title: Role of CD4 and CD8 T-lymphocytes, B-lymphocytes and Natural Killer cells in the prediction of radiation-induced late toxicity in cervical cancer patients.
abstract: OBJECTIVE
  To analyse the role of in vitro radio-induced apoptosis of lymphocyte subpopulations as predictive test for late effects in cervical cancer patients treated with radiotherapy.
  
  
  METHODS
  Ninety-four consecutive patients and four healthy controls were included in the study. Toxicity was evaluated using the Late Effects Normal Tissue-Subjective, Objective, Management, and Analytic (LENT-SOMA) scale. Peripheral blood lymphocyte subpopulations were isolated and irradiated at 0, 1, 2 and 8 Gy, and then collected 24, 48 and 72 h after irradiation. Apoptosis was measured by flow cytometry.
  
  
  RESULTS
  Radiation-induced apoptosis increased with radiation dose and time of incubation, and data fitted to a semi-logarithmic model defined by two constants: α (percentage of spontaneous cell death) and β (percentage of cell death induced at a determined radiation dose). Higher β values in cytotoxic T-lymphocytes (CD8) and bone cells (B-lymphocytes) were observed in patients with low bowel toxicity (hazard ratio (HR) = 0.96, p = 0.002 for B-cells); low rectal toxicity (HR = 0.96, p = 0.020; HR = 0.93, p = 0.05 for B and CD8 subpopulations respectively); low urinary toxicity (HR = 0.93, p = 0.003 for B-cells) and low sexual toxicity (HR = 0.93, p = 0.010 for CD8-cells).
  
  
  CONCLUSIONS
  Radiation-induced CD8 T-lymphocytes and, for the first time, B-lymphocytes apoptosis can predict differences in late toxicity in cervical cancer patients.
authors.affiliation: Instituto Canario de Investigación del Cáncer, Canary Islands, Spain.
authors.forename: Elisa
authors.initials: E
authors.lastname: Bordón
authors.forename: Luis Alberto
authors.initials: LA
authors.lastname: Henríquez-Hernández
authors.forename: Pedro Carlos
authors.initials: PC
authors.lastname: Lara
authors.forename: Beatriz
authors.initials: B
authors.lastname: Pinar
authors.forename: Carlos
authors.initials: C
authors.lastname: Rodríguez-Gallego
authors.forename: Marta
authors.initials: M
authors.lastname: Lloret
mesh_terms: D001681:Biological Assay / Q000379:methods*; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects*; D011832:Radiation Injuries / Q000209:etiology* / Q000473:pathology*; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000150:complications / Q000473:pathology* / Q000532:radiotherapy*