Identification of FasL as a crucial host factor driving COVID-19 pathology and lethality

The dysregulated immune response and inflammation resulting in severe COVID-19 are still incompletely understood. Having recently determined that aberrant death-ligand-induced cell death can cause lethal inflammation, we hypothesized that this process might also cause or contribute to inflammatory disease and lung failure following SARS-CoV-2 infection. To test this hypothesis, we developed a novel mouse-adapted SARS-CoV-2 model (MA20) that recapitulates key pathological features of COVID-19. Concomitantly with occurrence of cell death and inflammation, FasL expression was significantly increased on inflammatory monocytic macrophages and NK cells in the lungs of MA20-infected mice. Importantly, therapeutic FasL inhibition markedly increased survival of both, young and old MA20-infected mice coincident with substantially reduced cell death and inflammation in their lungs. Intriguingly, FasL was also increased in the bronchoalveolar lavage fluid of critically-ill COVID-19 patients. Together, these results identify FasL as a crucial host factor driving the immuno-pathology that underlies COVID-19 severity and lethality, and imply that patients with severe COVID-19 may significantly benefit from therapeutic inhibition of FasL.

The predictive value of comorbidities on postoperative complication rates and overall survival in left-sided oncological colorectal resections: a multicentre cohort study

INTRODUCTION

Surgical- and nonsurgical complications significantly worsen postoperative outcomes, and identification of patients at risk is crucial to improve care. This study investigated whether comorbidities, graded by the Charlson Comorbidity Index (CCI), impact complication rates and impair long-term outcome in a cohort of left-sided colorectal resections.

METHODS

Retrospective analysis of patients undergoing oncological left-sided colorectal resections due to colorectal cancer between 01/2015 and 12/2020 in two referral centers in Austria using electronic medical records and national statistical bureau survival data. Patients with recurrent disease, peritoneal carcinomatosis, and emergency surgeries were excluded. Comorbidities were assessed using the CCI, and complication severity was defined by the Clavien-Dindo classification (CDC). Logistic regression analysis was performed to identify factors influencing the risk for postoperative complications, and overall survival was assessed using data from the national statistics bureau.

RESULTS

A total of 471 patients were analyzed. Multinominal logistic regression analysis identified a CCI greater than or equal to 6 ( P =0.049; OR 1.59, 95% CI: 1.10-2.54) and male sex ( P =0.022; OR 1.47, 95% CI: 1.21-2.98) as independent risk factors for major complications. While patients with a high CCI had the worst postoperative survival rates, perioperative complications only impacted on overall survival in patients with low CCIs, but not in patients with high CCIs.

CONCLUSION

Although a high CCI is a risk factor for major postoperative complications, the presence of comorbidities should not result in withholding surgery.

Back to normal? The health care situation of home care receivers across Europe during the COVID-19 pandemic and its implications on health

The COVID-19 pandemic began impacting Europe in early 2020, posing significant challenges for individuals requiring care. This group is particularly susceptible to severe COVID-19 infections and depends on regular health care services. In this article, we examine the situation of European care recipients aged 50 years and older 18 months after the pandemic outbreak and compare it to the initial phase of the pandemic. In the descriptive section, we illustrate the development of (unmet) care needs and access to health care throughout the pandemic. Additionally, we explore regional variations in health care receipt across Europe. In the analytical section, we shed light on the mid- and long-term health consequences of COVID-19-related restrictions on accessing health care services by making comparisons between care recipients and individuals without care needs. We conducted an analysis using data from the representative Corona Surveys of the Survey of Health, Ageing and Retirement in Europe (SHARE). Our study examines changes in approximately 3,400 care-dependent older Europeans (aged 50+) interviewed in 2020 and 2021, comparing them with more than 45,000 respondents not receiving care. The dataset provides a cross-national perspective on care recipients across 27 European countries and Israel. Our findings reveal that in 2021, compared to the previous year, difficulties in obtaining personal care from someone outside the household were significantly reduced in Western and Southern European countries. Access to health care services improved over the course of the pandemic, particularly with respect to medical treatments and appointments that had been canceled by health care institutions. However, even 18 months after the COVID-19 outbreak, a considerable number of treatments had been postponed either by respondents themselves or by health care institutions. These delayed medical treatments had adverse effects on the physical and mental health of both care receivers and individuals who did not rely on care.

Meeting actual benchmarks for short- and long-term outcomes after cytoreductive surgery for peritoneal surface malignancy at a newly established academic treatment center

BACKGROUND

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy is a curative treatment for selected patients with peritoneal surface malignancy. Reaching actual outcomes benchmarks is challenging given the complex nature of peritoneal surface malignancy surgery. The aim of this study was to assess how the benchmarks for morbidity and oncologic outcome can be reached at a newly established program for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

METHODS

Building on existing institutional experience in complex abdominal surgery and interdisciplinary ovarian cancer treatment, a peritoneal surface malignancy center for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy was established at the Medical University of Vienna using a structured mentoring process. This is a retrospective analysis of the first 100 consecutive patients. Morbidity and mortality were assessed using the Clavien-Dindo classification, and oncologic outcomes using overall survival.

RESULTS

Major morbidity and mortality were 26% and 3%, and median overall survival was 49.0 months. In patients with colorectal peritoneal metastases, the median overall survival was 35.1 months (all colorectal peritoneal metastases patients) and 48.8 months in the subgroup with Peritoneal Surface Disease Severity Score ≤3. No median overall survival could be calculated in patients with low-grade appendiceal mucinous neoplasms, appendiceal adenocarcinoma, or peritoneal mesothelioma due to >50% of patients being alive at the end of follow-up.

CONCLUSION

We show that the current morbidity and oncological outcomes benchmarks can be reached within the first 100 cases of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy at a newly established peritoneal surface malignancy center. Previous institutional experience in complex abdominal surgery and a structured mentoring process are key factors in achieving this goal.

Evaluation of Intestinal Fibrosis with 68Ga-FAPI PET/MR Enterography in Crohn Disease

Background In Crohn disease, differentiation between active intestinal inflammation and fibrosis has implications for treatment, but current imaging modalities are not reliably accurate. Purpose To evaluate the predictive value of gallium 68 (68Ga)-labeled fibroblast activation protein inhibitor (FAPI) PET/MR enterography for the assessment of bowel wall fibrosis in Crohn disease. Materials and Methods In this prospective single-center study, consecutive participants with Crohn disease and obstructive symptoms underwent preoperative 68Ga-FAPI PET/MR enterography from May 2021 to January 2022. Histopathologic analysis of resected bowel segments was performed to grade active inflammation (A0-A2) and fibrosis (F0-F2), which served as the reference standard. The fibroblast activation protein (FAP) expression in bowel wall layers was analyzed immunohistochemically for each layer. 68Ga-FAPI-derived maximum standardized uptake value (SUVmax) was compared with histopathologic results by using mixed-model analysis of variance and Bonferroni-corrected post hoc tests. Results In 14 participants (mean age, 45 years ± 9 [SD]; 10 men), fibrosis was diagnosed histopathologically in 28 of 51 bowel segments (grade F1, n = 14; grade F2, n = 14). Mean SUVmax was higher in segments with fibrosis than without (7.6 vs 2.0; P < .001). In severe fibrosis, mean SUVmax was higher than in mild to moderate fibrosis (8.9 ± 0.9 vs 6.2 ± 0.9; P = .045). Bowel segments with isolated active inflammation had lower mean 68Ga-FAPI uptake than segments with combined active inflammation and fibrosis (SUVmax, 3.2 ± 0.4 vs 8.1 ± 0.1; P = .005). With an SUVmax cutoff value of 3.5, the area under the receiver operating characteristic curve for the prediction of fibrosis was 0.94 (95% CI: 0.9, 1.0), with sensitivity of 26 of 28 segments (93%) and specificity of five of six segments (83%). 68Ga-FAPI-derived SUVmax correlated with FAP expression across all bowel layers (R2 = 0.50, P < .001). Conclusion Higher gallium 68 fibroblast activation protein inhibitor uptake at PET/MR enterography was associated with histopathologically assessed bowel wall fibrosis in participants with Crohn disease, suggesting diagnostic potential for treatment decisions. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by O'Shea in this issue.

Mimicking tumor cell heterogeneity of colorectal cancer in a patient-derived organoid-fibroblast model

BACKGROUND & AIMS

Patient-derived organoid cancer models are generated from epithelial tumor cells and reflect tumor characteristics. However, they lack the complexity of the tumor microenvironment, which is a key driver of tumorigenesis and therapy response. Here, we developed a colorectal cancer organoid model that incorporates matched epithelial cells and stromal fibroblasts.

METHODS

Primary fibroblasts and tumor cells were isolated from colorectal cancer specimens. Fibroblasts were characterized for their proteome, secretome and gene expression signatures. Fibroblast/organoid co-cultures were analyzed by immunohistochemistry and compared to their tissue of origin, as well as on gene expression levels compared to standard organoid models. Bioinformatics deconvolution was used to calculate cellular proportions of cell subsets in organoids based on single cell RNA sequencing data.

RESULTS

Normal primary fibroblasts, isolated from tumor adjacent tissue, and cancer associated fibroblasts retained their molecular characteristics in vitro including higher motility of cancer associated compared to normal fibroblasts. Importantly, both CAFs and NFs supported cancer cell proliferation in 3D co-cultures, without the addition of classical niche factors. Organoids grown together with fibroblasts displayed a larger cellular heterogeneity of tumor cells compared to mono-cultures, and closely resembled the in vivo tumor morphology. Additionally, we observed a mutual crosstalk between tumor cells and fibroblasts in the co-cultures. This was manifested by considerably deregulated pathways such as cell-cell communication and extracellular matrix remodeling in the organoids. Thrombospondin-1 was identified as a critical factor for fibroblast invasiveness.

CONCLUSION

We developed a physiological tumor/stroma model, which will be vital as a personalized tumor model to study disease mechanisms and therapy response in CRC.

Impacts of Telomeric Length, Chronic Hypoxia, Senescence, and Senescence-Associated Secretory Phenotype on the Development of Thoracic Aortic Aneurysm

Thoracic aortic aneurysm (TAA) is an age-related and life-threatening vascular disease. Telomere shortening is a predictor of age-related diseases, and its progression is associated with premature vascular disease. The aim of the present work was to investigate the impacts of chronic hypoxia and telomeric DNA damage on cellular homeostasis and vascular degeneration of TAA. We analyzed healthy and aortic aneurysm specimens (215 samples) for telomere length (TL), chronic DNA damage, and resulting changes in cellular homeostasis, focusing on senescence and apoptosis. Compared with healthy thoracic aorta (HTA), patients with tricuspid aortic valve (TAV) showed telomere shortening with increasing TAA size, in contrast to genetically predisposed bicuspid aortic valve (BAV). In addition, TL was associated with chronic hypoxia and telomeric DNA damage and with the induction of senescence-associated secretory phenotype (SASP). TAA-TAV specimens showed a significant difference in SASP-marker expression of IL-6, NF-κB, mTOR, and cell-cycle regulators (γH2AX, Rb, p53, p21), compared to HTA and TAA-BAV. Furthermore, we observed an increase in CD163⁺ macrophages and a correlation between hypoxic DNA damage and the number of aortic telocytes. We conclude that chronic hypoxia is associated with telomeric DNA damage and the induction of SASP in a diseased aortic wall, promising a new therapeutic target.

Abstract A011: Epigenetic vulnerabilities in patient-derived colorectal cancer organoids

Colorectal cancer (CRC) is a major cause of cancer-related deaths worldwide. Here, we established human patient-derived colorectal cancer organoid cultures (PDOs) to decipher the patient-specific DNA methylation profile and drug sensitivity towards 5-aza-2’-deoxycytidine, a DNA methyltransferase inhibitor. Organoid lines (n=15) were generated from adjacent normal mucosa and tumor tissue located in different anatomical sites of the colon and rectum. The derived PDOs were characterized on a histopathological level and reproduced the grade and differentiation capacity of their parental tumors. Additional genotypic profiling of PDOs showed a high degree of similarity to the original patient tumors. However, the stability of the DNA methylation landscape of human cancer organoids remains largely unknown. In genome-wide methylation analysis of long-term organoid cultures (up to 6 months in culture), we observed surprisingly stable methylation signatures that recapitulates the patient’s profile whilst demonstrating the vast intertumoral heterogeneity among patients. Strikingly, we identified a tumor-specific methylation signature that consisted of 39 CpG sites, which were unmethylated in normal epithelial cells but highly (91-96%) methylated in all tumor cells analyzed. This signature allows for the estimation of the percentage of tumor content in resected tissues and might represent potent biomarkers for early CRC diagnostics. Notably, it has been demonstrated that PDOs have the potential to predict clinical outcome and response to chemo- and radiation therapy in patients. Herein, drug screening with 5-aza-2’-deoxycytidine revealed heterogeneous responses and a clustering into drug sensitive, median and resistant organoid lines. ATAC- and RNA-seq analyses identified pathways rendering drug sensitivity and resistance. Our findings highlight the utility of PDOs as an advanced model system to study the role of the epigenome, especially DNA methylation, and its impact on tumor burden and vulnerability towards epigenetic modifiers.

Citation Format: Loan Tran, Raheleh Sheibani Tezerji, Carlos Uziel Perez Malla, Anna Malzer, Ajna Logo, Katarina Misura, Theresia Mair, Thomas Dillinger, Madeleine Kuroll, Velina Atanasova, Julijan Kabiljo, Helga Schachner, Katharina Wöran, Judith Stift, Helmut Dolznig, Walter Pulverer, Michael Bergmann, Gerda Egger. Epigenetic vulnerabilities in patient-derived colorectal cancer organoids. [abstract]. In: Proceedings of the AACR Special Conference: Cancer Epigenomics; 2022 Oct 6-8; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_2):Abstract nr A011.

A Novel B7-H6-Targeted IgG-Like T Cell-Engaging Antibody for the Treatment of Gastrointestinal Tumors

PURPOSE

Advanced-stage gastrointestinal cancers represent a high unmet need requiring new effective therapies. We investigated the antitumor activity of a novel T cell-engaging antibody (B7-H6/CD3 ITE) targeting B7-H6, a tumor-associated antigen that is expressed in gastrointestinal tumors.

EXPERIMENTAL DESIGN

Membrane proteomics and IHC analysis identified B7-H6 as a tumor-associated antigen in gastrointestinal tumor tissues with no to very little expression in normal tissues. The antitumor activity and mode of action of B7-H6/CD3 ITE was evaluated in in vitro coculture assays, in humanized mouse tumor models, and in colorectal cancer precision cut tumor slice cultures.

RESULTS

B7-H6 expression was detected in 98% of colorectal cancer, 77% of gastric cancer, and 63% of pancreatic cancer tissue samples. B7-H6/CD3 ITE-mediated redirection of T cells toward B7-H6-positive tumor cells resulted in B7-H6-dependent lysis of tumor cells, activation and proliferation of T cells, and cytokine secretion in in vitro coculture assays, and infiltration of T cells into tumor tissues associated with tumor regression in in vivo colorectal cancer models. In primary patient-derived colorectal cancer precision-cut tumor slice cultures, treatment with B7-H6/CD3 ITE elicited cytokine secretion by endogenous tumor-infiltrating immune cells. Combination with anti-PD-1 further enhanced the activity of the B7-H6/CD3 ITE.

CONCLUSION

These data highlight the potential of the B7-H6/CD3 ITE to induce T cell-redirected lysis of tumor cells and recruitment of T cells into noninflamed tumor tissues, leading to antitumor activity in in vitro, in vivo, and human tumor slice cultures, which supports further evaluation in a clinical study.

The impact of the COVID-19 pandemic on the provision of instrumental help by older people across Europe

The outbreak of the COVID-19 pandemic in early 2020 introduced new challenges to social cohesion across Europe. Epidemiological control measures instituted in almost all European countries have impacted the possibility to provide help to others. In addition, individual characteristics contributed to whether individuals were able and willing to provide help to or receive help from others. Against this background, we focus on how private support networks of individuals aged 50 years and older across Europe were directly or indirectly affected by the COVID-19 pandemic. The focus of the paper is on the supply side. While the older population has been mainly perceived as recipients of instrumental help in the COVID-19 pandemic, the paper examines the patterns of providing instrumental help to others by the older generations and their changes during the pandemic. Has the provision of instrumental help increased or decreased in the course of the COVID-19 crisis? Have the groups of recipients changed during the pandemic? What were key determinants for helping others in 2021 as compared to the first phase of the pandemic 1 year before? And how did this differ across countries with different degrees of affectedness by COVID-19? To answer these questions, we analyzed representative data from the Survey of Health, Aging and Retirement in Europe (SHARE) and, in particular, the two waves of the SHARE Corona Survey, fielded in 27 European countries and Israel in 2020 and 2021. Results based on data from more than 45,000 respondents aged 50+ showed that help from children to parents has strongly increased in the first phase of the pandemic, while the opposite (parents helping their children) has decreased-especially in countries that have been hit hardest by the pandemic in 2020. This changed with the continuing crisis. Instrumental help provided to non-kin that was common in Western Europe in the first phase of the pandemic, yielding an optimistic view of increasing solidarity after the outbreak of COVID-19, strongly decreased 1 year later. Our findings provide a contribution to comparative research on micro- and macro-determinants that are crucial for the understanding of intergenerational support in times of crisis.

Impact of atrial flow regulator implantation on survival in patients with heart failure with reduced and preserved ejection fraction: a post-hoc analysis of the PRELIEVE study

Purpose

This analysis aims to assess the theoretical impact of atrial flow regulator implantation on mortality by comparing the observed survival rate with the median predicted probability for one-year survival.

Methods

The prospective, multicentre, open-label, non-randomised PRELIEVE study assessed the safety and efficacy of the atrial flow regulator in patients with symptomatic HFrEF (left ventricular ejection fraction (LVEF) ≥15% and &lt;40%) or HFpEF (LVEF ≥40% and &lt;70%) and elevated PCWP (≥15mmHg at rest or ≥25mmHg during exercise). In this analysis, after the first 60 patients completed twelve months of follow-up, the theoretical impact of atrial flow regulator implantation on survival was assessed by comparing the observed mortality rate with the median predicted probability for one-year mortality. Each subject's risk of mortality was predicted from individual baseline data using the Meta-Analysis Global Group in Chronic HF (MAGGIC) prognostic model.

Results

A total of 87 patients had undergone successful device implantation for the treatment of HFrEF (53%) and HFpEF (47%). Sixty patients had a complete twelve-month follow-up. The median follow-up was 351 days (interquartile range [IQR] 202–370). A total of six (7%) patients died during follow-up (8.6 deaths per 100 patient-years; 95% confidence interval [CI] 2.7 to 15.5), all of which had HFrEF. The median predicted mortality rate for the overall study population was 12.2 deaths per 100 patient-years (95% CI 10.2 to 14.7). While the observed mortality rate (0 deaths per 100 patient-years) was significantly lower than the median predicted mortality rate (9.3 deaths per 100 patient-years; 95% CI 8.4 to 11.1) in patients with HFpEF (−9.3 deaths per 100 patient-years; 95% CI −11.1 to −8.4), there was no difference in patients with HFrEF (−3.6 deaths per 100 patient-years; 95% CI −9.5 to 3.0) (Figure 1). Four deaths were HF-related deaths (5.7 HF-related deaths per 100 patient-years; 95% CI 1.4 to 11.9; 10.8 HF-related deaths per 100 patient-years; 95% CI 2.5 to 23.1 in the HFrEF subgroup).

Conclusion

In patients with HFpEF, the mortality rate following atrial flow regulator implantation was lower than the predicted mortality rate. These findings need to be confirmed by larger randomised, controlled trials.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Occlutech International AB

LY6G6D is a selectively expressed colorectal cancer antigen that can be used for targeting a therapeutic T-cell response by a T-cell engager

Colorectal cancer (CRC) is one of the most common cancers worldwide and demands more effective treatments. We sought to identify tumor selective CRC antigens and their therapeutic potential for cytotoxic T-cell targeting by transcriptomic and immunohistochemical analysis. LY6G6D was identified as a tumor selectively expressed CRC antigen, mainly in the microsatellite stable (MSS) subtype. A specific anti LY6G6D/CD3 T cell engager (TcE) was generated and demonstrated potent tumor cell killing and T cell activation in vitro. Ex vivo treatment of primary patient-derived CRC tumor slice cultures with the LY6G6D/CD3 TcE led to IFNγ secretion in LY6G6D positive tumor samples. In vivo, LY6G6D/CD3 TcE monotherapy demonstrated tumor regressions in pre-clinical mouse models of engrafted human CRC tumor cells and PBMCs. Lastly, 2D and 3D cocultures of LY6G6D positive and negative cells were used to explore the bystander killing of LY6G6D negative cells after specific activation of T cells by LY6G6D positive cells. LY6G6D/CD3 TcE treatment was shown to lyse target negative cells in the vicinity of target positive cells through a combined effect of IFNγ, TNFα and Fas/FasL. In summary, LY6G6D was identified as a selectively expressed CRC antigen that can be utilized to potently re-direct and activate cytotoxic T-cells to lyse LY6G6D expressing CRC using a TcE. This effect can be spread to target negative neighboring tumor cells, potentially leading to improved therapeutic efficacy.

Neoadjuvant Immunotherapy in Gastrointestinal Cancers - The New Standard of Care?

The development of immune checkpoint inhibitors (ICI) offers novel treatment possibilities for solid cancers, with the crucial benefit of providing higher cure rates. These agents have become part of standard treatments in the metastatic and adjuvant setting for select cancers, such as melanoma, non-small cell lung cancer (NSCLC) or urological malignancies. Currently, there is ample clinical interest in employing ICI in a neoadjuvant setting with a curative intent. This approach is especially supported by the scientific rationale that ICI primarily stimulate the host immune system to eradicate tumor cells, rather than being inherently cytotoxic. Aside from tumor downstaging, neoadjuvant immunotherapy offers the potential of an in situ cancer vaccination, leading to a systemic adjuvant immunological effect after tumor resection. Moreover, preclinical data clearly demonstrate a synergistic effect of ICI with radiotherapy (RT), chemoradiotherapy (CRT) or chemotherapy (ChT). This review harmonizes preclinical concepts with real world data (RWD) in the field of neoadjuvant ICI in gastrointestinal (GI) cancers and discusses their limitations. We believe this is a crucial approach, since up to now, neoadjuvant strategies have been primarily developed by clinicians, whereas the advances in immunotherapy primarily originate from preclinical research. Currently there is limited published data on neoadjuvant ICI in GI cancers, even though neoadjuvant treatments including RT, CRT or ChT are frequently employed in locally advanced/oligometastatic GI cancers (i.e. rectal, pancreatic, esophagus, stomach, etc.). Utilizing established therapies in combination with ICI provides an abundance of opportunities for innovative treatment regimens to further improve survival rates.

Interim analysis of neoadjuvant chemoradiotherapy with sequential ipilimumab and nivolumab in rectal cancer (CHINOREC): A prospective randomized, open-label, multicenter, phase II clinical trial

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Background: Immune checkpoint inhibitors (ICI) do not seem to be effective in solid cancers, which lack an immunogenic priming. Radiotherapy (RT) can induce an immunogenic cell death (ICD) and thereby restore the susceptibility to ICI, especially in microsatellite stable (MSS) cancers. This study evaluates safety, tolerability and feasibility of neoadjuvant chemoradiotherapy (CRT) with concomitant ipilimumab (IPI) and nivolumab (NIVO) in locally advanced rectal cancer (LARC). Here we present the first requisite interim analysis. Methods: This is a prospective, randomized, open-label, multicenter, phase II investigator- initiated trial (IIT). Key eligibility criteria are patients with LARC and the medical need for a neoadjuvant CRT, without metastatic disease that is considered incurable by local therapies. In total 80 patients will be randomized (ratio 30:50) to receive either neoadjuvant CRT alone (50 Gy in 2 Gy fractions over 25 working days + concurrent capecitabine 1650 mg/m2/d PO) or in combination with a single dose of IPI 1 mg/kg IV at day 7, following 3 cycles of NIVO 3 mg/kg IV Q2W, starting on day 14. Patients undergo surgery within 10-12 weeks post CRT. The primary endpoint is safety of neoadjuvant CRT with sequential IPI and NIVO following surgical resection. Surgical complications are graded by the “Clavien-Dindo Classification” v2.0 and treatment-related adverse events (TRAEs) by the Common Terminology Criteria of Adverse Events (CTCAE) v5.0. Interim analyses for the surgical complication “reoperation” will be assessed after every 10th patient in the IPI/NIVO treatment arm. Reoperation numbers are compared to historically known and published ratios. If the observed case numbers are above the calculated upper 95% confidence interval (95% CIup), the study will be terminated. Results: From 06/2020-02/2022, 36 patients have been accrued, of whom 23 were randomized to the CRT+IPI/NIVO arm. Of these, the first 10 patients who underwent successful surgery were used for the present interim analysis. No patient experienced a surgical complication with the need for a reoperation (3Grade IIIb). Any surgical complication occurred in 8 (80%) patients, with the most common being Grade I (70%) and Grade II (50%) events. Conclusions: The addition of sequentially applied IPI and NIVO to neoadjuvant CRT does not increase the number of surgical reoperation rates. The study meets it’s interim analysis criteria to be safe to continue accrual. Clinical trial information: NCT04124601.

One-year results from the FLXibility post-approval study: final real-world clinical outcomes with a next-generation left atrial appendage closure device

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Boston Scientific Corporation, Marlborough, MA, USA

Background

The WATCHMAN FLX left atrial appendage (LAA) closure device received CE-mark and FDA approval based on the results of the PINNACLE FLX IDE study, but evidence of outcomes with this next-generation device in everyday clinical practise is limited.

Purpose

The FLXibility Post-Approval Study collected real-world data on patients implanted with a WATCHMAN FLX in a routine clinical practise.

Methods

Patients were implanted with a WATCHMAN FLX per local standard of care, with a subsequent first follow-up visit from 45-120 days post-implant and a final follow-up at 1 year post procedure. A Clinical Event Committee adjudicated all major adverse events and TEE/CT imaging results were adjudicated by a core laboratory.

Results

Among 300 patients enrolled at 17 centres in Europe, the mean age was 74.6±8.0 years, mean CHA2DS2-VASc score was 4.3±1.6, mean HAS-BLED score was 2.6±1.0, and 62.1% were male. The device was successfully implanted in 99.0% (297/300) of patients; 97.0% (289/298) required only 1 device for an implantation attempt and no patient required &gt;2 devices. TEE was used for 78% of procedures and ICE for 22%. The post-implant medication regimen was DAPT for 87.3% (262/300). At first follow-up, among 170 patients with evaluable imaging, 87.6% (149/170) had no leak, 12.4% (21/170) had leak &gt;0mm to ≤5mm with 16 (9.4%) of these &lt;3mm, and no patient had leak &gt;5mm, per core lab adjudication. At 1 year, 93.3% (280/300) patients had final follow-up or death. At final follow-up, 61% of patients were on a single antiplatelet medication, 21% were on DAPT, 6% were on a direct oral anticoagulation medication, and 12% were not taking any antiplatelet/anticoagulation medication. One-year all-cause mortality was 10.8% (32/295), among which 5.1% (15/295) were cardiovascular or unexplained. Disabling stroke occurred in 1.0% (3/295) of patients and nondisabling stroke also in 1.0% (3/295) of patients; all were nonfatal. No patient experienced a systemic embolism. Device-related thrombus was detected in 2.4% (7/295) patients. Pericardial effusion requiring surgery or pericardiocentesis occurred in 1.0% (3/295), with all of these events occurring in the first 7 days post-procedure. Cumulative BARC-3 or -5 bleeding occurred in 3.7% (11/300) of patients from 0 to 7 days, in 7.3% (22/300) at 6 months, and in 8.1% (24/295) patients at 1 year. One patient (0.3%) had a peri-procedural device embolisation, with no subsequent device embolisations or any device migration reported for any patient through 1 year.

Conclusions

The WATCHMAN FLX device had excellent procedural success rates, with high effective LAA closure rates and low serious adverse event rates in everyday clinical practise.

Metastatic colorectal carcinoma-associated fibroblasts have immunosuppressive properties related to increased IGFBP2 expression

Fibroblasts are the most abundant stromal constituents of the tumour microenvironment in primary as well as metastatic colorectal cancer (CRC). Their supportive effect on tumour cells is well established. There is growing evidence that stromal fibroblasts also modulate the immune microenvironment in tumours. Here, we demonstrate a difference in fibroblast-mediated immune modulation between primary CRC and peritoneal metastasis. Cancer-associated fibroblasts (CAFs) were isolated from primary cancer and from peritoneal metastases (MAFs) from a total of 17 patients. The ectoenzyme CD38 was consistently expressed on the surface of all MAFs, while it was absent from CAFs. Furthermore, MAFs secreted higher levels of IGFBP2, CXCL2, CXCL6, CXCL12, PDGF-AA, FGFb, and IL-6. This was associated with a decreased activation of macrophages and a suppression of CD25 expression and proliferation of co-cultivated T-cells. Downregulation of IGFBP2 abolished these immunosuppressive effects of MAFs. Taken together, these results show that MAFs contribute to an immunosuppressive tumour microenvironment in CRC metastases by modulating the phenotype of immune cells through an IGFBP2-dependent mechanism.

The Role of Telocytes and Telocyte-Derived Exosomes in the Development of Thoracic Aortic Aneurysm

A hallmark of thoracic aortic aneurysms (TAA) is the degenerative remodeling of aortic wall, which leads to progressive aortic dilatation and resulting in an increased risk for aortic dissection or rupture. Telocytes (TCs), a distinct type of interstitial cells described in many tissues and organs, were recently observed in the aortic wall, and studies showed the potential regulation of smooth muscle cell (SMC) homeostasis by TC-released shed vesicles. The purpose of the present work was to study the functions of TCs in medial degeneration of TAA. During aneurysmal formation an increase of aortic TCs was identified in human surgical specimens of TAA-patients, compared to healthy thoracic aortic (HTA)-tissue. We found the presence of epithelial progenitor cells in the adventitial layer, which showed increased infiltration in TAA samples. For functional analysis, HTA- and TAA-telocytes were isolated, characterized, and compared by their protein levels, mRNA- and miRNA-expression profiles. We detected TC and TC-released exosomes near SMCs. TAA-TC-exosomes showed a significant increase of the SMC-related dedifferentiation markers KLF-4-, VEGF-A-, and PDGF-A-protein levels, as well as miRNA-expression levels of miR-146a, miR-221 and miR-222. SMCs treated with TAA-TC-exosomes developed a dedifferentiation-phenotype. In conclusion, the study shows for the first time that TCs are involved in development of TAA and could play a crucial role in SMC phenotype switching by release of extracellular vesicles.

Intensive care unit occupancy predictions in the COVID-19 pandemic based on age-structured modelling and differential flatness

The COVID-19 pandemic confronts governments and their health systems with great challenges for disease management. In many countries, hospitalization and in particular ICU occupancy is the primary measure for policy makers to decide on possible non-pharmaceutical interventions. In this paper a combined methodology for the prediction of COVID-19 case numbers, case-specific hospitalization and ICU admission rates as well as hospital and ICU occupancies is proposed. To this end, we employ differential flatness to provide estimates of the states of an epidemiological compartmental model and estimates of the unknown exogenous inputs driving its nonlinear dynamics. A main advantage of this method is that it requires the reported infection cases as the only data source. As vaccination rates and case-specific ICU rates are both strongly age-dependent, specifically an age-structured compartmental model is proposed to estimate and predict the spread of the epidemic across different age groups. By utilizing these predictions, case-specific hospitalization and case-specific ICU rates are subsequently estimated using deconvolution techniques. In an analysis of various countries we demonstrate how the methodology is able to produce real-time state estimates and hospital/ICU occupancy predictions for several weeks thus providing a sound basis for policy makers.

Typing of inflammatory lesions of the pituitary

Inflammatory pituitary lesions account for 1.8% of all specimens from the German Pituitary Tumor Registry. They occure in 0.5% of the autoptical specimens and in 2.2% of the surgical cases. Women are significantly more often affected than men and are often younger when first diagnosed. In general, primary and secondary inflammation can be distinguished, with secondary types occurring more frequently (75.1%) than idiopathic inflammatory lesions (15.4%). In primary inflammation, the lymphocytic type is more common (88.5%) than the granulomatous type of hypophysitis (11.5%). The most common causes of secondary inflammation are Rathke's cleft cysts (48.6%), followed by tumors (17.4%) such as the craniopharyngioma (9.1%), adenoma (5.5%) or germinoma (2.0%). More causes are tumor-like lesions (7.1%) such as xanthogranuloma (3.5%) or Langerhans histiocytosis (3.5%), abscesses (5.5%), generalized infections (5.1%), spreaded inflammations (4.7%) and previous surgeries (4.0%). In 1.6% of all specimens the reason for the inflammation remains unclear. The described classification of hypophysitis is important for specific treatment planning after surgery.

Functional Precision Medicine Provides Clinical Benefit in Advanced Aggressive Hematologic Cancers and Identifies Exceptional Responders

Personalized medicine aims to match the right drug with the right patient by using specific features of the individual patient's tumor. However, current strategies of personalized therapy matching provide treatment opportunities for less than 10% of patients with cancer. A promising method may be drug profiling of patient biopsy specimens with single-cell resolution to directly quantify drug effects. We prospectively tested an image-based single-cell functional precision medicine (scFPM) approach to guide treatments in 143 patients with advanced aggressive hematologic cancers. Fifty-six patients (39%) were treated according to scFPM results. At a median follow-up of 23.9 months, 30 patients (54%) demonstrated a clinical benefit of more than 1.3-fold enhanced progression-free survival compared with their previous therapy. Twelve patients (40% of responders) experienced exceptional responses lasting three times longer than expected for their respective disease. We conclude that therapy matching by scFPM is clinically feasible and effective in advanced aggressive hematologic cancers. SIGNIFICANCE: This is the first precision medicine trial using a functional assay to instruct n-of-one therapies in oncology. It illustrates that for patients lacking standard therapies, high-content assay-based scFPM can have a significant value in clinical therapy guidance based on functional dependencies of each patient's cancer.See related commentary by Letai, p. 290.This article is highlighted in the In This Issue feature, p. 275.

Visible blue light inhibits infection and replication of SARS-CoV-2 at doses that are well-tolerated by human respiratory tissue

The delivery of safe, visible wavelengths of light can be an effective, pathogen-agnostic, countermeasure that would expand the current portfolio of SARS-CoV-2 intervention strategies beyond the conventional approaches of vaccine, antibody, and antiviral therapeutics. Employing custom biological light units, that incorporate optically engineered light-emitting diode (LED) arrays, we harnessed monochromatic wavelengths of light for uniform delivery across biological surfaces. We demonstrated that primary 3D human tracheal/bronchial-derived epithelial tissues tolerated high doses of a narrow spectral band of visible light centered at a peak wavelength of 425 nm. We extended these studies to Vero E6 cells to understand how light may influence the viability of a mammalian cell line conventionally used for assaying SARS-CoV-2. The exposure of single-cell monolayers of Vero E6 cells to similar doses of 425 nm blue light resulted in viabilities that were dependent on dose and cell density. Doses of 425 nm blue light that are well-tolerated by Vero E6 cells also inhibited infection and replication of cell-associated SARS-CoV-2 by > 99% 24 h post-infection after a single five-minute light exposure. Moreover, the 425 nm blue light inactivated cell-free betacoronaviruses including SARS-CoV-1, MERS-CoV, and SARS-CoV-2 up to 99.99% in a dose-dependent manner. Importantly, clinically applicable doses of 425 nm blue light dramatically inhibited SARS-CoV-2 infection and replication in primary human 3D tracheal/bronchial tissue. Safe doses of visible light should be considered part of the strategic portfolio for the development of SARS-CoV-2 therapeutic countermeasures to mitigate coronavirus disease 2019 (COVID-19).

Telocytes in the human ascending aorta: Characterization and exosome-related KLF-4/VEGF-A expression

Telocytes (TCs), a novel interstitial cell entity promoting tissue regeneration, have been described in various tissues. Their role in inter‐cellular signalling and tissue remodelling has been reported in almost all human tissues. This study hypothesizes that TC also contributes to tissue remodelling and regeneration of the human thoracic aorta (HTA). The understanding of tissue homeostasis and regenerative potential of the HTA is of high clinical interest as it plays a crucial role in pathogenesis from aortic dilatation to lethal dissection. Therefore, we obtained twenty‐five aortic specimens of heart donors during transplantation. The presence of TCs was detected in different layers of aortic tissue and characterized by immunofluorescence and transmission electron microscopy. Further, we cultivated and isolated TCs in highly differentiated form identified by positive staining for CD34 and c‐kit. Aortic‐derived TC was characterized by the expression of PDGFR‐α, PDGFR‐β, CD29/integrin β‐1 and αSMA and the stem cell markers Nanog and KLF‐4. Moreover, TC exosomes were isolated and characterized for soluble angiogenic factors by Western blot. CD34⁺/c‐kit⁺ TCs shed exosomes containing the soluble factors VEGF‐A, KLF‐4 and PDGF‐A. In summary, TC occurs in the aortic wall. Correspondingly, exosomes, derived from aortic TCs, contain vasculogenesis‐relevant proteins. Understanding the regulation of TC‐mediated aortic remodelling may be a crucial step towards designing strategies to promote aortic repair and prevent adverse remodelling.

Short-course radiotherapy promotes pro-inflammatory macrophages via extracellular vesicles in human rectal cancer

BACKGROUND

Tumor-associated macrophages (TAM) constitute the most abundant immune cells in the tumor stroma initiating pro-inflammatory (M1) or immunosuppressive (M2) responses depending on their polarization status. Advances in tumor immunotherapy call for a detailed understanding of potential immunogenic mechanisms of irradiation routinely applied in rectal cancer patients.

METHODS

To test the effects of radiotherapy on TAM, we ex vivo irradiated tissue samples of human rectal cancer and assessed the phenotype by flow cytometry. We furthermore evaluated the distribution of leucocyte subsets in tissue sections of patients after short-course radiotherapy and compared findings to non-pretreated rectal cancer using an immunostaining approach. Organotypic assays (OTA) consisting of macrophages, cancer-associated fibroblast and cancer cell lines were used to dissect the immunological consequences of irradiation in macrophages.

RESULTS

We demonstrate that short-course neoadjuvant radiotherapy in rectal cancer patients is associated with a shift in the polarization of TAM towards an M1-like pro-inflammatory phenotype. In addition, ex vivo irradiation caused an increase in the phagocytic activity and enhanced expression of markers associated with stimulatory signals necessary for T-cell activation. In OTA we observed that this alteration in macrophage polarization could be mediated by extracellular vesicles (EV) derived from irradiated tumor cells. We identified high mobility group box 1 in EV from irradiated tumor cells as a potential effector signal in that crosstalk.

CONCLUSIONS

Our findings highlight macrophages as potential effector cells upon irradiation in rectal cancer by diminishing their immunosuppressive phenotype and activate pro-inflammation. Our data indicate that clinically applied short-term radiotherapy for rectal cancer may be exploited to stimulate immunogenic macrophages and suggest to target the polarization status of macrophages to enhance future immunotherapeutic strategies.

Estimation of exogenous drivers to predict COVID-19 pandemic using a method from nonlinear control theory

The currently ongoing COVID-19 pandemic confronts governments and their health systems with great challenges for disease management. Epidemiological models play a crucial role, thereby assisting policymakers to predict the future course of infections and hospitalizations. One difficulty with current models is the existence of exogenous and unmeasurable variables and their significant effect on the infection dynamics. In this paper, we show how a method from nonlinear control theory can complement common compartmental epidemiological models. As a result, one can estimate and predict these exogenous variables requiring the reported infection cases as the only data source. The method allows to investigate how the estimates of exogenous variables are influenced by non-pharmaceutical interventions and how imminent epidemic waves could already be predicted at an early stage. In this way, the concept can serve as an "epidemometer" and guide the optimal timing of interventions. Analyses of the COVID-19 epidemic in various countries demonstrate the feasibility and potential of the proposed approach. The generic character of the method allows for straightforward extension to different epidemiological models.

Early Postoperative Basal Insulin Therapy versus Standard of Care for the Prevention of Diabetes Mellitus after Kidney Transplantation: A Multicenter Randomized Trial

BACKGROUND

Post-transplantation diabetes mellitus (PTDM) might be preventable.

METHODS

This open-label, multicenter randomized trial compared 133 kidney transplant recipients given intermediate-acting insulin isophane for postoperative afternoon glucose ≥140 mg/dl with 130 patients given short-acting insulin for fasting glucose ≥200 mg/dl (control). The primary end point was PTDM (antidiabetic treatment or oral glucose tolerance test-derived 2 hour glucose ≥200 mg/dl) at month 12 post-transplant.

RESULTS

In the intention-to-treat population, PTDM rates at 12 months were 12.2% and 14.7% in treatment versus control groups, respectively (odds ratio [OR], 0.82; 95% confidence interval [95% CI], 0.39 to 1.76) and 13.4% versus 17.4%, respectively, at 24 months (OR, 0.71; 95% CI, 0.34 to 1.49). In the per-protocol population, treatment resulted in reduced odds for PTDM at 12 months (OR, 0.40; 95% CI, 0.16 to 1.01) and 24 months (OR, 0.54; 95% CI, 0.24 to 1.20). After adjustment for polycystic kidney disease, per-protocol ORs for PTDM (treatment versus controls) were 0.21 (95% CI, 0.07 to 0.62) at 12 months and 0.35 (95% CI, 0.14 to 0.87) at 24 months. Significantly more hypoglycemic events (mostly asymptomatic or mildly symptomatic) occurred in the treatment group versus the control group. Within the treatment group, nonadherence to the insulin initiation protocol was associated with significantly higher odds for PTDM at months 12 and 24.

CONCLUSIONS

At low overt PTDM incidence, the primary end point in the intention-to-treat population did not differ significantly between treatment and control groups. In the per-protocol analysis, early basal insulin therapy resulted in significantly higher hypoglycemia rates but reduced odds for overt PTDM-a significant reduction after adjustment for baseline differences-suggesting the intervention merits further study.Clinical Trial registration number: NCT03507829.

Stromal fibroblasts shape the myeloid phenotype in normal colon and colorectal cancer and induce CD163 and CCL2 expression in macrophages

Colorectal cancer (CRC) accounts for about 10% of cancer deaths worldwide. Colon carcinogenesis is critically influenced by the tumor microenvironment. Cancer associated fibroblasts (CAFs) and tumor associated macrophages (TAMs) represent the major components of the tumor microenvironment. TAMs promote tumor progression, angiogenesis and tissue remodeling. However, the impact of the molecular crosstalk of tumor cells (TCs) with CAFs and macrophages on monocyte recruitment and their phenotypic conversion is not known in detail so far. In a 3D human organotypic CRC model, we show that CAFs and normal colonic fibroblasts are critically involved in monocyte recruitment and for the establishment of a macrophage phenotype, characterized by high CD163 expression. This is in line with the steady recruitment and differentiation of monocytes to immunosuppressive macrophages in the normal colon. Cytokine profiling revealed that CAFs produce M-CSF, and IL6, IL8, HGF and CCL2 secretion was specifically induced by CAFs in co-cultures with macrophages. Moreover, macrophage/CAF/TCs co-cultures increased TC invasion. We demonstrate that CAFs and macrophages are the major producers of CCL2 and, upon co-culture, increase their CCL2 production twofold and 40-fold, respectively. CAFs and macrophages expressing high CCL2 were also found in vivo in CRC, strongly supporting our findings. CCL2, CCR2, CSF1R and CD163 expression in macrophages was dependent on active MCSFR signaling as shown by M-CSFR inhibition. These results indicate that colon fibroblasts and not TCs are the major cellular component, recruiting and dictating the fate of infiltrated monocytes towards a specific macrophage population, characterized by high CD163 expression and CCL2 production.

The Impact of COVID-19 on Informal Caregiving and Care Receiving Across Europe During the First Phase of the Pandemic

Purpose: We analyzed the effects of COVID-19 as well as its accompanying epidemiological control measures on health-related outcomes (physical and mental health) and unmet care needs of both caregivers and care recipients across Europe and Israel by taking into account country differences. Methods: We applied comparisons of adjusted predictions, controlling for a large set of relevant respondent characteristics, to investigate changes in the physical and mental health of caregivers and care recipients due to COVID-19. Furthermore, multilevel regression models were used to analyze the effect of individual and contextual indicators on the probability of reporting difficulties in receiving care. For the analyses, we used data from 26 countries with 51,983 respondents over 50 years based on the eighth wave of the Survey of Health, Aging and Retirement in Europe (SHARE), which had to be suspended in March 2020, and the SHARE Corona Survey fielded from June to August 2020. Results: During the first phase of the pandemic in spring/summer 2020, the frequency of providing personal care to parents increased in almost all European countries, while care to children, in turn, decreased. Parental caregivers who increased the frequency of providing personal care reported significantly more mental health strains, that is, feeling sad/depressed and anxious/nervous more often since the outbreak of the pandemic. With respect to receiving care, about one out of five care recipients had difficulty in obtaining adequate care from outside the household during the pandemic. The perception of unmet care needs was significantly associated with country differences regarding the duration of the stay-at-home orders. In contrast, the number of confirmed deaths did not have a significant effect on perceiving difficulties related to receiving care. Conclusions: Our findings show the extent of the burden to which caregivers and care recipients were exposed with respect to the unintended consequences of COVID-19-related epidemiological control measures. There is a great need within this population for interventions, which effectively reduce the burden as well as the symptoms of anxiety or depression for caregivers as well as care recipients. This should be recognized by (health) policymakers and social organizations.

Neoadjuvant chemoradiotherapy with sequential ipilimumab and nivolumab in rectal cancer (CHINOREC): A prospective randomized, open-label, multicenter, phase II clinical trial

TPS3623

Background: Immune checkpoint inhibitors (ICI), such as ipilimumab (anti-cytotoxic T-lymphocyte-associated protein 4) or nivolumab (anti-programmed cell death protein 1) have been proven to be an effective strategy in solid cancers. However, ICI seem not to be effective in microsatellite stable (MSS) cancers. As they might lack an immunogenic priming, radiotherapy (RT) is capable to induce an immunogenic cell death (ICD) and subsequently an immunogenic tumor immune microenvironment (TIME). Thus, RT might restore the susceptibility of MSS tumors to ICI and consequently leading to an effective anti-tumor immune response. Methods: This is a prospective, randomized, open-label, multicenter, phase II investigator-initiated clinical trial (IIT), including patients with locally advanced rectal cancer (LARC). Patients receive either neoadjuvant chemoradiotherapy (CRT) alone (50 Gy in 2 Gy fractions over 25 working days + capecitabine 1650 mg/m2/d PO) or in combination with ipilimumab (1 mg/kg IV on day 7) and nivolumab (3 mg/kg IV on day 14, 28 and 42). Patients will undergo surgery within 10-12 weeks post CRT. The primary endpoint is incidence of treatment-emergent adverse events (AEs) assessed by the Clavien-Dindo classification of surgical complications and the common terminology criteria of adverse events (CTCAE). Secondary objectives are radiographic and pathological therapy response. Serial liquid (plasma, serum and peripheral blood mononuclear cells) and tissue biopsies will be taken before, during and after neoadjuvant treatment. Genomic, transcriptomic, epigenomic and proteomic pattern of liquid and tissue biopsies, as well as the immune cell infiltrate of resected specimen, will be correlated with therapy response and clinical outcome. Currently 8 of planned 80 patients have been enrolled. Registration numbers: NCT no. NCT04124601, EudraCT no. 2019-003865-17. Clinical trial information: NCT04124601.

Comparison of four commercially available point-of-care tests to detect antibodies against canine distemper virus in dogs

Pre-vaccination antibody testing to determine dogs' immunity against canine distemper virus (CDV) is increasingly used. Four point-of-care tests (POC A-D) are available in Europe, but their diagnostic accuracy has not been compared. The study evaluated the diagnostic accuracy and usability of these tests. Sera of client-owned dogs (n = 198; healthy n = 22; unhealthy dogs n = 176) and specific pathogen-free (SPF) dogs (n = 40) were included. Virus neutralisation (VN) was performed as the reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy (OA) were determined. McNemar's test was used to determine significant differences between specificity and sensitivity of the tests and Cohen's kappa was used to assess agreement. The prevalence of anti-CDV antibodies by VN was 80% in client-owned dogs overall, with 100% prevalence in healthy dogs, and 0% in SPF dogs. POC-C and POC-D were considered easiest to perform. Specificity of all tests was high using sera from SPF dogs (88-100%). In healthy dogs, sensitivity was variable (45-98%). Specificity was low in all four POC tests when using sera from acutely ill dogs (6-53%) and clinically healthy dogs with chronic disease (5-77%). In client-owned dogs, including healthy and unhealthy dogs, agreement was poor between tests. All POC tests had a low specificity when investigating sera from ill client-owned dogs and usefullness of these tests especially in dogs that are acutely ill or have chronic disease is not supported by this study.

Bodyweight change and cognitive performance in the older population

Preservation of cognitive function is one of the major concerns in contemporary ageing societies. At the same time, overweight and obesity, which have been identified as risk factors for poor health development, have been increasing in many countries all over the world. This study examines the relationship between bodyweight change and cognitive decline in old age and it aims to determine whether and how changes in body mass index (BMI) affect the development of cognitive functioning in old age. Using longitudinal data from the Survey of Health, Ageing and Retirement in Europe (SHARE), covering four waves between 2006 and 2016 with 58,389 participants from 15 countries aged 50+, we estimated asymmetric fixed effects models by gender, adding possible confounding variables such as age, grip strength, health conditions, and physical activity. Additionally, we investigated possible heterogeneity in the BMI-cognition relation. We found a positive association between BMI change and change in cognitive performance, which was dominantly driven by BMI decrease. Weight loss was typically negatively related to cognition, particularly at low levels of BMI and mainly due to health conditions affecting both bodyweight and cognitive performance. Weight gain was, on average, not significantly related to cognitive performance; only respondents with preceding weight loss profited from small increases in BMI. Our analyses provide no support for an “obesity paradox” in cognition, according to which higher weight preserves cognition in old age. The association between weight change and cognitive performance in older age is based on weight changes being related to illness and recovery.

Long-termin vivomonitoring of gliotic sheathing of ultrathin entropic coated brain microprobes with fiber-based optical coherence tomography

Objective.Microfabricated neuroprosthetic devices have made possible important observations on neuron activity; however, long-term high-fidelity recording performance of these devices has yet to be realized. Tissue-device interactions appear to be a primary source of lost recording performance. The current state of the art for visualizing the tissue response surrounding brain implants in animals is immunohistochemistry + confocal microscopy, which is mainly performed after sacrificing the animal. Monitoring the tissue response as it develops could reveal important features of the response which may inform improvements in electrode design.Approach.Optical coherence tomography (OCT), an imaging technique commonly used in ophthalmology, has already been adapted for imaging of brain tissue. Here, we use OCT to achieve real-time,in vivomonitoring of the tissue response surrounding chronically implanted neural devices. The employed tissue-response-provoking implants are coated with a plasma-deposited nanofilm, which has been demonstrated as a biocompatible and anti-inflammatory interface for indwelling devices. We evaluate the method by comparing the OCT results to traditional histology qualitatively and quantitatively.Main results.The differences in OCT signal across the implantation period between the plasma group and the control reveal that the plasma-type coating of otherwise rigid brain probes (glass) only slightly improve the glial encapsulation in the brain parenchyma indicating that geometrical or mechanical influences are dominating the encapsulation process.Significance.Our approach can long-term monitor and compare the tissue-response to chronically-implanted neural probes with and withour plasma coating in living animal models. Our findings provide valuable insigh to the well acknowledged yet not solved challenge.

Surgical Complexity and Outcome During the Implementation Phase of a Robotic Colorectal Surgery Program-A Retrospective Cohort Study

Background

Robotic surgery holds particular promise for complex oncologic colorectal resections, as it can overcome many limitations of the laparoscopic approach. However, similar to the situation in laparoscopic surgery, appropriate case selection (simple vs. complex) with respect to the actual robotic expertise of the team may be a critical determinant of outcome. The present study aimed to analyze the clinical outcome after robotic colorectal surgery over time based on the complexity of the surgical procedure.

Methods

All robotic colorectal resections (n = 85) performed at the Department of Surgery, Medical University of Vienna, between the beginning of the program in April 2015 until December 2019 were retrospectively analyzed. To compare surgical outcome over time, the cohort was divided into 2 time periods based on case sequence (period 1: patients 1–43, period 2: patients 44–85). Cases were assigned a complexity level (I-IV) according to the type of resection, severity of disease, sex and body mass index (BMI). Postoperative complications were classified using the Clavien-Dindo classification.

Results

In total, 47 rectal resections (55.3%), 22 partial colectomies (25.8%), 14 abdomino-perineal resections (16.5%) and 2 proctocolectomies (2.4%) were performed. Of these, 69.4% (n = 59) were oncologic cases. The overall rate of major complications (Clavien Dindo III-V) was 16.5%. Complex cases (complexity levels III and IV) were more often followed by major complications than cases with a low to medium complexity level (I and II; 25.0 vs. 5.4%, p = 0.016). Furthermore, the rate of major complications decreased over time from 25.6% (period 1) to 7.1% (period 2, p = 0.038). Of note, the drop in major complications was associated with a learning effect, which was particularly pronounced in complex cases as well as a reduction of case complexity from 67.5% to 45.2% in the second period (p = 0.039).

Conclusions

The risk of major complications after robotic colorectal surgery increases significantly with escalating case complexity (levels III and IV), particularly during the initial phase of a new colorectal robotic surgery program. Before robotic proficiency has been achieved, it is therefore advisable to limit robotic colorectal resection to cases with complexity levels I and II in order to keep major complication rates at a minimum.

Short- and Long-term Outcome After Interventional VSD Closure: A Single-Center Experience in Pediatric and Adult Patients

Interventional closure of congenital ventricular septal defects (VSD) is recording a continuous rise in acceptance. Complete atrioventricular block (cAVB) and residual shunting are major concerns during follow-up, but long-term data for both are still limited. We retrospectively evaluated the outcome of patients with interventional VSD closure and focused on long-term results (> 1 year follow-up). Transcatheter VSD closures were performed between 1993 and 2015, in 149 patients requiring 155 procedures (104 perimembranous, 29 muscular, 19 residual post-surgical VSDs, and 3 with multiple defects). The following devices were used: 65 × Amplatzer™ Membranous VSD Occluder, 33 × Duct Occluder II, 27 × Muscular VSD Occluder, 3 × Duct Occluder I, 24 × PFM-Nit-Occlud®, and 3 × Rashkind-Occluder. The median age at time of implantation was 6.2 (0.01-66.1) years, median height 117 (49-188) cm, and median weight 20.9 (3.2-117) kg. Median follow-up time was 6.2 (1.1-21.3) years and closure rate was 86.2% at last follow-up. Complications resulting in device explantation include one case of cAVB with a Membranous VSD occluder 7 days after implantation and four cases due to residual shunt/malposition. Six (4%) deaths occurred during follow-up with only one procedural related death from a hybrid VSD closure. Overall, our reported results of interventional VSD closure show favorable outcomes with only one (0.7%) episode of cAVB. Interventional closure offers a good alternative to surgical closure and shows improved performance by using softer devices. However, prospective long-term data in the current era with different devices are still mandatory to assess the effectiveness and safety of this procedure.

Initial and long-term antithrombotic therapy after left atrial appendage closure with the WATCHMAN

Background

Evidence regarding post-procedural antithrombotic regimes other than used in randomized trials assessing percutaneous left atrial appendage (LAA) closure is limited.

Purpose

The present work aimed to compare different antithrombotic strategies applied in the real-world EWOLUTION study.

Methods

A total of 998 patients with successful WATCHMAN implantation at 47 centers were available for the present analysis. The composite ischemic endpoint of stroke, TIA, systemic embolism and device thrombus as well as the bleeding endpoint defined as at least major bleeding according to BARC were assessed during an initial period (from implant until first medication change) and long-term period (from first change until up to 2 years).

Results

The antithrombotic medication chosen in the initial phase was dual antiplatelet therapy (DAPT) in 60%, oral anticoagulation (OAC) in 27%, single antiplatelet therapy (SAPT) in 7% and no medication in 6%. In the long-term phase SAPT was used in 65%, DAPT in 23%, no therapy in 8% and OAC in 4%. No significant differences were found between the groups regarding the ischemic endpoint both in the initial period (Kaplan-Meier estimated rate 2.9% for DAPT vs. 4.3% for OAC vs. 3.9% for SAPT or no therapy; p=0.97) and in the second period (4.2% for SAPT vs. 1.8% for DAPT vs. 3.5% for no therapy; p=0.36). With respect to bleeding events the only difference was found in the initial phase with a higher incidence in patients under SAPT or no therapy (1.0% for DAPT vs. 0.8% for OAC vs. 7.4% for SAPT or no therapy; p=0.01). No differences in bleeding complications were observed during the second period (2.6% for SAPT vs. 2.9% for DAPT vs. 2.2% for no therapy; p=0.88).

Conclusions

Tailored antithrombotic treatment using even very reduced strategies such as SAPT or no therapy showed no significant differences regarding ischemic complications after LAA closure.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Boston Scientific

Determinants of Physical Activity and Sedentary Behavior in German Elementary School Physical Education Lessons

Physical activity (PA) in school physical education (PE) is a signature component of health promotion and health education. The study's aim was to explore PA levels and sedentary time in German elementary school PE lessons and relate them to selected personal and environmental PA determinants. Accelerometer measurements were collected from 328 students (47% male, mean age 8.7 ± 1.2 years) in 11 elementary schools in Baden-Wuerttemberg (Germany). PA levels and sedentary time were analyzed regarding gender, grade, body mass index, selected correlates of active living and health behaviors, as well as the PE teachers' PE education status. In line with previous research, the analyses of PA levels and sedentary time confirm gender and grade differences and highlight older girls as the less active group. Deviant weight status and parents' PA levels were found to be important determinants for PA levels and sedentary time of girls and offer starting points for intervention studies as well as gender-appropriate PE in elementary schools. Specialist PE teacher status proved to be a negative determinant of PA levels and sedentary time for boys and girls and should be investigated in further studies, especially regarding the didactic and methodological background.

Testicular immune cell populations and macrophage polarisation in adult male mice and the influence of altered activin A levels

Detailed morphological characterization of testicular leukocytes in the adult CX₃CR₁^gfp/+ transgenic mouse identified two distinct CX₃CR₁⁺ mononuclear phagocyte (macrophage and dendritic cell) populations: stellate/dendriform cells opposed to the seminiferous tubules (peritubular), and polygonal cells associated with Leydig cells (interstitial). Using confocal microscopy combined with stereological enumeration of CX₃CR₁^gfp/+ cells established that there were twice as many interstitial cells (68%) as peritubular cells (32%). Flow cytometric analyses of interstitial cells from mechanically-dissociated testes identified multiple mononuclear phagocyte subsets based on surface marker expression (CX₃CR₁, F4/80, CD11c). These cells comprised 80% of total intratesticular leukocytes, as identified by CD45 expression. The remaining leukocytes were CD3⁺ (T lymphocytes) and NK1.1⁺ (natural killer cells). Functional phenotype assessment using CD206 (an anti-inflammatory/M2 marker) and MHC class II (an activation marker) identified a potentially tolerogenic CD206⁺MHCII⁺ sub-population (12% of total CD45⁺ cells). Rare testicular subsets of CX₃CR₁⁺CD11c⁺F4/80⁺ (4.3%) mononuclear phagocytes and CD3⁺NK1.1⁺ (3.1%) lymphocytes were also identified for the first time. In order to examine the potential for the immunoregulatory cytokine, activin A to modulate testicular immune cell populations, testes from adult mice with reduced activin A (Inhba^+/-) or elevated activin A (Inha^+/-) were assessed using flow cytometry. Although the proportion of F4/80⁺CD11b⁺ leukocytes (macrophages) was not affected, the frequency of CD206⁺MHCII⁺cells was significantly lower and CD206⁺MHCII^- correspondingly higher in Inha^+/- testes. This shift in expression of MHCII in CD206⁺ macrophages indicates that changes in circulating and/or local activin A influence resident macrophage activation and phenotype and, therefore, the immunological environment of the testis.

From threat to cure: understanding of virus-induced cell death leads to highly immunogenic oncolytic influenza viruses

Oncolytic viruses constitute an emerging strategy in immunomodulatory cancer treatment. The first oncolytic virus, Talimogene laherparepvec (T-VEC), based on herpes simplex virus 1 (HSV-1), was approved by the Food and Drug Administration (FDA) and European Medicines Agency (EMA) in 2015. The field of oncolytic virotherapy is still in its beginnings, since many promising viruses remain only superficially explored. Influenza A virus causes a highly immunogenic acute infection but never leads to a chronic disease. While oncolytic influenza A viruses are in preclinical development, they have not made the transition into clinical practice yet. Recent insights into different types of cell death caused by influenza A virus infection illuminate novel possibilities of enhancing its therapeutic effect. Genetic engineering and experience in influenza A virus vaccine development allow safe application of the virus in patients. In this review we give a summary of efforts undertaken to develop oncolytic influenza A viruses. We discuss strategies for targeting viral replication to cancerous lesions and arming them with immunogenic transgenes. We furthermore describe which modes of cell death are induced by influenza A virus infection and how these insights may be utilized to optimize influenza A virus-based oncolytic virus design.

P534Central sleep apnea in pacing-induced cardiomyopathy: prevalence, improvement by upgrading to cardiac resynchronisation therapy and impact on structural responder rates and long-term outcome

Funding Acknowledgements

ÖNB Jubiläumsfondsprojekt Nr. 15974, ISR grant by Boston Scientific, St. Paul, MN, USA

Background

Central sleep apnea (CSA) in pacing induced cardiomyopathy (PICM) is poorly studied. Specifically, it is unknown whether upgrading from right ventricular pacing (RVP) to cardiac resynchronisation therapy (CRT) improves CSA.

Methods

Fifty-three patients with impaired left ventricular ejection fraction, frequent right ventricular pacing due to high-grade atrioventricular block and heart failure symptoms despite optimal medical therapy underwent upgrading to CRT. Within one month after left ventricular lead implantation (but still not activated), sleep apnea was assessed in all participants by single-night polysomnography (PSG). Nineteen patients with moderate or severe CSA defined by an apnea hypopnea index (AHI) &gt; 15 events per hour were re-scheduled for a follow up PSG 3-5 months after initiation of cardiac resynchronization therapy. Of this cohort, thirteen patients with stable mild heart failure agreed to be randomized to CRT versus RVP in a cross-over design.

Results

CSA (AHI &gt; 5 events per hour) was diagnosed in 26 (49.1%), OSA in 16 (30.2%) patients suffering from PICM . Eleven (20.8%) patients did not have any form of sleep apnea. Moderate to severe CSA (AHI &gt; 15 events per hour) was significantly improved (without specific CPAP therapy) by 102 (96-172) days of CRT: AHI decreased from 39.4 events per hour at baseline to 21.6 by CRT (p &lt; 0.001). Furthermore, CRT led to a substantial decrease in left ventricular endsystolic volumes: baseline 141 ml (103-155), significant improvement under CRT (102 ml, 65-138; p &lt; 0.001), whereas no effect with ongoing RV-pacing (147 ml, 130-161; p = 0.865). Preexistent CSA did not affect the structural response of CRT (56.5% in patients with CSA, 62.5% of patients with obstructive sleep apnea and 54.5% in patients without sleep apnea; p = 0.901) and had no impact on major adverse cardiac events (p = 0.412) and/or survival (p = 0.623) during long-term follow-up.

Conclusions

CSA is highly prevalent in patients with PICM and is significantly improved by upgrading to CRT. Preexistent CSA does not hamper structural improvement and long-term outcome after upgrading to CRT. Thus, CSA seems to occur as a consequence of PICM, rather than as a pathophysiological mediator.

Abstract Figure.

Crohn's disease: prevalence, MR features, and clinical significance of enteric and colonic sinus tracts

Objectives

Enteric and colonic sinus tracts are inflammatory complications that precede intestinal fistulas in patients with Crohn’s disease (CD). The aim of this study was to retrospectively determine the prevalence, morphologic features, and outcome of sinus tracts using MR imaging.

Methods

A consecutive cohort of 642 patients with known CD, referred for MR enterography or MR enteroclysis (study period 01/2014–09/2019), was evaluated retrospectively for the presence of sinus tracts, their locations, presence and length of coexisting strictures, bowel wall thickness, CDMI score, upstream dilation, and bowel distension. Clinical outcome was assessed using medical records. For metric data, means and standard deviation, as well as one-way ANOVA and Pearson’s correlation coefficient, were calculated.

Results

In 36/642 patients with CD undergoing MRE, 49 sinus tracts (forty in small intestine, nine in left-sided colon) were detected with a prevalence of 6.9% in patients with MR-visible signs of CD (n = 519, overall prevalence of 5.6%). Mean segmental bowel wall thickness was 8.9 mm, and mean CDMI score was 9.3. All sinus tracts were located within a stenotic segment, showing mesenteric orientation within the small bowel and upstream dilation in 13 patients. Of 36 patients, 19 underwent immediate surgery and seven developed clinical progression within the segment containing the sinus tract.

Conclusions

Sinus tracts occur in 6.9% of patients with visible signs of CD. They are located within stenotic, severely thickened bowel segments with high MR inflammation scores. Their detection is clinically important, because they indicate a more aggressive phenotype and, if left untreated, may show severe progression.

Key Points

• Sinus tracts occur in 6.9% of patients with MR-visible signs of Crohn’s disease.

• Sinus tracts are a radiological indicator of early penetrating Crohn’s disease, with a high risk of progression, and require dedicated treatment.

• Sinus tracts can be recognized by characteristic findings and typically occur in stenotic, severely thickened bowel segments with high MR inflammation scores.

Immune-related acute and lymphocytic gastritis in a patient with metastatic melanoma treated with pembrolizumab immunotherapy

Here, we present a case of acute and lymphocytic gastritis related to therapy with pembrolizumab for metastatic melanoma. After an asymptomatic phase with moderate histological inflammation (observed at 9 months of immunotherapy), gastritis became symptomatic and severe on repeated biopsies (13 months after the beginning of pembrolizumab). Symptoms and histological lesions both improved with proton pump inhibitor and steroid therapy, as well as interruption of pembrozulimab. The interest of this case lays in the relative rarity of gastritis over small and large intestinal inflammatory lesions caused by immune checkpoint inhibitors as well as in the features of the inflammatory infiltrate, which may be purely lymphocytic (mainly T-cells, with a prevalence of CD8+ over CD4+ lymphocytes) or mixed lymphocytic and granulocytic, requiring the exclusion of other causes of disease. To our knowledge, only 7 cases of immune-related gastritis have been previously documented in the current literature, of which 4, included the current one, were exclusively associated with pembrozulimab therapy.

Reading Fast, Reading Slow: The Effect of Interviewers' Speed in Reading Introductory Texts on Response Behavior

Guidelines for interviewers frequently include instructions to read question texts exactly as they are worded. Deviations from these guidelines on standardized interviewing might affect the comparability of survey answers and impair the quality of data. This paper contributes to the literature on interviewer behavior by analyzing how interviewers change their reading behavior during fieldwork and whether this behavioral change influences the response behavior of survey respondents. We use item-level paradata from the Survey of Health, Ageing and Retirement in Europe (SHARE) to measure interviewers' reading times and focus our analyses on introductory questions that do not require an immediate response by the respondent. In contrast to prior research, this focus enables us to disentangle the reading times of interviewers from the response times of respondents. Based on fixed effects regression, our results show systematic changes in interviewers' reading times of introductory items: First, reading times significantly decrease over the survey's field period, even after controlling for relevant respondent characteristics and specific aspects of the interview situation. Second, a cross-national comparison, including fourteen European countries plus Israel, reveals that the decrease is uniform in almost all countries, suggesting its generalizability across different cultural contexts. Third, the decrease in reading times influences response behavior to varying degrees. Response behavior is affected if introductions contain relevant information for understanding or fulfilling the required task and especially if the response refers to within-survey requests. On the basis of these findings, we discuss the possible consequences for questionnaire design, interviewer training, and fieldwork monitoring.

Sixth Immunotherapy of Cancer conference (ITOC): advances and perspectives-a meeting report

Immunotherapy has moved to the forefront of cancer treatment, illustrated by the accelerating pace of novel therapy approvals. In this complex environment, scientists rely on cutting edge conferences to stay informed. The Immunotherapy of Cancer (ITOC) conference was established jointly with the Society of the Immunotherapy of Cancer to bring the European researchers together. In its sixth edition, the ITOC conference has recently been held in Vienna, Austria.

Direct EPR detection of atomic nitrogen in an atmospheric nitrogen plasma jet

In this study, an atmospheric nitrogen plasma jet generated by a custom-built micro-plasma device was analyzed at room temperature by continuous wave and pulse EPR spectroscopy in real time. Transiently formed nitrogen atoms were detected without the necessity to use spin-traps or other reagents for their stabilization. In contrast to results from optical emission spectroscopy, only signals from the ⁴S ground state of ¹⁴N and ¹⁵N could be detected. EPR data analysis revealed an isotropic g value of 1.9971 and isotropic hyperfine coupling constants of a(¹⁴N) = (10.47 ± 0.02) MHz and a(¹⁵N) = (14.69 ± 0.02) MHz. Moreover, lifetime and relaxation data could be determined; both are discussed in terms of spectral widths and actual concentrations of the transiently formed nitrogen species within the plasma jet. The data show that the lifetimes of atomic nitrogen and charged particles such as N⁺ must be different, and for the latter below the observation time window of EPR spectroscopy. We demonstrate that the real-time (pulsed) EPR technique is a fast and reliable alternative to detect atomic nitrogen in atmospheric pressure plasma jets. The method may be used for a continuous monitoring of the quality of plasma jets.

Mesenteric granulomas independently predict long-term risk of surgical recurrence in Crohn's disease

AIM

The risk factors that predict surgical recurrence in Crohn's disease (CD) remain controversial. Postoperative anti-tumour necrosis factor (anti-TNF) therapy might lower recurrence rates whilst the presence of mesenteric granulomas has been postulated to increase the risk. We hypothesized that mesenteric granulomas indicate disease severity and might predict the risk of surgical recurrence, irrespective of immunosuppressive therapy.

METHOD

We performed a retrospective review of all consecutive patients undergoing operations for CD between January 2000 and December 2014 at a single tertiary referral centre and assessed the perioperative factors and histological findings at the time of surgery. Surgical recurrence rates and the immunosuppressive regimen were assessed through retrospective chart review and telephone interviews.

RESULTS

A total of 274 patients were eligible for analysis. Median follow-up was 8.54 (5.48-14.42) years. A total of 63 patients (23.0%) underwent surgery for recurrent CD after a median of 4.75 (2.10-7.96) years. In final histology, 35 (12.8%) patients had mesenteric granulomas. TNF inhibitors were administered postoperatively in 104 (38.0%) and thiopurines in 137 (50.0%) patients. In univariate analysis, only the presence of mesenteric granulomas [hazard ratio (HR) 1.95; 95% CI 1.05-3.62; P = 0.035] significantly increased the risk for recurrent surgery while postoperative anti-TNF (HR 0.85; 95% CI 0.49-1.50; P = 0.581) or thiopurine therapy (HR 1.03; 95% CI 0.61-1.73; P = 0.916) did not. In multivariate analysis, only the presence of mesenteric granulomas significantly influenced the risk of surgical recurrence (HR 1.94, 95% CI 1.04-3.60; P = 0.037).

CONCLUSION

Intestinal and mesenteric granulomas should be differentiated in pathology reports, because mesenteric, but not intestinal, granulomas may be associated with an increased risk of surgical recurrence.

Restoration of intestinal continuity after stoma formation for Crohn’s disease in the era of biological therapy

Background

The rate of restoration of intestinal continuity after colonic resection and stoma creation in patients with Crohn’s disease has not been well-documented in the era of biologics. Thus, the incidence of restoration of intestinal continuity since the introduction of biological drugs was assessed.

Methods

Consecutive patients (n = 43) who underwent colonic resection with ileostomy or colostomy formation for Crohn’s disease at a single tertiary referral center between 2002 and 2014 were identified. Data from individual chart review were analyzed retrospectively. Patients were personally contacted for follow-up.

Results

Of the 43 patients 8 (18.4%) had a proctectomy leaving 35 patients (81.4%) with the rectum preserved. Of the 30 patients qualifying for final analysis restoration of bowel continuity was finally achieved in 10 patients (33.3%). Permanent stoma rates were comparable in the group of patients with and without biological therapy after surgery (64.3% vs. 60%). The median follow-up period was 7 years (range 3–15 years). Of the patients 20 suffered from perianal disease involvement (66.7%), which was associated with a higher rate of permanent stoma (n = 16/20, 80%) in contrast to patients without perianal disease (n = 4/10, 40%, p = 0.045).

Conclusion

The overall incidence of stoma formation was low for patients with Crohn’s disease; however, once a stoma is created the chance of ending up with a permanent stoma is high even in the era of biologics. Despite the use of new therapeutic agents perianal disease increases the risk of a permanent stoma.

Enhanced Protein Immobilization on Polymers-A Plasma Surface Activation Study

Over the last years, polymers have gained great attention as substrate material, because of the possibility to produce low-cost sensors in a high-throughput manner or for rapid prototyping and the wide variety of polymeric materials available with different features (like transparency, flexibility, stretchability, etc.). For almost all biosensing applications, the interaction between biomolecules (for example, antibodies, proteins or enzymes) and the employed substrate surface is highly important. In order to realize an effective biomolecule immobilization on polymers, different surface activation techniques, including chemical and physical methods, exist. Among them, plasma treatment offers an easy, fast and effective activation of the surfaces by micro/nanotexturing and generating functional groups (including carboxylic acids, amines, esters, aldehydes or hydroxyl groups). Hence, here we present a systematic and comprehensive plasma activation study of various polymeric surfaces by optimizing different parameters, including power, time, substrate temperature and gas composition. Thereby, the highest immobilization efficiency along with a homogenous biomolecule distribution is achieved with a 5-min plasma treatment under a gas composition of 50% oxygen and nitrogen, at a power of 1000 W and a substrate temperature of 80 °C. These results are also confirmed by different surface characterization methods, including SEM, XPS and contact angle measurements.