Project description:This study evaluated whether worsened outcomes in sex mismatch are related to mismatch of organ size in heart transplantation.Sizing for organ allocation in heart transplantation currently incorporates only body weight differences between the donor and recipient. Weight correlates poorly to cardiac size, and donor–recipient weight differences are not associated with differential survival. Heart size correlates with sex, and donor–recipient sex mismatch conveys worse-than-expected outcomes.We performed a retrospective cohort study of 31,634 donor–recipient adult heart transplant pairings from the United Network for Organ Sharing transplantation registry. We used predictive models to calculate the predicted total heart mass (pHM) for recipient and donor pairs. We assessed organ size mismatch by calculating the percent difference between the donor and recipient pHM as [(pHM(recipient) – pHM(donor))/(pHM(recipient))]*100.The most-undersized pHM septile demonstrated higher mortality during the first year post-transplantation (hazard ratio [HR]: 1.27; p < 0.001), which remained robust in adjusted models (HR: 1.25; p = 0.03). Survival did not vary across septiles of weight differences. On univariate analysis, sex mismatch was associated with higher mortality in male patients, but not in female patients. Controlling for differences in pHM reversed these associations. Adjusted models demonstrated worse survival associated with sex mismatch in female patients (1-year HR: 1.28; p = 0.02) but no difference in male patients (1-year HR, 1.00; p = 1.0).Differences in donor–recipient pHM modulated the survival associated with donor–recipient sex mismatch and identified donor heart undersizing as an otherwise occult and potentially preventable cause of mortality following orthotopic heart transplantation.
Project description:Lung transplantation can potentially be a life-saving treatment for patients with non-resolving COVID-19-associated respiratory failure. Concerns limiting transplant include recurrence of SARS-CoV-2 infection in the allograft, technical challenges imposed by viral-mediated injury to the native lung, and potential risk for allograft infection by pathogens associated with ventilator-associated pneumonia in the native lung. Most importantly, the native lung might recover, resulting in long-term outcomes preferable to transplant. Here, we report results of the first successful lung transplantation procedures in patients with non-resolving COVID-19-associated respiratory failure in the United States. We performed sm-FISH to detect both positive and negative strands of SARS-CoV-2 RNA in the explanted lung tissue, extracellular matrix imaging using SHIELD tissue clearance, and single cell RNA-Seq on explant and warm post-mortem lung biopsies from patients who died from severe COVID-19 pneumonia. Lungs from patients with prolonged COVID-19 were free of virus but pathology showed extensive evidence of injury and fibrosis which resembled end-stage pulmonary fibrosis. We used a machine learning approach to project single cell RNA-Seq data from patients with late stage COVID-19 onto a single cell atlas of pulmonary fibrosis, revealing similarities across cell lineages. There was no recurrence of SARS-CoV-2 or pathogens associated with pre-transplant ventilator associated pneumonias following transplantation. Our findings suggest that some patients with severe COVID-19 develop fibrotic lung disease for which lung transplantation is the only option for survival.
Project description:IntroductionKidney transplant recipients are at increased susceptibility to many viral infections leading to justifiable anxiety about the effects of coronavirus disease 2019 (COVID-19).MethodsWe performed literature searches from multiple resources in April and August 2020 for relevant English and Chinese literature. Abstracts were screened, followed by full-text review with data extraction of reports that included at least 20 kidney transplant recipients with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and completed outcomes.ResultsTwenty studies had sufficient data, which we have summarized. Studies were predominantly descriptive and came from France, Italy, Spain, Turkey, United Kingdom, and United States. Quality assessment demonstrated limitations in selection of comparison groups and controlling for additional factors. Mortality rates from published studies were variable. Based on early data early from Spain, 46% of patients who developed COVID-19 within 60 days of transplantation died. Acute kidney injury was common, and mycophenolate was discontinued in most patients.ConclusionGiven the rapid global spread of COVID-19, reliable evidence is needed to inform public health policies. Hospitalized kidney transplant recipients with COVID-19 are at a high risk of death in early reports but interpretation of these data requires caution, as studies were susceptible to period effects. Reassuringly, the quality of observational data is improving. Detailed and comprehensive data collection through linked registries will be necessary to conduct accurate analyses of risk factors for adverse outcomes, not least given the risks of stopping imunosuppression. This report highlights the early mortality excess in transplant recipients but medium- and longer-term outcomes remain uncertain and merit careful investigation.
Project description:The COVID-19 pandemic has brought unprecedented challenges to the transplant community. The reduction in transplantation volume during this time is partly due to concerns over potentially increased susceptibility and worsened outcomes of COVID-19 in immunosuppressed recipients. The consequences of COVID-19 on patients waitlisted for kidney transplantation, however, have not previously been characterized. We studied 56 waitlisted patients and 80 kidney transplant recipients diagnosed with COVID-19 between March 13 and May 20, 2020. Despite similar demographics and burden of comorbidities between waitlisted and transplant patients, waitlisted patients were more likely to require hospitalization (82% vs. 65%, P = .03) and were at a higher risk of mortality (34% vs. 16%, P = .02). Intubation was required in one third of hospitalized patients in each group, and portended a very poor prognosis. The vast majority of patients who died were male (84% waitlist, 100% transplant). Multivariate analysis demonstrated waitlist status, age, and male sex were independently associated with mortality. COVID-19 has had a dramatic impact on waitlisted patients, decreasing their opportunities for transplantation and posing significant mortality risk. Understanding the impact of COVID-19 on waitlist patients in comparison to transplant recipients may aid centers in weighing the risks and benefits of transplantation in the setting of ongoing COVID-19.
Project description:Italy was the first Western country to face the COVID-19 pandemic. Here we report the results of a national survey on kidney transplantation activity in February and March 2020, and the results of a three-round Delphi consensus promoted by four scientific societies: the Italian Society of Organ Transplantation, the Italian Society of Nephrology, the Italian Society of Anesthesia and Intensive Care, and the Italian Group on Antimicrobial Stewardship. All 41 Italian transplant centers were invited to express their opinion in the Delphi rounds along with a group of seven experts. The survey revealed that, starting from March 2020, there was a decline in kidney transplantation activity in Italy, especially for living-related transplants. Overall, 60 recipients tested positive for SARS-CoV2 infection, 57 required hospitalization, 17 were admitted to the ICU, and 11 died. The online consensus had high response rates at each round (95.8%, 95.8%, and 89.5%, respectively). Eventually, 27 of 31 proposed statements were approved (87.1%), 12 at the first or second round (38.7%), and 3 at the third (9.7%). Based on the Italian experience, we discuss the reasons for the changes in kidney transplantation activity during the COVID-19 pandemic in Western countries. We also provide working recommendations for the organization and management of kidney transplantation under these conditions.
Project description:Physical distancing has been argued as one of the effective means to combat the spread of COVID-19 before a vaccine or therapeutic drug becomes available. How far people can be spatially separated is partly behavioral but partly constrained by population density. Most models developed to predict the spread of COVID-19 in the U.S. do not include population density explicitly. This study shows that population density is an effective predictor of cumulative infection cases in the U.S. at the county level. Daily cumulative cases by counties are converted into 7-day moving averages. Treating the weekly averages as the dependent variable and the county population density levels as the explanatory variable, both in logarithmic scale, this study assesses how population density has shaped the distributions of infection cases across the U.S. from early March to late May, 2020. Additional variables reflecting the percentages of African Americans, Hispanic-Latina, and older adults in logarithmic scale are also included. Spatial regression models with a spatial error specification are also used to account for the spatial spillover effect. Population density alone accounts for 57% of the variation (R-squared) in the aspatial models and up to 76% in the spatial models. Adding the three population subgroup percentage variables raised the R-squared of the aspatial models to 72% and the spatial model to 84%. The influences of the three population subgroups were substantial, but changed over time, while the contributions of population density have been quite stable after the first several weeks, ascertaining the importance of population density in shaping the spread of infection in individual counties, and in their neighboring counties. Thus, population density and sizes of vulnerable population subgroups should be explicitly included in transmission models that predict the impacts of COVID-19, particularly at the sub-county level.
Project description:ObjectivesThe lack of effective treatments for coronavirus disease 2019 (COVID-19) has mandated the repurposing of several drugs, including antiretrovirals and remdesivir (RDV). These compounds may induce acute kidney injury and are not recommended in patients with poor renal function, such as kidney transplant (KTx) recipients.MethodsThe records of 42 KTx recipients with COVID-19 were reviewed. Some of them were receiving antiretrovirals (n = 10) or RDV (n = 8) as part of COVID-19 management. Most patients were male (71%) and their median age was 52 years. The median glomerular filtration rate in these patients was 56 ml/min. Regarding disease severity, 36% had mild disease, 19% had moderate disease, 31% had severe disease, and 12% had critical disease. Subgroups, i.e., patients receiving antiretrovirals, RDV, or no antivirals, were comparable in terms of patient age, comorbidities, and immunosuppression.ResultsSeven patients (16.6%) died during hospitalization. Acute kidney injury was found in 24% of KTx recipients at admission. Upon discharge, estimated glomerular filtration rate (eGFR) increased in 32% and decreased in 39% of the KTx recipients compared with the admission rate. The decrease was more prevalent in the RDV group (80%) compared with KTx recipients without any antiviral treatment (29%) (p < 0.05). Most patients (62%) returned to baseline eGFR values within 1 month of discharge. The proportion was similar between the patients receiving antiviral treatment and those not receiving this treatment.ConclusionsKTx recipients run a high risk of COVID-19-related renal impairment. Antivirals appear to be safe for use without major risks for kidney injury.