Deletion of adipocyte Sine Oculis Homeobox Homolog 1 prevents lipolysis and attenuates skin fibrosis.

Background: The cardinal feature of systemic sclerosis (SSc) is skin thickening and tightening. Targetable mechanisms for skin features remain elusive. Drugs successful in treating internal organ manifestations have failed efficacy in skin. Dermal white adipose tissue (DWAT) is amongst the understudied contributors to skin manifestations. This study proposes the role of sine oculis homeobox homolog 1 (SIX1), a gene previously unrecognized as a contributor to dermal lipoatrophy characteristic of early skin fibrosis in SSc. Methods: Skin gene expression of SIX1 was analyzed in the GENISOS and PRESS SSc cohorts. Correlation analysis was performed with Spearman rank analysis. Novel mouse models were developed using the Cre-loxp system to knock out Six1 in all cells and mature adipocytes. Subcutaneous bleomycin was used to model early DWAT atrophy and dermal fibrosis characteristic of SSc. Findings: SIX1 was upregulated in SSc skin, the expression of which correlates with adipose-associated genes and molecular pathways. Genetic deletion of Six1 in all cells in mice challenged with bleomycin abrogated end-stage fibrotic gene expression and dermal adipocyte shrinkage. Adipocyte specific Six1 deletion was able to attenuate the early increase in skin thickness, a hallmark of experimental skin fibrosis. Further studies revealed a link between elevated SIX1 and increased expression of SERPINE1 and its protein PAI-1 which are known pro-fibrotic mediators. Interpretation: This work identifies SIX1 as an early marker of skin fibrosis in SSc. We also demonstrate a causative role of Six1 in skin fibrosis by promoting adipocyte loss and show that deletion of Six1 in adipocytes has the potential of impacting early disease progression.

Treatment in primary biliary cholangitis: Beyond ursodeoxycholic acid.

Primary biliary cholangitis (PBC) is a rare cholestatic immune-mediated liver disease. The clinical course varies from mild to severe, with a substantial group of patients developing cirrhosis within a decade. These patients are at risk of hepatocellular carcinoma, decompensation and liver failure. First line Ursodeoxycholic acid (UDCA) treatment improves the cholestatic surrogate markers, and was recently associated with a favorable survival free of liver transplantation, even in case of an incomplete biochemical response. However, despite adequate UDCA therapy, patients remain at risk of liver disease progression. Therefore, on-treatment multifactor-based risk stratification is necessary to identify patients in need of additional therapy. This requires a personalized approach; especially as recent studies suggest that complete biochemical normalization as most stringent response criterion might be preferred in selected patients to optimize their outcome. Today, stricter biochemical goals might actually be reachable with the addition of farnesoid X receptor or peroxisome proliferator-activated receptor agonists, or, in highly-selected cases, use of corticosteroids. Randomized controlled trials showed improvements in the key biochemical surrogate markers with the addition of these drugs, which have also been associated with improved clinical outcome. Considering this evolving PBC landscape, with more versatile treatment options and treatment goals, this review recapitulates the recent insight in UDCA therapy, the selection of patients with a residual risk of liver disease progression and the results of the currently available second line treatment options.

Embedded macrophages induce intravascular coagulation in 3D blood vessel-on-chip.

Macrophages are innate immune cells that prevent infections and help in wound healing and vascular inflammation. While these cells are natural helper cells, they also contribute to chronic diseases, e.g., by infiltrating the endothelial layer in early atherosclerosis and by promoting vascular inflammation. There is a crosstalk between inflammatory pathways and key players in thrombosis, such as platelets and endothelial cells - a phenomenon known as 'thromboinflammation'. The role of the embedded macrophages in thromboinflammation in the context of vascular disease is incompletely understood. Blood vessels-on-chips, which are microfluidic vascular cell culture models, have been used extensively to study aspects of vascular disease, like permeability, immune cell adhesion and thrombosis. Blood perfusion assays in blood vessel-on-chip models benefit from multiple unique aspects of the models, such as control of microvessel structure and well-defined flow patterns, as well as the ability to perform live imaging. However, due to their simplified nature, blood vessels-on-chip models have not yet been used to capture the complex cellular crosstalk that is important in thromboinflammation. Using induced pluripotent stem cell-derived endothelial cells and polarized THP-1 monocytes, we have developed and systematically set up a 3D blood vessel-on-chip with embedded (lipid-laden) macrophages, which is created using sequential cell seeding in viscous finger patterned collagen hydrogels. We have set up a human whole blood perfusion assay for these 3D blood vessels-on-chip. An increased deposition of fibrin in the blood vessel-on-chip models containing lipid-laden macrophages was observed. We anticipate the future use of this advanced vascular in vitro model in drug development for early atherosclerosis or aspects of other vascular diseases.

Citizen involvement in COVID-19 contact tracing with digital tools: a qualitative study to explore citizens' perspectives and needs.

BACKGROUND: Contact tracing (CT) is a key strategy when dealing with outbreaks of infectious diseases such as COVID-19. The scale of the COVID-19 pandemic has often left public health professionals (PHPs), who are responsible for the execution of CT, unable to keep up with the rapid and largescale spread of the virus. To enhance or support its execution, and potentially lower the workload for PHPs, citizens may be more actively involved in CT-tasks that are commonly executed by PHPs (referred to as 'self-led CT'). There is limited insight into citizens' perspectives on and needs for self-led CT for COVID-19. This study aims to explore the perspectives and needs of Dutch citizens on taking more responsibilities in the execution of CT for COVID-19, potentially through the use of digital tools. METHODS: An exploratory qualitative study was performed, in which online semi-structured interviews were conducted. Questions were based on the Reasoned Action Approach and Health Belief Model. Interviews were audio-recorded and transcribed verbatim. A thematic analysis was conducted to identify citizens' perspectives and needs to participate in self-led CT. RESULTS: We conducted 27 interviews with Dutch citizens. Seven main themes were identified from the interviews: 1) 'Citizens' perspectives on self-led CT are influenced by prior experiences with regular CT', 2) 'Citizens' felt responsibilities and the perceived responsibilities of the PHS in CT shape their perspectives on self-led CT', 3) 'Anticipated impacts of self-led CT on the CT-process', 4) 'Citizens' attitude towards the application of self-led CT depends on their own perceived skills and the willingness and skills of others', 5) 'Shame and social stigma may hamper participation in self-led CT', 6) 'Concerns about privacy and data security: a barrier for self-led CT', and 7) 'Citizens' perspectives and anticipated needs for the implementation and application of self-led CT in practice'. CONCLUSIONS: Most interviewees hold a positive attitude towards self-led CT and using digital tools for this purpose. However, their intention for self-led CT may depend on various factors, such as prior experiences with regular CT, and their perceived self-efficacy to participate. Perspectives and needs of citizens should be considered for the future implementation of self-led CT in practice.

The perceived waning of biologics in severe asthma.

BACKGROUND: Biologics are highly effective in severe asthma and used at fixed dosing intervals. However, in clinical practice, dosing intervals are sometimes shortened if patients perceive a decreased biologic effect before the next administration. The occurrence and clinical relevance of this perceived waning of biological effect is unknown. OBJECTIVE: To explore (1) the frequency, severity and conditions, (2) associated symptoms and (3) relationship with clinical characteristics of the patient-perceived waning effect of biologics before the next administration. METHODS: Severe asthma patients receiving biological treatment ≥4 months were included. Based on 17 semi-structured patient interviews, we developed a questionnaire focusing on the waning effect of biologics before the next administration, which was distributed among 129 patients. Clinical characteristics, including asthma control (ACQ) and quality of life (AQLQ) scores, were collected from patient files. RESULTS: 65/101 patients who completed the questionnaire reported a waning of biological effect, graded as severe (median (IQR) 6.5 (5-7.5) on a 0-10 BORG-scale). Waning manifested in a broad spectrum of symptoms. Patients reporting waning had higher ACQ and lower AQLQ scores versus those without (p < 0.05) and higher BORG-scores were associated with higher exacerbation rate (ρ = 0.309, p = 0.013). A third of all patients were in favor of extending or shortening their dosing interval. CONCLUSION: Two-thirds of severe asthma patients report waning of biologic effect at the end of the dosing interval, which is associated with poorer asthma control and quality of life. The diversity in observed waning of effect opens the way for research into more individualized dosing of biologics.

Time-trends in disease characteristics and comorbidities in patients with chronic hepatitis B in the period 1980-2020.

BACKGROUND & AIMS: The incidence of chronic hepatitis B (CHB) is declining due to successful implementation of vaccination programs and widespread use of antiviral therapy. We aimed to study time-trends in disease characteristics and comorbidities in newly referred CHB patients. METHODS: We collected information on hepatitis B virus (HBV) related disease characteristics (including hepatitis B e-antigen (HBeAg) status, viremia, stage of liver fibrosis and indication for treatment and/or hepatocellular carcinoma (HCC) surveillance) and presence of comorbidities in all CHB patients referred to our center from 1980 through 2020. Patient characteristics were compared according to referral date (before 2000, between 2000 and 2010 and after 2010). RESULTS: We identified 1515 eligible patients. Patients referred after 2010 were older (36 versus 34 years, p < 0.001), more often non-Caucasian (82.3% versus 55.0%, p < 0.001) and more frequently HBeAg negative (81.5% versus 49.8%, p < 0.001) when compared to patients referred before 2000. Adjusted for ethnicity, sex and age, patients referred after 2010 were less likely to have significant fibrosis (adjusted odds ratio [aOR]:0.178, p < 0.001) or indication for antiviral therapy (aOR:0.342, p < 0.001) but were more likely to be affected by the metabolic syndrome (aOR:1.985, p = 0.013), hepatic steatosis (aOR:1.727, p < 0.001) and metabolic dysfunction associated fatty liver disease (MAFLD) (aOR:1.438, p = 0.013). CONCLUSIONS: The characteristics of the CHB populations are changing. Newly referred patients are older, have less active HBV related liver disease but are more likely to be co-affected by MAFLD. These findings provide guidance for adequate allocation of resources to cope with the changing characteristics of the CHB population. FUNDING: Foundation for Liver and Gastrointestinal Research Rotterdam, the Netherlands and Gilead Sciences.

Thin endometrial lining: is it more prevalent in patients utilizing preimplantation genetic testing for monogenic disease (PGT-M) and related to prior hormonal contraceptive use?

STUDY QUESTION: Is a thin endometrial lining before ovulation triggering more prevalent in patients utilizing preimplantation genetic testing for monogenic disease (PGT-M) compared to the regular IVF/ICSI population and is this associated with prior hormonal contraceptive use? SUMMARY ANSWER: Thin (<8 mm) endometrial lining is more prevalent in PGT-M patients compared to the regular IVF/ICSI population and is associated with both longer prior hormonal contraceptive use and a shorter cessation interval of hormonal contraceptives before IVF/ICSI treatment. WHAT IS KNOWN ALREADY: Thin endometrial lining has been associated with lower pregnancy rates in IVF/ICSI cycles and increased chances of miscarriage and low birth weight. Endometrial thinning and atrophy occur during hormonal contraceptive use. Patients utilizing PGT-M typically use hormonal contraceptives up until treatment to avoid the risk of conception of a genetically affected child. Whether this could negatively affect endometrial thickness achieved during subsequent IVF/ICSI cycles is not known. STUDY DESIGN, SIZE, DURATION: A retrospective case control study was performed, including all PGT-M patients attending the University Medical Centre Groningen (cases), between 2009 and 2018. The control group consisted of two non-PGT IVF/ICSI patients for each PGT-M patient, matched for age and treatment period. PARTICIPANTS/MATERIALS, SETTING, METHODS: First cycles of 122 PGT-M patients and 240 controls were included. Cessation interval of hormonal contraceptives was categorized as late cessation (cessation <1 year prior to treatment) or early cessation (>1 year prior to treatment). Endometrial thickness was routinely measured on the day of hCG triggering or 1 day prior. The prevalence of an endometrial lining <8 mm was compared between PGT-M patients and controls. Hormonal contraceptive use (both duration and cessation interval) was compared between both groups. Univariable and multivariable regression analyses were performed to identify risk factors for thin endometrial lining. In addition, cycle and pregnancy outcomes were compared within control/PGT-M groups between patients with endometrial lining > or <8 mm. MAIN RESULTS AND THE ROLE OF CHANCE: Thin endometrial lining on the day of hCG triggering was found significantly more often in the PGT-M group, compared to controls: 32% vs 11% (mean difference 21.0%, 95% CI: 11.7, 30.3%). As expected, more patients in the PGT-M group ceased their hormonal contraception late (<1 year): 64% vs 2% in the control group (mean difference 61.9%, 95% CI: 53.0, 70.8%). Average duration of hormonal contraceptive use was 10.6 years in the PGT-M group vs 9.3 years in controls (mean difference 1.3 years, 95% CI: 0.2, 2.3 years). Multivariable logistic regression analysis identified late cessation (OR: 6.0, 95% CI: 1.9-19.2) and duration of prior hormonal contraceptive use (OR per year increase 1.1, 95% CI: 1.0-1.2) as significant independent risk factors for a thin endometrial lining. In relation to outcome, we found a statistically significant increase in miscarriage rate in PGT-M patients with an endometrial lining <8 mm compared to those with an endometrial lining >8 mm (20.0% vs 1.7%, mean difference 18.3%, 95% CI: 2.3, 34.3%). A trend towards lower birth weight and gestation- and gender-adjusted birth weight (z-score) was also found in this group. No statistically significant differences were detected in pregnancy rate, live birth rate, or incidence of preterm delivery or SGA. Within the control group, no statistically significant differences were found in outcomes between patients with an endometrial lining <8 compared to an endometrial lining >8 mm. LIMITATIONS, REASONS FOR CAUTION: The study is retrospective. Various types of hormonal contraceptives were reported which possibly exert different effects on the endometrial lining. In relation to pregnancy outcome measures, numbers were very limited; therefore, no firm conclusions should be drawn. WIDER IMPLICATIONS OF THE FINDINGS: This study provides further insight into the role of prior hormonal contraceptive use as a possible contributor to the occurrence of thin endometrial lining during ART treatment. Future studies should provide more information on its clinical relevance, to determine whether PGT-M patients can be reassured, or should be counselled to stop hormonal contraceptive use and change to an alternative contraceptive method prior to PGT treatment. STUDY FUNDING/COMPETING INTERESTS: No specific funding was used and no conflicts of interests are declared. TRIAL REGISTRATION NUMBER: N/A.

Dutch public health professionals' perspectives and needs regarding citizen involvement in COVID-19 contact tracing through digital support tools: an exploratory qualitative study.

BACKGROUND: Contact tracing (CT) is an important, but resource-intensive tool to control outbreaks of communicable diseases. Under pandemic circumstances, public health services may not have sufficient resources at their disposal to effectively facilitate CT. This may be addressed by giving cases and their contact persons more autonomy and responsibility in the execution of CT by public health professionals, through digital contact tracing support tools (DCTS-tools). However, the application of this approach has not yet been systematically investigated from the perspective of public health practice. Therefore, we investigated public health professionals' perspectives and needs regarding involving cases and contact persons in CT for COVID-19 through DCTS-tools. METHODS: Between October 2020 and February 2021, we conducted online semi-structured interviews (N = 17) with Dutch public health professionals to explore their perspectives and needs regarding the involvement of cases and contact persons in CT for COVID-19 through DCTS-tools, in the contact identification, notification, and monitoring stages of the CT-process. Interviews were audio recorded and transcribed verbatim. A thematic analysis was performed. RESULTS: Four main themes related to Dutch public health professionals' perspectives and needs regarding involving cases and contact persons in CT for COVID-19 through DCTS-tools emerged from the data: 'Distinct characteristics of CT with DCTS-tools'; 'Anticipated benefits and challenges of CT for COVID-19 with DCTS- tools'; 'Circumstances in CT for COVID-19 that permit or constrain the application of DCTS-tools'; and 'Public health professionals' needs regarding the development and application of DCTS-tools for CT'. Public health professionals seem to have a positive attitude towards involving cases and contact persons through DCTS-tools. Public health professionals' (positive) attitudes seem conditional on the circumstances under which CT is performed, and the fulfilment of their needs in the development and application of DCTS-tools. CONCLUSIONS: Dutch public health professionals seem positive towards involving cases and contact persons in CT for COVID-19 through DCTS-tools. Through adequate implementation of DCTS-tools in the CT-process, anticipated challenges can be overcome. Future research should investigate the perspectives and needs of cases and contact persons regarding DCTS-tools, and the application of DCTS-tools in practice.

Comment on "Terahertz pump-probe of liquid water at 12.3 THz" by F. Novelli, C. Hoberg, E. M. Adams, J. M. Klopf and M. Havenith, Phys. Chem. Chem. Phys., 2022, 24, 653-665.

The interpretation of the data presented by Novelli at al. as the nonlinear response of water is questioned.

Cell type-specific changes in transcriptomic profiles of endothelial cells, iPSC-derived neurons and astrocytes cultured on microfluidic chips.

In vitro neuronal models are essential for studying neurological physiology, disease mechanisms and potential treatments. Most in vitro models lack controlled vasculature, despite its necessity in brain physiology and disease. Organ-on-chip models offer microfluidic culture systems with dedicated micro-compartments for neurons and vascular cells. Such multi-cell type organs-on-chips can emulate neurovascular unit (NVU) physiology, however there is a lack of systematic data on how individual cell types are affected by culturing on microfluidic systems versus conventional culture plates. This information can provide perspective on initial findings of studies using organs-on-chip models, and further optimizes these models in terms of cellular maturity and neurovascular physiology. Here, we analysed the transcriptomic profiles of co-cultures of human induced pluripotent stem cell (hiPSC)-derived neurons and rat astrocytes, as well as one-day monocultures of human endothelial cells, cultured on microfluidic chips. For each cell type, large gene expression changes were observed when cultured on microfluidic chips compared to conventional culture plates. Endothelial cells showed decreased cell division, neurons and astrocytes exhibited increased cell adhesion, and neurons showed increased maturity when cultured on a microfluidic chip. Our results demonstrate that culturing NVU cell types on microfluidic chips changes their gene expression profiles, presumably due to distinct surface-to-volume ratios and substrate materials. These findings inform further NVU organ-on-chip model optimization and support their future application in disease studies and drug testing.

Multiplexed blood-brain barrier organ-on-chip.

Organ-on-chip devices are intensively studied in academia and industry due to their high potential in pharmaceutical and biomedical applications. However, most of the existing organ-on-chip models focus on proof of concept of individual functional units without the possibility of testing multiple experimental stimuli in parallel. Here we developed a polydimethylsiloxane (PDMS) multiplexed chip with eight parallel channels branching from a common access port through which all eight channels can be addressed simultaneously without the need for extra pipetting steps thus increasing the reproducibility of the experimental results. At the same time, eight outlets provide individual entry to each channel with the opportunity to create eight different experimental conditions. A multiplexed chip can be assembled as a one-layer device for studying monocultures or as a two-layer device for studying barrier tissue functions. For a two-layer device, a ∼2 µm thick transparent PDMS membrane with 5 µm through-hole pores was fabricated in-house using a soft lithography technique, thereby allowing visual inspection of the cell-culture in real-time. The functionality of the chip was studied by recapitulating the blood-brain barrier. For this, human cerebral microvascular endothelial cells (hCMEC/D3) were cultured in mono- or coculture with human astrocytes. Immunostaining revealed a cellular monolayer with the expression of tight junction ZO-1 and adherence junction VE-cadherin proteins in endothelial cells as well as glial fibrillary acidic protein (GFAP) expression in astrocytes. Furthermore, multiplexed permeability studies of molecule passage through the cellular barrier exhibited expected high permeability coefficients for smaller molecules (4 kDa FITC-dextran) whereas larger molecules (20 kDa) crossed the barrier at a lower rate. With these results, we show that our device can be used as an organ-on-chip model for future multiplexed drug testing.

Modular operation of microfluidic chips for highly parallelized cell culture and liquid dosing via a fluidic circuit board.

Microfluidic systems enable automated and highly parallelized cell culture with low volumes and defined liquid dosing. To achieve this, systems typically integrate all functions into a single, monolithic device as a "one size fits all" solution. However, this approach limits the end users' (re)design flexibility and complicates the addition of new functions to the system. To address this challenge, we propose and demonstrate a modular and standardized plug-and-play fluidic circuit board (FCB) for operating microfluidic building blocks (MFBBs), whereby both the FCB and the MFBBs contain integrated valves. A single FCB can parallelize up to three MFBBs of the same design or operate MFBBs with entirely different architectures. The operation of the MFBBs through the FCB is fully automated and does not incur the cost of an extra external footprint. We use this modular platform to control three microfluidic large-scale integration (mLSI) MFBBs, each of which features 64 microchambers suitable for cell culturing with high spatiotemporal control. We show as a proof of principle that we can culture human umbilical vein endothelial cells (HUVECs) for multiple days in the chambers of this MFBB. Moreover, we also use the same FCB to control an MFBB for liquid dosing with a high dynamic range. Our results demonstrate that MFBBs with different designs can be controlled and combined on a single FCB. Our novel modular approach to operating an automated microfluidic system for parallelized cell culture will enable greater experimental flexibility and facilitate the cooperation of different chips from different labs.

Spin preservation during THz orbital pumping of shallow donors in silicon.

We investigate the spin relaxation under conditions of optical excitation between the Rydberg orbital states of phosphorus donor impurities in silicon. Here we show that the spin relaxation is less than a few percent, even after multiple excitation/relaxation cycles. The observed high level of spin preservation may be useful for readout cycling or in quantum information schemes where coupling of neighbor qubits is via orbital excitation.

Acid solvation versus dissociation at "stardust conditions": Reaction sequence matters.

Chemical reactions at ultralow temperatures are of fundamental importance to primordial molecular evolution as it occurs on icy mantles of dust nanoparticles or on ultracold water clusters in dense interstellar clouds. As we show, studying reactions in a stepwise manner in ultracold helium nanodroplets by mass-selective infrared (IR) spectroscopy provides an avenue to mimic these "stardust conditions" in the laboratory. In our joint experimental/theoretical study, in which we successively add H2O molecules to HCl, we disclose a unique IR fingerprint at 1337 cm-1 that heralds hydronium (H3O+) formation and, thus, acid dissociation generating solvated protons. In stark contrast, no reaction is observed when reversing the sequence by allowing HCl to interact with preformed small embryonic ice-like clusters. Our ab initio simulations demonstrate that not only reaction stoichiometry but also the reaction sequence needs to be explicitly considered to rationalize ultracold chemistry.

Microfabricated tuneable and transferable porous PDMS membranes for Organs-on-Chips.

We present a novel and highly reproducible process to fabricate transferable porous PDMS membranes for PDMS-based Organs-on-Chips (OOCs) using microelectromechanical systems (MEMS) fabrication technologies. Porous PDMS membranes with pore sizes down to 2.0 µm in diameter and a wide porosity range (2-65%) can be fabricated. To overcome issues normally faced when using replica moulding and extend the applicability to most OOCs and improve their scalability and reproducibility, the process includes a sacrificial layer to easily transfer the membranes from a silicon carrier to any PDMS-based OOC. The highly reliable fabrication and transfer method does not need of manual handling to define the pore features (size, distribution), allowing very thin (<10 µm) functional membranes to be transferred at chip level with a high success rate (85%). The viability of cell culturing on the porous membranes was assessed by culturing two different cell types on transferred membranes in two different OOCs. Human umbilical endothelial cells (HUVEC) and MDA-MB-231 (MDA) cells were successfully cultured confirming the viability of cell culturing and the biocompatibility of the membranes. The results demonstrate the potential of controlling the porous membrane features to study cell mechanisms such as transmigrations, monolayer formation, and barrier function. The high control over the membrane characteristics might consequently allow to intentionally trigger or prevent certain cellular responses or mechanisms when studying human physiology and pathology using OOCs.

Graves' disease and celiac disease in a patient with myotonic dystrophy type 2.

We report a patient with progressive proximal muscle weakness in her legs, early-onset cataract and perceptive hearing loss, who was recently diagnosed with myotonic dystrophy type 2 (DM2). She also had two autoimmune disorders in her history, namely Graves' disease and celiac disease. Previous studies have shown a high frequency of autoimmune diseases (21%) in patients with DM2. This is the first report of a patient with DM2 and two autoimmune diseases which both have not yet been described in DM2. The cause of this association might be explained at DNA, mRNA and protein levels, including genetic mutation in flanking genes and the toxic effect of the DM2 mutation on proteins involved in inflammation. This case report widens the spectrum of autoimmune diseases in DM2 and has implications both for clinical practice and for research.

Differential effects of donor-specific HLA antibodies in living versus deceased donor transplant.

The presence of donor-specific anti-HLA antibodies (DSAs) is associated with increased risk of graft failure after kidney transplant. We hypothesized that DSAs against HLA class I, class II, or both classes indicate a different risk for graft loss between deceased and living donor transplant. In this study, we investigated the impact of pretransplant DSAs, by using single antigen bead assays, on long-term graft survival in 3237 deceased and 1487 living donor kidney transplants with a negative complement-dependent crossmatch. In living donor transplants, we found a limited effect on graft survival of DSAs against class I or II antigens after transplant. Class I and II DSAs combined resulted in decreased 10-year graft survival (84% to 75%). In contrast, after deceased donor transplant, patients with class I or class II DSAs had a 10-year graft survival of 59% and 60%, respectively, both significantly lower than the survival for patients without DSAs (76%). The combination of class I and II DSAs resulted in a 10-year survival of 54% in deceased donor transplants. In conclusion, class I and II DSAs are a clear risk factor for graft loss in deceased donor transplants, while in living donor transplants, class I and II DSAs seem to be associated with an increased risk for graft failure, but this could not be assessed due to their low prevalence.

The therapeutic potential of polymersomes loaded with 225Ac evaluated in 2D and 3D in vitro glioma models.

Alpha emitters have great potential in targeted tumour therapy, especially in destroying micrometastases, due to their high linear energy transfer (LET). To prevent toxicity caused by recoiled daughter atoms in healthy tissue, alpha emitters like 225Ac can be encapsulated in polymeric nanocarriers (polymersomes), which are capable of retaining the daughter atoms to a large degree. In the translation to a (pre-)clinical setting, it is essential to evaluate their therapeutic potential. As multicellular tumour spheroids mimic a tumour microenvironment more closely than a two-dimensional cellular monolayer, this study has focussed on the interaction of the polymersomes with U87 human glioma spheroids. We have found that polymersomes distribute themselves throughout the spheroid after 4 days which, considering the long half-life of 225Ac (9.9 d) (Vaidyanathan and Zalutsky, 1996), allows for irradiation of the entire spheroid. A decrease in spheroidal growth has been observed upon the addition of only 0.1 kBq 225Ac, an effect which was more pronounced for the 225Ac in polymersomes than when only coupled to DTPA. At higher activities (5 kBq), the spheroids have been found to be destroyed completely after two days. We have thus demonstrated that 225Ac containing polymersomes effectively inhibit tumour spheroid growth, making them very promising candidates for future in vivo testing.