T cell factor 1 (TCF-1) defines T cell differentiation in colorectal cancer.

The presence of precursor to exhausted (Tpex) CD8+ T cells is important to maintain robust immunity following treatment with immune checkpoint inhibition (ICI). Impressive responses to ICI are emerging in patients with stage II-III mismatch repair (MMR)-deficient (dMMR) colorectal cancer (CRC). We found 64% of dMMR and 15% of mismatch repair-proficient (pMMR) stage III CRCs had a high frequency of tumor infiltrating lymphocytes (TIL-hi). Furthermore, expression of TCF-1 (Tcf7) by CD8+ T cells predicted improved patient prognosis and Tpex cells (CD3+CD8+TCF-1+PD-1+) were abundant within lymphoid aggregates of stage III CRCs. In contrast, CD3+CD8+TCF-1-PD-1+ cells were more abundant at the invasive front and tumor core, while γδ T cells were equally abundant in all tumor areas. Interestingly, no differences in the frequency of Tpex cells were observed between TIL-hi dMMR and TIL-hi pMMR CRCs. Therefore, Tpex cell function and ICI response rates in TIL-hi CRC warrants further investigation.

Graft-Derived Cell-Free DNA Quantification following Liver Transplantation Using Tissue-Specific DNA Methylation and Donor-Specific Genotyping Techniques: An Orthogonal Comparison Study.

Background: Graft-derived cell-free DNA (gdcfDNA) analysis has shown promise as a non-invasive tool for monitoring organ health following solid organ transplantation. A number of gdcfDNA analysis techniques have been described; however, the majority rely on sequencing or prior genotyping to detect donor-recipient mis-matched genetic polymorphisms. Differentially methylated regions of DNA can be used to identify the tissue-of-origin of cell-free DNA (cfDNA) fragments. In this study, we aimed to directly compare the performance of gdcfDNA monitoring using graft-specific DNA methylation analysis and donor-recipient genotyping techniques in a pilot cohort of clinical samples from patients post-liver transplantation. Results: 7 patients were recruited prior to LT, 3 developed early, biopsy-proven TCMR in the first 6 weeks post-LT. gdcfDNA was successfully quantified in all samples using both approaches. There was a high level of technical correlation between results using the two techniques (Spearman testing, rs = 0.87, p < 0.0001). gdcfDNA levels quantified using the genotyping approach were significantly greater across all timepoints in comparison to the tissue-specific DNA methylation-based approach: e.g., day 1 post-LT median 31,350 copies/mL (IQR 6731-64,058) vs. 4133 copies/mL (IQR 1100-8422), respectively. Qualitative trends in gdcfDNA levels for each patient were concordant between the two assays. Acute TCMR was preceded by significant elevations in gdcfDNA as quantified by both techniques. Elevations in gdcfDNA, using both techniques, were suggestive of TCMR in this pilot study with a 6- and 3-day lead-time prior to histological diagnosis in patients 1 and 2. Conclusions: Both the graft-specific methylation and genotyping techniques successfully quantified gdcfDNA in patients post-LT with statistically significant concordance. A direct comparison of these two techniques is not only important from a technical perspective for orthogonal validation, but significantly adds weight to the evidence that gdcfDNA monitoring reflects the underlying biology. Both techniques identified LT recipients who developed acute TCMR, with several days lead-time in comparison to conventional diagnostic workflows. Whilst the two assays performed comparably, gdcfDNA monitoring based on graft-specific DNA methylation patterns in cfDNA offers major practical advantages over the donor-recipient genotyping, and hence enhances the potential to translate this emerging technology into clinical practice.

Evaluating treatment response following locoregional therapy for hepatocellular carcinoma: A review of the available serological and radiological tools for assessment.

Hepatocellular carcinoma (HCC) is an aggressive primary malignancy of the liver and is the third most common cause of cancer-related global mortality. There has been a steady increase in treatment options for HCC in recent years, including innovations in both curative and non-curative therapies. These advances have brought new challenges and necessary improvements in strategies of disease monitoring, to allow early detection of HCC recurrence. Current serological and radiological strategies for post-treatment monitoring and prognostication and their limitations will be discussed and evaluated in this review.

Endoscopy training in Australia during COVID-19: Efficacy and knowledge assessment of gastroenterology and general surgery trainees.

Background and Aim: During COVID-19, restrictions to elective endoscopy were introduced worldwide. A reduction in procedures may impact trainees' endoscopy learning. This study aims to assess Australian advanced gastroenterology and general surgery trainees' self-perceived efficacy and knowledge in endoscopy during the pandemic. Methods: All Australian gastroenterology and general surgery trainees in their last 2 years of accredited training were invited to participate through email (2020-2021 and 2021-2022 training cycles). The primary outcome was to assess trainees' self-efficacy and knowledge regarding gastrointestinal endoscopy. Secondary outcomes included subgroup analysis between gastroenterology and general surgery trainees. Self-perceived efficacy was assessed with Likert-scale questions on 20 endoscopy procedures and knowledge was assessed through 21 endoscopy-related multiple choice questions. Results: Eighty-one trainees responded to a self-efficacy questionnaire and 77 responded to the knowledge questionnaire. Over 90% of the trainees were confident or extremely confident in diagnostic endoscopy, but only half demonstrated similar efficacy for therapeutic endoscopy. The efficacy for basic endoscopy procedures was higher for gastroenterology trainees (64.0% vs 51.1%, P < 0.001). Last-year trainee achievement of conjoint committee requirements for upper gastrointestinal endoscopy was achieved in 95.8% of gastroenterology trainees versus 22.2% of surgical trainees (P < 0.001). The median score on the knowledge questionnaire was also higher for the gastroenterology subset (90.5% vs 71.4%, P < 0.001). Conclusion: During COVID-19, endoscopy trainees' self-efficacy in endoscopic diagnostic procedures was achieved for most trainees. The differences in self-perceived efficacy and knowledge between gastroenterology and surgical trainees may be reflective of the different opportunities for learning between the two groups.

Low Levels of Hepatocyte-Specific Methylation in Cell-Free DNA Are a Strong Negative Predictor for Acute T Cell-Mediated Rejection Requiring Treatment Following Liver Transplantation.

Graft-derived cell-free DNA (gdcfDNA) quantification is a promising, minimally invasive tool for detecting acute T cell-mediated rejection (ATCMR) following liver transplantation (LT). We investigated the utility of measuring hepatocyte-specific methylation in cfDNA (HS-cfDNA) to quantify gdcfDNA, examining its accuracy in detecting ATCMR in a prospective, cross-sectional study. Blood was collected from LT recipients immediately prior to graft biopsy for suspected rejection. HS-cfDNA was quantified using droplet-digital polymerase chain reaction. Prebiopsy liver function tests (LFTs) and HS-cfDNA levels were correlated with biopsy results and the primary outcome of treated biopsy-proven acute rejection (tBPAR). A total of 51 patients were recruited; 37 had evidence of rejection on biopsy and 20 required treatment. As much as 11 patients needed inpatient treatment for rejection. HS-cfDNA significantly outperformed LFTs in identifying patients with tBPAR, particularly those needing inpatient treatment (area under the curve, 73.0%; 95% confidence interval, 55.4%-90.6%; P = 0.01). At a threshold of <33.5% of the total cfDNA fraction, HS-cfDNA had a specificity of 97%, correctly excluding tBPAR in 30/31 patients. Quantifying graft-specific methylation in cfDNA has a major advantage over previous gdcfDNA techniques: it does not require genotyping/sequencing, lending it greater feasibility for translation into transplantation care. Low levels of HS-cfDNA were a strong negative predictor for tBPAR (negative predictive value, 86%) and may have a future role in triaging patients prior to invasive graft biopsies.

A Synthetic DNA Construct to Evaluate the Recovery Efficiency of Cell-Free DNA Extraction and Bisulfite Modification.

BACKGROUND: Despite improvements in the genetic and epigenetic analysis of cell-free DNA (cfDNA), there has been limited focus on assessing the preanalytical variables of recovery efficiency following cfDNA extraction and bisulfite modification. Quantification of recovery efficiency after these steps can facilitate quality assurance and improve reliability when comparing serial samples. METHODS: We developed an exogenous DNA Construct to Evaluate the Recovery Efficiency of cfDNA extraction and BISulfite modification (CEREBIS) after cfDNA extraction and/or subsequent bisulfite modification from plasma. The strategic placement of cytosine bases in the 180 bp CEREBIS enabled PCR amplification of the construct by a single primer set both after plasma DNA extraction and following subsequent bisulfite modification. RESULTS: Plasma samples derived from 8 organ transplant donors and 6 serial plasma samples derived from a liver transplant recipient were spiked with a known number of copies of CEREBIS. Recovery of CEREBIS after cfDNA extraction and bisulfite modification was quantified with high analytical accuracy by droplet digital PCR. The use of CEREBIS and quantification of its recovery was useful in identifying problematic extractions. Furthermore, its use was shown to be invaluable towards improving the reliability of the analysis of serial samples. CONCLUSIONS: CEREBIS can be used as a spike-in control to address the preanalytical variable of recovery efficiency both after cfDNA extraction from plasma and following bisulfite modification. Our approach can be readily implemented and its application may have significant benefits, especially in settings where longitudinal quantification of cfDNA for disease monitoring is necessary.

Variation in Human Research Ethics Committee and governance processes throughout Australia: a need for a uniform approach.

BACKGROUND: In Australia, ethics committees across different states vary in application, requirement and process for the ethical review and approval for clinical research. This may lead to confusion and delays in the enablement of multicentre research projects. This study explores the effect of differing processes for Ethics and Governance in the establishment of the CovidSurg-Cancer study during the global COVID-19 pandemic. METHODS: An anonymous, structured web-based questionnaire was designed using the Research Electronic Data Capture application (REDCap) platform to capture consultant surgeons, fellows, and trainees experience in the ethics application process. 'CovidSurg-Cancer' was an international multicentre collaborative study to assess the impact of COVID-19 on the outcomes of patients undergoing cancer surgery. The ethics process to set up this observational study was used as to explore the differing processes applied across Australia. RESULTS: The CovidSurg-Cancer study was successfully set up in 14 hospitals. Four hospitals approved the study directly as an audit. Of the remaining sites, 10 ethics applications underwent Human Research Ethics Committee review following which two (14%) were subsequently approved as an audit activity and eight hospitals (57%) were given formal ethical approval with waiver of consent. Ethics application acceptance from another Australian Human Research Ethics Committee was provided with six applications; however, only three were reciprocated without the requirement for further agreements. A third of (30%) respondents suggested that the details of the application pathway, process and documentation were unclear. CONCLUSION: Ethics processes are varied across Australia with considerable repetition. A centralized, harmonized application process would enhance collaborative research.

A Fine Needle Recanalization Technique for Iliac Artery Occlusions in Endovascular Surgery.

BACKGROUND: Endovascular intervention for chronic total occlusions (CTOs) in aortoiliac occlusive disease (AIOD) poses technical challenges. In this manuscript, our experience of fine needle recanalization for the treatment of iliac artery CTO is described. METHOD: A prospective database recorded treatment of 11 limbs in 11 patients since 2011 using this technique. The majority of these CTO were of the common iliac artery (n = 9). RESULTS: Technical success rate was 91% (n = 10). One failed case was due to tortuous iliac anatomy. There was no restenosis of the treated segments at 8 weeks and no major complications, perforations, major limb loss, or periprocedural mortality. CONCLUSIONS: This technique is a safe and viable adjunct for difficult CTO in AIOD with suitable anatomy. It benefits from being a simple, low-profile, low-cost coaxial system and should be part of the armamentarium with other advanced endovascular techniques.

Emergency presentations of acute biliary pain: changing patterns of management in a tertiary institute.

BACKGROUND: Acute biliary pain is the most common presentation of gallstone disease. Untreated patients risk recurrent pain, cholecystitis, obstructive jaundice, pancreatitis and multiple hospital presentations. We examine the outcome of implementing a policy to offer laparoscopic cholecystectomy on index presentation to patients with biliary colic in a tertiary hospital in Australia. METHODS: This is a retrospective cohort study of adult patients presenting to the emergency department (ED) with biliary pain during three 12-month periods. Outcomes in Group A, 3 years prior to policy implementation, were compared with groups 2 and 7 years post implementation (Groups B and C). Primary outcomes were representations to ED, admission rate and time to cholecystectomy. RESULTS: A total of 584 patients presented with biliary colic during the three study periods. Of these, 391 underwent cholecystectomy with three Strasberg Type A bile leaks and no bile duct injuries. The policy increased admission rates (A = 15.8%, B = 62.9%, C = 29.5%, P < 0.001) and surgery on index presentation (A = 12.0%, B = 60.7%, C = 27.4%, P < 0.001). There was a decline in time to cholecystectomy (days) (A = 143, B = 15, C = 31, P < 0.001), post-operative length of stay (days) (A = 3.6, B = 3.2, C = 2.0, P < 0.05) and representation rates to ED (A = 42.1%, B = 7.1%, C = 19.9%, P < 0.001). There was a decline in policy adherence in the later cohort. CONCLUSION: Index hospital admission and cholecystectomy for biliary colic decrease patient representations, time to surgery, post-operative stay and complications of gallstone disease. This study demonstrates the impact of the policy with initial improvement, the dangers of policy attrition and the need for continued reinforcement.