Identification of alpha-enolase as an autoantigen associated with severe asthma.
BACKGROUND
Approximately 5% to 10% of patients with asthma have severe disease that is not effectively controlled by typical therapies. The existence of an autoantigen associated with severe asthma has been previously reported.


OBJECTIVE
We attempted to identify the autoantigen.


METHODS
Severe asthma was defined as patients having at least 1 severe asthmatic exacerbation requiring an emergency department visit or admission in the last year despite continuous typical therapies. Autoantibodies to airway epithelial cells (A549) were examined in sera from patients with severe asthma by immunoblot analysis.


RESULTS
IgG autoantibodies to the 52-kd airway epithelial cell antigen were detected in sera from 32 of 78 patients with severe asthma (41%), 9 of 83 patients with mild-to-moderate asthma (11%), and 2 of 58 healthy controls (3%; P < .001). The 52-kd autoantigen was identified as alpha-enolase by mass spectrometry analysis and confirmed by using recombinant human alpha-enolase protein. The detection of IgG autoantibodies to alpha-enolase was the most significant indicator for distinguishing severe asthma from mild-to-moderate asthma, even after adjusting for the effects of other clinical variables, including age, sex, atopy, and FEV(1) (adjusted odds ratio, 5.2; 95% CI, 2.1-12.9; P < .001).


CONCLUSIONS
The alpha-enolase was identified as an autoantigen associated with severe asthma. Further studies are needed to determine the significance of this autoantigen in severe asthma.


CONCLUSIONS
IgG autoantibodies to alpha-enolase could be a biological marker for severe asthma.
Nahm
Dong-Ho
DH
Department of Allergy and Rheumatology, Ajou University Hospital, Suwon 443-721, Korea. donghonahm@yahoo.co.kr
Lee
Kwang-Hoon
KH
Shin
Jee-Young
JY
Ye
Young-Min
YM
Kang
Yup
Y
Park
Hae-Sim
HS
D000328:Adult; D001249:Asthma / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood / Q000276:immunology; D001324:Autoantigens / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D002460:Cell Line; D004847:Epithelial Cells / Q000276:immunology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D008297:Male; D010751:Phosphopyruvate Hydratase / Q000276:immunology*; D020545:Respiratory Mucosa / Q000276:immunology
D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; D007074:Immunoglobulin G; D010751:Phosphopyruvate Hydratase