Effect of Hemadsorption Therapy in Critically Ill Patients with COVID-19 (CYTOCOV-19): A Prospective Randomized Controlled Pilot Trial.

INTRODUCTION: Immunomodulatory therapies have shown beneficial effects in patients with severe COVID-19. Patients with hypercytokinemia might benefit from the removal of inflammatory mediators via hemadsorption. METHODS: Single-center prospective randomized trial at the University Medical Center Hamburg-Eppendorf (Germany). Patients with confirmed COVID-19, refractory shock (norepinephrine ≥0.2 µg/kg/min to maintain a mean arterial pressure ≥65 mm Hg), interleukin-6 (IL-6) ≥500 ng/L, and an indication for renal replacement therapy or extracorporeal membrane oxygenation were included. Patients received either hemadsorption therapy (HT) or standard medical therapy (SMT). For HT, a CytoSorb® adsorber was used for up to 5 days and was replaced every 18-24 h. The primary endpoint was sustained hemodynamic improvement (norepinephrine ≤0.05 µg/kg/min ≥24 h). RESULTS: Of 242 screened patients, 24 were randomized and assigned to either HT (N = 12) or SMT (N = 12). Both groups had similar severity as assessed by SAPS II (median 75 points HT group vs. 79 SMT group, p = 0.590) and SOFA (17 vs. 16, p = 0.551). Median IL-6 levels were 2,269 (IQR 948-3,679) and 3,747 (1,301-5,415) ng/L in the HT and SMT groups at baseline, respectively (p = 0.378). Shock resolution (primary endpoint) was reached in 33% (4/12) versus 17% (2/12) in the HT and SMT groups, respectively (p = 0.640). Twenty-eight-day mortality was 58% (7/12) in the HT compared to 67% (8/12) in the SMT group (p = 1.0). During the treatment period of 5 days, 6/12 (50%) of the SMT patients died, in contrast to 1/12 (8%) in the HT group. CONCLUSION: HT was associated with a non-significant trend toward clinical improvement within the intervention period. In selected patients, HT might be an option for stabilization before transfer and further therapeutic decisions. This finding warrants further investigation in larger trials.

MR-proAdrenomedullin as a predictor of renal replacement therapy in a cohort of critically ill patients with COVID-19.

BACKGROUND: About 20% of ICU patients with COVID-19 require renal replacement therapy (RRT). Mid-regional pro-adrenomedullin (MR-proADM) might be used for risk assessment. This study investigates MR-proADM for RRT prediction in ICU patients with COVID-19. METHODS: We analysed data of consecutive patients with COVID-19, requiring ICU admission at a university hospital in Germany between March and September 2020. Clinical characteristics, details on AKI, and RRT were assessed. MR-proADM was measured on admission. RESULTS: 64 patients were included (49 (77%) males). Median age was 62.5y (54-73). 47 (73%) patients were ventilated and 50 (78%) needed vasopressors. 25 (39%) patients had severe ARDS, and 10 patients needed veno-venous extracorporeal membrane oxygenation. 29 (45%) patients required RRT; median time from admission to RRT start was 2 (1-9) days. MR-proADM on admission was higher in the RRT group (2.491 vs. 1.23 nmol/l; p = 0.002) and showed the highest correlation with renalSOFA. ROC curve analysis showed that MR-proADM predicts RRT with an AUC of 0.69 (95% CI: 0.543-0.828; p = 0.019). In multivariable logistic regression MR-proADM was an independent predictor (OR: 3.813, 95% CI 1.110-13.102, p<0.05) for RRT requirement. CONCLUSION: AKI requiring RRT is frequent in ICU patients with COVID-19. MR-proADM on admission was able to predict RRT requirement, which may be of interest for risk stratification and management.

Mechanical ventilation and mortality among 223 critically ill patients with coronavirus disease 2019: A multicentric study in Germany.

BACKGROUND: There are large uncertainties with regard to the outcome of patients with coronavirus disease 2019 (COVID-19) and mechanical ventilation (MV). High mortality (50-97%) was proposed by some groups, leading to considerable uncertainties with regard to outcomes of critically ill patients with COVID-19. OBJECTIVES: The aim was to investigate the characteristics and outcomes of critically ill patients with COVID-19 requiring intensive care unit (ICU) admission and MV. METHODS: A multicentre retrospective observational cohort study at 15 hospitals in Hamburg, Germany, was performed. Critically ill adult patients with COVID-19 who completed their ICU stay between February and June 2020 were included. Patient demographics, severity of illness, and ICU course were retrospectively evaluated. RESULTS: A total of 223 critically ill patients with COVID-19 were included. The majority, 73% (n = 163), were men; the median age was 69 (interquartile range = 58-77.5) years, with 68% (n = 151) patients having at least one chronic medical condition. Their Sequential Organ Failure Assessment score was a median of 5 (3-9) points on admission. Overall, 167 (75%) patients needed MV. Noninvasive ventilation and high-flow nasal cannula were used in 31 (14%) and 26 (12%) patients, respectively. Subsequent MV, due to noninvasive ventilation/high-flow nasal cannula therapy failure, was necessary in 46 (81%) patients. Renal replacement therapy was initiated in 33% (n = 72) of patients, and owing to severe respiratory failure, extracorporeal membrane oxygenation was necessary in 9% (n = 20) of patients. Experimental antiviral therapy was used in 9% (n = 21) of patients. Complications during the ICU stay were as follows: septic shock (40%, n = 90), heart failure (8%, n = 17), and pulmonary embolism (6%, n = 14). The length of ICU stay was a median of 13 days (5-24), and the duration of MV was 15 days (8-25). The ICU mortality was 35% (n = 78) and 44% (n = 74) among mechanically ventilated patients. CONCLUSION: In this multicentre observational study of 223 critically ill patients with COVID-19, the survival to ICU discharge was 65%, and it was 56% among patients requiring MV. Patients showed high rate of septic complications during their ICU stay.

Perforation of the ascending colon during implantation of an indwelling peritoneal catheter: a case report.

BACKGROUND: Tunneled peritoneal drainage catheters are described as an effective and relatively safe method in the management of malignant and non-malignant refractory ascites. Therapeutic advantages, linked to their use, are self-management of ascites and palliative care at home. Complications occur rarely. We describe an ascending colon perforation after implantation of a peritoneal drainage in a patient with refractory ascites due to liver cirrhosis. CASE PRESENTATION: The 68-year-old male was admitted to the intensive care unit due to severe community acquired pneumonia. The ascites drainage was inserted in order to reduce the intra-abdominal pressure and enable appropriate ventilation. A few hours later, bowel content could be detected in the tube and an abdominal computed tomography confirmed the intestinal perforation. Notably, there was no pneumoperitoneum and peritonitis had not yet set in. The catheter was removed during an emergency laparotomy and sutured closure of both perforation sites was performed. CONCLUSION: Patients with septated ascites and intraperitoneal adhesions are at potential higher risk of bowel perforation during implantation of an indwelling peritoneal catheter. A mini-laparotomy is, therefore, necessary in order to ensure safe implantation and positioning of the catheter in those cases.

Divergent Function of Programmed Death-Ligand 1 in Donor Tissue versus Recipient Immune System in a Murine Model of Bronchiolitis Obliterans.

Costimulatory molecules, such as the programmed death ligand (PD-L1), might exert differential effects on T-cell function, depending on the clinical setting and/or immunological environment. Given the impact of T cells on bronchiolitis obliterans (BO) in lung transplantation, we used an established tracheal transplant model inducing BO-like lesions to investigate the impact of PD-L1 on alloimmune responses and histopathological outcome in BO. In contrast to other transplant models in which PD-L1 generally shows protective functions, we demonstrated that PD-L1 has divergent effects depending on its location in donor versus recipient tissue. Although PD-L1 deficiency in donor tissue worsened histopathological outcome, and increased systemic inflammatory response, recipient PD-L1 deficiency induced opposite effects. Mechanistic studies revealed PD-L1-deficient recipients were hyporesponsive toward alloantigen, despite increased numbers of CD8+ effector T cells. The function of PD-L1 on T cells after unspecific stimulation was dependent on both cell type and strength of stimulation. This novel function of recipient PD-L1 may result from the high degree of T-cell activation within the highly immunogenic milieu of the transplanted tissue. In this model, both decreased T-cell alloimmune responses and the reduction of BO in PD-L1-deficient recipients suggest a potential therapeutic role of selectively blocking PD-L1 in the recipient. Further investigation is warranted to determine the impact of this finding embedded in the complex pathophysiological context of BO.

CD11c+ Dendritic Cells Accelerate the Rejection of Older Cardiac Transplants via Interleukin-17A.

BACKGROUND: Organ transplantation has seen an increased use of organs from older donors over the past decades in an attempt to meet the globally growing shortage of donor organs. However, inferior transplantation outcomes when older donor organs are used represent a growing challenge. METHODS AND RESULTS: Here, we characterize the impact of donor age on solid-organ transplantation using a murine cardiac transplantation model. We found a compromised graft survival when older hearts were used. Shorter graft survival of older hearts was independent of organ age per se, because chimeric young or old organs repopulated with young passenger leukocytes showed comparable survival times. Transplantation of older organs triggered more potent alloimmune responses via intragraft CD11c+ dendritic cells augmenting CD4+ and CD8+ T-cell proliferation and proinflammatory cytokine production, particularly that of interleukin-17A. Of note, depletion of donor CD11c+ dendritic cells before engraftment, neutralization of interleukin-17A, or transplantation of older hearts into IL-17A(-/-) mice delayed rejection and reduced alloimmune responses to levels observed when young hearts were transplanted. CONCLUSIONS: These results demonstrate a critical role of old donor CD11c+ dendritic cells in mounting age-dependent alloimmune responses with an augmented interleukin-17A response in recipient animals. Targeting interleukin-17A may serve as a novel therapeutic approach when older organs are transplanted.

TIM-3 regulates innate immune cells to induce fetomaternal tolerance.

TIM-3 is constitutively expressed on subsets of macrophages and dendritic cells. Its expression on other cells of the innate immune system and its role in fetomaternal tolerance has not yet been explored. In this study, we investigate the role of TIM-3-expressing innate immune cells in the regulation of tolerance at the fetomaternal interface (FMI) using an allogeneic mouse model of pregnancy. Blockade of TIM-3 results in accumulation of inflammatory granulocytes and macrophages at the uteroplacental interface and upregulation of proinflammatory cytokines. Furthermore, TIM-3 blockade inhibits the phagocytic potential of uterine macrophages resulting in a build up of apoptotic bodies at the uteroplacental interface that elicits a local immune response. In response to inflammatory cytokines, Ly-6C(hi)G(neg) monocytic myeloid-derived suppressor cells expressing inducible NO synthase and arginase 1 are induced. However, these suppressive cells fail to downregulate the inflammatory cascade induced by inflammatory granulocytes (Ly-6C(int)G(hi)) and apoptotic cells; the increased production of IFN-γ and TNF-α by inflammatory granulocytes leads to abrogation of tolerance at the FMI and fetal rejection. These data highlight the interplay between cells of the innate immune system at the FMI and their influence on successful pregnancy in mice.

Interruption of dendritic cell-mediated TIM-4 signaling induces regulatory T cells and promotes skin allograft survival.

Dendritic cells (DCs) are the central architects of the immune response, inducing inflammatory or tolerogenic immunity, dependent on their activation status. As such, DCs are highly attractive therapeutic targets and may hold the potential to control detrimental immune responses. TIM-4, expressed on APCs, has complex functions in vivo, acting both as a costimulatory molecule and a phosphatidylserine receptor. The effect of TIM-4 costimulation on T cell activation remains unclear. In this study, we demonstrate that Ab blockade of DC-expressed TIM-4 leads to increased induction of induced regulatory T cells (iTregs) from naive CD4(+) T cells, both in vitro and in vivo. iTreg induction occurs through suppression of IL-4/STAT6/Gata3-induced Th2 differentiation. In addition, blockade of TIM-4 on previously activated DCs still leads to increased iTreg induction. iTregs induced under TIM-4 blockade have equivalent potency to control and, upon adoptive transfer, significantly prolong skin allograft survival in vivo. In RAG(-/-) recipients of skin allografts adoptively transferred with CD4(+) T cells, we show that TIM-4 blockade in vivo is associated with a 3-fold prolongation in allograft survival. Furthermore, in this mouse model of skin transplantation, increased induction of allospecific iTregs and a reduction in T effector responses were observed, with decreased Th1 and Th2 responses. This enhanced allograft survival and protolerogenic skewing of the alloresponse is critically dependent on conversion of naive CD4(+) to Tregs in vivo. Collectively, these studies identify blockade of DC-expressed TIM-4 as a novel strategy that holds the capacity to induce regulatory immunity in vivo.

TIM-3: a novel regulatory molecule of alloimmune activation.

T cell Ig domain and mucin domain (TIM)-3 has previously been established as a central regulator of Th1 responses and immune tolerance. In this study, we examined its functions in allograft rejection in a murine model of vascularized cardiac transplantation. TIM-3 was constitutively expressed on dendritic cells and natural regulatory T cells (Tregs) but only detected on CD4(+)FoxP3(-) and CD8(+) T cells in acutely rejecting graft recipients. A blocking anti-TIM-3 mAb accelerated allograft rejection only in the presence of host CD4(+) T cells. Accelerated rejection was accompanied by increased frequencies of alloreactive IFN-γ-, IL-6-, and IL-17-producing splenocytes, enhanced CD8(+) cytotoxicity against alloantigen, increased alloantibody production, and a decline in peripheral and intragraft Treg/effector T cell ratio. Enhanced IL-6 production by CD4(+) T cells after TIM-3 blockade plays a central role in acceleration of rejection. Using an established alloreactivity TCR transgenic model, blockade of TIM-3 increased allospecific effector T cells, enhanced Th1 and Th17 polarization, and resulted in a decreased frequency of overall number of allospecific Tregs. The latter is due to inhibition in induction of adaptive Tregs rather than prevention of expansion of allospecific natural Tregs. In vitro, targeting TIM-3 did not inhibit nTreg-mediated suppression of Th1 alloreactive cells but increased IL-17 production by effector T cells. In summary, TIM-3 is a key regulatory molecule of alloimmunity through its ability to broadly modulate CD4(+) T cell differentiation, thus recalibrating the effector and regulatory arms of the alloimmune response.

Cognitive function at 2443 µmol/l creatinine.

BACKGROUND: One hallmark of uremia is the impairment of neuro-cognitive function. Anecdotal clinical description from the early days of chronic dialysis therapy impressively illustrates the improvement of those functions by chronic hemodialysis treatment. Fortunately, today, uremia is only rarely observed in industrialized countries as many patients seek medical/nephrological attention prior to the occurrence of deadly complications of uremia. CASE PRESENTATION: We report a rare case of severe uremia and describe the day to day improvement in neuro-cognitive function by dialysis using state of the arte test battery--starting at a serum creatinine of 2443 µmol/l. CONCLUSIONS: Especially executive functions, which are assumed to be localized in the frontal cerebral regions, are impaired in severe uremia and improve remarkably with the correction of severe uremia, i.e., initiation of dialysis.

Targeting Tim-1 to overcome resistance to transplantation tolerance mediated by CD8 T17 cells.

The ability to induce durable transplantation tolerance predictably and consistently in the clinic is a highly desired but elusive goal. Progress is hampered by lack of appropriate experimental models in which to study resistance to transplantation tolerance. Here, we demonstrate that T helper 1-associated T box 21 transcription factor (Tbet) KO recipients exhibit allograft tolerance resistance specifically mediated by IL-17-producing CD8 T (T17) cells. Neutralization of IL-17 facilitates long-term cardiac allograft survival with combined T cell co-stimulation (CD28-CD80/86 and CD154-CD40) blockade in Tbet KO recipients. We have used this T17-biased Tbet KO model of allograft tolerance resistance to study the impact of targeting a T cell-co-stimulatory pathway, and demonstrate that targeting T cell Ig and mucin domain-1 (Tim-1) with anti-Tim-1 overcomes this resistance by specifically inhibiting the pathogenic IL-17-producing CD8 T17 cells. These data indicate that in the absence of Th1 immunity, CD8 T17 alloreactivity constitutes a barrier to transplantation tolerance. Targeting TIM-1 provides an approach to overcome resistance to tolerance in clinical transplantation.

The TIM-1:TIM-4 pathway enhances renal ischemia-reperfusion injury.

CD4+ T cells contribute to the pathogenesis of ischemia-reperfusion injury, which is the primary cause of delayed graft failure after kidney transplantation. The TIM-1:TIM-4 pathway participates in the activation/differentiation of CD4+ T cells, suggesting that it may modulate ischemia-reperfusion injury. Here, we studied the role of TIM-1 in a murine uninephrectomized renal ischemia-reperfusion injury model. Blocking the TIM-1:TIM-4 pathway with an antagonistic monoclonal antibody protected renal function and diminished reperfusion injury resulting from 30 minutes of ischemia. Histologic examination showed significantly less evidence of renal damage as evidenced by diminished tubular necrosis, preservation of the brush border, fewer cast formations, and less tubular dilation. Blocking TIM-1 also reduced the number of apoptotic cells and diminished local inflammation within ischemic kidneys, the latter shown by decreased recruitment of macrophages, neutrophils, and CD4+ T cells and by reduced local production of proinflammatory cytokines. Furthermore, TIM-1 blockade significantly improved survival after ischemia-reperfusion injury. Taken together, these data suggest that the TIM-1:TIM-4 pathway enhances injury after renal ischemia-reperfusion injury and may be a therapeutic target.

[Analgesia for ventilation - what's new?] / Analgosedierung bei Beatmung.

MONITORING OF ANALGESIA, SEDATION AND DELIRIUM: The prerequisite for monitoring goal-oriented analgesia and screening for the presence of delirium is the use of validated measuring instruments such as the Richmond Agitation and Sedation Scale as well as an adequate medical and intensive care staffing ratio. IMPLEMENTATION OF ANALGESIA AND SEDATION: The goal, if possible, is an awake, oriented, cooperative patient who is free of pain. In this regard, multimodal analgesic treatment is of great importance. The lowest possible sedation should also be aimed for in COVID-19 patients, although deep sedation is recommended for invasively ventilated COVID-19 patients in the prone position.

Green tea extract-associated acute liver injury: Case report and review.

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Critical Care Providers' Moral Distress: Frequency, Burden, and Potential Resources.

BACKGROUND: Critical Care Providers (CCPs) experience situations that challenge their ethics and professional standards and may entail moral distress (MD). AIM: To analyze MD perceived by CCPs in intensive care units (ICUs) or emergency departments (EDs) and further clarify whether CCPs who rely on spiritual resources differ in their perception of MD from those who do not utilize these resources. METHODS: A cross-sectional anonymous survey was administered using a modified version of the German language version of the Moral Distress Scale (MDS) with 2 × 12 items to assess the frequency and the respective perceived burden of specific situations by applying a 5-point Likert scale. Explorative factor analysis was performed and the sub-constructs of the respective items regarding MD frequency and burden were identified. Job burden and professional satisfaction were measured using visual analogue scales (VAS) and a four-point Likert scale, respectively. The 15-item SpREUK questionnaire was applied to measure spiritual attitudes and behaviours and to differentiate between religious and spiritual persons. Data from 385 German-speaking CCPs were included (55% physicians, 45% nurses). RESULTS: Conflict situations are similar for physicians and nurses although they are perceived as more burdensome by nurses. Among physicians, the MDS factor Looking away/Resignation scores highest for assistant physician residents, whereas distress caused by looking away is more often perceived by specialist physicians without a managerial position. Work satisfaction is inversely associated with MD and emotional exhaustion is positively associated with it. Participants' spirituality is marginally associated with MD. The best predictors of both MD frequency and burden are emotional exhaustion with further influences of work satisfaction, being a nurse, and being a non-believer on the frequency of MD perception. Being a nurse, participants' experience in ICU/ED, and being of the male gender are further predictors of MD burden. CONCLUSIONS: MD is experienced differently by different groups of CCPs depending on their place in the hierarchy of responsibility. As MD perception is best predicted by emotional exhaustion, these situations should be avoided. Although some CCPs may rely on spiritual resources, all need individual and team support to cope with MD.

Chronic Critical Illness in Patients with COVID-19: Characteristics and Outcome of Prolonged Intensive Care Therapy.

The spread of SARS-CoV-2 caused a worldwide healthcare threat. High critical care admission rates related to Coronavirus Disease 2019 (COVID-19) respiratory failure were observed. Medical advances helped increase the number of patients surviving the acute critical illness. However, some patients require prolonged critical care. Data on the outcome of patients with a chronic critical illness (CCI) are scarce. Single-center retrospective study including all adult critically ill patients with confirmed COVID-19 treated at the Department of Intensive Care Medicine at the University Medical Center Hamburg-Eppendorf, Germany, between 1 March 2020 and 8 August 2021. We identified 304 critically ill patients with COVID-19 during the study period. Of those, 55% (n = 167) had an ICU stay ≥21 days and were defined as chronic critical illness, and 45% (n = 137) had an ICU stay <21 days. Age, sex and BMI were distributed equally between both groups. Patients with CCI had a higher median SAPS II (CCI: 39.5 vs. no-CCI: 38 points, p = 0.140) and SOFA score (10 vs. 6, p < 0.001) on admission. Seventy-three per cent (n = 223) of patients required invasive mechanical ventilation (MV) (86% vs. 58%; p < 0.001). The median duration of MV was 30 (17-49) days and 7 (4-12) days in patients with and without CCI, respectively (p < 0.001). The regression analysis identified ARDS (OR 3.238, 95% CI 1.827-5.740, p < 0.001) and referral from another ICU (OR 2.097, 95% CI 1.203-3.654, p = 0.009) as factors significantly associated with new-onset of CCI. Overall, we observed an ICU mortality of 38% (n = 115) in the study cohort. In patients with CCI we observed an ICU mortality of 28% (n = 46) compared to 50% (n = 69) in patients without CCI (p < 0.001). The 90-day mortality was 28% (n = 46) compared to 50% (n = 70), respectively (p < 0.001). More than half of critically ill patients with COVID-19 suffer from CCI. Short and long-term survival rates in patients with CCI were high compared to patients without CCI, and prolonged therapy should not be withheld when resources permit prolonged therapy.

Outcomes of critically ill coronavirus disease 2019 patients requiring kidney replacement therapy: A retrospective cohort study.

Background: Coronavirus disease 2019 (COVID-19) has resulted in high hospitalization rates worldwide. Acute kidney injury (AKI) in patients hospitalized for COVID-19 is frequent and associated with disease severity and poor outcome. The aim of this study was to investigate the incidence of kidney replacement therapy (KRT) in critically ill patients with COVID-19 and its implication on outcome. Methods: We retrospectively analyzed all COVID-19 patients admitted to the Department of Intensive Care Medicine at the University Medical Center Hamburg-Eppendorf (Germany) between 1 March 2020 and 31 July 2021. Demographics, clinical parameters, type of organ support, length of intensive care unit (ICU) stay, mortality and severity scores were assessed. Results: Three-hundred critically ill patients with COVID-19 were included. The median age of the study population was 61 (IQR 51-71) years and 66% (n = 198) were male. 73% (n = 219) of patients required invasive mechanical ventilation. Overall, 68% (n = 204) of patients suffered from acute respiratory distress syndrome and 30% (n = 91) required extracorporeal membrane oxygenation (ECMO). We found that 46% (n = 139) of patients required KRT. Septic shock (OR 11.818, 95% CI: 5.941-23.506, p < 0.001), higher simplified acute physiology scores (SAPS II) (OR 1.048, 95% CI: 1.014-1.084, p = 0.006) and vasopressor therapy (OR 5.475, 95% CI: 1.127-26.589, p = 0.035) were independently associated with the initiation of KRT. 61% (n = 85) of patients with and 18% (n = 29) without KRT died in the ICU (p < 0.001). Cox regression found that KRT was independently associated with mortality (HR 2.075, 95% CI: 1.342-3.208, p = 0.001) after adjusting for confounders. Conclusion: Critically ill patients with COVID-19 are at high risk of acute kidney injury with about half of patients requiring KRT. The initiation of KRT was associated with high mortality.

The emerging role of T cell Ig mucin 1 in alloimmune responses in an experimental mouse transplant model.

T cell Ig mucin 1 (TIM-1) plays an important role in regulating immune responses in autoimmune and asthma models, and it is expressed on both Th1 and Th2 cells. Using an antagonistic TIM-1-specific antibody, we studied the role of TIM-1 in alloimmunity. A short course of TIM-1-specific antibody monotherapy prolonged survival of fully MHC-mismatched vascularized mouse cardiac allografts. This prolongation was associated with inhibition of alloreactive Th1 responses and preservation of Th2 responses. TIM-1-specific antibody treatment was more effective in Th1-type cytokine-deficient Stat4(-/-) recipients as compared with Th2-type cytokine-deficient Stat6(-/-) recipients. Subtherapeutic doses of rapamycin plus TIM-1-specific antibody resulted in allograft acceptance and prevented the development of chronic allograft vasculopathy. Allograft survival via this treatment was accompanied by a Th1- to Th2-type cytokine switch. Depletion of natural Tregs abrogated the graft-protecting effect of the TIM-1-specific antibody. Importantly, CD4(+)CD25(+) Tregs obtained from long-term survivors had enhanced regulatory activity as compared with naive CD4(+)CD25(+) Tregs. Consistent with this, TIM-1-specific antibody treatment both preserved Tregs and prevented the expansion of alloreactive effector Th1 cells in an alloreactive TCR transgenic adoptive transfer model. These studies define previously unknown functions of TIM-1 in regulating alloimmune responses in vivo and may provide a novel approach to promoting transplantation tolerance.

Characteristics and Risk Factors for Intensive Care Unit Cardiac Arrest in Critically Ill Patients with COVID-19-A Retrospective Study.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causing the coronavirus disease 2019 (COVID-19) led to an ongoing pandemic with a surge of critically ill patients. Very little is known about the occurrence and characteristic of cardiac arrest in critically ill patients with COVID-19 treated at the intensive care unit (ICU). The aim was to investigate the incidence and outcome of intensive care unit cardiac arrest (ICU-CA) in critically ill patients with COVID-19. This was a retrospective analysis of prospectively recorded data of all consecutive adult patients with COVID-19 admitted (27 February 2020-14 January 2021) at the University Medical Centre Hamburg-Eppendorf (Germany). Of 183 critically ill patients with COVID-19, 18% (n = 33) had ICU-CA. The median age of the study population was 63 (55-73) years and 66% (n = 120) were male. Demographic characteristics and comorbidities did not differ significantly between patients with and without ICU-CA. Simplified Acute Physiological Score II (SAPS II) (ICU-CA: median 44 points vs. no ICU-CA: 39 points) and Sequential Organ Failure Assessment (SOFA) score (median 12 points vs. 7 points) on admission were significantly higher in patients with ICU-CA. Acute respiratory distress syndrome (ARDS) was present in 91% (n = 30) with and in 63% (n = 94) without ICU-CA (p = 0.002). Mechanical ventilation was more common in patients with ICU-CA (97% vs. 67%). The median stay in ICU before CA was 6 (1-17) days. A total of 33% (n = 11) of ICU-CAs occurred during the first 24 h of ICU stay. The initial rhythm was non-shockable (pulseless electrical activity (PEA)/asystole) in 91% (n = 30); 94% (n = 31) had sustained return of spontaneous circulation (ROSC). The median time to ROSC was 3 (1-5) minutes. Patients with ICU-CA had significantly higher ICU mortality (61% vs. 37%). Multivariable logistic regression showed that the presence of ARDS (odds ratio (OR) 4.268, 95% confidence interval (CI) 1.211-15.036; p = 0.024) and high SAPS II (OR 1.031, 95% CI 0.997-1.065; p = 0.077) were independently associated with the occurrence of ICU-CA. A total of 18% of critically ill patients with COVID-19 suffered from a cardiac arrest within the intensive care unit. The occurrence of ICU-CA was associated with presence of ARDS and severity of illness.