Introduction

Anti- TNFα are the first advanced therapy in inflammatory bowel disease (IBD). However, up to 50% of patients will lose response during treatment. One of the most common mechanisms is immunogenicity. This is associated with obesity, smoking, monotherapy or the presence of HLA-DQA1*05. The gut microbiota appears to play an important role in pathogenesis and response to treatment. This can be altered by several factors, such as antibiotics. Therefore, antibiotics could (potentially) affect immunogenicity and response to treatment.

Aims & Methods

The aim of our study is to evaluate the effect of antibiotic treatment on the development of immunogenicity to anti-TNFα drugs in patients with IBD.
This is a retrospective case – control study of patients with IBD from a tertiary hospital treated with anti- TNFα, with data collected from June 2005 to January 2023. A group of patients who has developed antibodies against the drug (ADA) through a non-tolerant test has been compared. Two controls were selected per case, matched by type of IBD, mono/combotherapy, previous biological treatment, and type of anti- TNFα (infliximab/adalimumab).
The epidemiological variables and their association with the prescription of antibiotics and omeprazole 6 months before and 6 months after the start of biological treatment have been analysed.

Results

100 patients have been included (30 cases / 70 controls): 50% men, 27% smokers, 55% Crohn’s disease, 70% infliximab, 61% associated immunosuppression. 60% required intensification. No differences were found in any baseline characteristics between cases and controls. Anti-TNF withdrawal occurred in 19/30 cases (time until withdrawal: 19.5±27.52 months).
The use of antibiotics during de 6 months after the start of biological treatment was associated with developing ADA (76.7% vs. 38.6%; p<0.0001). The use of quinolones (33% vs. 11%; p=0.009) and penicillins (17% vs 4%, p=0.03) were associated with de development of ADA. In the multivariate analysis (adjusted for immunosuppressants, tobacco, obesity, number of biologicals), only the use of antibiotics in the first 6 months was associated with the development of ADA (OR 3.95, p<0.01).

Conclusion

Taking antibiotics during the first months after starting anti-TNFα is associated with an increased risk of ADA. The antibiotics that show the greatest association are quinolones and penicillins.

Introduction

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas represents around 80 % of incidental-discovered cysts and one of the most frequent causes of access for pancreatic clinical evaluation. Fukuoka guidelines (2017) have been the clinical reference point until the recently published Kyoto guidelines (2024) that bring out various new key points including “stop surveillance” concept as an appropriate approach in specific patients.

Aims & Methods

The aim of the study is to observe clinical validity of new recommendations of Kyoto guidelines, particularly in patients with unchanged BD-IPMN ≤ 20 mm after 5 years of surveillance. This is an observational retrospective single-center study. Patients were evaluated in our Digestive Disease Unit from Jan 2018 to Jan 2024 and they were handled according to Fukuoka guidelines.

Results

A total of 163 patients (M: F=56:107) with a median age of 70 y/o (44-92). BD-IPMN were 152 (93.5%), located in the pancreatic head (70, 46%), body (63, 41.4%) and tail (19, 12.5%). During surveillance, 29 (18%) and 3 (2.2%) patients developed, respectively, ‘worrisome features’ (WF) and ‘high-risk stigmata’ (HRS). Overall, 39 (23.9%) patients underwent surveillance for ≥ 5 years. Particularly, 20 (51.3%) of these patients had BD-IPMN ≤ 20 mm unchanged during a median time follow-up of 77 months (60-144): median IPMN dimension was 12 mm (7-20) and median age was 71 y/o (59-87). They performed a median of 7 (3-10) exams (RMN, CT, EUS) with no evidence of WF or HRS beyond 5 years of follow-up. However, in IPMN ≥ 20 mm with surveillance ≥ 5 years, 14 (35.8%) and 2 (5.1%) patients developed, respectively, WF and HRS at a median of 22 months (6-120) from diagnosis with consequent different timing of follow-up or surgical strategy.

Conclusion

Based on our experience, no one patient with BD-IPMN ≤ 20 mm during FU ≥ 5 years developed any WF or HRS. This confirmed the latest points of view of Kyoto guidelines, providing patients the possibility to stop surveillance. This could have an important role in the patient’s psychological aspects and in decreasing request overload of radiological or endoscopic exams.

References

1. Tanaka M et al. Revisions of international consensus Fukuoka guidelines for the management of IPMN of the pancreas. Pancreatology. 2017 Sep-Oct;17(5):738-753.
2. Ohtsuka T et al. International evidence-based Kyoto guidelines for the management of intraductal papillary mucinous neoplasm of the pancreas. Pancreatology. 2024 Mar;24(2):255-270