Introduction

Pancreatic exocrine insufficiency (PEI) is characterized by a significant reduction in pancreatic exocrine activity within the intestine, impairing normal digestive processes ⁽¹⁾. This condition results in malnutrition-related complications and a diminished quality of life. Faecal pancreatic elastase serves as an optimal biomarker for evaluating pancreatic function in individuals with PEI. Its high stability ensures that faecal pancreatic elastase is concentrated during intestinal transit, thereby accurately reflecting total pancreatic secretion. The BÜHLMANN fPELA^® turbo is a particle-enhanced turbidimetric immunoassay (PETIA) that is commercially available for the automated quantification of pancreatic elastase in faecal extracts using clinical chemistry analyzers. Additionally, BÜHLMANN has developed the Quantum Blue^® fPELA, a lateral flow immunoassay (LFIA) designed for environments requiring lower sample volumes. This study aimed to evaluate the clinical performance of both assays and compare them to a commercially available ELISA reference method.

Aims & Methods

A total of 189 symptomatic patients, comprising 82 non-PEI controls and 107 PEI-diagnosed patients, were utilized to compare the clinical performance of PETIA and LFIA against the ELISA reference assay. Sensitivity and specificity for both assays were determined using cutoffs of 100 μg/g and 200 μg/g.

Results

The area under the curve (AUC) was 0.809 for the BÜHLMANN fPELA^® turbo (optimal cut-off: 166 μg/g), 0.792 for the Quantum Blue^® fPELA (optimal cut-off: 109 μg/g), and 0.814 for the reference ELISA (optimal cut-off: 154 μg/g). At clinically relevant cut-offs of 100 μg/g and 200 μg/g, the BÜHLMANN fPELA^® turbo demonstrated sensitivity of 0.57 and 0.74, and specificity of 0.9 and 0.76, respectively. The Quantum Blue^® fPELA showed sensitivity of 0.62 and 0.71, and specificity of 0.93 and 0.74, respectively. The reference ELISA exhibited sensitivity of 0.64 and 0.73, and specificity of 0.87 and 0.70, respectively. A direct method comparison using at least 60 samples within the linear measuring range of all assays revealed a relative median difference in Bland-Altman analysis of 9.3% between the BÜHLMANN fPELA^® turbo and the reference ELISA, 10.8% between the ELISA and the Quantum Blue^® fPELA, and 11.0% between the PETIA and the LFIA.

Conclusion

The study demonstrated that both the BÜHLMANN fPELA^® turbo and the Quantum Blue^® fPELA exhibit strong diagnostic performance to detect PEI in symptomatic patient population and high concordance with the reference ELISA assay. The BÜHLMANN fPELA^® turbo, a particle-enhanced turbidimetric immunoassay, is an accurate, non-invasive, automated test ideal for large-scale determination of pancreatic elastase levels in faecal extracts. Meanwhile, the Quantum Blue^® fPELA rapid test is well-suited for smaller laboratories, offering a faster time to result compared to traditional ELISA methods, while offering a coequal clinical performance.

References

(1) Philips ME, et al. BMJ Open Gastro 2021; 8: e000643

Disclosure

Conflict of interest: CR, DT, HI, AT, MU, RT, MS, TS, SN and CG are employees of BÜHLMANN Laboratories AG

Introduction

Several risk stratification scores have been developed for predicting endoscopic treatment or patient survival in non-variceal upper gastrointestinal bleeding (NVUGIB).

Aims & Methods

Our aim was to compare the performance of some previously described scores Forrest, (Canada-United Kingdom-Adelaide (CANUKA) score, Glasgow-Blatchford score (GBS), HARBINGER score, neutrophil-to-lymphocyte ratio (NLR), red cell distribution width (RDW), Rockall pre-endoscopy and complete scores) in predicting the following outcomes in patients with NVUGIB: need for endoscopic intervention, in-hospital rebleeding rate, need for red blood cell (RBC) transfusion, need for surgical or interventional radiological procedure, 30-day mortality.
Patients undergoing emergency endoscopy for upper GI bleeding at the Department of Emergency Medicine at Semmelweis University between January 1, 2022 and December 31, 2023 were included in a retrospective cohort analysis. Endoscopic treatment was applied to lesions with high-risk stigmata (HRS) defined by ESGE, based on the Forrest classification. Statistical methods included ROC analysis, through which we obtained the AUROC values.

Results

There were 528 patients with NVUGIB, including 99 patients (61 males, 38 females, mean age 72) with high-risk stigmata (HRS) and 429 patients (246 males, 183 females, mean age 70) with low-risk stigmata (LRS). In-hospital rebleeding rate was 3.6% (n=19/528), All-caused 30-day mortality was 17.8% (n=94/528). Due to missing data in 51 patients, scoring systems were analyzed in 477 patients. Area under receiver operator characteristic curves (AUROC) were generated for predicting need for endoscopic intervention: Forrest: 0.91, CANUKA: 0.57, GBS: 0.58, NLR: 0.55, RDW: 0.46, Rockall (pre-endoscopy): 0.53, Rockall (complete): 0.69, HARBINGER: 0.57; in-hospital rebleeding rate: Forrest: 0.65, CANUKA: 0.67, GBS: 0.55, NLR: 0.50, RDW: 0.51, Rockall (pre-endoscopy): 0.54, Rockall (complete): 0.70, HARBINGER: 0.67; need for RBC transfusion: Forrest: 0.64, CANUKA: 0.79, GBS: 0.80, NLR: 0.51, RDW: 0.68, Rockall (pre-endoscopy): 0.62, Rockall (complete): 0.66, HARBINGER: 0.64; need for surgical or interventional radiological procedure: Forrest: 0.77, CANUKA: 0.62, GBS: 0.56, NLR: 0.64, RDW: 0.46, Rockall (pre-endoscopy): 0.57, Rockall (complete): 0.72; 30-day mortality: Forrest: 0.53, CANUKA: 0.70, GBS: 0.65, NLR: 0.67, RDW: 0.60, Rockall (pre-endoscopy): 0.70, Rockall (complete): 0.70, HARBINGER: 0.62.

Conclusion

Currently used risk stratification scores have a suboptimal performance (AUROC ≤ 0.8) as per ESGE guideline in predicting the need for endoscopic therapy, in-hospital rebleeding, need for surgical or interventional radiological procedure and 30-day mortality. GBS and CANUKA scores proved to be effective in estimating the need for RBC transfusion, whereas CANUKA and Rockall scores seem to be acceptable in estimating 30-day mortality. Further prospective studies on larger patient cohorts exploiting artificial intelligence are needed to analyze and optimize risk stratification scores for NVUGIB.

Introduction

Immune checkpoint inhibitors (CPI) have revolutionised cancer outcomes, but frequently trigger immune related adverse effects, including life-threatening colitis. Tissue resident memory (TRM) T cells are key cells involved in the pathogenesis of CPI-induced colitis (CPI-C), but the mediators they produce to facilitate disease are poorly defined.

Aims & Methods

We utilised our previously published in vivo pre-clinical model of CPI-C, which occurs when mice are given combination anti-CTLA4 and anti-PD1 and a proinflammatory microbiota mix, to define the role of the Granzyme A/B cytotoxicity pathway in disease. Disease was induced in wildtype (WT) and Granzyme A/B double knockout (GzmAB^-/-) mice. Clinical outcomes (colon and spleen mass, histology and infiltrating neutrophils) from these mice were assessed to measure the severity in disease. T cell populations were also analysed using flow cytometry.

Results

GzmAB^-/-mice showed a significant reduction in disease features compared to WT mice, with reduced colon mass, reduction in infiltrating neutrophils and fewer inflammatory monocytes. Flow cytometry analysis of the T cell compartment revealed a significant reduction in both bulk CD4 and CD8 T cells and also CD4 and CD8 tissue resident memory T cells in both the cLP and IEL in GzmAB^-/-mice treated with CPI-C in comparison to WT mice treated with CPI-C. GzmAB^-/-mice treated with CPI-C also had a reduction in IFNγ and TNFα production from both CD4 T cells and CD8 T cells. These data highlight the importance of granzymes in inducing the disease phenotype in CPI-C. In order to investigate whether CD4 T cells or CD8 T cells were more important, we depleted these cells in vivo in WT mice treated with CPI-C at both 1 and 3 weeks. Here, we found that WT mice with CD4 T cells depleted got significantly worse disease with colon masses increasing and there being increased infiltrating neutrophils. There was an increase in cytotoxic cytokines being produced by CD8 T cells when CD4 T cells were depleted. However, when CD8 T cells were depleted, there was no change in any clinical features or cytokine production from CD4 T cells.

Conclusion

Using GzmAB^-/- mice we have demonstrated that CPI-colitis is at least partially dependent on the granzyme cytotoxicity pathway. Targeting the cells that produce granzyme in the colon of patients with CPI-colitis might offer an attractive novel treatment option for patients with CPI-colitis.

References

1. Lo, J.W., Cozzetto, D., Alexander, J.L. et al. Immune checkpoint inhibitor-induced colitis is mediated by polyfunctional lymphocytes and is dependent on an IL23/IFNγ axis. Nat Commun 14, 6719 (2023). https://doi.org/10.1038/s41467-023-41798-2
2. Luoma A. M. et al. Molecular pathways of colon inflammation induced by cancer immunotherapy. Cell 182, 655-671.e22 (2020).
3. Sasson, S. C. et al. Interferon-gamma-producing CD8(+) tissue resident memory T cells are a targetable hallmark of immune checkpoint inhibitor-colitis. Gastroenterology 161, 1229–1244.e1229 (2021).
4. Gupta T, Antanaviciute A, Hyun-Jung Lee C, et al. Tracking in situ checkpoint inhibitor-bound target T cells in patients with checkpoint-induced colitis. Cancer Cell. 2024 May 13;42(5):797-814.e15. doi: 10.1016/j.ccell.2024.04.010. PMID: 38744246.