Background: Serum antibodies in inflammatory bowel disease (IBD) patients have been extensively investigated. However, data on adult patients at diagnosis is scarcely available and results on stability over time are inconsistent. Our aim was to investigate serological antibodies in newly diagnosed untreated IBD patients and to relate them to disease severity, -location and response to therapy. Furthermore, we analysed antibody stability over time.
Methods: Baseline anti-Saccharomyces cerevisiae antibodies (ASCA), anti-chitobioside carbohydrate antibodies (ACCA), anti-laminaribioside carbohydrate antibodies (ALCA) and anti-mannobioside carbohydrate antibodies (AMCA) were measured with enzyme-linked immunosorbent assays and perinuclear anti-neutrophilic cytoplasmic antibodies (pANCA) was measured by indirect immunofluorescence in serum samples of 120 untreated IBD patients at diagnosis (86 Crohn's Diseaes (CD), 29 ulcerative colitis (UC), five IBD unclassified (IBDU)) and 19 gender and age-matched healthy controls. Presence and levels of antibodies were associated with disease outcomes. Serial assessment of antibodies was available in 71 IBD patients.
Results: At baseline, 43% of CD patients were positive for any antibody (mainly ASCA) and 41% of UC patients (mainly pANCA) (Table 1). There was a clear difference in antibody profile between UC (Glycan–pANCA+) and CD (Glycan+pANCA–) but no association was found with disease phenotype or disease activity scores at diagnosis.
Furthermore, no independent associations were found with future disease course like treatment response, progression to complicated disease behaviour, anti-TNF therapy or surgery.
An antibody status change occurred in 6–15% of IBD patients (see Table 2).
Conclusions: This study does not support the routine use of serological antibodies in adult IBD patients as tool for disease activity or to predict future disease course. At most, the antibody profile supports the distinction between CD and UC and could be usefull in IBDU patients. As antibodies are relatively stable over time and during therapy, the moment of analyses does not seem to be crucial.