ALLERGOL. ET IMMUNOPATHOL., 1998;26(1):3-4
EDITORIAL
BETTING ON IMMUNOTHERAPY
Few medications or therapeutic procedures have remained in the first line of use for as long as immunotherapy has. Since its introduction by Noon and Friedman in 1911, immunotherapy has undergone notable advances in every aspect. As an empirical treatment, much trial-and-error experience has resulted in a relatively close understanding of the immunological mechanisms involved in achieving acceptable tolerance levels, notably the reduction in the patient''s sensitivity to the allergen, although there is still room for improvement. Doctors experienced with this procedure know that it also usually provides protection against the risk of new sensitizations, which are common in patients who are not treated with immunotherapy.
Highly purified allergen extracts (major and minor allergens) of allergy-producing products are available and the systems for evaluating the potency of allergy extracts have improved, which enhances the safety of treatment. In the near future, we expect extracts to be obtained using recombinant DNA techniques or other procedures, as discussed by L. Berrens in this number of Allergologia et Immunopathologia (1).
Agreement exists regarding the effectiveness and use of immunotherapy in the treatment of desensitization to insect venoms when the risks associated with insect bites are important. However, there is no unanimity of opinion regarding the use of immunotherapy in respiratory disease, asthma and rhinoconjunctivitis.
Opponents of immunotherapy base their arguments on the adverse effects of this treatment, which in exceptional cases can be fatal (2, 3). However, these risks are no more common and are equally severe as those associated with other medications, such as beta-lactams and acetyl-salicylic acid. In some of the more severe reactions attributed to immunotherapy, other causal factors have been found, including dosage errors or noncompliance with standard recommendations in administering the dose.
Other opponents question the effectiveness of immunotherapy in view of the demonstrated effectiveness of new medications, particularly the long-lasting beta-mimetics and inhaled corticoids. Both of these medications are effective in improving respiratory function by improving bronchial permeability, that is, by targeting the pathogenic process, inflammation. However, in the case of allergic asthma these medications do not target the origin of the process, as immunotherapy does. Therefore, the patient requires life-long medication, the amount of which varies with the patient''s state at any given moment. Immunotherapy prevents the symptoms of asthma and rhinitis, thus conserving respiratory functional capacity as long as therapy begins early, almost always in childhood. It should be noted that immunotherapy and anti-inflammatory treatment are compatible and can be given simultaneously in many cases, although anti-inflammatory therapy can be safely discontinued once the patient becomes symptom-free. Finally, not only is immunotherapy effective, it is less expensive than other procedures, which should interest national health authorities everywhere (4, 5).
From the above, it should be apparent that immunotherapy requires an exact allergological diagnosis and early onset. The WHO recommendation that treatment be limited to patients over the age of 5 years is valid for allergologists with little pediatric experience, but not for pediatric allergologists, who have not encountered difficulties with early therapy as long as the causal diagnosis is correct.
Given a correct diagnosis and clear awareness of its indications and contraindications, immunotherapy has been successful in a high percentage of patients, as long as guidelines are followed and surveillance is carried out in accordance with expert recommendations and specialist supervision (6, 7). On the other hand, new modalities of application are being tested, such as sublingual or oral, which have potential to reduce the scant risk associated with classic subcutaneous administration. There has been more experience with topical nasal products, but the results are harder to confirm.
Confirming the effectiveness of immunotherapy, the WHO recently published a report containing the statement that "immunotherapy is the only treatment that can affect the natural course of allergic diseases and it may prevent the onset of asthma" (in reference to its use in the treatment of allergic rhinitis as the initial phase of asthma) (8). Therefore, given the weight of these arguments we believe that immunotherapy still should be considered as the most appropriate basic treatment for respiratory allergic disease.
F. Muñoz-López
REFERENCES
1. Berrens L. Novel approaches to immunotherapy: epitopes, determinants, activators or modulators? Allergol et Immunopathol 1998;26:27-33.
2. Businco L, Zannino L, Cantari A et al. Systemic reactions to specific immunotherapy in children with respiratory allergy: a prospective study. Pediatr Allerg Immunol 1995;6:44-7.
3. Steward II, GE y Lockey RF. Systemic reactions from allergen immunotherapy. J Allergy Clin Immunol [Editorial] 1992;90/4(1):567-78.
4. Negro Álvarez JM. Cost of specific immunotherapy. J Invest Allergol Clin Immunol 1997;7/5:362-3.
5. Libro BLanco: El futuro de la Alergología e Inmunología Clínica en España en el horizonte del año 2005. Public. Bernard Krief. Informe preliminar.
6. Álvarez Cuesta E et al. La inmunoterapia a través de sus publicaciones. Análisis de los últimos cinco años (1986-1990). Rev Esp Alergol Inmunol Clin 1992;7/1:55-64.
7. Abramson MJ, Puy RM y Weiner JM. Is allergen immunotherapy effective in asthma? A meta-analysis of randomized controlled trials. Am J Respir Crit Care Med 1995;151:969-74.
8. World Health Organization. Position Paper on Specific Immunotherapy. Draft. Geneve. January 1997.
