Transplantation of organs from SARS-CoV-2-positive donors: Preliminary experience from Spain.

BACKGROUND: The utilization of non-lung organs from deceased donors with a positive polymerase chain reaction (PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the time of donation can be lifesaving, although the safety of this policy must be assessed. METHODS: This is a nationwide, prospective study, reporting the experience on the utilization of non-lung organs from SARS-CoV-2-positive donors between December 15, 2020 and May 31, 2022 in Spain. RESULTS: A total of 69 patients received a solid organ transplant (41 kidney, 18 liver, 8 heart, and 2 combined liver-kidney) obtained from 32 donors with a positive SARS-CoV-2 PCR at the time of donation (four of them with a cycle threshold value <30). All recipients tested negative for SARS-CoV-2 and were free of coronavirus disease 2019 (COVID-19) symptoms prior to transplantation. Nasopharyngeal swab turned positive for SARS-CoV-2 PCR in 4 (5.8%) recipients at 3, 8, 11, and 20 days after transplantation, though evidence did not support a donor-derived COVID-19. Four kidney recipients lost their grafts and two patients died: one heart recipient due to cardiogenic shock and one combined liver-kidney recipient due to lung hypertension and right heart failure. Graft losses and patient deaths were deemed unrelated to the donor SARS-CoV-2 status by the treating teams. No other adverse reactions were reported. CONCLUSIONS: This preliminary experience supports the safety of the use of organs other than lungs from SARS-CoV-2 PCR-positive donors, in alignment with previous series. However, the impact of SARS-CoV-2 infection upon organ quality should be established in future research.

The role of antibody responses against glycans in bioprosthetic heart valve calcification and deterioration.

Bioprosthetic heart valves (BHVs) are commonly used to replace severely diseased heart valves but their susceptibility to structural valve degeneration (SVD) limits their use in young patients. We hypothesized that antibodies against immunogenic glycans present on BHVs, particularly antibodies against the xenoantigens galactose-α1,3-galactose (αGal) and N-glycolylneuraminic acid (Neu5Gc), could mediate their deterioration through calcification. We established a large longitudinal prospective international cohort of patients (n = 1668, 34 ± 43 months of follow-up (0.1-182); 4,998 blood samples) to investigate the hemodynamics and immune responses associated with BHVs up to 15 years after aortic valve replacement. Early signs of SVD appeared in <5% of BHV recipients within 2 years. The levels of both anti-αGal and anti-Neu5Gc IgGs significantly increased one month after BHV implantation. The levels of these IgGs declined thereafter but anti-αGal IgG levels declined significantly faster in control patients compared to BHV recipients. Neu5Gc, anti-Neu5Gc IgG and complement deposition were found in calcified BHVs at much higher levels than in calcified native aortic valves. Moreover, in mice, anti-Neu5Gc antibodies were unable to promote calcium deposition on subcutaneously implanted BHV tissue engineered to lack αGal and Neu5Gc antigens. These results indicate that BHVs manufactured using donor tissues deficient in αGal and Neu5Gc could be less prone to immune-mediated deterioration and have improved durability.

Pretransplantation EASIX predicts intensive care unit admission in allogeneic hematopoietic cell transplantation.

The Endothelial Activation and Stress Index (EASIX) is a laboratory-based prognosis index defined as creatinine × lactate dehydrogenase/platelets. When measured at pretransplantation evaluation (EASIX-PRE), it predicts allogeneic hematopoietic cell transplantation (alloHCT) mortality. This study explores its ability to predict intensive care unit (ICU) admission and validates EASIX-PRE predictive power for overall survival (OS) and nonrelapse mortality (NRM) in 167 consecutive patients undergoing alloHCT. EASIX-PRE was calculated retrospectively in all patients and transformed into log2 values (log2-EASIX-PRE). Log2-EASIX-PRE predicted ICU admission (hazard ratio [HR], 1.41; P < .001), OS (HR, 1.19; P = .011), and NRM (HR, 1.28; P = .004). The most discriminating EASIX-PRE cutoff value for risk of ICU admission was the 75th percentile (2.795); for OS and NRM, it was the median value (1.703). Patients with EASIX-PRE >2.795 had higher incidence of ICU admission in comparison with patients with lower EASIX-PRE values (day +180, 35.8% vs 12.8%; HR, 2.28; P = .010). Additionally, patients with EASIX-PRE >1.073 had lower OS (2 years, 57.7% vs 68.7%; HR, 1.98; P = .006) and higher NRM (2 years, 38.7% vs 18.5%; HR, 2.92; P = .001) than patients with lower EASIX-PRE results. Log2-EASIX-PRE was not associated with incidence of transplantation-associated microangiopathy, sinusoidal obstruction syndrome, or acute graft-versus-host disease. This study proposes EASIX-PRE as a prognostic tool to identify patients undergoing alloHCT at increased risk of severe organ dysfunction and who would therefore require ICU admission. Early identification of patients at high risk of severe events could contribute to personalized intervention design. Additionally, it validates the association between EASIX-PRE and OS and NRM in those undergoing alloHCT.

Outcomes in patients treated with chimeric antigen receptor T-cell therapy who were admitted to intensive care (CARTTAS): an international, multicentre, observational cohort study.

BACKGROUND: Chimeric antigen receptor (CAR) T-cell therapy can induce side-effects such as cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome (ICANS), which often require intensive care unit admission. The aim of this study was to describe management of critically ill CAR T-cell recipients in intensive care. METHODS: This international, multicentre, observational cohort study was done in 21 intensive care units in France, Spain, the USA, the UK, Russia, Canada, Germany, and Austria. Eligible patients were aged 18 years or older; had received CAR T-cell therapy in the past 30 days; and had been admitted to intensive care for any reason. Investigators retrospectively included patients admitted between Feb 1, 2018, and Feb 1, 2019, and prospectively included patients admitted between March 1, 2019, and Feb 1, 2020. Demographic, clinical, laboratory, treatment, and outcome data were extracted from medical records. The primary endpoint was 90-day mortality. Factors associated with mortality were identified using a Cox proportional hazard model. FINDINGS: 942 patients received CAR T-cell therapy, of whom 258 (27%) required admission to intensive care and 241 (26%) were included in the analysis. Admission to intensive care was needed within median 4·5 days (IQR 2·0-7·0) of CAR T-cell infusion. 90-day mortality was 22·4% (95% CI 17·1-27·7; 54 deaths). At initial evaluation on admission, isolated cytokine release syndrome was identified in 101 patients (42%), cytokine release syndrome and ICANS in 93 (39%), and isolated ICANS in seven (3%) patients. Grade 3-4 cytokine release syndrome within 1 day of admission to intensive care was found in 50 (25%) of 200 patients and grade 3-4 ICANS in 38 (35%) of 108 patients. Bacterial infection developed in 30 (12%) patients. Life-saving treatments were used in 75 (31%) patients within 24 h of admission to intensive care, primarily vasoactive drugs in 65 (27%) patients. Factors independently associated with 90-day mortality by multivariable analysis were frailty (hazard ratio 2·51 [95% CI 1·37-4·57]), bacterial infection (2·12 [1·11-4·08]), and lifesaving therapy within 24 h of admission (1·80 [1·05-3·10]). INTERPRETATION: Critical care management is an integral part of CAR T-cell therapy and should be standardised. Studies to improve infection prevention and treatment in these high-risk patients are warranted. FUNDING: Groupe de Recherche Respiratoire en Réanimation Onco-Hématologique.

The direct and indirect effects of COVID-19 pandemic in a real-life hematological setting.

BACKGROUND: Clinical outcomes of novel coronavirus 2019 disease (COVID-19) in onco-hematological patients are unknown. When compared to non-immunocompromised patients, onco-hematological patients seem to have higher mortality rates. AIMS: We describe the characteristics and outcomes of a consecutive cohort of 24 onco-hematological patients with COVID-19 during the first month of the pandemic. We also describe variations in healthcare resource utilization within our hematology department. METHODS AND RESULTS: Data from patients between the first month of the pandemic were retrospectively collected. Clinical and logistic data were also collected and compared with the average values from the prior 3 months of activity. Prevalence of COVID-19 in our hematological population was 0.4%. Baseline characteristics were as follows: male sex: 83%, lymphoid diseases: 46%, median age: 69 (22-82) years. Median follow-up in survivors was 14 (9-28) days and inpatient mortality rate was 46%. Average time to moderate/severe respiratory insufficiency and death were 3 (1-10) and 10 (3-18) days, respectively. Only 1 out of every 12 patients who developed moderate to severe respiratory insufficiency recovered. Upon univariate analysis, the following factors were associated with higher mortality: age ≥ 70 years (P = .01) and D-dimer ≥900 mcg/L (P = .04). With respect to indirect effects during the COVID-19 pandemic, and when compared with the prior 3 months of activity, inpatient mortality (excluding patients with COVID-19 included in the study) increased by 56%. This was associated with a more frequent use of vasoactive drugs (+300%) and advanced respiratory support (+133%) in the hematology ward. In the outpatient setting, there was a reduction in initial visits (-55%) and chemotherapy sessions (-19%). A significant increase in phone visits was reported (+581%). CONCLUSION: COVID-19 pandemic is associated with elevated mortality in hematological patients. Negative indirect effects are also evident within this setting.

Liquid biopsy for disease monitoring after anti-CD19 chimeric antigen receptor T cell in diffuse large B-cell lymphoma.

Objectives: Chimeric antigen receptor T cells (CARTs) against CD19 antigen represent an effective therapy for relapsed/refractory diffuse large B-cell lymphoma (rrDLBCL). There is no diagnostic test able to predict which patients with residual disease will relapse from those that will reach a delayed complete response. Positron emission tomography/computed tomography scan (PET-CT) is characterized by a significant number of false positive results after immunotherapy. Circulating tumor DNA (ctDNA) may be a good-useful tool to quantify minimal residual disease and for monitoring disease response. Methods: We present a patient with DLBCL treated with CART cells in which we tested the combined use of ctDNA and PET-CT scan. Results: Disease reassessment with PET-CT scan showed a partial remission (3 weeks) and a very good partial remission (2 months). A clinical progression at 3 months was confirmed with PET-CT scan. Levels of ctDNA progressively decreased and became undetectable. An initial increase in KMT2D p.E4385G variant allele frequency confirmed disease progression. Conclusions: Our case shows how the complementary use of ctDNA and PET-CT scan could be a helpful tool in the clinical management of these patients.

Heart Donation From Donors After Controlled Circulatory Death.

The gold-standard therapy for advanced-stage heart failure is cardiac transplantation. Since the first heart transplant in 1967, the majority of hearts transplanted came from brain death donors. Nevertheless, in recent years, the option of donation after circulatory death (DCD) is gaining importance to increase donor pool. Currently, heart-transplant programs using controlled donation after circulatory death (cDCD) have been implemented in the United Kingdom, Belgium, Australia, United States of America, and, recently, in Spain. In this article, we performed a concise review of the literature in heart cDCD; we summarize the pathophysiology involved in ischemia and reperfusion injury during this process, the different techniques of heart retrieval in cDCD donors, and the strategies that can be used to minimize the damage during retrieval and until transplantation. Heart transplant using DCD hearts is in continuous improvement and must be implemented in experienced cardiac transplant centers.

Diagnosis and outcome of acute respiratory failure in immunocompromised patients after bronchoscopy.

OBJECTIVE: We wished to explore the use, diagnostic capability and outcomes of bronchoscopy added to noninvasive testing in immunocompromised patients. In this setting, an inability to identify the cause of acute hypoxaemic respiratory failure is associated with worse outcome. Every effort should be made to obtain a diagnosis, either with noninvasive testing alone or combined with bronchoscopy. However, our understanding of the risks and benefits of bronchoscopy remains uncertain. PATIENTS AND METHODS: This was a pre-planned secondary analysis of Efraim, a prospective, multinational, observational study of 1611 immunocompromised patients with acute respiratory failure admitted to the intensive care unit (ICU). We compared patients with noninvasive testing only to those who had also received bronchoscopy by bivariate analysis and after propensity score matching. RESULTS: Bronchoscopy was performed in 618 (39%) patients who were more likely to have haematological malignancy and a higher severity of illness score. Bronchoscopy alone achieved a diagnosis in 165 patients (27% adjusted diagnostic yield). Bronchoscopy resulted in a management change in 236 patients (38% therapeutic yield). Bronchoscopy was associated with worsening of respiratory status in 69 (11%) patients. Bronchoscopy was associated with higher ICU (40% versus 28%; p<0.0001) and hospital mortality (49% versus 41%; p=0.003). The overall rate of undiagnosed causes was 13%. After propensity score matching, bronchoscopy remained associated with increased risk of hospital mortality (OR 1.41, 95% CI 1.08-1.81). CONCLUSIONS: Bronchoscopy was associated with improved diagnosis and changes in management, but also increased hospital mortality. Balancing risk and benefit in individualised cases should be investigated further.

No impact of surviving sepsis campaign care bundles in reducing sepsis-associated acute kidney injury
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BACKGROUND: The impact of Surviving Sepsis Campaign (SSC) care bundles in reducing sepsis-associated acute kidney injury (SA-AKI) was evaluated. METHODS: We conducted an observational single-center cohort study. Accomplishment of SSC care bundles was registered in all patients with severe sepsis admitted to the critical care department of a university hospital during three different periods. The main outcome measured was SA-AKI incidence defined as any worsening of AKI stage within the first 7 days from onset of sepsis. RESULTS: Among 260 patients with severe sepsis or septic shock finally meeting inclusion criteria, 82 (31.5%) patients developed SA-AKI. None of the SSC care tasks significantly decreased SA-AKI incidence, although a trend was observed with an initial better blood glucose control as well as with a more protective ventilation strategy. Hypotension requiring fluid challenge (hazard ratio (HR), 2.3; 95% confidence interval (CI), 1.2 - 4.2) and the presence of an abdominal sepsis etiology (HR, 1.8; 95% CI, 1.1 - 3.1) were independently associated with SA-AKI. Patients who developed SA-AKI had a higher 90-day mortality rate (62.2 vs. 40.4%). CONCLUSION: In a cohort of septic patients, none of the SSC care tasks significantly decreased SA-AKI incidence within the first week after onset of sepsis.
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Invasive Pulmonary Aspergillosis with Disseminated Infection in Immunocompetent Patient.

Invasive pulmonary aspergillosis (IPA) is a rare pathology with increasing incidence mainly in critical care settings and recently in immunocompetent patients. The mortality of the disease is very high, regardless of an early diagnosis and aggressive treatment. Here, we report a case of a 56 yr old previously healthy woman who was found unconscious at home and admitted to the emergency room with mild respiratory insufficiency. In the first 24 hours she developed an acute respiratory failure with new radiographic infiltrates requiring Intensive Care Unit admission. A severe obstructive pattern with impossibility of ventilation because of bilateral atelectasis was observed, requiring emergent venovenous extracorporeal membrane oxygenator device insertion. Bronchoscopy revealed occlusion of main bronchi, demonstrating by biopsy an invasive infection by Aspergillus fumigatus and A. flavus. Despite an aggressive treatment and vital support the patient had a fatal outcome. The forensic study confirms the diagnosis of IPA but also revealed the presence of disseminated aspergillosis.

Necroptosis: A Novel Cell Death Modality and Its Potential Relevance for Critical Care Medicine.

Cell death is intertwined with life in development, homeostasis, pathology, and aging. Until recently, apoptosis was the best known form of programmed cell death, whereas necrosis was for a long time considered accidental owing to physicochemical injury. However, identification of crucial signaling and execution molecules, which are highly regulated, revealed that necrosis encompasses several cell death modalities that can be therapeutically targeted. The best understood form of regulated necrosis is necroptosis, which is transduced by the kinase activities of receptor interacting protein kinase-1 and receptor interacting protein kinase-3, eventually leading to the activation of mixed lineage kinase domain-like and plasma membrane permeabilization. We are only beginning to appreciate the role of necroptosis in different pathological conditions, including critical illnesses. In this review, we discuss the molecular mechanisms of necroptosis and analyze the effect of inhibiting necroptosis in experimental models of critical illnesses. In view of the identification of an increasing number of cell death modalities, we also briefly discuss the simultaneous targeting of multiple cell death modalities because, depending on the cell type and cellular conditions, various types of cell death may contribute to the pathology.

Transcription of the chicken Grin1 gene is regulated by the activity of SP3 and NRSF in undifferentiated cells and neurons.

The NMDA (N-methyl-D-aspartate) receptors are important in the regulation of neuronal development, synaptic plasticity, learning and memory, and are involved in several brain pathologies. The NR1 subunit is essential for the assembly of functional receptors, as it forms the calcium-permeable ion channel and contains the obligatory co-agonist binding site. Previous studies have shown that NR1 gene (Grin1) expression is up-regulated during neuronal differentiation and its expression is widespread in the central nervous system. We have previously cloned the chicken Grin1 gene and 1.9 kb of the 5'-regulatory region. In the present study, we analysed the molecular mechanisms that regulate chicken Grin1 gene transcription in undifferentiated cells and neurons. By functional analysis of chicken Grin1-luciferase gene 5'-regulatory region constructs, we demonstrate that the basal promoter is delimited within 210 bp upstream from the main transcription initiation site. DNA-protein binding and functional assays revealed that the 5'-UTR (untranslated region) has one consensus NRSE (neuron-restrictive silencing element) that binds NRSF (neuron-restrictive silencing factor), and one SP (stimulating protein transcription factor) element that binds SP3, both repressing Grin1 gene transcription in undifferentiated P19 cells (embryonic terato-carcinoma cells) and PC12 cells (phaeochromocytoma cells). The promoter region lacks a consensus TATA box, but contains one GSG/SP (GSG-like box near a SP-consensus site) that binds SP3 and up-regulates gene transcription in embryonic chicken cortical neurons. Taken together, these results demonstrate a dual role of SP3 in regulating the expression of the Grin1 gene, by repressing transcription in the 5'-UTR in undifferentiated cells as well as acting as a transcription factor, increasing Grin1 gene transcription in neurons.

Papel de los receptores de glutamato durante la diferenciación neuronal

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Abstract: L-glutamate (Glu) is the main excitatory neurotransmitter in the Central Nervous System (CNS). The glutamate receptors (GluRs) are distributed in all CNS regions and they llave been classified in two big families. The first big family is formed by the ionotropic glutamate receptors (iGluRs) or ligandgated ion channels, which allow selective crossing of ions through selective ion channels permeable to Ca2+, Na+ and K+. Depending of the electrophysio-logical and pharmacological properties of diese receptors, they are classified in three families: the a-amino-3-hydroxi-5-methyl-4-isoxazol-propionic acid (AMPA) receptors, the kainate receptors (KA) and the N-methyl-D-aspartate (NMDA) receptors. The general structure of iGluRs, consists of an extracellular amino terminal domain (NTD), two ligandbinding domains (S1 and S2), three transmembrane segments (TM1, TM2 and TM3), a reentrant pore loop and an intracellular carboxyl terminal domain (CTD). They are generally assembled into a tetrameric structure, formed by hetero-oligomeric integral protein subunits, which are encoded by different genes. The AMPA receptors family includes GluR-1, GluR-2, GluR-3 and GluR-4; the kainate receptors family comprises GluR-5, GluR-6, GluR-7, K1 and K2; and the NMDA receptors family is conformed by NR1, NR2 (NR2A-D) and NR3 (NR3A and 3B). In addition, alternative splicing of the primary transcripts increases the diversity of ionotropic receptor variants. The second great family is composed by the metabotropic glutamate receptors (mGluRs), which are associated to G-proteins that work through intracellular signaling generated by second messengers (inositol 3-phosphate, diacylglycerol and cAMP). As a general characteristic of their structure, the mGluRs have a large extracellular NTD, seven transmembrane passages connected by intracellular and extracellular loops, and an intracellular CTD. The mGluRs are divided in three groups: class I receptors include mGluR1 and mGluR5; class II receptors include mGluR2 and mGluR3; and class III receptors include mGluR4, mGluR6, mGluR7 and mGluR8. Generally, class I receptors are coupled to a Gq associated to phosphoinositides hydrolysis and function as postsynaptic receptors with an increased neuronal excitability. Class II and III receptors are coupled to Gi/Go, and are associated with adenylyl cyclase inhibition and function as pre-synaptic receptors diminishing neurotransmitter release. As in the case of iGluRs, there are many isoforms for mGluRs generated by alternative splicing of the pre-mRNA. The physiological relevance for studying GluRs is due to the key role they play in various neurodegenerative diseases, such as Huntington's disease, Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, stroke, epilepsy, HIV dementia, Creutzfeld-Jacob's disease and hypoglycemia. They are also involved in psychiatric disorders like schizophrenia, depression, anxiety disorder and post-traumatic stress disease. Moreover, the GluRs are involved in all the related steps of CNS development and neuronal differentiation. The great variability of responses to Glu is due in part to extracellular Glu concentration, as well as to the diversity of GluRs. It has been observed that differential expression of GluRs subunits is related to the stage of development and to the region of CNS. Thus, the pattern of differential expression of GluRs in a temporal and spatial manner is fundamental to understand the role of Glu in the CNS development. During neurogenesis, the early developing brain contains high levels of extracellular Glu. The activation of different GluRs, activates in turn intracellular second messenger signaling pathways, modifying the intracellular calcium concentration [Ca2+]i, which triggers transcriptional activation of cell cycle regulatory genes that promote cellular growth, regeneration, differentiation and neuronal survival. Furthermore, GluRs can stimulate growth of the pre-synaptic dendritic tree and harboring of post-synaptic dendrites, as well as to promote synaptic consolidation and maintenance. Other important mechanisms to generate mature neural networks are synaptic elimination, which diminishes the established neuronal contacts during synaptic refinement, and silencing of GluRs activity, which favors synaptic elimination during neuronal network formation. In addition, GluRs play an important role in the formation of inhibitory synapses during CNS development. GluR activation promotes dendritic growth through the generation of intracellular second messengers. However, biphasic changes of [Ca2+]i, in response to GluR activation, are related to the inhibitory and stimulatory dendritic growth phases. Therefore, a transitory increase of [Ca2+]i is related to a calmodulin-dependent dendritic growth, while a sustain rise of intracellular calcium is related to a calpain-dependent dendritic retraction resulting in dendritic microtubule polymer reduction. Another mechanism for dendritic growth is mediated through extracellular calcium influx, which triggers a cascade of intracelullar signaling path-ways, such as phosphorylation of Tiam1, Ras/Rac activation and recruiting protein kinases, phosphoinositide-dependent kinase and Akt, which are involved in the protein synthesis necessary for dendritic development and neuronal plasticity. It has been shown that excessive GluR activation can alter neuronal migration. Superficial cortical neurons release Glu producing a concentration gradient, which in turn promotes neuronal migration to the cortical plate, changing the cytoskeleton dynamics. The neuronal migration rate depends on increased intra-cellular calcium through GluRs. The GluRs can inhibit migration due to cytoskeleton depolymerization, or due to mechanisms influencing the direction of the migration of phillopodias. Although the NMDA receptors are the most studied in the development of CNS and during neuronal differentiation, in this review we also analyze the importance of the great variety of iGluRs and mGluRs during the development of the brain. We review the establishment and maintenance of synapses, cellular growth and differentiation through symmetric and asymmetric division, as well as neuronal survival, dendritic growth, synapsis elimination, receptor activity silencing and neuronal migration. All of the above processes play key steps in the establishment and development of mature neuronal networks, which are fundamental to consolidate the formation of all regions of the CNS from embryogenesis to adult life.