In vitro basophil histamine release induced by mannitol in a patient with a mannitol-induced anaphylactoid reaction

Anaphylactoid reactions in man are associated with the infusion of diagnostic and therapeutic agents. The etiology of such reactions remains unknown, but clinically they have the signs and symptoms that mimic those associated with in vivo histamine release. We report that the leukocytes of a patient who suffered an anaphylactoid reaction associated with the infusion of mannitol repeatedly released histamine in vitro when the leukocytes were challenged with low concentrations of mannitol (less than 0.1 M). In 44% deuterium oxide buffer, the patient's cells were tenfold more reactive to mannitol as compared to normal leukocytes and were pharmacologically modulated in a fashion similar to IgE-dependent release. The temperature optimum for this nonhyperosmolar (less than 0.1M) mannitol-induced, deuterium oxide-dependent release was the same as that for IgE-dependent release. Desensitization of the patient's cells with anti-IgE completely suppressed release induced by low concentrations of mannitol but did not affect the hyperosmolar (greater than 0.1M) mannitol-induced release of basophil histamine. These studies suggest that patients experiencing anaphylactoid reactions may be identified by use of in vitro basophil histamine release.