The effect of blood storage on lymphocyte subpopulations

Duplicate heparinized blood samples were drawn from 22 subjects; 2 healthy subjects, 1 vitiligo and 19 with thyroid or parathyroid diseases. All 22 portion of specimens was immediately processed and examined for T cell subsets by indirect immunofluorescence, using monoclonal antibodies as control. 10 another portion of specimens were stored at 4 degrees C for 24 hours before testing. 12 another portion of specimens were pretreated with Ficoll-Hypaque separation before storage. When the whole blood was stored at 4 degrees C overnight and compared with samples tested with fresh cells, there was a significant decrease in OKT3+ cells (total T cells) (p less than 0.05) and a slight decrease in OKT4+ cells (T helper/inducer cells) and in OKT4/OKT8 ratio. However, these abnormalities were reversed when the lymphocytes were separated before storage. There was a significant decrease of natural killer cells (p less than 0.05) when specimens were pre-treated with Ficoll-Hypaque before storage. The reactivity of Ia+ cells was altered after overnight storage (p greater than 0.05).