

  20. Canonica GW, Cox L, Pawankar R, Baena-Cagnani CE, Blaiss M, Bonini S et al (2014) Sublingual immunotherapy: World Allergy Organization position paper 2013 update. World Allergy Organ J 7(1):6

    Article  PubMed  PubMed Central  Google Scholar 

  21. Passalacqua G, Canonica GW (2015) Allergen immunotherapy: focus on tablets. Ann Allergy Asthma Immunol 115:4–9

    Article  CAS  PubMed  Google Scholar 

  22. Passalacqua G (2011) Specific immunotherapy: beyond the clinical scores. Ann Allergy Asthma Immunol 107:401–406

    Article  PubMed  Google Scholar 

  23. Hankin CS, Cox L (2014) Allergy immunotherapy: what is the evidence for cost saving? Curr Opin Allergy Clin Immunol 14:363–370

    Article  CAS  PubMed  Google Scholar 

  24. Jutel M, Agache I, Bonini S, Burks AW, Calderon M, Canonica W et al (2015) International consensus on allergy immunotherapy. J Allergy Clin Immunol. doi:10.1016/j.jaci.2015.04.047

  25. Kaul S, May SL, Vieths S (2011) Regulatory environment for allergen-specific immunotherapy. Allergy 66:753–764

    Article  CAS  PubMed  Google Scholar 

  26. Bonini S (2012) Regulatory aspects of allergen-specific immunotherapy: Europe sets the scene for a global approach. World Allergy Organ J 5:120–123

    Article  PubMed  PubMed Central  Google Scholar 

  27. Jameson JL, Longo LS (2015) Precision medicine: personalized, problematic and promising. N Eng J Med 372:2229–2234

    Article  CAS  Google Scholar 

  28. Gustafsson M, Colm EN, Zhang H, Barabási AL, Baranzini S, Brunak S et al (2014) Modules, networks and systems medicine for understanding disease and aiding diagnosis. Genome Med 6:82

    Article  PubMed  PubMed Central  Google Scholar 

  29. Bousquet J, Anto JM, Sterk PJ, Adcock IM, Chung KF, Roca J et al (2011) Systems medicine and integrated care to combat chronic noncommunicable diseases. Genome Med 3(7):43

    Article  PubMed  PubMed Central  Google Scholar 

  30. Bousquet J, Addis A, Adcock I, Agache I, Agusti A, Alonso A et al (2014) Integrated care pathways for airway diseases (AIRWAYS-ICPs). Eur Respir J 44:304–323

    Article  CAS  PubMed  Google Scholar 

Download references

Authors’ contributions

GP and GWC have equally contributed in the conception and drafting of the article. Both authors read and approved the final manuscript.


None to disclose.

Compliance with ethical guidelines

Competing interest The authors declare that they have no competing interests.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Giovanni Passalacqua.

Rights and permissions

Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Passalacqua, G., Canonica, G.W. AIT (allergen immunotherapy): a model for the “precision medicine”. Clin Mol Allergy 13, 24 (2015).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: