title: Amifostine enhances recovery and expansion of peripheral FAS/CD95+ T- and NK-cell subpopulations during radiotherapy of patients with head-neck cancer.
abstract: OBJECTIVE
  Experimental studies suggest that the FAS/APO-1/CD95 (cytokine receptor protein TNF-receptor superfamily, member 6) cell surface molecule is involved in the apoptotic effect of radiotherapy. In this study we investigated the role of amifostine in protecting the CD95+ (CD: cluster of differentiation) lymphocytic subpopulation in patients with head and neck cancer undergoing radiotherapy.
  
  
  METHODS
  Using flow-cytometry we examined the expression of FAS/CD95 antigen on CD4+ (helper/inducer T cells), CD8+ (suppressor/cytotoxic T cells) and CD56+ (NK, natural killer) T-lymphocytes of 28 patients with head and neck cancer undergoing radiotherapy (with and without amifostine).
  
  
  RESULTS
  The numbers of peripheral blood lymphocytes were significantly reduced after treatment from (mean value +/- STD error) 1477 +/- 129 to 1015 +/- 77 for T lymphocytes, 700 +/- 70 to 454 +/- 38 for CD4, 449 +/- 46 to 296 +/- 34 for CD8 and, 140 +/- 18 to 118 +/- 13 for NK, before and after treatment, respectively. CD95 expressing lymphocytes showed a faster recovery rate in patients receiving amifostine. CD95 expressing CD56 lymphocytes increased during radiotherapy in patients receiving daily cytoprotection with amifostine to values higher than the pre-treatment levels (p = 0.004).
  
  
  CONCLUSIONS
  It is suggested that amifostine enhances recovery of T- and NK-lymphocyte subpopulations expressing the CD95 antigen in head-neck cancer patients undergoing RT and may enhance the efficacy of the later by interfering FAS-related immunological pathways.
authors.affiliation: Department of Radiotherapy/Oncology, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: George V
authors.initials: GV
authors.lastname: Koukourakis
authors.forename: Constantinos N
authors.initials: CN
authors.lastname: Baksevanis
authors.forename: Haralambos
authors.initials: H
authors.lastname: Zambatis
authors.forename: Angelos
authors.initials: A
authors.lastname: Gritzapis
authors.forename: Efstratios
authors.initials: E
authors.lastname: Maltezos
authors.forename: Costantinos
authors.initials: C
authors.lastname: Simopoulos
authors.forename: Michael I
authors.initials: MI
authors.lastname: Koukourakis
mesh_terms: D000328:Adult; D000368:Aged; D004999:Amifostine / Q000494:pharmacology*; D017209:Apoptosis / Q000528:radiation effects; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000528:radiation effects*; D019002:CD56 Antigen / Q000032:analysis; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000528:radiation effects*; D005260:Female; D005434:Flow Cytometry; D006258:Head and Neck Neoplasms / Q000276:immunology / Q000532:radiotherapy*; D006801:Humans; D007694:Killer Cells, Natural / Q000187:drug effects / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D019014:fas Receptor / Q000032:analysis*
chemical_list: D019002:CD56 Antigen; D011837:Radiation-Protective Agents; D019014:fas Receptor; D004999:Amifostine