Comparison of whole-blood eosinophil counts in extrinsic asthmatics with acute and chronic asthma.

Venous whole-blood eosinophil counts were performed on 50 occasions in 42 patients with varying patterns of asthma. None of the patients studied had received systemic corticosteroids during the previous year. Patients with acute severe asthma, as defined by symptomatic airways obstruction with a tachycardia of at least 120 beats/min, showed eosinopenia (21 x 10(9)/l +/- SD 57 x 10(9)/l). Patients with chronic asthma, as defined by symptomatic airways obstruction with a heart rate of less than 100 beats/min, showed appreciable eosinophilia (1048 x 10(9)/l +/- SD 708 x 10(9)/l). Finally, asymptomatic patients had a variable total eosinophil count but with values lower than those of patients with chronic asthma (345 x 10(9)/l +/- SD 431 x 10(9)/l). Eosinophilia may contain chronic asthma, thereby mediating bronchial damage, whereas absence of eosinophils in acute asthma enables vasoactive mediators to enter the systemic circulation, possibly causing circulatory disturbances.