Detection of anti-Saccharomyces cerevisiae antibodies in Crohn's disease: is it a reliable diagnostic and prognostic marker?
BACKGROUND
In the past few years, serologic markers have been proposed in inflammatory bowel disease. Anti-Saccharomyces cerevisiae antibodies showed high specificity for Crohn's disease. A prognostic role for serology has also been hypothesised.


OBJECTIVE
To evaluate anti-Saccharomyces cerevisiae antibody distribution in an unselected Italian inflammatory bowel disease population. To analyse whether anti-Saccharomyces cerevisiae antibody status (positive/negative) and/or anti-Saccharomyces cerevisiae antibody titres are associated with clinical variables and outcome measures in Crohn's disease patients.


METHODS
A series of 299 inflammatory bowel disease patients were evaluated; serum samples were taken and a short clinical history was recorded. anti-Saccharomyces cerevisiae antibodies IgG enzyme-linked immunosorbent assay Medilab (Milan, Italy) kit was used in order to determine anti-Saccharomyces cerevisiae antibody status.


RESULTS
Sensitivity, specificity and likelihood ratio for positive test in the differential diagnosis of inflammatory bowel disease was 59%, 89%, 8.1, respectively. Clinical variables significantly associated with anti-Saccharomyces cerevisiae antibody status in logistic regression were found to be ileal location (p=0.01) and earlier age at diagnosis (p<0.01). Among ileal Crohn's disease patients, there was a trend in concordance between anti-Saccharomyces cerevisiae antibody titres and higher number of surgical procedures which was not statistically significant applying more complex statistics.


CONCLUSIONS
In an Italian inflammatory bowel disease population, anti-Saccharomyces cerevisiae antibodies status showed characteristics similar to those previously reported. Anti-Saccharomyces cerevisiae antibody positivity is associated with ileal involvement and with earlier onset of Crohn's disease.
Sostegni
R
R
Gastroenterology Unit, Ospedale Mauriziano Umberto I, Torino, Italy.
Daperno
M
M
Ercole
E
E
Rigazio
C
C
Bresso
F
F
Masoero
G
G
Castellino
F
F
Zaffino
C
C
Rocca
R
R
Molinaro
G C
GC
Rocca
G
G
Astegiano
M
M
Pera
A
A
D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000302:isolation & purification*; D015415:Biomarkers; D003424:Crohn Disease / Q000276:immunology* / Q000382:microbiology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis; D016014:Linear Models; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D012441:Saccharomyces cerevisiae / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D015415:Biomarkers