Faculty Bibliography

BACKGROUND AND AIMS:Scores from the Model for End-Stage Liver Disease (MELD), which are used to prioritize candidates for deceased donor livers, are widely acknowledged to be negatively correlated with the 90-day survival rate without a liver transplant. However, inconsistent and outdated estimates of survival probabilities by MELD preclude useful applications of the MELD score. APPROACH AND RESULTS:Using data from all prevalent liver waitlist candidates from 2016 to 2019, we estimated 3-day, 7-day, 14-day, 30-day, and 90-day without-transplant survival probabilities (with confidence intervals) for each MELD score and status 1A. We used an adjusted Kaplan-Meier model to avoid unrealistic assumptions and multiple observations per person instead of just the observation at listing. We found that 90-day without-transplant survival has improved over the last decade, with survival rates increasing >10% (in absolute terms) for some MELD scores. We demonstrated that MELD correctly prioritizes candidates in terms of without-transplant survival probability but that status 1A candidates' short-term without-transplant survival is higher than that of MELD 40 candidates and lower than that of MELD 39 candidates. Our primary result is the updated survival functions themselves. CONCLUSIONS:We calculated without-transplant survival probabilities for each MELD score (and status 1A). The survival function is an invaluable tool for many applications in liver transplantation: awarding of exception points, calculating the relative demand for deceased donor livers in different geographic areas, calibrating the pediatric end-stage liver disease score, and deciding whether to accept an offered liver.

UNLABELLED:Kidney transplantation (KT) is controversial in patients with pretransplant pulmonary hypertension (PtPH). We aimed to quantify post-KT graft and patient survival as well as survival benefit in recipients with PtPH. METHODS/UNASSIGNED:Using UR Renal Data System (2000-2018), we studied 90 819 adult KT recipients. Delayed graft function, death-censored graft failure, and mortality were compared between recipients with and without PtPH using inverse probability weighted logistic and Cox regression. Survival benefit of KT was determined using stochastic matching and stabilized inverse probability treatment Cox regression. RESULTS/UNASSIGNED: < 0.01) compared with those who remained on the waitlist. CONCLUSIONS/UNASSIGNED:Although PtPH is associated with inferior post-KT outcomes, KT is associated with better survival compared with remaining on the waitlist. Therefore, KT is a viable treatment modality for appropriately selected patients with PtPH.

BACKGROUND:The human immunodeficiency virus (HIV)-1 latent reservoir (LR) in resting CD4+ T cells is a barrier to cure. LR measurements are commonly performed on blood samples and therefore may miss latently infected cells residing in tissues, including lymph nodes. METHODS:We determined the frequency of intact HIV-1 proviruses and proviral inducibility in matched peripheral blood (PB) and lymph node (LN) samples from 10 HIV-1-infected patients on antiretroviral therapy (ART) using the intact proviral DNA assay and a novel quantitative viral induction assay. Prominent viral sequences from induced viral RNA were characterized using a next-generation sequencing assay. RESULTS:The frequencies of CD4+ T cells with intact proviruses were not significantly different in PB versus LN (61/106 vs 104/106 CD4+ cells), and they were substantially lower than frequencies of CD4+ T cells with defective proviruses. The frequencies of CD4+ T cells induced to produce high levels of viral RNA were not significantly different in PB versus LN (4.3/106 vs 7.9/106), but they were 14-fold lower than the frequencies of cells with intact proviruses. Sequencing of HIV-1 RNA from induced proviruses revealed comparable sequences in paired PB and LN samples. CONCLUSIONS:These results further support the use of PB as an appropriate proxy for the HIV-1 LR in secondary lymphoid organs.

Transplant recipients were excluded from the initial clinical trials determining safety and efficacy of the landmark COVID-19 vaccines. Further, there is increasing evidence that immunosuppressed transplant recipients have a blunted antibody response to COVID-19 vaccination. In a concerning report by Sattler et al. in this issue of the JCI, kidney transplant recipients not only lacked a humoral response following two doses of Pfizer BNT162b2, but also displayed substantial impairment of the cellular response to SARS-CoV-2 antigens. This Commentary addresses potential strategies for transplant providers to evaluate and augment vaccine immunogenicity given the likelihood that COVID-19 will remain a world-wide threat to the health of transplant recipients.

Organ transplant patients have poor immune responses to COVID-19 vaccines; thus designing vaccine strategies to protect this vulnerable population from SARS-CoV-2 infection is crucial.

A widely accepted severe acute respiratory syndrome 2 (SARS-CoV-2) vaccine could protect vulnerable populations, but the willingness of solid organ transplant recipients (SOTRs) to accept a potential vaccine remains unknown.

BACKGROUND AND OBJECTIVES:Patients with kidney failure report a high symptom burden, which likely increases while on dialysis due to physical and mental stressors and decreases after kidney transplantation due to restoration of kidney function. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS:=190), and post-transplantation symptom score trajectories (mixed effects models). RESULTS:At evaluation, candidates reported being moderately to extremely bothered by fatigue (32%), xeroderma (27%), muscle soreness (26%), and pruritus (25%); 16% reported high and 21% reported very high symptom burden. Candidates with very high symptom burden were at greater waitlist mortality risk (adjusted subdistribution hazard ratio, 1.67; 95% confidence interval, 1.06 to 2.62). By transplantation, 34% experienced an increased symptom burden, whereas 42% remained unchanged. The estimated overall symptom score was 82.3 points at transplantation and 90.6 points at 3 months (10% improvement); the score increased 2.75 points per month (95% confidence interval, 2.38 to 3.13) from 0 to 3 months, and plateaued (-0.06 points per month; 95% confidence interval, -0.30 to 0.18) from 3 to 12 months post-transplantation. There were early (first 3 months) improvements in nine of 11 symptoms; pruritus (23% improvement) and fatigue (21% improvement) had the greatest improvements. CONCLUSIONS:Among candidates, very high symptom burden was associated with waitlist mortality, but for those surviving and undergoing kidney transplantation, symptoms improved.

Immunosuppression and comorbidities might place solid organ transplant (SOT) recipients at higher risk from COVID-19, as suggested by recent case series. We compared 45 SOT vs. 2427 non-SOT patients who were admitted with COVID-19 to our health-care system (March 1, 2020 - August 21, 2020), evaluating hospital length-of-stay and inpatient mortality using competing-risks regression. We compared trajectories of WHO COVID-19 severity scale using mixed-effects ordinal logistic regression, adjusting for severity score at admission. SOT and non-SOT patients had comparable age, sex, and race, but SOT recipients were more likely to have diabetes (60% vs. 34%, p < .001), hypertension (69% vs. 44%, p = .001), HIV (7% vs. 1.4%, p = .024), and peripheral vascular disorders (19% vs. 8%, p = .018). There were no statistically significant differences between SOT and non-SOT in maximum illness severity score (p = .13), length-of-stay (sHR: _0.9 1.1_1.4 , p = .5), or mortality (sHR: _0.1 0.4_1.6 , p = .19), although the severity score on admission was slightly lower for SOT (median [IQR] 3 [3, 4]) than for non-SOT (median [IQR] 4 [3-4]) (p = .042) Despite a higher risk profile, SOT recipients had a faster decline in disease severity over time (OR = _0.76 0.81_0.86 , p < .001) compared with non-SOT patients. These findings have implications for transplant decision-making during the COVID-19 pandemic, and insights about the impact of SARS-CoV-2 on immunosuppressed patients.