Anti-alpha-enolase antibodies in patients with inflammatory Bowel disease.
BACKGROUND
Patients with inflammatory bowel disease (IBD) carry autoantibodies such as perinuclear antineutrophil cytoplasmic antibodies (pANCA). alpha-Enolase has been proposed as a target antigen in IBD. We evaluated the prevalence and diagnostic value of anti-alpha-enolase antibodies in IBD and related disorders.


METHODS
We used a classic proteomic approach with extracts from granulocytes and pANCA-positive ulcerative colitis (UC) sera to confirm alpha-enolase as a target antigen. By means of Western blot analysis, we screened a cohort of 525 subjects for the presence of anti-alpha-enolase antibodies. We performed GeneArray experiments on RNA extracted from colonic mucosal biopsies from 35 IBD and 6 control patients.


RESULTS
We detected anti-alpha-enolase antibodies 49.0% of patients with UC, 50.0% of patients with Crohn's disease, 30.5% of patients with primary sclerosing cholangitis, 37.8% of patients with autoimmune hepatitis, 34.0% of patients with ANCA-positive vasculitis, 31.0% of non-IBD gastrointestinal controls, and 8.5% of healthy controls. Gene array experiments showed a significant upregulation of alpha-enolase mRNA in colonic mucosal biopsies from patients with IBD, but not from controls. There was no association between the presence of pANCA and anti-alpha-enolase antibodies. Preabsorption with alpha-enolase did not eliminate the pANCA pattern on indirect immunofluorescence.


CONCLUSIONS
Anti-alpha-enolase antibodies are present in a substantial proportion of patients with IBD, patients with various inflammatory/autoimmune disorders, and non-IBD gastrointestinal controls. Therefore, anti-alpha-enolase antibodies are of limited diagnostic value for the diagnosis of IBD.
Vermeulen
Nathalie
N
Department of Internal Medicine, University Hospital Leuven, Leuven, Belgium.
Arijs
Ingrid
I
Joossens
Sofie
S
Vermeire
Severine
S
Clerens
Stefan
S
Van den Bergh
Karolien
K
Michiels
Georges
G
Arckens
Lutgarde
L
Schuit
Frans
F
Van Lommel
Leentje
L
Rutgeerts
Paul
P
Bossuyt
Xavier
X
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D045744:Cell Line, Tumor; D015331:Cohort Studies; D003106:Colon / Q000201:enzymology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000276:immunology; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis* / Q000276:immunology; D007413:Intestinal Mucosa / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D010751:Phosphopyruvate Hydratase / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D040901:Proteomics; D012333:RNA, Messenger / Q000096:biosynthesis; D015854:Up-Regulation
D019268:Antibodies, Antineutrophil Cytoplasmic; D012333:RNA, Messenger; D010751:Phosphopyruvate Hydratase