Evaluation of stabilized blood cell products as candidate preparations for quality assessment programs for CD4 T-cell counting.
BACKGROUND
Exceptionally robust cell preparations are needed for quality assessment programs (QAPs) such as the International Program for Quality Assessment and Standardization for Immunological Measures (QASI) relevant to HIV/AIDS. A suitable product must withstand environmental stress related to transportation for a minimum of 6 days. The two objectives of this study are (1) to evaluate the performance of various commercial preparations with multicenter participation and (2) to evaluate the robustness of stabilized blood cell products.


METHODS
Phase 1: The performance of stabilized blood cell products was evaluated in a multicenter QAP utilizing various staining procedures and flow cytometers. Absolute cell enumeration was achieved using single-platform T-cell subset methodology. Phase 2: The robustness of stabilized blood cell products was evaluated by monitoring T-cell subset values from samples stored at 4 degrees C, 22 degrees C, and 37 degrees C for up to 10 days.


RESULTS
The largest interlaboratory variation in both absolute and relative T-cell values was 16% in samples with CD4 levels > or =400 cells per microliter and 21% in samples with CD4 levels <400 cells per microliter. Six preparations retained their phenotypic expression for 7 days at 4 degrees C and 22 degrees C. However, only two preparations remained stable for 4 days at 37 degrees C.


CONCLUSIONS
Some stabilized cell preparations are more robust and therefore more suitable for quality assessment purposes.
National Laboratory for HIV Immunology, Bureau of HIV/AIDS, STD and TB, Health Canada, LCDC 0603B1, Tunney's Pasture, Ottawa, Ontario K1A 0L2, Canada.
Michèle
M
Bergeron
Atousa
A
Shafaie
Tao
T
Ding
Sieglinde
S
Phaneuf
Nadia
N
Soucy
Francis
F
Mandy
John
J
Bradley
John
J
Fahey
D017252:CD3 Complex / Q000097:blood; D015704:CD4 Antigens / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology*; D005434:Flow Cytometry / Q000295:instrumentation / Q000379:methods / Q000592:standards; D006679:HIV Seropositivity / Q000097:blood; D006801:Humans; D016130:Immunophenotyping / Q000295:instrumentation* / Q000379:methods* / Q000592:standards; D010641:Phenotype; D011786:Quality Control; D015203:Reproducibility of Results; D013048:Specimen Handling; D013696:Temperature
D017252:CD3 Complex; D015704:CD4 Antigens