Radioimmunometric determination of histamine in myeloproliferative syndromes

Quantitative analysis of histamine is increasingly used in clinical haematology. The present study demonstrates the properties of and potential indication for a novel histamine radioimmunoassay (RIA) in clinical haematology. The sensitivity of this test assay corresponds to a histamine level of 0.1 to 0.5 nM, the non-specific cross reaction with endogenous histamine metabolites appears to be less than 0.1%. The total histamine levels in the peripheral blood of healthy donors (n = 10) ranged from 10 to 100 ng/ml, the plasma histamine values from 0.02 to 0.6 ng/ml blood. Increased levels of total histamine were measured in myeloproliferative syndromes, i.e. in patients with chronic myeloid leukemia (CML) (8 of 9), myelofibrosis (OMS) (2 of 4), and polycythaemia vera (PCV) (1 of 2). An excessive increase in total histamine was observed in healthy rhesus monkeys (n = 10) treated with recombinant human interleukin-3 (rhIL-3). The total histamine value correlated with the absolute number of circulating blood basophils (correlation coefficient: 0.9). The calculated content of histamine per basophil was found to be 0.5 to 1.5 pg. Plasma histamine values in patients suffering from myeloproliferative syndromes were within the normal range. In contrast, a moderate to marked increase in plasma histamine values was observed in monkeys during IL-3 treatment. The radioimmunometric analysis of histamine clearly represents a useful new test system in clinical haematology, especially in the follow up of malignant as well as IL-3-induced myeloproliferation.