Histamine synthesis by white cells during storage of platelet concentrates.

OBJECTIVES: To resolve the question whether histamine, like some cytokines, is actively synthesized during storage of platelet concentrates.
METHODS: We prepared conventional buffy coat platelet concentrates and stored them in the usual way at 22 degrees C. Disodium cromoglycate was added to one series, saline to the controls. Samples were taken at intervals, to be tested for histamine and interleukin-6 (IL-6).
RESULTS: The plasma histamine level increased from a median of 1.02 ng/ml (range 0.11-3.27) to 12.9 ng/ml (range 4.30-32.9) whereas the total histamine content of the platelet concentrates remained unchanged during the 5-day storage period. In contrast, the total content of IL-6 increased rapidly.
CONCLUSION: Histamine is not synthesized during storage of platelets, whereas IL-6 is. The addition of disodium cromoglycate, a substance that inhibits granulocyte activation, had no effect on the release of histamine or on the total histamine content at various storage times.