Korean J Clin Pathol.  1997 Apr;17(2):331-338.

Minimal Change of Lymphocyte Subsets in 24 Hours-Stored Whole Blood Sample

• Kim HS
• Lee SH
• Park MH

Abstract

BACKGROUND: In recent years, lymphocyte subset analysis in peripheral blood is widely performed using erythrocytes-lysed whole blood and two color immunofluorescence/flow cytometry method. Use of fresh blood drawn within 6 hours of staining is recommended, and some patients have to revisit the hospital for blood collection. We tested whether 24 hours-refrigerated/stored whose blood can be used for lymphocyte subset analysis.
METHODS
Twenty consecutive blood samples from patients (including nine HIV positive patients) collected in EDTA-vacutainer were tested: 1) on the day of sampling using fresh blood kept at room temperature for up to 6 hours until staining (as recommended by the manufacturer) and 2) on the following day using the same tube of blood refrigerated for 24 hours after the first staining. Two colon immunofluorescenc staining was done using Simultest(TM) IMK-Lymphocyte kit (Beckon Dickinson, U.S.A.) and flow cytometric analysis was performed using FACScan and SimulSET(TM) software (Becton Dickinson, U.S.A.). Results of alive kinds of Lymphocyte subsets (CD3+, CDl9+, CD3+CD4+CD3+CD8+, CD3-CDl6+ and/or CD56+) on day 1 and day 2 were compared by pained-t test and Wilcoxon signed rank test.
RESULTS
There was no significant change of values for all of the lymphocyte subsets except CD3+CD8+suppressor/cytotoxic (S/C) T cells. There was a slight but statistically significant change in S/C T cells (39.9%-->41.8%: 1.9%, p=0.008) after 24 hours of refrigeration, and this change was observed mainly in HIV-positive patient group. However, there was no significant change in the absolute count of helper/inducer T cells or CD4/CD8 ratio, and the change of S/C T cells in these patients was not considered to be of clinical significance.
CONCLUSIONS
The difference in the values of lymphocyte subsets between fresh blood and 24 hours-refrigerated blood was negligible and it is concluded that 24 hours-stored blood samples can be used for lymphocyte subset analysis for clinical purposes.

MeSH Terms

Colon
HIV
Humans
Lymphocyte Subsets*
Lymphocytes*
Refrigeration
T-Lymphocytes