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.

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 °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.