Influence of ultra-endurance exercise on immunoglobulin isotypes and subclasses

Background: Strenuous exercise is associated with tissue damage. This activates the innate immune system and local inflammation. Interaction between innate and adaptive immunity is essential for maintaining health, suggesting that the adaptive immune system may also be altered by exercise. Objectives: To determine exercise induced changes in the adaptive immune system by measuring the immunoglobulin isotype and subclass response to an ultra-marathon. Methods: Venepuncture was performed on 11 experienced volunteers (six men, five women; mean (SD) age 43 (9.8) years) 24 hours before the projected finishing time and immediately after and 3, 24, and 72 hours after an ultra-marathon (90 km). Serum was stored at -80°C. IgM, IgD, IgA, IgG, IgG1, 2, 3, and 4, and total IgE were measured. Results: The following immunoglobulins were significantly (p≤0.05) altered after the race: IgD, immediately (-51%) and 24 hours (-41%) after; IgM 24 hours after (-23%); total IgG immediately after (+12%). There were no reports of symptoms of upper respiratory tract infections after the ultra-marathon. Conclusions: In experienced ultra-endurance runners, alterations in immunoglobulin concentrations after a race suggest an enhanced immune response, including isotype switching, interactions with the innate immune system, and a secondary antibody response. These alterations may have a role in the maintenance of subject health after an ultra-marathon.