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4. A Versatile Low-Complexity Feedback Scheme for FDD Systems via Generative Modeling

Author

Turan, Nurettin, Fesl, Benedikt, Koller, Michael, Joham, Michael, and Utschick, Wolfgang

Subjects
Computer Science - Information Theory, Electrical Engineering and Systems Science - Signal Processing
Abstract

In this work, we propose a versatile feedback scheme which can be deployed for both single- and multi-user multiple-input multiple-output (MIMO) frequency division duplex (FDD) systems. Particularly, we propose to use a Gaussian mixture model (GMM) with a reduced number of parameters for codebook construction, feedback encoding, and precoder design. The GMM is fitted offline at the base station (BS) to uplink (UL) training samples to approximate the channel distribution of all possible mobile terminals (MTs) located inside the BS cell. Afterwards, a codebook is constructed, where each codebook entry is based on one GMM component. By extracting directional information of the constructed codebook, the proposed GMM-based feedback approach allows to jointly design the precoders of a multi-user MIMO (MU-MIMO) system using common precoding algorithms. Alternatively, the GMM's sample generation ability can be utilized to design the precoders using a state-of-the-art stochastic iterative algorithm. After offloading the GMM to the MTs, they determine their feedback simply as the index of the GMM component with the highest responsibility for their received pilot signal. This strategy exhibits low complexity and allows for parallelization. Simulation results show that the proposed approach outperforms conventional methods, especially for a reduced number of pilots., Comment: arXiv admin note: text overlap with arXiv:2205.12002

Published
2023

5. On the Mean Square Error Optimal Estimator in One-Bit Quantized Systems

Author

Fesl, Benedikt, Koller, Michael, and Utschick, Wolfgang

Subjects
Computer Science - Information Theory, Electrical Engineering and Systems Science - Signal Processing
Abstract

This paper investigates the mean square error (MSE)-optimal conditional mean estimator (CME) in one-bit quantized systems in the context of channel estimation with jointly Gaussian inputs. We analyze the relationship of the generally nonlinear CME to the linear Bussgang estimator, a well-known method based on Bussgang's theorem. We highlight a novel observation that the Bussgang estimator is equal to the CME for different special cases, including the case of univariate Gaussian inputs and the case of multiple pilot signals in the absence of additive noise prior to the quantization. For the general cases we conduct numerical simulations to quantify the gap between the Bussgang estimator and the CME. This gap increases for higher dimensions and longer pilot sequences. We propose an optimal pilot sequence, motivated by insights from the CME, and derive a novel closed-form expression of the MSE for that case. Afterwards, we find a closed-form limit of the MSE in the asymptotically large number of pilots regime that also holds for the Bussgang estimator. Lastly, we present numerical experiments for various system parameters and for different performance metrics which illuminate the behavior of the optimal channel estimator in the quantized regime. In this context, the well-known stochastic resonance effect that appears in quantized systems can be quantified.

Published
2022
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6. Evaluation of a Gaussian Mixture Model-based Channel Estimator using Measurement Data

Author

Turan, Nurettin, Fesl, Benedikt, Grundei, Moritz, Koller, Michael, and Utschick, Wolfgang

Subjects
Computer Science - Information Theory, Electrical Engineering and Systems Science - Signal Processing
Abstract

In this work, we use real-world data in order to evaluate and validate a machine learning (ML)-based algorithm for physical layer functionalities. Specifically, we apply a recently introduced Gaussian mixture model (GMM)-based algorithm in order to estimate uplink channels stemming from a measurement campaign. For this estimator, there is an initial (offline) training phase, where a GMM is fitted onto given channel (training) data. Thereafter, the fitted GMM is used for (online) channel estimation. Our experiments suggest that the GMM estimator learns the intrinsic characteristics of a given base station's whole radio propagation environment. Essentially, this ambient information is captured due to universal approximation properties of the initially fitted GMM. For a large enough number of GMM components, the GMM estimator was shown to approximate the (unknown) mean squared error (MSE)-optimal channel estimator arbitrarily well. In our experiments, the GMM estimator shows significant performance gains compared to approaches that are not able to capture the ambient information. To validate the claim that ambient information is learnt, we generate synthetic channel data using a state-of-the-art channel simulator and train the GMM estimator once on these and once on the real data, and we apply the estimator once to the synthetic and once to the real data. We then observe how providing suitable ambient information in the training phase beneficially impacts the later channel estimation performance.

Published
2022

7. GMM-based Codebook Construction and Feedback Encoding in FDD Systems

Author

Turan, Nurettin, Koller, Michael, Fesl, Benedikt, Bazzi, Samer, Xu, Wen, and Utschick, Wolfgang

Subjects
Computer Science - Information Theory, Electrical Engineering and Systems Science - Signal Processing
Abstract

We propose a precoder codebook construction and feedback encoding scheme which is based on Gaussian mixture models (GMMs). In an offline phase, the base station (BS) first fits a GMM to uplink (UL) training samples. Thereafter, it designs a codebook in an unsupervised manner by exploiting the GMM's clustering capability. We design one codebook entry per GMM component. After offloading the GMM-but not the codebook-to the mobile terminal (MT) in the online phase, the MT utilizes the GMM to determine the best fitting codebook entry. To this end, no channel estimation is necessary at the MT. Instead, the MT's observed signal is used to evaluate how responsible each component of the GMM is for the signal. The feedback consists of the index of the GMM component with the highest responsibility and the BS then employs the corresponding codebook entry. Simulation results show that the proposed codebook design and feedback encoding scheme outperforms conventional Lloyd clustering based codebook design algorithms, especially in configurations with reduced pilot overhead.

Published
2022

8. Variational Autoencoder Leveraged MMSE Channel Estimation

Author

Baur, Michael, Fesl, Benedikt, Koller, Michael, and Utschick, Wolfgang

Subjects
Electrical Engineering and Systems Science - Signal Processing, Computer Science - Information Theory, Statistics - Machine Learning
Abstract

We propose to utilize a variational autoencoder (VAE) for data-driven channel estimation. The underlying true and unknown channel distribution is modeled by the VAE as a conditional Gaussian distribution in a novel way, parameterized by the respective first and second order conditional moments. As a result, it can be observed that the linear minimum mean square error (LMMSE) estimator in its variant conditioned on the latent sample of the VAE approximates an optimal MSE estimator. Furthermore, we argue how a VAE-based channel estimator can approximate the MMSE channel estimator. We propose three variants of VAE estimators that differ in the data used during training and estimation. First, we show that given perfectly known channel state information at the input of the VAE during estimation, which is impractical, we obtain an estimator that can serve as a benchmark result for an estimation scenario. We then propose practically feasible approaches, where perfectly known channel state information is only necessary in the training phase or is not needed at all. Simulation results on 3GPP and QuaDRiGa channel data attest a small performance loss of the practical approaches and the superiority of our VAE approaches in comparison to other related channel estimation methods., Comment: Accepted for publication at Asilomar 2022

Published
2022
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9. Channel Estimation based on Gaussian Mixture Models with Structured Covariances

Author

Fesl, Benedikt, Joham, Michael, Hu, Sha, Koller, Michael, Turan, Nurettin, and Utschick, Wolfgang

Subjects
Computer Science - Information Theory, Electrical Engineering and Systems Science - Signal Processing
Abstract

In this work, we propose variations of a Gaussian mixture model (GMM) based channel estimator that was recently proven to be asymptotically optimal in the minimum mean square error (MMSE) sense. We account for the need of low computational complexity in the online estimation and low cost for training and storage in practical applications. To this end, we discuss modifications of the underlying expectation-maximization (EM) algorithm, which is needed to fit the parameters of the GMM, to allow for structurally constrained covariances. Further, we investigate splitting the 2D time and frequency estimation problem in wideband systems into cascaded 1D estimations with the help of the GMM. The proposed cascaded GMM approach drastically reduces the complexity and memory requirements. We observe that due to the training on realistic channel data, the proposed GMM estimators seem to inherently perform a trade-off between saving complexity/parameters and estimation performance. We compare these low-complexity approaches to a practical and low cost method that relies on the power delay profile (PDP) and the Doppler spectrum (DS). We argue that, with the training on scenario-specific data from the environment, these practical baselines are outperformed by far with equal estimation complexity.

Published
2022
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10. Improving completion rates of patient-reported outcome measures in cancer clinical trials: Scoping review investigating the implications for trial designs

Author

van der Weijst, Lotte, Machingura, Abigirl, Alanya, Ahu, Lidington, Emma, Velikova, Galina, Flechtner, Hans-Henning, Schmidt, Heike, Lehmann, Jens, Ramage, John K., Ringash, Jolie, Wac, Katarzyna, Oliver, Kathy, Taylor, Katherine J., Wintner, Lisa, Senna, Lúcia P.C., Koller, Michael, Husson, Olga, Bultijnck, Renée, Wilson, Roger, Singer, Susanne, Bjelic-Radisic, Vesna, van der Graaf, Winette T.A., and Pe, Madeline

Published
2024
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11. A harmonized occupational biomonitoring approach

Author

Hopf, Nancy B., Rousselle, Christophe, Poddalgoda, Devika, Lamkarkach, Farida, Bessems, Jos, Schmid, Kaspar, Jones, Kate, Takaki, Koki, Casteleyn, Ludwine, Zare Jeddi, Maryam, Bader, Michael, Koller, Michael, Browne, Patience, FitzGerald, Rex, Viegas, Susana, Göen, Thomas, Santonen, Tiina, Väänänen, Virpi, Duca, Radu - Corneliu, and Pasanen-Kase, Robert

Published
2024
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14. An Asymptotically MSE-Optimal Estimator based on Gaussian Mixture Models

Author

Koller, Michael, Fesl, Benedikt, Turan, Nurettin, and Utschick, Wolfgang

Subjects
Electrical Engineering and Systems Science - Signal Processing
Abstract

This paper investigates a channel estimator based on Gaussian mixture models (GMMs) in the context of linear inverse problems with additive Gaussian noise. We fit a GMM to given channel samples to obtain an analytic probability density function (PDF) which approximates the true channel PDF. Then, a conditional mean estimator (CME) corresponding to this approximating PDF is computed in closed form and used as an approximation of the optimal CME based on the true channel PDF. This optimal CME cannot be calculated analytically because the true channel PDF is generally unknown. We present mild conditions which allow us to prove the convergence of the GMM-based CME to the optimal CME as the number of GMM components is increased. Additionally, we investigate the estimator's computational complexity and present simplifications based on common model-based insights. Further, we study the estimator's behavior in numerical experiments including multiple-input multiple-output (MIMO) and wideband systems.

Published
2021
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15. An Asymptotically Optimal Approximation of the Conditional Mean Channel Estimator based on Gaussian Mixture Models

Author

Koller, Michael, Fesl, Benedikt, Turan, Nurettin, and Utschick, Wolfgang

Subjects
Computer Science - Information Theory, Electrical Engineering and Systems Science - Signal Processing
Abstract

This paper investigates a channel estimator based on Gaussian mixture models (GMMs). We fit a GMM to given channel samples to obtain an analytic probability density function (PDF) which approximates the true channel PDF. Then, a conditional mean channel estimator corresponding to this approximating PDF is computed in closed form and used as an approximation of the optimal conditional mean estimator based on the true channel PDF. This optimal estimator cannot be calculated analytically because the true channel PDF is generally not available. To motivate the GMM-based estimator, we show that it converges to the optimal conditional mean estimator as the number of GMM components is increased. In numerical experiments, a reasonable number of GMM components already shows promising estimation results.

Published
2021

16. CSI Clustering with Variational Autoencoding

Author

Baur, Michael, Würth, Michael, Koller, Michael, Andrei, Vlad-Costin, and Utschick, Wolfgang

Subjects
Electrical Engineering and Systems Science - Signal Processing, Computer Science - Machine Learning
Abstract

The model order of a wireless channel plays an important role for a variety of applications in communications engineering, e.g., it represents the number of resolvable incident wavefronts with non-negligible power incident from a transmitter to a receiver. Areas such as direction of arrival estimation leverage the model order to analyze the multipath components of channel state information. In this work, we propose to use a variational autoencoder to group unlabeled channel state information with respect to the model order in the variational autoencoder latent space in an unsupervised manner. We validate our approach with simulated 3GPP channel data. Our results suggest that, in order to learn an appropriate clustering, it is crucial to use a more flexible likelihood model for the variational autoencoder decoder than it is usually the case in standard applications.

Published
2021
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17. Irinotecan and temozolomide in combination with dasatinib and rapamycin versus irinotecan and temozolomide for patients with relapsed or refractory neuroblastoma (RIST-rNB-2011): a multicentre, open-label, randomised, controlled, phase 2 trial

Author

Corbacioglu, Selim, Lode, Holger, Ellinger, Susanne, Zeman, Florian, Suttorp, Meinolf, Escherich, Gabriele, Bochennek, Konrad, Gruhn, Bernd, Lang, Peter, Rohde, Marius, Debatin, Klaus Michael, Steinbach, Daniel, Beilken, Andreas, Ladenstein, Ruth, Spachtholz, Rainer, Heiss, Peter, Hellwig, Dirk, Tröger, Anja, Koller, Michael, Menhart, Karin, Riemenschneider, Markus J, Zoubaa, Saida, Kietz, Silke, Jakob, Marcus, Sommer, Gunhild, Heise, Tilman, Hundsdörfer, Patrick, Kühnle, Ingrid, Dilloo, Dagmar, Schönberger, Stefan, Schwabe, Georg, von Luettichau, Irene, Graf, Norbert, Schlegel, Paul-Gerhardt, Frühwald, Michael, Jorch, Norbert, Paulussen, Michael, Schneider, Dominik T, Metzler, Markus, Leipold, Alfred, Nathrath, Michaela, Imschweiler, Thomas, Christiansen, Holger, Schmid, Irene, Crazzolara, Roman, Niktoreh, Naghmeh, Cario, Gunnar, Faber, Joerg, Demmert, Martin, Babor, Florian, Fröhlich, Birgit, Bielack, Stefan, Bernig, Toralf, Greil, Johann, Eggert, Angelika, Simon, Thorsten, and Foell, Juergen

Published
2024
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21. Clinical Characterization of Arrhythmia-Induced Cardiomyopathy in Patients With Tachyarrhythmia and Idiopathic Heart Failure

Author

Schach, Christian, Körtl, Thomas, Zeman, Florian, Luttenberger, Bianca, Mühleck, Franziska, Baum, Paul, Lavall, Daniel, Vosshage, Nicola H., Resch, Markus, Ripfel, Sarah, Meindl, Christine, Ücer, Ekrem, Hamer, Okka W., Baessler, Andrea, Arzt, Michael, Koller, Michael, Sohns, Christian, Maier, Lars S., Wachter, Rolf, and Sossalla, Samuel

Published
2024
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22. Surgical site infections after kidney transplantation are independently associated with graft loss

Author

Amico, Patrizia, Aubert, John-David, Banz, Vanessa, Beckmann, Sonja, Beldi, Guido, Berger, Christoph, Berishvili, Ekaterine, Berzigotti, Annalisa, Binet, Isabelle, Bochud, Pierre-Yves, Branca, Sanda, Bucher, Heiner, Catana, Emmanuelle, Cairoli, Anne, Chalandon, Yves, De Geest, Sabina, De Rougemont, Olivier, De Seigneux, Sophie, Dickenmann, Michael, Dreifuss, Joëlle Lynn, Duchosal, Michel, Fehr, Thomas, Ferrari-Lacraz, Sylvie, Garzoni, Christian, Golshayan, Déla, Goossens, Nicolas, Haidar, Fadi, Halter, Jörg, Heim, Dominik, Hess, Christoph, Hillinger, Sven, Hirsch, Hans H., Hirt, Patricia, Hoessly, Linard, Hofbauer, Günther, Huynh-Do, Uyen, Immer, Franz, Koller, Michael, Laesser, Bettina, Lamoth, Frédéric, Lehmann, Roger, Leichtle, Alexander, Manuel, Oriol, Marti, Hans-Peter, Martinelli, Michele, McLin, Valérie, Mellac, Katell, Merçay, Aurélia, Mettler, Karin, Mueller, Nicolas J., Müller-Arndt, Ulrike, Müllhaupt, Beat, Nägeli, Mirjam, Oldani, Graziano, Pascual, Manuel, Passweg, Jakob, Pazeller, Rosemarie, Posfay-Barbe, Klara, Rick, Juliane, Rosselet, Anne, Rossi, Simona, Rothlin, Silvia, Ruschitzka, Frank, Schachtner, Thomas, Schaub, Stefan, Scherrer, Alexandra, Schnyder, Aurelia, Schuurmans, Macé, Schwab, Simon, Sengstag, Thierry, Simonetta, Federico, Stampf, Susanne, Steiger, Jürg, Stirnimann, Guido, Stürzinger, Ueli, Van Delden, Christian, Venetz, Jean-Pierre, Villard, Jean, Vionnet, Julien, Wick, Madeleine, Wilhelm, Markus, Yerly, Patrick, Schreiber, Peter W., Hoessly, Linard D., Boggian, Katia, Neofytos, Dionysios, van Delden, Christian, Egli, Adrian, Hirzel, Cédric, Schmied, Bruno, Guerke, Lorenz, Matter, Maurice, de Rougemont, Olivier, Bonani, Marco, Sidler, Daniel, and Kuster, Stefan P.

Published
2024
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23. Linking antibiotic resistance gene patterns with advanced faecal pollution assessment and environmental key parameters along 2300 km of the Danube River

Author

Schachner-Groehs, Iris, Koller, Michael, Leopold, Melanie, Kolm, Claudia, Linke, Rita B, Jakwerth, Stefan, Kolarević, Stoimir, Kračun-Kolarević, Margareta, Kandler, Wolfgang, Sulyok, Michael, Vierheilig, Julia, Toumi, Marwene, Farkas, Rózsa, Toth, Erika, Kittinger, Clemens, Zarfel, Gernot, Farnleitner, Andreas H, and Kirschner, A.K.T.

Published
2024
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26. Outcome of Patients Transplanted for C3 Glomerulopathy and Primary Immune Complex-Mediated Membranoproliferative Glomerulonephritis

Author

Amico, Patrizia, Aubert, John-David, Banz, Vanessa, Beckmann, Sonia, Beldi, Guido, Berger, Christoph, Berishvili, Ekaterine, Binet, Isabelle, Bochud, Pierre-Yves, Branca, Sanda, Bucher, Heiner, Catana, Emmanuelle, Chalandon, Yves, De Geest, Sabina, De Seigneux Michael Dickenmann, Sophie, Dreifuss, Joëlle Lynn, Duchosal, Michel, Fehr, Thomas, Ferrari-Lacraz, Sylvie, Garzoni, Christian, Gaudet, Christophe, Golshayan, Déla, Goossens, Nicolas, Halter, Jörg, Heim, Dominik, Hess, Christoph, Hillinger, Sven, Hirsch, Hans H., Hirt, Patricia, Hofbauer, Günther, Huynh-Do, Uyen, Immer, Franz, Koller, Michael, Laager, Mirjam, Laesser, Bettina, Lamoth, Frédéric, Lehmann, Roger, Leichtle, Alexander, Manuel, Oriol, Marti, Hans-Peter, Martinelli, Michele, McLin, Valérie, Mellac, Katell, Mercay, Aurelia, Mettler, Karin, Mueller, Nicolas J., Müller, Antonia, Müller-Arndt, Ulrike, Müllhaupt, Beat, Nägeli, Mirjam, Oldani, Graziano, Pascual, Manuel, Passweg, Jakob, Posfay-Barbe, Klara, Rick, Juliane, Rosselet, Anne, Rossi, Simona, Rothlin, Silvia, Ruschitzka, Frank, Schachtner, Thomas, Schanz, Urs, Schaub, Stefan, Schwab, Simon, Schnyder, Aurelia, Schuurmans, Macé, Sengstag, Thierry, Simonetta, Federico, Steiger, Jürg, Stirniman, Guido, Stürzinger, Ueli, Van Delden, Christian, Venetz, Jean-Pierre, Villard, Jean, Vionnet, Julien, Wick, Madeleine, Wilhlem, Markus, Yerly, Patrick, Halfon, Matthieu, Taffé, Patrick, Bucher, Christian, Haidar, Fadi, Huynh-do, Uyen, Mani, Laila-Yasmin, Wehmeier, Caroline, Fakhouri, Fadi, and Golshayan, Dela

Published
2024
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28. Minimally important differences for interpreting EORTC QLQ-C30 change scores over time: A synthesis across 21 clinical trials involving nine different cancer types

Author

Musoro, Jammbe Z., Coens, Corneel, Sprangers, Mirjam A.G., Brandberg, Yvonne, Groenvold, Mogens, Flechtner, Hans-Henning, Cocks, Kim, Velikova, Galina, Dirven, Linda, Greimel, Elfriede, Singer, Susanne, Pogoda, Katarzyna, Gamper, Eva M., Sodergren, Samantha C., Eggermont, Alexander, Koller, Michael, Reijneveld, Jaap C., Taphoorn, Martin J.B., King, Madeleine T., and Bottomley, Andrew

Published
2023
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30. An international study of clinical, demographic and competence-related determinants of communication with professionals

Author

Arraras, Juan Ignacio, primary, Giesinger, Johannes, additional, Shamieh, Omar, additional, Bahar, Iqbal, additional, Koller, Michael, additional, Bredart, Anne, additional, Costantini, Anna, additional, Greimel, Eva, additional, Sztankay, Monika, additional, Wintner, Lisa M., additional, Sousa, Marina Carreiro, additional, Ishiki, Hiroto, additional, Kontogianni, Meropi, additional, Wolan, Maja, additional, Kikawa, Yuichiro, additional, Lanceley, Anne, additional, Gioulbasanis, Ioannis, additional, Harle, Amelie, additional, Zarandona, Uxue, additional, Kulis, Dagmara, additional, Gašpert, Tihana, additional, and Kuljanic, Karin, additional

Published
2024
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34. The MELD upgrade exception: a successful strategy to optimize access to liver transplantation for patients with high waiting list mortality

Author

Amico, Patrizia, Axel, Andres, Aubert, John-David, Banz, Vanessa, Sonja, Beckmann, Beldi, Guido, Benden, Christian, Berger, Christoph, Binet, Isabelle, Bochud, Pierre-Yves, Branca, Sanda, Bucher, Heiner, Carrel, Thierry, Catana, Emmanuelle, Chalandon, Yves, de Geest, Sabina, de Rougemont, Olivier, Dickenmann, Michael, Dreifuss, Joëlle L., Duchosal, Michel, Fehr, Thomas, Ferrari-Lacraz, Sylvie, Garzoni, Christian, Soccal, Paola G., Gaudet, Christophe, Giostra, Emiliano, Golshayan, Déla, Hadaya, Karine, Halter, Jörg, Hauri, Dimitri, Heim, Dominik, Hess, Christoph, Hillinger, Sven, Hirsch, Hans, Hirt, Patricia, Hofbauer, Günther, Huynh-Do, Uyen, Immer, Franz, Koller, Michael, Laesser, Bettina, Lang, Brian, Lehmann, Roger, Leichtle, Alexander, Lovis, Christian, Manuel, Oriol, Marti, Hans-Peter, Martin, Pierre Y., Martinelli, Michele, Mellac, Katell, Merçay, Aurélia, Mettler, Karin, Meylan, Pascal, Mueller, Nicolas, Müller, Antonia, Müller, Thomas, Müller-Arndt, Ulrike, Müllhaupt, Beat, Nägeli, Mirjam, Pascual, Manuel, Posfay-Barbe, Klara, Rick, Juliane, Rosselet, Anne, Rossi, Simona, Rothlin, Silvia, Ruschitzka, Frank, Schanz, Urs, Schaub, Stefan, Schnyder, Aurelia, Schuurmans, Macé, Simonetta, Federico, Staufer, Katharina, Stampf, Susanne, Steiger, Jürg, Stirniman, Guido, Stürzinger, Ueli, Toso, Christian, Van Delden, Christian, Venetz, Jean-Pierre, Villard, Jean, Vionnet, Julien, Wick, Madeleine, Wilhlem, Markus, Yerly, Patrick, Dirchwolf, Melisa, Becchetti, Chiara, Gschwend, Sarah G., Dutkowski, Philipp, Beyeler, Franziska, Schropp, Jonas, and Dufour, Jean-François

Published
2022
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39. Antibody and T-Cell Response to Bivalent Booster SARS-CoV-2 Vaccines in People With Compromised Immune Function: COVERALL-3 Study.

Author

Amstutz, Alain, Chammartin, Frédérique, Audigé, Annette, Eichenberger, Anna L, Braun, Dominique L, Amico, Patrizia, Stoeckle, Marcel P, Hasse, Barbara, Papadimitriou-Olivgeris, Matthaios, Manuel, Oriol, Bongard, Cédric, Schuurmans, Macé M, Hage, René, Damm, Dominik, Tamm, Michael, Mueller, Nicolas J, Rauch, Andri, Günthard, Huldrych F, Koller, Michael T, and Schönenberger, Christof M

Subjects
SARS-CoV-2, COVID-19 vaccines, BOOSTER vaccines, CLINICAL trial registries, HIV
Abstract

Background Bivalent messenger RNA (mRNA) vaccines, designed to combat emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, incorporate ancestral strains and a new variant. Our study assessed the immune response in previously vaccinated individuals of the Swiss HIV Cohort Study (SHCS) and the Swiss Transplant Cohort Study (STCS) following bivalent mRNA vaccination. Methods Eligible SHCS and STCS participants received approved bivalent mRNA SARS-CoV-2 vaccines (mRNA-1273.214 or BA.1-adapted BNT162b2) within clinical routine. Blood samples were collected at baseline, 4 weeks, 8 weeks, and 6 months postvaccination. We analyzed the proportion of participants with anti-spike protein antibody response ≥1642 units/mL (indicating protection against SARS-CoV-2 infection), and in a subsample T-cell response (including mean concentrations), stratifying results by cohorts and population characteristics. Results In SHCS participants, baseline anti-spike antibody concentrations ≥1642 units/mL were observed in 87% (96/112), reaching nearly 100% at follow-ups. Among STCS participants, 58% (35/60) had baseline antibodies ≥1642 units/mL, increasing to 80% at 6 months. Except for lung transplant recipients, all participants showed a 5-fold increase in geometric mean antibody concentrations at 4 weeks and a reduction by half at 6 months. At baseline, T-cell responses were positive in 96% (26/27) of SHCS participants and 36% (16/45) of STCS participants (moderate increase to 53% at 6 months). Few participants reported SARS-CoV-2 infections, side-effects, or serious adverse events. Conclusions Bivalent mRNA vaccination elicited a robust humoral response in individuals with human immunodeficiency virus (HIV) or solid organ transplants, with delayed responses in lung transplant recipients. Despite a waning effect, antibody levels remained high at 6 months and adverse events were rare. Clinical Trials Registration. NCT04805125. [ABSTRACT FROM AUTHOR]

Published
2024
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40. An international field study for the reliability and validity of the EORTC communication questionnaire EORTC QLQ-COMU26.

Author

Arraras, Juan Ignacio, Giesinger, Johannes, Shamieh, Omar, Bahar, Iqbal, Koller, Michael, Bredart, Anne, Costantini, Anna, Greimel, Eva, Sztankay, Monika, Wintner, Lisa M., de Sousa, Marina Carreiro, Ishiki, Hiroto, Kontogianni, Meropi, Wolan, Maja, Kikawa, Yuichiro, Lanceley, Anne, Gioulbasanis, Ioannis, Harle, Amelie, Zarandona, Uxue, and Kulis, Dagmara

Subjects
PATIENTS' attitudes, CONFIRMATORY factor analysis, TEST validity, MEDICAL personnel, SATISFACTION
Abstract

Background: The EORTC Quality of Life Group has developed a questionnaire to evaluate cancer patients' perception of their communication with healthcare professionals (HCPs): the EORTC QLQ-COMU26. In this study we test the validity and reliability of this novel measure in an international and culturally diverse sample of cancer patients. Methods: Cancer patients completed the following EORTC questionnaires at two time points (before and during treatment): the QLQ-COMU26 (including a debriefing questionnaire), the QLQ-C30, and specific IN-PATSAT32 scales. These data were used to assess: the cross-cultural applicability, acceptability, scale structure, reliability, convergent/divergent validity, known-groups validity, and responsiveness to change of the QLQ-COMU26. Results: Data were collected from 498 patients with various cancer diagnoses in 10 European countries, Japan, Jordan and India (overall 5 cultural regions). At most, only 3% of patients identified an item as confusing and 0.6% as upsetting, which indicates that the questionnaire was clear and did not trigger negative emotional responses. Confirmatory factor analysis and multi-trait scaling confirmed the hypothesised QLQ-COMU26 scale structure comprising six multi-item scales and four single items (RMSEA = 0.025). Reliability was good for all scales (internal consistency > 0.70; test–retest reliability > 0.85). Convergent validity was supported by correlations of ≥ 0.50 with related scales of the IN-PATSAT32 and correlations < 0.30 with unrelated QLQ-C30 scales. Known-groups validity was shown according to sex, education, levels of anxiety and depression, satisfaction with communication, disease stage and treatment intention, professional evaluated, and having a companion during the visit. The QLQ-COMU26 captured changes over time in groups that were defined based on changes in the item of satisfaction with communication. Conclusion: The EORTC QLQ-COMU26 is a reliable and valid measure of patients' perceptions of their communication with HCPs. The EORTC QLQ-COMU26 can be used in daily clinical practice and research and in various cancer patient groups from different cultures. This questionnaire can help to improve communication between patients and healthcare professionals. [ABSTRACT FROM AUTHOR]

Published
2024
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41. Health-Related Quality of Life and Treatment Satisfaction of Patients with Malignant IDH Wild-Type Gliomas and Their Caregivers.

Author

Fischl, Anna, Gerken, Michael, Lindberg-Scharf, Patricia, Haedenkamp, Tareq M., Rosengarth, Katharina, Hillberg, Andrea, Vogelhuber, Martin, Schön, Ingrid, Proescholdt, Martin, Araceli, Tommaso, Koller, Michael, Herrmann, Anne, Kölbl, Oliver, Pukrop, Tobias, Riemenschneider, Markus J., Schmidt, Nils Ole, Klinkhammer-Schalke, Monika, Linker, Ralf, Hau, Peter, and Bumes, Elisabeth

Subjects
PATIENT satisfaction, QUALITY of life, PSYCHOLOGICAL distress, SYMPTOM burden, ISOCITRATE dehydrogenase
Abstract

(1) Background: Clinical aspects like sex, age, Karnofsky Performance Scale (KPS) and psychosocial distress can affect the health-related quality of life (HR-QoL) and treatment satisfaction of patients with malignant isocitrate dehydrogenase wild-type (IDHwt) gliomas and caregivers. (2) Methods: We prospectively investigated the HR-QoL and patient/caregiver treatment satisfaction in a cross-sectional study with univariable and multiple regression analyses. Questionnaires were applied to investigate the HR-QoL (EORTC QLQ-C30, QLQ-BN20) and treatment satisfaction (EORTC PATSAT-C33). (3) Results: A cohort of 61 patients was investigated. A higher KPS was significantly associated with a better HR-QoL regarding the functional scales of the EORTC QLQ-C30 (p < 0.004) and a lower symptom burden regarding the EORTC QLQ-BN20 (p < 0.001). The patient treatment satisfaction was significantly poorer in the patients older than 60 years in the domain of family involvement (p = 0.010). None of the investigated aspects showed a significant impact on the treatment satisfaction of caregivers. (4) Conclusions: We demonstrated that in patients with IDHwt gliomas, the KPS was the most important predictor for a better HR-QoL in functional domains. Data on the HR-QoL and treatment satisfaction in patients with IDHwt gliomas and their caregivers are rare; therefore, further efforts should be made to improve supportive care in this highly distressed cohort. [ABSTRACT FROM AUTHOR]

Published
2024
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46. An international field study for the reliability and validity of the EORTC Communication Questionnaire EORTC QLQ-COMU26

Author

Arraras, Juan Ignacio, primary, Giesinger, Johannes, additional, Shamieh, Omar, additional, Bahar, Iqbal, additional, Koller, Michael, additional, Bredart, Anne, additional, Costantini, Anna, additional, Greimel, Eva, additional, Sztankay, Monika, additional, Wintner, Lisa M., additional, de Sousa, Marina Carreiro, additional, Ishiki, Hiroto, additional, Kontogianni, Meropi, additional, Wolan, Maja, additional, Kikawa, Yuichiro, additional, Lanceley, Anne, additional, Gioulbasanis, Ioannis, additional, Harle, Amelie, additional, Zarandona, Uxue, additional, Kulis, Dagmara, additional, and Kuljanic, Karin, additional

Published
2024
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48. A database for oncological research and quality assurance: implementation and first experiences with the University Clinical Cancer Registry Regensburg

Author

Saibold, Anna, primary, Koller, Michael, additional, Mueller, Karolina, additional, Koelbl, Oliver, additional, Vielsmeier, Veronika, additional, Pukrop, Tobias, additional, Spies, Oliver, additional, Eilers, Vivian, additional, Brese, Cathleen, additional, Amann, Denise, additional, and Maurer, Julia, additional

Published
2024
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49. Immunogenicity of High-Dose Versus MF59-Adjuvanted Versus Standard Influenza Vaccine in Solid Organ Transplant Recipients: The Swiss/Spanish Trial in Solid Organ Transplantation on Prevention of Influenza (STOP-FLU Trial)

Author

Swiss National Science Foundation, Sánchez-Céspedes, Javier [0000-0003-2707-1979], Mombelli, Matteo, Neofytos, Dionysios, Huynh-Do, Uyen, Sánchez-Céspedes, Javier, Stampf, Susanne, Golshayan, Dela, Dahdal, Suzan, Stirnimann, Guido, Schnyder, Aurelia, Garzoni, Christian, Venzin, Reto M., Magenta, Lorenzo, Schönenberger, Melanie, Walti, Laura, Hirzel, Cédric, Munting, Aline, Dickenmann, Michael, Koller, Michael, Aubert, John-David, Steiger, Jürg, Pascual, Manuel, Mueller, Thomas F., Schuurmans, Macé, Berger, Christoph, Binet, Isabelle, Villard, Jean, Mueller, Nicolas J., Egli, Adrian, Cordero, Van Delden, Christian, Manuel, Oriol, Swiss National Science Foundation, Sánchez-Céspedes, Javier [0000-0003-2707-1979], Mombelli, Matteo, Neofytos, Dionysios, Huynh-Do, Uyen, Sánchez-Céspedes, Javier, Stampf, Susanne, Golshayan, Dela, Dahdal, Suzan, Stirnimann, Guido, Schnyder, Aurelia, Garzoni, Christian, Venzin, Reto M., Magenta, Lorenzo, Schönenberger, Melanie, Walti, Laura, Hirzel, Cédric, Munting, Aline, Dickenmann, Michael, Koller, Michael, Aubert, John-David, Steiger, Jürg, Pascual, Manuel, Mueller, Thomas F., Schuurmans, Macé, Berger, Christoph, Binet, Isabelle, Villard, Jean, Mueller, Nicolas J., Egli, Adrian, Cordero, Van Delden, Christian, and Manuel, Oriol

Abstract

[Background] The immunogenicity of the standard influenza vaccine is reduced in solid-organ transplant (SOT) recipients, so new vaccination strategies are needed in this population., [Methods] Adult SOT recipients from 9 transplant clinics in Switzerland and Spain were enrolled if they were >3 months after transplantation. Patients were randomized (1:1:1) to a MF59-adjuvanted or a high-dose vaccine (intervention), or a standard vaccine (control), with stratification by organ and time from transplant. The primary outcome was vaccine response rate, defined as a ≥4-fold increase of hemagglutination-inhibition titers to at least 1 vaccine strain at 28 days postvaccination. Secondary outcomes included polymerase chain reaction–confirmed influenza and vaccine reactogenicity., [Results] A total of 619 patients were randomized, 616 received the assigned vaccines, and 598 had serum available for analysis of the primary endpoint (standard, n = 198; MF59-adjuvanted, n = 205; high-dose, n = 195 patients). Vaccine response rates were 42% (84/198) in the standard vaccine group, 60% (122/205) in the MF59-adjuvanted vaccine group, and 66% (129/195) in the high-dose vaccine group (difference in intervention vaccines vs standard vaccine, 0.20; 97.5% confidence interval [CI], .12–1); P < .001; difference in high-dose vs standard vaccine, 0.24 [95% CI, .16–1]; P < .001; difference in MF59-adjuvanted vs standard vaccine, 0.17 [97.5% CI, .08–1]; P < .001). Influenza occurred in 6% of the standard, 5% in the MF59-adjuvanted, and 7% in the high-dose vaccine groups. Vaccine-related adverse events occurred more frequently in the intervention vaccine groups, but most of the events were mild., [Conclusions] In SOT recipients, use of an MF59-adjuvanted or a high-dose influenza vaccine was safe and resulted in a higher vaccine response rate.

Published
2024

50. Immune monitoring-guided vs fixed duration of antiviral prophylaxis against cytomegalovirus in solid-organ transplant recipients. A Multicenter, Randomized Clinical Trial

Author

Manuel, Oriol; https://orcid.org/0000-0001-7607-0943, Laager, Mirjam, Hirzel, Cédric, Neofytos, Dionysios, Walti, Laura N, Hoenger, Gideon, Binet, Isabelle, Schnyder, Aurelia, Stampf, Susanne, Koller, Michael, Mombelli, Matteo, Kim, Min Jeong, Hoffmann, Matthias, Koenig, Katrin, Hess, Christoph, Burgener, Anne-Valérie, Cippà, Pietro E; https://orcid.org/0000-0002-9507-0057, Hübel, Kerstin, Mueller, Thomas F; https://orcid.org/0000-0003-2236-2312, Sidler, Daniel, Dahdal, Suzan, Suter-Riniker, Franziska, Villard, Jean, Zbinden, Andrea; https://orcid.org/0000-0001-8328-7614, Pantaleo, Giuseppe, Semmo, Nasser, Hadaya, Karine, Enríquez, Natalia, Meylan, Pascal R, Froissart, Marc, et al, Mueller, Nicolas J; https://orcid.org/0000-0002-1059-3191, Manuel, Oriol; https://orcid.org/0000-0001-7607-0943, Laager, Mirjam, Hirzel, Cédric, Neofytos, Dionysios, Walti, Laura N, Hoenger, Gideon, Binet, Isabelle, Schnyder, Aurelia, Stampf, Susanne, Koller, Michael, Mombelli, Matteo, Kim, Min Jeong, Hoffmann, Matthias, Koenig, Katrin, Hess, Christoph, Burgener, Anne-Valérie, Cippà, Pietro E; https://orcid.org/0000-0002-9507-0057, Hübel, Kerstin, Mueller, Thomas F; https://orcid.org/0000-0003-2236-2312, Sidler, Daniel, Dahdal, Suzan, Suter-Riniker, Franziska, Villard, Jean, Zbinden, Andrea; https://orcid.org/0000-0001-8328-7614, Pantaleo, Giuseppe, Semmo, Nasser, Hadaya, Karine, Enríquez, Natalia, Meylan, Pascal R, Froissart, Marc, et al, and Mueller, Nicolas J; https://orcid.org/0000-0002-1059-3191

Abstract

BACKGROUND: The use of assays detecting cytomegalovirus (CMV)-specific T-cell-mediated immunity may individualize the duration of antiviral prophylaxis in transplant recipients. METHODS: In this open-label randomized trial, adult kidney and liver transplant recipients from six centers in Switzerland were enrolled if they were CMV-seronegative with seropositive donors or CMV-seropositive receiving anti-thymocyte globulins. Patients were randomized to a duration of antiviral prophylaxis based on immune-monitoring (intervention) or a fixed duration (control). Patients in the control group were planned to receive 180 days (CMV-seronegative) or 90 days (CMV-seropositive) of valganciclovir. Patients were assessed monthly with a CMV-specific interferon gamma release assay (T-Track® CMV); prophylaxis in the intervention group was stopped if the assay was positive. The primary outcomes were the proportion of patients with clinically significant CMV infection and reduction in days of prophylaxis. Between-group differences were adjusted for CMV serostatus. RESULTS: Overall, 193 patients were randomized (92 in the immune-monitoring and 101 in the control group) of which 185 had evaluation of the primary endpoint (87 and 98 patients, respectively). Clinically significant CMV infection occurred in 26/87 (adjusted percentage, 30.9%) in the immune-monitoring group and in 32/98 (adjusted percentage, 31.1%) in the control group (adjusted risk difference -0.1, 95%CI -13.0%, 12.7%; p = 0.064). The duration of antiviral prophylaxis was shorter in the immune-monitoring group (adjusted difference -26.0 days, 95%-CI -41.1 to -10.8 days, p < 0.001). CONCLUSIONS: Immune monitoring resulted in a significant reduction of antiviral prophylaxis, but we were unable to establish noninferiority of this approach on the co-primary endpoint of CMV infection.

Published
2024

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