A comparison of the available methods for the measurement of histamine in sputum

Abstract
Sputum samples from patients with chronic bronchitis were assayed for histamine content using a bioassay, and/or fluorometric assay and single or double radioenzymatic techniques. Comparison showed that all the assays produced significant differences in the measurement of sputum histamine. All the assays showed significant differences in the measurement of histamine released from human basophils. In general the fluorometric assay give the highest values for histamine in sputum and the double-isotope radioenzymatic assay the lowest. No differences were found between the bioassay, fluorometric assay and the single-isotope radioenzymatic assay for the measurement of histamine added to Tyrode''s solution. In biological samples some of the assays may additionally be measuring metabolites of histamine or other components present in the samples, and underline the need to measure the levels of histamine and its metabolites separately in sputum. [Type-1 allergic mechanisms involving mediator release from mast cells are important in the development of extrinsic atopic asthma.].