Diagnostic and prognostic significance of pancreatic autoantibodies and intestinal goblet cell antibodies in inflammatory bowel diseases

Background: serological profiling of inflammatory bowel diseases (IBD) using autoantibodies represents an additional non-invasive tool for differential diagnosis and prognosis of the clinical course of Crohn’s disease (CD) and ulcerative colitis (UC). Aim: to determine the frequency, diagnostic and prognostic significance of pancreatic autoantibodies (PAB), autoantibodies to glycoprotein 2 (GP2) and intestinal goblet cells antibodies (GAB) in assessing the clinical outcomes of CD and UC. Materials and methods: the study included 117 patients with CD, 45 with UC and 24 with IBD unclassified (IBDU). The comparison group consisted of 36 patients with other gastrointestinal diseases (irritable bowel syndrome with diarrhea (IBS-D), celiac disease, autoimmune gastritis (AIH)), the control group consisted of 29 conditionally healthy individuals. The content of PAB and GAB class IgG was measured by the IIF method (EUROIMMUN AG, Germany), GP2 classes IgA and IgG and fecal calprotectin (FCP) – by the ELISA method (Generic Assays GmbH, Germany, BÜHLMANN Laboratories AG, Switzerland). Results: the frequency of PAB IgG, GP2 IgA and GP2 IgG in patients with CD was 25.6%, 24% and 12%, respectively, which was significantly higher compared to patients with UC (6.6%, 15.5% and 4.4%), IBDU (4.1%, 12.5% and 0%), AIH (5.2%, 0% and 5.2%), IBS-D (0%, 0% and 0%) and the control group (6.9%, 3.4% and 6.9%) (p<0.05), while it did not differ from patients with celiac disease (9%, 18.2% and 9%). Combined determination of PAB IgG+ and/or GP2 IgA+/G+ has the highest predictive value in the differential diagnosis of CD from UC using the cutt-off value of GP2 IgG at ≥5.0 U/ml (sensitivity – 47%, specificity – 87%, AUC (95% CI): 0.64 (0.55–0.73), p<0.05). Seropositivity for PABs correlates with the level of FCP in CD, and also serves as an unfavorable prognostic marker of severe exacerbation, complicated form and the need for surgical treatment of CD. The incidence of GAB IgG in patients with CD was 21.3% vs. with UC – 35.5% (p = 0.2), IBDU – 25% (p = 0.9) and celiac disease – 9% (p = 0.4), while it was seronegative in patients with IBS-D, AIH and the control group. Determination of GAB IgG has a good predictive value in the diagnosis of UC, especially in combination with a seronegative result of determining PABs (sensitivity – 32%, specificity – 91.1% (AUC (95% CI) = 0.62 (0.54–0.69), p = 0.002), and can also serve as an additional marker of terminal ileitis and the need for surgical treatment of CD. Conclusion: serological examination of IBD with combined determination of PAB IgG, GP2 IgA, GP2 IgG and GAB IgG allows to increase the efficiency of differential diagnostics and prediction of individual course of CD and UC.