title: Use of internal control T-cell populations in the flow cytometric evaluation for T-cell neoplasms.
abstract: Flow cytometry is an important tool for identification of neoplastic T-cells, but immunophenotypic abnormalities are often subtle and must be distinguished from nonneoplastic subsets. Use of internal control (IC) T-cells in the evaluation for T-cell neoplasms was explored, both as a quality measure and as a reference for evaluating abnormal antigen expression.
  
  
  
  All peripheral blood specimens (3-month period), or those containing abnormal T-cells (29-month period), stained with CD45 V500, CD2 V450, CD3 PE-Cy7, CD7 PE, CD4 Per-CP-Cy5.5, CD8 APC-H7, CD56 APC, CD16&57 FITC, were evaluated. IC T-cells were identified (DIVA, BD Biosciences) and median fluorescence intensity (MFI) recorded. Selected files were merged and reference templates generated (Infinicyt, Cytognos).
  
  
  
  IC T-cells were present in all specimens, including those with abnormal T-cells, but subsets were less well-represented. IC T-cell CD3 MFI differed between instruments (p = 0.0007) and subsets (p < 0.001), but not specimen categories, and served as a longitudinal process control. Merged files highlighted small unusual IC-T subsets: CD2+(dim) (0.25% total), CD2- (0.03% total). An IC reference template highlighted neoplastic T-cells, but was limited by staining variability (IC CD3 MFI reference samples different from test (p = 0.003)).
  
  
  
  IC T-cells present in the majority of specimens can serve as positive and longitudinal process controls. Use of IC T-cells as an internal reference is limited by variable representation of subsets. Analysis of merged IC T-cells from previously analyzed patient samples can alert the interpreter to less-well-recognized non-neoplastic subsets. However, application of a merged file IC reference template was limited by staining variability. © 2016 Clinical Cytometry Society.
authors.affiliation: Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
authors.forename: Alicia M
authors.initials: AM
authors.lastname: Hunt
authors.affiliation: University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors.forename: Wendy
authors.initials: W
authors.lastname: Shallenberger
authors.affiliation: Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Ten Eyck
authors.affiliation: Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania. Craig.Fiona@Mayo.edu.
authors.forename: Fiona E
authors.initials: FE
authors.lastname: Craig
mesh_terms: D017252:CD3 Complex / Q000378:metabolism; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D016130:Immunophenotyping; D008232:Lymphoproliferative Disorders / Q000175:diagnosis* / Q000276:immunology; D009369:Neoplasms / Q000175:diagnosis* / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D017252:CD3 Complex
keywords: T-cell neoplasm; flow cytometry; internal control; quality control; standardization