The effects of anticoagulant and temperature on the measurements of helper and suppressor cells.

This study compared the effects of anticoagulant, storage time, and temperature on the phenotypic determination of the percentages of helper and suppressor Thymus-derived (T) lymphocytes in human peripheral blood. Blood was drawn in ACD, heparin, and EDTA and stored for up to 4 days at room temperature or 4 degrees C. A dual immunofluorescent labeling method, using fluoresceinated-helper (LEU 3a + b) and B-phycoerythrinated-suppressor (LEU 2a) antibodies, was used to simultaneously determine the percentages of the lymphocyte types in whole blood preparations by flow cytometry. Light scatter distributions were stable for ACD or heparinized blood at room temperature, whereas EDTA or 4 degrees C caused changes in the granulocyte distributions. Phenotypic determination of helper/suppressor lymphocytes was most stable for ACD or heparinized blood at room temperature. However, heparinized and EDTA blood showed marked decreases in the percentages of helper cells at 4 degrees C, and EDTA blood stored at room temperature showed an increase in helper cells. The percentages of suppressor cells did not change appreciably regardless of the anticoagulant, storage time, or temperature.