[Radioimmunologic assay of the major basic protein of eosinophilic granules in sputum. A diagnostic contribution in...

The concentration of major basic protein (MBP) of the eosinophilic granules in bronchial expectoration (Sputum) were measured by radioimmunoassay in 204 subjects suffering from various illnesses of both the respiratory tract and other systems. 31 of these subjects were later revealed to have asthma and all had very high sputum MBP levels. The MBP level was much greater in asthmatics than any other respiratory or non-respiratory ailment and in a statistically significant fashion (p less than 0.001). 25 other subjects who were in hospital for exacerbations of asthma were subsequently tested; their MBP concentrations were higher still. During the course of their hospital stay the sputum MBP levels fell significantly following treatment with steroids and broncho-dilators. The measurement of the MBP level would seem useful in those situations where the diagnosis of asthma is not evident from the history and may help in predicting the effectiveness of steroid treatment.