Heterogeneity of asthma according to blood inflammatory patterns.

Rachel Nadif (1) , Valérie Siroux (2) , Marie-Pierre Oryszczyn (1) , Coralie Ravault (1, 3) , Christophe M. Pison (1) , Isabelle Pin (2, 4) , Francine Kauffmann (1)

1 Recherche en épidémiologie et biostatistique
2 INSERM U823 - Institut d'oncologie/développement Albert Bonniot de Grenoble
3 DIM - Département d'information médicale / Hôpital Plaisir-Grignon
4 Service de Pédiatrie

RATIONALE: There is increasing interest regarding asthma heterogeneity in relation to inflammatory patterns. OBJECTIVES: To assess phenotypic characteristics, in particular clinical presentation of the disease, in 381 well-characterised adults with asthma from the French Epidemiological study on the Genetics and Environment of Asthma (EGEA) according to their blood inflammatory pattern. METHODS: Four blood inflammatory patterns were defined according to eosinophil (EOS) and neutrophil (NEU) count cut-off points. Samples with > or =250 EOS/mm(3) were classified as EOS(hi) and those with > or =5000 NEU/mm(3) as NEU(hi). Clinical characteristics include typical asthma and chronic obstructive pulmonary disease (COPD)-like symptoms, as well as composite quantitative scores addressing the activity of the disease. RESULTS: A substantial number of those with asthma (56.2%) had the EOS(lo) pattern (<250 EOS/mm(3)). Patients with asthma who had the EOS(hi) pattern had higher immunoglobulin E (IgE), a lower forced expiratory volume in 1 s (FEV(1)) and presented a more active asthma than those with the EOS(lo) pattern. Among those with the EOS(lo) pattern, neutrophil inflammation (NEU(hi)) was related to a less frequent positive skin prick test response (OR 0.44, 95% CI 0.20 to 0.96). Among those with the EOS(hi) pattern, neutrophil inflammation did not explain current asthma or asthma activity, and was significantly related to nocturnal symptoms (OR 5.21, 95% CI 1.44 to 18.8) independently of age, sex, smoking and inhaled corticosteroid treatment. In non-smokers with asthma, COPD-like symptoms, in particular chronic phlegm, were more frequent in those with neutrophil inflammation, independent of eosinophil inflammation (OR 2.35, 95% CI 1.08 to 5.10). CONCLUSIONS: Besides eosinophilia, neutrophil inflammation assessed in the blood is related to specific characteristics of asthma. Considering simultaneously neutrophilic and eosinophilic inflammation may contribute to help to disentangle this complex disease.

Mots clés: eosinophil; neutrophil; signs and symptoms; respiratory.; respiratory

Domaines: Santé publique et épidémiologie

Rachel Nadif, Valérie Siroux, Marie-Pierre Oryszczyn, Coralie Ravault, Christophe M. Pison, et al.. Heterogeneity of asthma according to blood inflammatory patterns.. Thorax, 2009, 64 (5), pp.374-80. ⟨10.1136/thx.2008.103069⟩. ⟨inserm-00349133⟩