Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1999 Sep;160(3):1001-8.
doi: 10.1164/ajrccm.160.3.9812110.

Evidence that severe asthma can be divided pathologically into two inflammatory subtypes with distinct physiologic and clinical characteristics

S E Wenzel  1 , L B Schwartz, E L Langmack, J L Halliday, J B Trudeau, R L Gibbs, H W Chu
Affiliations

Evidence that severe asthma can be divided pathologically into two inflammatory subtypes with distinct physiologic and clinical characteristics

S E Wenzel et al. Am J Respir Crit Care Med. 1999 Sep.

Abstract

The mechanisms associated with the development of severe, corticosteroid (CS)-dependent asthma are poorly understood, but likely heterogenous. It was hypothesized that severe asthma could be divided pathologically into two inflammatory groups based on the presence or absence of eosinophils, and that the inflammatory subtype would be associated with distinct structural, physiologic, and clinical characteristics. Thirty-four severe, refractory CS-dependent asthmatics were evaluated with endobronchial biopsy, pulmonary function, allergy testing, and clinical history. Milder asthmatic and normal control subjects were also evaluated. Tissue cell types and subbasement membrane (SBM) thickness were evaluated immunohistochemically. Fourteen severe asthmatics [eosinophil (-)] had nearly absent eosinophils (< 2 SD from the normal mean). The remaining 20 severe asthmatics were categorized as eosinophil (+). Eosinophil (+) severe asthmatics had associated increases (p < 0.05) in lymphocytes (CD3+, CD4+, CD8+), mast cells, and macrophages. Neutrophils were increased in severe asthmatics and not different between the groups. The SBM was significantly thicker in eosinophil (+) severe asthmatics than eosinophil (-) severe asthmatics and correlated with eosinophil numbers (r = 0.50). Despite the absence of eosinophils and the thinner SBM, the FEV(1) was marginally lower in eosinophil (-) asthmatics (p = 0.05) with no difference in bronchodilator response. The eosinophil (+) group (with a thicker SBM) had more intubations than the eosinophil (-) group (p = 0.0004). Interestingly, this group also had a decreased FVC/slow vital capacity (SVC). These results suggest that two distinct pathologic, physiologic, and clinical subtypes of severe asthma exist, with implications for further research and treatment.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

Publication types