Inflammatory subtypes in cough-variant asthma: association with maintenance doses of inhaled corticosteroids.

Abstract

BACKGROUND:

Sputum cell-subtype profiles in cough-variant asthma (CVA) are unknown.

METHODS:

Ninety-eight inhaled corticosteroid (ICS)-naive CVA patients were classified according to sputum eosinophil (eos)/neutrophil (neu) counts, as reported in subjects with asthma, as eosinophilic (E) (eos ≥ 1.0%, neu < 61%; n = 28), neutrophilic (N) (eos < 1.0%, neu ≥ 61%; n = 31), mixed granulocytic (M) (eos ≥ 1.0%, neu ≥ 61%; n = 12), and paucigranulocytic (P) (eos < 1.0%, neu < 61%; n = 27) subtypes. Patient characteristics; sputum levels of eosinophil cationic protein (ECP), IL-8, and neutrophil elastase (NE); and daily ICS doses required to maintain control during follow-up (6, 12, 18, and 24 months) were compared, retrospectively.

RESULTS:

Subtype N patients, predominantly women, were marginally older than the other subtypes, but FEV(1), airway responsiveness, and total and specific IgE results did not differ. ECP levels were higher in M and E than in N and P subtypes, being similar between M and E or N and P subtypes. Levels of IL-8 and NE were higher in M than in other subtypes, being similar among the latter. ICS doses were initially similar in all subtypes (800 μg equivalent of beclomethasone) but were higher in M than in N and P subtypes throughout follow-up, with E being intermediate between M and N or P subtypes. ICS doses decreased (halved or quartered) in E, N, and P patients followed for 24 months (P < .0001 for all) but remained unchanged in M subjects. IL-8 and NE levels correlated positively with ECP levels.

CONCLUSIONS:

In addition to eosinophils, neutrophils, which are possibly activated in the presence of eosinophils, may participate in the pathophysiology of CVA.

• Authors: Hirofumi Matsuoka, Akio Niimi, Hisako Matsumoto, Masaya Takemura, Tetsuya Ueda, Masafumi Yamaguchi, Makiko Jinnai, Hideki Inoue, Isao Ito, Kazuo Chin, Michiaki Mishima
• Journal: Chest (Chest) Vol. 138 Issue 6 Pg. 1418-25 (Dec 2010) ISSN: 1931-3543 [Electronic] United States
• PMID: 20671058 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Adrenal Cortex Hormones

Topics

• Administration, Inhalation
• Adrenal Cortex Hormones (administration & dosage)
• Adult
• Analysis of Variance
• Asthma (complications, drug therapy, immunology, physiopathology)
• Bronchial Provocation Tests
• Cohort Studies
• Cough (classification, complications, immunology, physiopathology)
• Dose-Response Relationship, Drug
• Drug Administration Schedule
• Eosinophils
• Female
• Follow-Up Studies
• Humans
• Leukocyte Count
• Male
• Middle Aged
• Neutrophils
• Pneumonia (complications, diagnosis)
• Severity of Illness Index
• Sputum (cytology, immunology)
• Statistics, Nonparametric
• Treatment Outcome