Quantitative determination of 1,4-methyl-imidazoleacetic acid in urine by high performance liquid chromatography.

A reversed phase ion-pair high performance liquid chromatographic (HPLC) method for quantitative determination of the major histamine metabolite 1,4-methyl-imidazoleacetic acid (1,4-MIAA) in urine is described. The sample handling is minimal as the sample only has to be centrifuged and diluted before analysis, in contrast to earlier gas chromatographic and thin-layer chromatographic methods. The method correlates well with a thin-layer chromatographic determination (r = 0.79, n = 15), and results from analysis of urine from different patients suffering from mastocytosis, chronic urticaria, atopic dermatitis and asthma are presented together with samples from normal individuals. Most of the patients analysed showed increased excretion of 1,4-MIAA compared with the controls. Future applications of the method, including analysis on patients with food allergy and patients with abnormalities in their histamine metabolism, are discussed.