Published online Nov 14, 2023. doi: 10.3748/wjg.v29.i42.5728
Peer-review started: June 28, 2023
First decision: September 1, 2023
Revised: October 3, 2023
Accepted: November 2, 2023
Article in press: November 2, 2023
Published online: November 14, 2023
Processing time: 137 Days and 21.4 Hours
Defective neutrophil regulation in inflammatory bowel disease (IBD) is thought to play an important role in the onset or manifestation of IBD, as it could lead to damage of the intestinal mucosal barrier by the infiltration of neutrophils in the inflamed mucosa and the accumulation of pathogens. Like neutrophils in the context of innate immune responses, immunoglobulin A (IgA) as an acquired immune response partakes in the defense of the intestinal epithelium. Under normal conditions, IgA contributes to the elimination of microbes, but in con
To determine the predictive potential of Ig subtypes of a novel serological marker, anti-CHI3L1 autoantibodies (aCHI3L1) in determining the disease phenotype, therapeutic strategy and long-term disease course in a prospective referral cohort of adult IBD patients.
Sera of 257 Crohn’s disease (CD) and 180 ulcerative colitis (UC) patients from a tertiary IBD referral center of Hungary (Division of Gastroenterology, Department of Internal Medicine, Faculty of Medicine, University of Debrecen) were assayed for IgG, IgA, and secretory IgA (sIgA) type aCHI3L1 by enzyme-linked immunosorbent assay using recombinant CHI3L1, along with 86 healthy controls (HCONT).
The IgA type was more prevalent in CD than in UC (29.2% vs 11.1%) or HCONT (2.83%; P < 0.0001 for both). However, sIgA subtype aCHI3L1 positivity was higher in both CD and UC patients than in HCONT (39.3% and 32.8% vs 4.65%, respectively; P < 0.0001). The presence of both IgA and sIgA aCHI3L1 antibodies was associated with colonic involvement (P < 0.0001 and P = 0.038, respectively) in patients with CD. Complicated disease behavior at sample procurement was associated with aCHI3L1 sIgA positivity (57.1% vs 36.0%, P = 0.009). IgA type aCH3L1 was more prevalent in patients with frequent relapse during the disease course in the CD group (46.9% vs 25.7%, P = 0.005). In a group of patients with concomitant presence of pure inflammatory luminal disease and colon involvement at the time of diagnosis, positivity for IgA or sIgA type aCH3L1 predicted faster progression towards a complicated disease course in time-dependent models. This association disappeared after merging subgroups of different disease locations.
CHI3L1 is a novel neutrophil autoantigenic target in IBD. The consideration of antibody classes along with location-based prediction may transform the future of serology in IBD.
Core Tip: The tolerance brake to chitinase 3-like 1 (CHI3L1), a novel neutrophil autoantigenic target in inflammatory bowel disease (IBD), the presence of immunoglobulin A (IgA) autoantibodies against this specific target, as well as the precise function and underlying processes of CHI3L1 in the development of IBD, continue to be uncertain. In the present prospective observational study, we first reported an enhanced formation of IgA and secretory IgA (sub)type against CHI3L1 in adult patients with Crohn’s disease, which was associated with the clinical phenotype and development of a complicated disease course during follow-up in a tertiary referral IBD center in Hungary. By taking into account the classes of antibodies and utilizing location-based predictions, serology in IBD may undergo a significant transformation in the future.