Evaluation of Cyto-chex Tubes for the Measurement of Monocyte Expression of HLA-DR Molecules by Flow Cytometry

The expression of mHLA-DR, measured by flow cytometry, is today the reference marker to guide immunostimulatory therapies (IFN-γ) in the most severely immunocompromised patients. Nevertheless, pre-analytical constraints (storage of samples at +4°C before analysis) limit the wide use of mHLA-DR in clinical practice (problem of transporting samples to sites with a flow cytometer). Recent studies have shown that samples taken on Cyto-Chex Blood Collection Tubes (BCT) (containing a cell membrane stabilizer) were, for mHLA-DR, stable at room temperature during 72 hours after sampling. The main objective of this study is to compare the expression of mHLA-DR from samples taken simultaneously from standard tubes (EDTA) and new generation Cyto-Chex BCT tubes, to validate using Cyto Chex BCT tube in the clinical practice.

The investigators think that mHLA-DR quantification performed from Cyto-Chex BCT tubes is reliable and similar to quantification performed from EDTA tubes.