Absolute CD4+ T-lymphocyte and CD34+ stem cell counts by single-platform flow cytometry: the way forward.
To determine the potential advantage of single-platform technology in the enumeration of CD4+ T lymphocyte and CD34+ stem cells, data has been analysed from the UK NEQAS for Leucocyte Immunophenotyping schemes. The inter-laboratory CVs for CD4+ T lymphocyte counts were consistently lower for single-platform (mean 13.7%, range 10-18.3%) compared to dual-platform methodology (mean 23.4%, range 14.5-43.7%). Subgroup analysis of single-platform users demonstrated mean overall inter-laboratory CVs of 17.2%, 13% and 7.1% for the FlowCount, TruCount and volumetric approach respectively. The lowest inter-laboratory CVs obtained for a single sample by each single platform approach were 4% (TruCount), 4.4% (volumetric), 4.6% (FACSCount) and 12.7% (FlowCount). Similarly, the mean inter-laboratory CV for CD34+ stem cell enumeration using non-standardized single-platform approaches was 18.6% (range 3.1-36.9%) compared to 28.6% (range 19-44.2%) for the dual-platform technology. Our results suggest absolute cell subset enumeration should be performed by single-platform technology and that such an approach should improve the quality control of multi-centre clinical trial data for CD4+ T lymphocyte and CD34+ stem cells.
Barnett
D
D
UK NEQAS for Leucocyte Immunophenotyping, Department of Haematology, Royal Hallamshire Hospital, Sheffield. d.barnett@sheffield.ac.uk
Granger
V
V
Whitby
L
L
Storie
I
I
Reilly
J T
JT
D018952:Antigens, CD34 / Q000032:analysis*; D015704:CD4 Antigens / Q000032:analysis*; D015496:CD4-Positive T-Lymphocytes; D005434:Flow Cytometry / Q000379:methods*; D006412:Hematopoietic Stem Cells; D006801:Humans; D018655:Lymphocyte Count / Q000379:methods*
D018952:Antigens, CD34; D015704:CD4 Antigens