ORCID Profile
0000-0001-8828-8739
Current Organisation
KU Leuven
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Publisher: Research Square Platform LLC
Date: 20-10-2020
DOI: 10.21203/RS.3.RS-45324/V2
Abstract: Background :The COVID-19 pandemic has imposed an enormous burden on health care systems around the world. In the past, the administration of convalescent plasma of patients having recovered from SARS and severe influenza to patients actively having the disease, showed promising effects on mortality and appeared safe. Whether or not this also holds true for the novel SARS-CoV-2 virus is currently unknown. Methods :DAWn-Plasma is a multicentre nation-wide, randomized, open-label, phase II proof-of-concept clinical trial, evaluating the clinical efficacy and safety of the addition of convalescent plasma to the standard of care in patients hospitalized with COVID-19 in Belgium. Patients hospitalized with a confirmed diagnosis of COVID-19 are eligible when they are symptomatic (i.e. clinical or radiological signs) and have been diagnosed with COVID-19 in the 72 hours before study inclusion through a PCR (nasal/nasopharyngeal swab or bronchoalveolar lavage) or a chest-CT scan showing features compatible with COVID-19 in the absence of an alternative diagnosis. Patients are randomized in a 2:1 ratio to either standard of care and convalescent plasma (active treatment group) or standard of care only. The active treatment group receives 2 units of 200 to 250 mL of convalescent plasma within 12 hours after randomization, with a second administration of 2 units 24 to 36 hours after ending the first administration. The trial aims to include 483 patients and will recruit from 25 centres across Belgium. The primary endpoint is the proportion of patients that require mechanical ventilation or have died at day 15. The main secondary endpoints are clinical status on day 15 and day 30 after randomization, as defined by the WHO Progression 10-point ordinal scale, and safety of the administration of convalescent plasma. Discussion: This trial will either provide support or discourage the use of convalescent plasma as early intervention for the treatment of hospitalized patients with COVID-19 infection. Trial registration: Clinicaltrials.gov, Identifier: NCT04429854. Registered 12 June 2020 - Retrospectively registered, t2/show/NCT04429854.
Publisher: Elsevier BV
Date: 2020
Publisher: Research Square Platform LLC
Date: 18-08-2020
DOI: 10.21203/RS.3.RS-45324/V1
Abstract: Background : The COVID-19 pandemic has imposed an enormous burden on health care systems around the world. In the past, the administration of convalescent plasma of patients having recovered from SARS and severe influenza to patients actively having the disease, showed promising effects on mortality and appeared safe. Whether or not this also holds true for the novel SARS-CoV-2 virus is currently unknown. Methods : DAWn-Plasma is a multicentre nation-wide, randomized, open-label, phase II proof-of-concept clinical trial, evaluating the clinical efficacy and safety of the addition of convalescent plasma to the standard of care in patients hospitalized with COVID-19 in Belgium. Patients hospitalized with a confirmed diagnosis of COVID-19 are eligible when they are symptomatic (i.e. clinical or radiological signs) and have been diagnosed with COVID-19 in the 72 hours before study inclusion through a PCR (nasal/nasopharyngeal swab or bronchoalveolar lavage) or a chest-CT scan showing features compatible with COVID-19 in the absence of an alternative diagnosis. Patients are randomized in a 2:1 ratio to either standard of care and convalescent plasma (active treatment group) or standard of care only. The active treatment group receives 2 units of 200 to 250 mL of convalescent plasma within 12 hours after randomization, with a second administration of 2 units 24 to 36 hours after ending the first administration. The trial aims to include 483 patients and will recruit from 25 centres across Belgium. The primary endpoint is the proportion of patients that require mechanical ventilation or have died at day 15. The main secondary endpoints are clinical status on day 15 and day 30 after randomization, as defined by the WHO Progression 10-point ordinal scale, and safety of the administration of convalescent plasma. Discussion: This trial will either provide support or discourage the use of convalescent plasma as early intervention for the treatment of hospitalized patients with COVID-19 infection. Trial registration: Clinicaltrials.gov, Identifier: NCT04429854. Registered 12 June 2020 - Retrospectively registered, t2/show/NCT04429854.
Publisher: Springer Science and Business Media LLC
Date: 27-11-2020
DOI: 10.1186/S13063-020-04876-0
Abstract: The COVID-19 pandemic has imposed an enormous burden on health care systems around the world. In the past, the administration of convalescent plasma of patients having recovered from SARS and severe influenza to patients actively having the disease showed promising effects on mortality and appeared safe. Whether or not this also holds true for the novel SARS-CoV-2 virus is currently unknown. DAWn-Plasma is a multicentre nation-wide, randomized, open-label, phase II proof-of-concept clinical trial, evaluating the clinical efficacy and safety of the addition of convalescent plasma to the standard of care in patients hospitalized with COVID-19 in Belgium. Patients hospitalized with a confirmed diagnosis of COVID-19 are eligible when they are symptomatic (i.e. clinical or radiological signs) and have been diagnosed with COVID-19 in the 72 h before study inclusion through a PCR (nasal/nasopharyngeal swab or bronchoalveolar lavage) or a chest-CT scan showing features compatible with COVID-19 in the absence of an alternative diagnosis. Patients are randomized in a 2:1 ratio to either standard of care and convalescent plasma (active treatment group) or standard of care only. The active treatment group receives 2 units of 200 to 250 mL of convalescent plasma within 12 h after randomization, with a second administration of 2 units 24 to 36 h after ending the first administration. The trial aims to include 483 patients and will recruit from 25 centres across Belgium. The primary endpoint is the proportion of patients that require mechanical ventilation or have died at day 15. The main secondary endpoints are clinical status on day 15 and day 30 after randomization, as defined by the WHO Progression 10-point ordinal scale, and safety of the administration of convalescent plasma. This trial will either provide support or discourage the use of convalescent plasma as an early intervention for the treatment of hospitalized patients with COVID-19 infection. ClinicalTrials.gov NCT04429854 . Registered on 12 June 2020 - Retrospectively registered.
Publisher: Elsevier BV
Date: 09-2023
Publisher: Springer Science and Business Media LLC
Date: 18-12-2020
DOI: 10.1038/S41523-020-00209-1
Abstract: Currently, there are no markers to identify patients with liver-only or liver-dominant metastases that would benefit from hepatic surgery. Here we characterized histopathological growth patterns (HGPs) of liver metastases in a consecutive series of 36 breast cancer patients who underwent hepatic surgery. Survival analyses showed that the presence of a desmoplastic HGP in the liver metastases (a rim of fibrous tissue separating cancer cells from the liver parenchyma, present in 20 (56%) patients) is independently associated with favorable progression-free and overall survival when compared with the replacement HGP (cancer cells growing into the liver parenchyma, present in 16 (44%) patients).
Publisher: Elsevier BV
Date: 02-2023
DOI: 10.1016/J.PATHOL.2022.05.015
Abstract: The identification of a somatic mutation associated with myeloid malignancy is of diagnostic importance in myeloproliferative neoplasms (MPNs). In iduals with no mutation detected in common screening tests for variants in JAK2, CALR, and MPL are described as 'triple-negative' and pose a diagnostic challenge if there is no other evidence of a clonal disorder. To identify potential drivers that might explain the clinical phenotype, we used an extended sequencing panel to characterise a cohort of 44 previously diagnosed triple-negative MPN patients for canonical mutations in JAK2, MPL and CALR at low variant allele frequency (found in 4/44 patients), less common variants in the JAK-STAT signalling pathway (12 patients), or other variants in recurrently mutated genes from myeloid malignancies (18 patients), including hotspot variants of potential clinical relevance in eight patients. In one patient with thrombocytosis we identified biallelic germline MPL variants. Neither MPL variant was activating in cell proliferation assays, and one of the variants was not expressed on the cell surface, yet co-expression of both variants led to thrombopoietin hypersensitivity. Our results highlight the clinical value of extended sequencing including germline variant analysis and illustrate the need for detailed functional assays to determine whether rare variants in JAK2 or MPL are pathogenic.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 22-03-2023
Abstract: Endothelial cells (ECs) grant access of disseminated cancer cells to distant organs. However, the molecular players regulating the activation of quiescent ECs at the premetastatic niche (PMN) remain elusive. Here, we find that ECs at the PMN coexpress tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) and its cognate death receptor 5 (DR5). Unexpectedly, endothelial TRAIL interacts intracellularly with DR5 to prevent its signaling and preserve a quiescent vascular phenotype. In absence of endothelial TRAIL, DR5 activation induces EC death and nuclear factor κB 38–dependent EC stickiness, compromising vascular integrity and promoting myeloid cell infiltration, breast cancer cell adhesion, and metastasis. Consistently, both down-regulation of endothelial TRAIL at the PMN by proangiogenic tumor-secreted factors and the presence of the endogenous TRAIL inhibitors decoy receptor 1 (DcR1) and DcR2 favor metastasis. This study discloses an intracrine mechanism whereby TRAIL blocks DR5 signaling in quiescent endothelia, acting as gatekeeper of the vascular barrier that is corrupted by the tumor during cancer cell dissemination.
Publisher: Springer Science and Business Media LLC
Date: 04-08-2022
DOI: 10.1038/S41523-022-00453-7
Abstract: The impact of adiposity on the efficacy of endocrine treatment in patients with estrogen receptor positive breast cancer is poorly investigated. Here, we retrospectively investigated in a cohort of 56 patients whether body mass index and/or mammary adiposity are associated with anti-proliferative response in the neoadjuvant setting. Anti-proliferative response was defined as high Ki67 at baseline (Ki67 bl ) and low Ki67 at surgery (Ki67 srg ), using the 14% cut-off. Mammary adipocyte size was assessed on hematoxylin and eosin slides from the surgical s les using digital pathology. A higher proportion of tumors with an anti-proliferative response was observed in patients with obesity (54.5%) as compared to patients with normal weight (9.0%) and patients with overweight (40.0%) ( p = 0.031), confirmed by multivariable regression analysis adjusted for baseline Ki67 (OR, obese vs normal weight: 13.76, 95%CI: 1.49–207.63, p = 0.020). Larger adipocyte diameter was identified as predictor of anti-proliferative response (OR per increase in diameter of 5 μm for adipocytes distant from the tumor: 2.24, 95%CI: 1.01–14.32, p = 0.046). This study suggests that anti-proliferative response to neoadjuvant letrozole might be more frequent in patients with increased systemic or mammary adiposity.
Publisher: Elsevier BV
Date: 07-2023
No related grants have been discovered for Tatjana Geukens.