title: Use of allogeneic apheresis stem cell products as an interlaboratory proficiency challenge.
abstract: AABB Standards requires that laboratories participate in a proficiency test (PT) program for critical analytes. Institutions can purchase commercial PT materials; however, PT can also be performed through interlaboratory exchange. We investigated the utility of allogeneic hematopoietic progenitor cell apheresis (HPC-A) products as an interlaboratory PT challenge for total nucleated cell count (TNC) and CD34 assessment.
  
  
  
  Three-year retrospective and comparative review of unrelated allogeneic HPC-A products received by the University of Michigan between January 2011 and December 2013. Internal TNC and CD34 count were compared to the external collecting facility by paired t test and linear regression. The absolute and percent difference between external and internal counts and 95% limits of agreeability (95% LA) were determined. Results were analyzed relative to donor center location (international, domestic), time zone (domestic), and calendar year.
  
  
  
  There was a strong correlation between internal and external TNC, regardless of donor center location or year. For CD34, there was a good correlation between centers (R = 0.88-0.91; slope = 0.95-0.98x) with a median difference of -1% (95% LA, -50%, +47%). This was considerably better than commercial PT challenges, which showed a persistent negative bias for absolute CD34 and CD3 counts.
  
  
  
  Allogeneic HPC-A products represent an interlaboratory PT exchange for all critical analytes, including TNC and CD34 count, cell viability, and sterility. Allogeneic HPC-A products, which are fresh and transported under validated conditions, are less subject to preanalytical variables that may impact commercial PT samples such as aliquoting and sample homogeneity, commercial additives, and sample stability during manufacturing and transport.
authors.affiliation: Department of Pathology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Laura
authors.initials: L
authors.lastname: Cooling
authors.affiliation: Department of Pathology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Kelly
authors.initials: K
authors.lastname: Roxbury
authors.affiliation: Department of Pathology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Sandra
authors.initials: S
authors.lastname: Hoffmann
authors.affiliation: Department of Pathology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Joan
authors.initials: J
authors.lastname: DeBusscher
authors.affiliation: Department of Pathology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Usha
authors.initials: U
authors.lastname: Kota
authors.affiliation: Department of Internal Medicine, Division of Hematology/Oncology and Blood and Marrow Transplant Program, University of Michigan, Ann Arbor, Michigan.|Bone Marrow Transplant Program, Florida Hospital Cancer Institute, Orlando, Florida.
authors.forename: Steven
authors.initials: S
authors.lastname: Goldstein
authors.affiliation: Department of Pathology, University of Michigan, Ann Arbor, Michigan.
authors.forename: Robertson
authors.initials: R
authors.lastname: Davenport
mesh_terms: D000328:Adult; D064591:Allografts; D018952:Antigens, CD34 / Q000276:immunology; D001781:Blood Component Removal; D002470:Cell Survival / Q000502:physiology; D004900:Erythroblasts / Q000378:metabolism; D005260:Female; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism
chemical_list: D018952:Antigens, CD34