Introduction

Acute pancreatitis (AP) is one of the most common gastrointestinal diseases necessitating acute hospitalisation. It is associated with notable morbidity and mortality, with a growing recognition of post-discharge mortality's importance. Nonetheless, comprehensive population-based studies in this regard are lacking.

Aims & Methods

In a Danish nationwide population-based cohort study, we aimed to investigate the post-discharge mortality risk in AP patients, including cause-specific mortality. We included all adults (>18 years) hospitalised with incident AP from January 1, 2002, through December 31, 2017. For each patient, we matched five individuals from the general population based on age and sex. The date of hospital discharge was used as the index date. Cox regression analysis was used to assess post-discharge mortality risk at 90 days, 1, 2, and 5 years. Models were adjusted for demographics, comorbidities and alcohol and smoking-related diseases. Furthermore, we examined the cause-specific mortality, including cardiovascular death, pancreatic ductal adenocarcinoma (PDAC), mortality from other cancers, and infection-related mortality, using Cox regression analysis.

Results

Among 28,763 adults with incident AP, 956 (3.3%) died in hospital. The 27,807 patients surviving the index AP event were matched with 139,035 comparison individuals (mean age 58.1 years, 51.1% men). The cumulative post-discharge mortality at 90 days was 5.02% for the AP cohort and 0.55% for the comparison cohort. The mortality risk was significantly increased in AP patients at 90 days (adjusted hazard ratio [aHR] 7.62; 95% CI 6.86-8.45), 1 year (aHR 3.39; 95% CI 3.19-3.60), 2 years (aHR 2.47; 95% CI 2.36-2.60), and 5 years (aHR 1.85; 95% CI 1.79-1.92) post-discharge. Cause-specific mortality analysis revealed heightened risks of death from cardiovascular disease (90 days aHR 2.94; 95% CI 2.32-3.73), infectious disease (90 days aHR 11.67; 95% CI 6.78-20.07), PDAC (90 days aHR 73.08; 95% CI 22.58-236.54), and other cancers (90 days aHR 3.43; 95% CI 2.75-4.28) among AP patients when compared to the comparison group.

Conclusion

Patients discharged after an incident episode of AP are at increased risk of death compared to the general population. While PDAC presents the highest cause-specific mortality risk, cardiovascular and infectious mortality rates are also notably heightened post-discharge.

Introduction

Tertiary lymphoid structure (TLS) is a pathological structure existing in chronic inflammation or autoimmune diseases by promoting the immunotherapy response. However TLS neogenesis has not been evaluated in primary biliary cholangitis (PBC).

Aims & Methods

To determine the characteristics of liver TLSs neogenesis in patients with PBC and investigate the effect of inhibition of TLSs in a murine model of PBC. We performed a retrospective study of patients with PBC who underwent liver biopsy from April 2015 to November 2022. The cohort was divided into two groups based on TLS neogenesis (TLS- vs TLS+). A comparison of the severity of cholangitis between two groups was performed. Bulk RNA sequencing was performed between the groups of TLS- and TLS+ in liver biopsy. Sphingosine-1-phosphate receptor agonist FTY720 was administrated to suppress TLSs formation in dnTGFβRII mice, in which liver TLSs were developed.

Results

In total, 70 patients were included in the study cohort, of which 50 patients with TLSs formation and 20 patients without TLSs formation. The group of TLS+ showed a higher level of serum liver function compared with TLS- (Table1). The level of IgM and the proportion of liver cirrhosis were higher in the group of TLS+. Transcriptomic analysis in liver biopsy indicated a group of 1,548 significantly upregulated genes and 1,365 downregulated genes comparing the group of TLS+ with TLS-. The KEGG pathway identified liver with TLS expression signatures associated with phospholipase D signaling pathway and B cell receptor signaling pathway. GO assessment of DEGs confirmed the activation of immune system process and leukocyte migration. FTY720 significantly attenuated serum liver function and reduced the levels of inflammation cytokines in dnTGFβRII mice. Notably, TLSs were significantly smaller in FTY720-treated mice, with the levels of TLS-related chemokine and lymphotoxin decreasing significantly. Flow cytometry indicated the percentage of CD19⁺ B cells and CD4⁺ T cells out of the liver CD45⁺population was reduced significantly in FTY720-treated liver.

_{Table1: Clinical and demographic characteristics in patients of tertiary lymphoid structures at the time of biopsy}

	TLS+ (n=50)	TLS-(n=20)	P Value
Female, n (%)	44 (88.0)	19 (95.0)	0.445
Age at liver biopsy	54.5 (48.0-62.5)	50.0 (46.0-55.0)	0.528
ALT (U/L)	46.5 (31.0-79.5)	26.0 (12.0-39.0)	0.018*
AST (U/L)	50.5 (30.0-90.3)	27.0 (22.0-40.0)	0.005*
ALP (U/L)	196.0 (114.3-305.5)	107.0 (72.0-154.0)	0.008*
GGT (U/L)	150.0 (62.5-299.0)	153.0 (61.0-306.0)	0.826
IgG (g/L)	1765.0 (1507.5-2037.5)	1770.0 (1290.0-1890.0)	0.207
IgM (g/L)	342.0 (187.8-507.3)	206.0 (138.0-338.0)	0.013*
Liver cirrhosis, n (%)	14 (28.0)	0	0.007*

Note: Data are presented as a percentage or as the median (25th-75th percentile). Comparisons between the groups were performed by chi-squared tests or nonparametric tests. *P < 0.05.
Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALP, alkaline phosphatase; GGT, gamma glutamyl transpeptidase;IgG, immunoglobulin G; IgM, immunoglobulin M.

Conclusion

Our results suggest the potential role of TLSs in building the severity of cholangitis and this understanding may guide therapeutic interventions of PBC.

References

[1]Sato Y, Silina K, van den Broek M, Hirahara K, Yanagita M. The roles of tertiary lymphoid structures in chronic diseases. Nat Rev Nephrol. 2023 : 1-13.
[2]Zhang QY, Ye XP, Zhou Z, et al. Lymphocyte infiltration and thyrocyte destruction are driven by stromal and immune cell components in Hashimoto's thyroiditis. Nat Commun. 2022. 13(1): 775.
[3]Al-Diwani A, Theorell J, Damato V, et al. Cervical lymph nodes and ovarian teratomas as germinal centres in NMDA receptor-antibody encephalitis. Brain. 2022. 145(8): 2742-2754.

Disclosure

Nothing to disclosure

Introduction

Blood-based liquid biopsy for comprehensive genomic profiling is available for cancer patients; however, given the limited amount of circulating tumor-derived DNA in plasma, it remained challenging to detect pancreatic ductal adenocarcinoma (PDA) at earlier stages. We sought to determine the usefulness of pancreatic juice-containing DNA collected from a site more proximal to the tumor in the early diagnosis of pancreatic cancer.

Aims & Methods

We evaluated the mutation detection in DNA from the duodenal fluid as an alternative biospecimen obtained by a less-invasive approach relative to endoscopic biopsy. In 296 patients diagnosed with PDA (n=175), IPMN (n=61), or other pancreatic diseases (n=60) were recruited in seven institutions. Duodenal fluid was collected from the duodenal lumen through the endoscopic channel and pancreatic juice was obtained directly from the pancreatic duct through a catheter during the ERP examination. Together with plasma cfDNA, both digestive fluid-included DNA was extracted, and molecular barcode sequencing (Ion Amplseq HD) targeting five pancreatic cancer-associated genes, namely, KRAS, GNAS, TP53, CDKN2A, and SMAD4, were performed. Detected mutations were evaluated for concordance with surgically resected tissue or needle biopsy.

Results

DNA extracted from the duodenal fluids (DFDNA) and pancreatic juice (PjDNA) had a much higher yield (avg. 25.4 ng/mL, and 7.7 ng/mL, respectively) than plasma cell-free DNA (avg. 1.3 ng/ml). While most plasma cfDNA had a typical fragmentation pattern with the highest peak at 160 bp, DFDNA and PjDNA showed various fragmentation patterns. Using molecular barcode sequencing, hotspot mutations detected in the DFDNA (n=148) showed 50.7% concordance of the mutations in resected PDA lesions, whereas only 24.1% concordance in the plasma cfDNA (n=114). In contrast to plasma cfDNA, where liquid-tissue matches were limited to advanced stages of cancer, DFDNA assay enabled the higher concordance through a wide range of PDA stages, even Stage 0 (83.3%) or I (45.5%) UICC 8th, or IPMN cases. Furthermore, PjDNA showed a much higher concordance rate (88%, n=25) than DFDNA. In DFDNA and PjDNA, mutations that originated from the primary lesions and from multicentric/concomitant lesions such as IPMN were detected effectively.

Conclusion

Digestive fluid-derived DNA can be a potent biospecimen to detect mutations with higher yield and sensitivity than plasma cfDNA. For practical diagnostics testing, optimized collection and storage of the duodenal fluid and methods for purification of the nucleic acids are needed. Besides as a diagnostic tool, genomic profiling of DFDNA can offer better surveillance for individuals at high-risk or annual checkups for healthy people. PjDNA can predict the presence of neoplastic lesions with extremely high probability and has a powerful potential for further testing before a more definitive diagnosis, even without histological evidence of cancer.

Disclosure

Yusuke Ono, Kenji Takahashi, Yusuke Mizukami: Research grants from Hitachi High-Tech Corporation.