title: Effect of weight loss on T-cell receptor-mediated T-cell function in elite athletes.
abstract: OBJECTIVE
  Long-term intensive exercise by athletes may sometimes lead to a susceptibility to infections. In the present study, we examined the differences in immune function between amateur wrestlers experiencing weight loss (WL) and those without WL who underwent similar intensive exercise training.
  
  
  METHODS
  Eighteen elite amateur wrestlers who attended the Japanese national championship were classified into two groups. One group consisted of those with either slight or no WL (without WL) (<4%; mean, 1%) (N = 9), and the other group consisted of those who needed a significant WL (with WL) (> or = 4%; mean, 7%) (N = 9) during a 1-month period of intensive training. The leukocyte counts as well as the leukocyte subsets in the peripheral blood were examined. The proliferation and cytokine production in T lymphocytes in response to bacterial superantigens (staphylococcal enterotoxin B, streptococcal pyrogenic exotoxin A) and anti-CD3 antibody (Ab) were also examined.
  
  
  RESULTS
  The total leukocyte counts and leukocyte subsets did not differ substantially between the groups and were also not different from the findings before starting the intensive exercise training. Natural killer cells and T cells among the lymphocytes significantly increased in both groups, whereas the increase in each group was not different. Although the T-cell responses to bacterial superantigens were not different, the anti-CD3 Ab-stimulated proliferation and interferon-gamma production of lymphocytes from the wrestlers with WL were significantly lower than those of the wrestlers without WL. This hyporesponsiveness to CD3 stimulation recovered 2 months after the tournament when the wrestlers reverted to their normal weight.
  
  
  CONCLUSIONS
  Intensive exercise in athletes accompanied by a rapid WL was found to compromise the CD3/T-cell receptor-mediated T-cell function in athletes.
authors.affiliation: Department of Sport Science, Physical Training School of National Defense Agency, Ooizumigakuen-chou, Nerima-ku, Tokyo 178-8501, Japan.
authors.forename: Tomohito
authors.initials: T
authors.lastname: Imai
authors.forename: Shuhji
authors.initials: S
authors.lastname: Seki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Dobashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohkawa
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Habu
authors.forename: Hoshio
authors.initials: H
authors.lastname: Hiraide
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D000942:Antigens, Bacterial / Q000008:administration & dosage; D001773:Blood Cells / Q000378:metabolism; D004768:Enterotoxins; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D008297:Male; D010806:Physical Education and Training / Q000379:methods; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D015431:Weight Loss / Q000276:immunology*; D014952:Wrestling / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D004768:Enterotoxins; D011948:Receptors, Antigen, T-Cell; C031818:enterotoxin B, staphylococcal; D007371:Interferon-gamma