title: Novel automated blood separations validate whole cell biomarkers.
abstract: BACKGROUND
  Progress in clinical trials in infectious disease, autoimmunity, and cancer is stymied by a dearth of successful whole cell biomarkers for peripheral blood lymphocytes (PBLs). Successful biomarkers could help to track drug effects at early time points in clinical trials to prevent costly trial failures late in development. One major obstacle is the inaccuracy of Ficoll density centrifugation, the decades-old method of separating PBLs from the abundant red blood cells (RBCs) of fresh blood samples.
  
  
  RESULTS
  To replace the Ficoll method, we developed and studied a novel blood-based magnetic separation method. The magnetic method strikingly surpassed Ficoll in viability, purity and yield of PBLs. To reduce labor, we developed an automated platform and compared two magnet configurations for cell separations. These more accurate and labor-saving magnet configurations allowed the lymphocytes to be tested in bioassays for rare antigen-specific T cells. The automated method succeeded at identifying 79% of patients with the rare PBLs of interest as compared with Ficoll's uniform failure. We validated improved upfront blood processing and show accurate detection of rare antigen-specific lymphocytes.
  
  
  CONCLUSIONS
  Improving, automating and standardizing lymphocyte detections from whole blood may facilitate development of new cell-based biomarkers for human diseases. Improved upfront blood processes may lead to broad improvements in monitoring early trial outcome measurements in human clinical trials.
authors.affiliation: Immunobiology Laboratories, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massaschusetts, United States of America.
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Burger
authors.forename: Limei
authors.initials: L
authors.lastname: Wang
authors.forename: Liqin
authors.initials: L
authors.lastname: Ban
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Okubo
authors.forename: Willem M
authors.initials: WM
authors.lastname: Kühtreiber
authors.forename: Ashley K
authors.initials: AK
authors.lastname: Leichliter
authors.forename: Denise L
authors.initials: DL
authors.lastname: Faustman
mesh_terms: D001331:Automation; D015415:Biomarkers / Q000378:metabolism; D002469:Cell Separation / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008214:Lymphocytes / Q000166:cytology* / Q000378:metabolism; D060526:Magnetic Fields; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D015415:Biomarkers