Introduction

The natural history of coeliac disease (CD) is still unknown. Clinically, CD appears both in childhood and adulthood, but whether CD can be acquired in adulthood is unknown. In addition, spontaneous normalization in serological tests has been observed in adults with initially positive serology. The aim of the present study was to assess serological signs of CD in pre-diagnostic samples of individuals from the general population with a subsequent CD diagnosis.

Aims & Methods

The study was based on the Trøndelag Health Study (HUNT). The HUNT study has been conducted in four comprehensive surveys inviting all adult inhabitants (>20 years of age) of Nord-Trøndelag County, Norway: HUNT1 (1984-1986), HUNT2 (1995-1997), HUNT3 (2006-2008) and HUNT4 (2017-2019). Blood samples were drawn from the participants during HUNT2, 3 and 4, and sera were aliquoted and stored at -80° Celsius at HUNT Biobank for future analyses. Of about 56,000 participants in HUNT4, 26,000 had participated in HUNT2 and 34,000 had participated in HUNT3, corresponding to approximately 20 and 10 years of follow-up, respectively.
Sera from participants in HUNT4 have were analysed for CD using a newly developed serological assay for detection of anti- transglutaminase 2 (anti-TG2) IgA. All seropositive participants were invited to a clinical validation study with upper endoscopy and tissue sampling to confirm the diagnosis histologically using the Marsh criteria. Available historical sera from HUNT2 and HUNT3 from seropositive participants in HUNT4 were analysed with the same serological assay.

Results

Of 686 seropositive participants in HUNT4 with available historical samples, 564 serum samples collected in HUNT2 and 594 serum samples collected in HUNT3 were analysed. Of the seropositive participants in HUNT4, 38% (215/564) and 24% (143/594) were seronegative in HUNT2 and HUNT3, respectively. Of 472 seropositive participants in HUNT4 with available historical sera from both HUNT2 and HUNT3, 19% (91/472) were seronegative in both surveys and 22% (104/472) were seronegative in one of the surveys. Hereof, 87 were negative in HUNT2, but positive in HUNT3. The remaining 17 were positive in HUNT2, but negative in HUNT3.
Of the 686 seropositive participants in HUNT4, 438 individuals have participated in the clinical validation study by March 2022. Of these, 62% (272/438) received a subsequent CD diagnosis and 8% (34/438) had already a biopsy-verified CD diagnosed before HUNT4.
Of 267 previously seronegative participants in HUNT2 and/or HUNT3 that participated in the clinical validation study, 3% (8/267) received a CD diagnosis before HUNT4 and 52% (139/267) received a subsequent CD diagnosis after HUNT4. Of 17 seropositive participants in HUNT2 with negative seroconversion in HUNT3, 2 participants received a subsequent CD diagnosis after HUNT4.

Conclusion

Our study demonstrates that CD may occur at any age, also in adulthood. In addition, a significant proportion of CD individuals may have lived with undiagnosed CD for several decades. Some individuals with negative serology, even with high IgA TG2 titres, can test negative later. Individuals with previous elevation of CD serology and conversion to negative serology are still be at risk of a subsequent CD diagnosis.

Introduction

Infectious complications of acute pancreatitis include bacteremia and infected (peri-) pancreatic necrosis (IPN). These are thought to originate from the gastro-intestinal tract due to inflammation and increased intestinal permeability. Gram-negative rod-shaped bacteria (GNRB) and Enterococcus species are most frequently cultured in IPN, and recent evidence shows that the latter is associated with increased mortality.¹ We hypothesized that these infections are preceded by an increase of abundance of pathogenic bacteria in the gastrointestinal microbiota.

Aims & Methods

Our aim was to early identify patients at risk for IPN through microbiota surveillance of the upper and lower gastrointestinal tract during the first 30 days of a first episode of acute pancreatitis. We prospectively included patients from 20 hospitals collaborating in the Dutch Pancreatitis Study Group. Saliva and rectal swabs were collected twice weekly until IPN or discharge, and the microbiota profiled using 16S rDNA sequencing. For the current study, as predefined, we first analyzed the subgroup of patients who developed (peri-) pancreatic necrosis. Further analyses including the entire cohort and focuses on other clinical endpoints will follow. Community State Type (CST) analysis was used for microbiota clustering without the input of clinical outcomes. Univariate time-to-event (survival) analyses with serial, time-dependent predictors were used for the prediction of IPN.

Results

Overall, 319 patients were included of whom 57 (17.8%) developed necrotizing pancreatitis and formed the study population of the current analysis. In this group the rate of IPN was 36.8% (21/57). CSTs associated with IPN showed at Genus-level increased abundance of Enterococcus (rectal) and Staphylococcus (saliva), but not GNRB. Clinical factors such as age, gender, biliary etiology and bacteremia, as well as alpha diversity (Inverse Simpsons Index) were not associated with IPN (see table). Enterococcus colonization in rectal swabs and Staphylococcus in saliva at optimal cut-offs were predictive for IPN (respectively, HR 4.23, 95% CI 1.61–11.10, p=0.004; HR 10.80, 95% CI 2.13-55.09, p=0.004), which occurred for the first time at median 10 (range 4 – 17) days after hospital admission and median 23 days (range 2 - 96) before IPN. Antibiotic use (>24 hours within the week before sample collection) was not associated with Enterococcus or Staphylococcus colonization. Two of five patients with Enterococcus colonization had Enterococcus species in the first pancreatic culture, as compared to one in seven patients without colonization. Initial colonization of these taxa in samples taken at the time of hospital admission did not differ, highlighting the importance of longitudinal sampling in these patients.

Conclusion

Colonization of the gut microbiota early in the course of necrotizing pancreatitis with Enterococcus or Staphylococcus was a predictive factor for IPN. The time interval between colonization and IPN appeared long enough to allow for prophylaxis. Future clinical trials should focus on prophylactic, targeted antibiotics guided by microbiota surveillance.

References

1. Timmerhuis HC, van den Berg FF, Noorda PC, et al. Over- and Misuse of Antibiotics and the Clinical Consequence in Necrotizing Pancreatitis: An Observational Multicenter Study. Ann Surg 2023; Publish Ahead of Print:10.1097/SLA.0000000000005790.

Disclosure

Timmerhuis HC, van den Berg FF, Noorda PC, et al. Over- and Misuse of Antibiotics and the Clinical Consequence in Necrotizing Pancreatitis: An Observational Multicenter Study. Ann Surg 2023; Publish Ahead of Print:10.1097/SLA.0000000000005790.