Cytomorphological variations and blood histamine in bronchial asthma.

The absolute counts on basophil and eosinophil leucocytes, percentage of vacuolated eosinophil cells and whole blood histamine were determined in 30 controls and 34 patients with bronchial asthma. The basophil counts rose from the quiescent to pre-attack stage and then fell in the acute stage of bronchial asthma. The eosinophil counts, the percentage of vacuolated eosinophils and the blood histamine content increased significantly during an asthmatic attack. An attack of bronchial asthma was precipitated if the blood histamine rose to or above 200 ng/ml or a 50% rise occurred from its quiescent level. The inter-relationship between cytomorphological variations and blood histamine content in various stages of bronchial asthma is discussed.