[Inflammatory response of rapid onset asthma exacerbation]

The association between onset of asthma exacerbation and the inflammatory response has not been sufficiently studied.

To determine the differential mechanisms of the rapid onset (RO) asthma exacerbation.

We designed a prospective, multicentre study that included 34 patients who suffered from asthma exacerbation. They were distributed into three groups of asthmatics, depending of the time of onset: from 0 to 24h, from 25 to 144h and more than 145h. We collected clinical data, sputum, blood and urine samples when first seen at the clinic and the next 24h later, and differential cell counts and biomarkers were determined

The asthmatics who suffered a RO exacerbation showed a higher elastase concentration, (1.028±1.140; 310±364; 401±390ng/ml) (P<0.05) and albumin (46.2±4.3; 42±3.4; 39.9±4.8g/l) (P<0.05) in the blood sample. Neutrophils, eosinophils (blood or sputum), eosinophil cationic protein (ECP) (blood), interleukin 8 (IL(8)) (blood) and leukotriene E4 (LTE(4)) (urine) were high in the three groups (P>0.05). We demonstrated an association between the onset of exacerbation and the severity of obstruction (FEV(1)) (r=-0.360; P=0.037), eosinophils in sputum (r=-0.399; P=0.029), albumin (r=-0.442; P=0.013), and IL(8) in sputum (r=0.357; P=0.038).

The results suggest a rapid inflammatory response, both neutrophilic and eosinophilic, in the asthmatic exacerbation. However, the swelling in the bronchi may play an important role in the initial inflammatory response in the exacerbations depending of time of onset.