Aims

Characterization of the immune system in elite athletes compared with a healthy  age-matched control group (amateur athletes & non-sportive persons):

  • Identification of the reasons of the susceptibility to infections & allergies in elite athletes
  • Role of metabolic changes in the susceptibility to infections & allergies in elite athletes

Discovery of new biomarkers for the susceptibility to infections & allergies:

  • Identification of molecular target structures and the metabolism of the susceptibility to infections and allergies
  • Effects of intensive trainings on the immune response and cellular metabolism

Burden of Allergic Diseases and infection susceptibility.

With an epidemic rise during the last 60 years, allergic diseases are affecting the lives of more than one billion people worldwide, and their prevalence is expected to reach up to 4 billion in 2050. Currently, 300 million people (4.2%) suffer from asthma, 500 million (6.5%) from atopic dermatitis (AD), 900 million (12 %) from allergic rhinitis (AR) and 700 million (9%) from food allergy (FA) worldwide. The prevalence of these four allergic diseases is approximately 1.7 million 22% in Switzerland. AD is the most prevalent chronic disease in childhood. Asthma represents one of the highest costs to health care system. AR is the number one disease for job absenteeism (missing work days) and presenteeism (being on the job, but not fully functioning because of disease). Approximately, 5-10% of all of these diseases present with severe forms and can cause deaths.

It is well known that professional athletes have a huge loss of performance and achievements because of particularly upper respiratory infections. The reasons for this have not been clarified. 

There are no comprehensive surveys relating the reported high prevalence of asthma and allergic diseases in athletes to comorbidities and immune changes associated with intense chronic exercise and development of infections.

In a recent study that SIAF was fully involved in, immunological analyses of the athletes and comtrols (Bonini et al. Curr Opin Allergy Clin Immunol. 2015 Apr;15(2):184-92. Asthma, allergy and the Olympics: a 12-year survey in elite athletes.) a 12-year survey has evaluated several clinical, functional and immunological parameters in order to assess features, trend and burden of asthma, allergy, infections and autoimmune diseases, in a large homogeneous population of Olympic athletes.

Six hundred and fifty-nine Italian Olympic athletes were studied through four cross-sectional surveys performed between 2000 and 2012 before the Summer and Winter Olympics. Clinical diagnosis of allergic, autoimmune and infectious diseases was complemented by: skin-prick tests (n = 569); pulmonary function tests (n = 415); total (n = 158) and specific (n = 72) serum IgE; serum autoantibodies (n = 30), cytokines and growth factors (n = 92); flow cytometry (n = 135).

It was demonstrated that the prevalence of asthma and/or exercise-induced bronchoconstriction was 14.7%, with a significant increase (P = 0.04) from 2000 (11.3%) to 2008 (17.2%). The prevalence of rhinitis, conjunctivitis, skin allergic diseases and anaphylaxis was 26.2%, 20.0%, 14.8% and 1.1%, respectively. Sensitization to inhalant allergens was documented in 49.0% of athletes, being 32.7% in 2000 and 56.5% in 2008 (P < 0.0001). Food, drug and venom allergy was present in 7.1%, 5.0% and 2.1% of athletes, respectively. The high prevalence of asthma and allergy was associated with recurrent upper respiratory tract (10.3%) and herpes (18.2%) infections, an abnormal T cell subset profile and a general down-regulation of serum cytokines with a significantly lower IFN-γ/IL-4 ratio. The immunological analyses of this study has been performed in the SIAF. It was concluded that a chronic and intensive physical exercise may cause a transient immunodepression with immunological changes associated with respiratory tract diseases. This concept is now fully open for further detailed research in a longitudinal cohort.

Value for patients and clinical procedures 

The emerging concept of disease endotypes in allergic diseases, infection and athletes: The heterogeneity of allergic and infectious diseases in relation to patients’ observable characteristics (phenotype), underlying pathogenic mechanisms (endotype), and clinically significant outcomes has been well known beyond any doubt. It is generally accepted that the clinical differences in treatment responses or disease course over time are related to underlying variations in genetic, pharmacologic, physiologic, biologic, and/or immunologic mechanisms that produce disease subclasses named endotypes. There is clear evidence for the success of endotype driven treatments, such as the use of allergen-specific immunotherapy or highly successful intervention with capsaicin for the neurogenic endotype of allergic rhinitis (AR). Novel treatments with biologicals according to disease endotypes is emerging.

Strong need for biomarkers: There is a huge need for biomarkers of infection susceptibility, asthma, AR, food allergy and atopic dermatitis that are complicated by remarkable heterogeneity. This complexity includes different patterns of onset and clinical presentation and marked variations in the rate of disease remission or progression, together adding to the considerable challenge in determining the appropriate prevention and clinical outcome.

Strong overlap in molecular mechanisms and disease endotypes: Allergic diseases are overlapping. Approximately 30% of AD patients have asthma and AR, 40% of asthma patients suffer from AR, and almost all infants with AD develop food allergy (FA). Individual reasons for these are not known. A big fraction of asthma, AD, AR, and FA have a type 2 inflammation endotype that shows similar molecular mechanisms linked to the activation of Th2 cells, type 2 innate lymphoid cells, IgE+ B cells, mast cells and inflammatory dendritic cells. Many subgroups of type 2 endotype exist that remain to be elucidated and biomarkers discovered. It is well established that type 2 inflammation endotype can cause a local immune deficiency and susceptibility to infections. It remains to be investigated in sportlers by using front techniques that are available in the SIAF.