Faculty Bibliography

Background. Coronavirus disease 2019 (COVID-19)"“associated pulmonary aspergillosis (CAPA) is likely underdiagnosed, and current diagnostic tools are either invasive or insensitive. Methods. A retrospective study of mechanically ventilated patients with COVID-19 admitted to 5 Johns Hopkins hospitals between March 2020 and June 2021 was performed. Multivariable logistic regression was used for the CAPA prediction model building. Performance of the model was assessed using the area under the receiver operating characteristic curve (AUC). Results. In the cohort of 832 patients, 98 (11.8%) met criteria for CAPA. Age, time since intubation, dexamethasone for COVID-19 treatment, underlying pulmonary circulatory diseases, human immunodeficiency virus, multiple myeloma, cancer, or hematologic malignancies were statistically significantly associated with CAPA and were included in the CAPA prediction model, which showed an AUC of 0.75 (95% confidence interval, .70"“.80). At a screening cutoff of ≥0.085, it had a sensitivity of 82%, a specificity of 51%, a positive predictive value of 18.6%, and a negative predictive value of 95.3%. (The CAPA screening score calculator is available at www.transplantmodels.com). Conclusions. We developed a CAPA risk score as a noninvasive tool to aid in CAPA screening for patients with severe COVID-19. Our score will also identify a group of patients who are unlikely to have CAPA and who therefore need not undergo additional diagnostics and/or empiric antifungal therapy.

BACKGROUND:Disparities in pediatric kidney transplantation (KT) result in reduced access and worse outcomes for minority children. We assessed the impact of recent systems changes on these disparities. METHODS:This is a retrospective cohort study of pediatric patients utilizing data from the US Renal Data System (n = 7547) and Scientific Registry of Transplant Recipients (n = 6567 waitlisted and n = 6848 transplanted patients). We compared access to transplantation, time to deceased donor kidney transplant (DDKT), and allograft failure (ACGF) in the 5 years preceding implementation of the Kidney Allocation System (KAS) to the 5 years post-KAS implementation 2010-2014 vs. 2015-2019, respectively. RESULTS:p = 0.05) while there was no difference in 3- or 5-year ACGF among LDKT recipients. CONCLUSIONS:After KAS implementation, there is equity in time to DDKT. Pre-KAS increased hazard of ACGF among Black children has decreased in the post-KAS era; however, persistent disparities exist in time to transplant listing among Black and Hispanic children when compared to white children. A higher resolution version of the Graphical abstract is available as Supplementary information.

OBJECTIVE:The feasibility and 6-month outcome safety of lung transplants (LTs) from hepatitis C virus (HCV)-viremic donors for HCV-seronegative recipients (R-) were established in 2019, but longer-term safety and uptake of this practice nationally remain unknown. METHODS:testing, rank-sum testing, and Cox regression to compare posttransplant outcomes between HCV D+/R- and D-/R- LT recipients. RESULTS:HCV D+/R- LT increased from 2 to 97/year; centers performing HCV D+/R- LT increased from 1 to 25. HCV D+/R- versus HCV D-/R- LT recipients had more obstructive disease (35.7% vs 23.3%, P < .001), lower lung allocation score (36.5 vs 41.1, P < .001), and longer waitlist time (P = .002). HCV D+/R- LT had similar risk of acute rejection (adjusted odds ratio [aOR], 0.87; P = .58), extracorporeal membranous oxygenation (aOR, 1.94; P = .10), and tracheostomy (aOR, 0.42; P = .16); similar median hospital stay (P = .07); and lower risk of ventilator > 48 hours (aOR, 0.68; P = .006). Adjusting for donor, recipient, and transplant characteristics, risk of all-cause graft failure and mortality were similar at 30 days, 1 year, and 3 years for HCV D+/R- versus HCV D-/R- LT (all P > .1), as well as for high- (≥20/year) versus low-volume LT centers and high- (≥5/year) versus low-volume HCV D+/R- LT centers (all P > .5). CONCLUSIONS:HCV D+/R- and HCV D-/R- LT have similar outcomes at 3 years posttransplant. These results underscore the safety of HCV D+/R- LT and the potential benefit of expanding this practice further.

Kidney transplant recipients (KTRs) show poorer response to SARS-CoV-2 mRNA vaccination, yet response patterns and mechanistic drivers following third doses are ill-defined. We administered third monovalent mRNA vaccines to n = 81 KTRs with negative or low-titer anti-receptor binding domain (RBD) antibody (n = 39 anti-RBD^NEG; n = 42 anti-RBD^LO), compared with healthy controls (HCs, n = 19), measuring anti-RBD, Omicron neutralization, spike-specific CD8⁺%, and SARS-CoV-2-reactive T cell receptor (TCR) repertoires. By day 30, 44% anti-RBD^NEG remained seronegative; 5% KTRs developed BA.5 neutralization (vs 68% HCs, P < .001). Day 30 spike-specific CD8⁺% was negative in 91% KTRs (vs 20% HCs; P = .07), without correlation to anti-RBD (r_s = 0.17). Day 30 SARS-CoV-2-reactive TCR repertoires were detected in 52% KTRs vs 74% HCs (P = .11). Spike-specific CD4⁺ TCR expansion was similar between KTRs and HCs, yet KTR CD8⁺ TCR depth was 7.6-fold lower (P = .001). Global negative response was seen in 7% KTRs, associated with high-dose MMF (P = .037); 44% showed global positive response. Of the KTRs, 16% experienced breakthrough infections, with 2 hospitalizations; prebreakthrough variant neutralization was poor. Absent neutralizing and CD8⁺ responses in KTRs indicate vulnerability to COVID-19 despite 3-dose mRNA vaccination. Lack of neutralization despite CD4⁺ expansion suggests B cell dysfunction and/or ineffective T cell help. Development of more effective KTR vaccine strategies is critical. (NCT04969263).

BACKGROUND:Medication non-adherence contributes to post-transplant graft rejection and failure; however, limited knowledge about the reasons for non-adherence hinders the development of interventions to improve adherence. We conducted focus groups with solid organ transplant recipients regarding overlooked challenges in the process of transplant medication self-management and examined their adherence strategies and perceptions towards the post-transplant medication regimen. METHODS:We conducted four focus groups with n = 31 total adult transplant recipients. Participants had received kidney, liver, or combined liver/kidney transplant at Johns Hopkins Hospital between 2014 and 2019. Focus groups were audio-recorded and transcribed. Transcripts were analyzed inductively, using the constant comparative method. RESULTS:Responses generally fell into two major categories: (1) barriers to adherence and (2) "adherence landscape". We define the former as factors directly labeled as barriers to adherence by participants and the latter as factors that heavily influence the post-transplant medication self-management process. CONCLUSIONS:We propose a shift in the way healthcare providers and researchers, address the question of medication non-adherence. Rather than asking why patients are non-adherent, we suggest that constructing and understanding patients' "adherence landscape" will provide an optimal way to align the goals of patients and providers and boost health outcomes.

Purpose of Review: Irreversible cognitive impairment is a contraindication to liver transplantation, but growing evidence suggests many etiologies of liver disease have cognitive manifestations independent of hepatic encephalopathy and with variable reversibilities. Recent Findings: While cognitive sequelae of chronic alcohol use have long been recognized, cognitive dysfunction associated with other liver disease etiologies such as chronic hepatitis C infection, non-alcoholic fatty liver disease, and primary biliary cirrhosis has been recognized. While mechanisms vary and are incompletely understood, inflammation appears to play a central role in causing cognitive dysfunction associated with these diseases. Summary: Further research is needed to determine optimal cognitive assessment tools for patients with liver disease, identify patients at greatest risk for cognitive impairment, determine which elements of cognitive impairment are reversible, and identify effective therapies. This information will inform neurologic evaluation at time of liver transplant evaluation as well as expectations for neurologic recovery post-transplant.

Purpose of Review: This review presents an overview of the clinical syndrome of frailty and its association with kidney transplantation outcomes, recent developments in refining frailty assessment, and considerations for its implementation into kidney transplant evaluation. Recent Findings: Recent studies show that frailty is associated with adverse clinical outcomes before and after kidney transplantation, including decreased likelihood of listing and increased risks of mortality. However, frailty assessment has yet to be fully adopted by transplant centers; a study found that 40.9% of centers reported never assessing frailty at evaluation of kidney transplant candidates. Geriatric transplant experts and kidney transplant candidates agree that frailty is a valid consideration for evaluating candidacy. Summary: While frailty is an important consideration for treatment of patients with end-stage renal disease, its use in kidney transplant evaluation remains under-utilized. Future research is necessary to refine the frailty phenotype for effective integration into a kidney transplant context.

Background: Pediatric transplant candidates have historically been disadvantaged on the transplant waitlist, with nearly half of pediatric deceased donor organs allocated to adult recipients (Hsu, Gastroenterology, 2017), and allocation pediatric end-stage liver disease (PELD) scores that underestimate children's expected 3-month mortality compared to that of adult patients (Chang, JAMA Pediatrics, 2018). Disparities in organ distribution prompted revision of the liver allocation policy in 2020 from donation services areas (DSA) to a series of distance-based concentric circles called acuity circles (AC) before being offered nationally (US GAO, 2022), which was designed to minimize geographic inequity in liver transplant. Prior to implementation of the new liver allocation policy, analysis using the Liver Simulated Allocation Model projected that AC allocation would decrease disparities for pediatric liver transplant candidates and recipients by increasing transplants and decreasing waitlist mortality (Mogul, Transplantation, 2020). In this study, we evaluate differences in pediatric whole liver transplants performed before and after the implementation of acuity circle liver allocation policy.
Study Design: We evaluated patient characteristics, adjusted MELD/PELD at time of transplant, calculated donor age at time of transplant among pediatric whole liver transplant recipients in low versus high-volume pediatric liver transplant centers performed before and after implementation of AC-based liver allocation policy using the Scientific Registry of Transplant Recipients.
Result(s): Before and after the implementation of ACs, differences in pediatric liver transplants by age group (<2 years, 2-5 years old, 5-12 years old, and 12-18 years old) remained significantly different between low and high-volume pediatric transplant centers. Under DSA allocation policy, the median MELD/PELD at transplant was 37.0 (IQR 30.0-41.0) in low-volume centers and 40.0 (IQR 30.0-41.0) in high-volume centers. After the implementation of acuity circles, median MELD/PELD at transplant decreased to 35.0 (IQR 21.0-41.0) in low-volume centers and 35.0 (IQR 25.0-41.0) in high-volume centers. Finally, donor age at time of transplant increased from 8.0 (IQR 2.00-18.0) to 13.5 (IQR 4.5-21.0) at low-volume centers, and from 3.0 (IQR 1.0-14.0) to 4.0 (IQR 1.0-14.0) at high-volume centers before and after the implementation of ACs.
Conclusion(s): The change from DSAs to ACs in allocation policy and the shift from regional to national review boards have affected the characteristics of organ recipients, adjusted MELD/PELD at time of transplant, and donor age at time of transplant differentially between whole liver transplant recipients at low-and high-volume pediatric liver transplant centers

Neutralizing antibody (nAb) responses are attenuated in solid organ transplant recipients (SOTRs) despite severe acute respiratory syndrome-coronavirus-2 vaccination. Preexposure prophylaxis (PrEP) with the antibody combination tixagevimab and cilgavimab (T+C) might augment immunoprotection, yet in vitro activity and durability against Omicron sublineages BA.4/5 in fully vaccinated SOTRs have not been delineated. Vaccinated SOTRs, who received 300 + 300 mg T+C (ie, full dose), within a prospective observational cohort submitted pre and postinjection samples between January 31, 2022, and July 6, 2022. The peak live virus nAb was measured against Omicron sublineages (BA.1, BA.2, BA.2.12.1, and BA.4), and surrogate neutralization (percent inhibition of angiotensin-converting enzyme 2 receptor binding to full length spike, validated vs live virus) was measured out to 3 months against sublineages, including BA.4/5. With live virus testing, the proportion of SOTRs with any nAb increased against BA.2 (47%-100%; P < .01), BA.2.12.1 (27%-80%; P < .01), and BA.4 (27%-93%; P < .01), but not against BA.1 (40%-33%; P = .6). The proportion of SOTRs with surrogate neutralizing inhibition against BA.5, however, fell to 15% by 3 months. Two participants developed mild severe acute respiratory syndrome-coronavirus-2 infection during follow-up. The majority of fully vaccinated SOTRs receiving T+C PrEP achieved BA.4/5 neutralization, yet nAb activity commonly waned by 3 months postinjection. It is critical to assess the optimal dose and interval of T+C PrEP to maximize protection in a changing variant climate.

Background Pre-liver transplant (LT) sarcopenia is associated with poor survival. Methods exist for measuring body composition with use of CT scans; however, it is unclear which components best predict post-LT outcomes. Purpose To quantify the association between abdominal CT-based body composition measurements and post-LT mortality in a large North American cohort. Materials and Methods This was a retrospective cohort of adult first-time deceased-donor LT recipients from 2009 to 2018 who underwent pre-LT abdominal CT scans, including at the L3 vertebral level, at Johns Hopkins Hospital. Measurements included sarcopenia (skeletal muscle index [SMI] <50 in men and <39 in women), sarcopenic obesity, myosteatosis (skeletal muscle CT attenuation <41 mean HU for body mass index [BMI] <25 and <33 mean HU for BMI ≥25), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and VAT/SAT ratio. Covariates in the adjusted models were selected with use of least absolute shrinkage and selection operator regression with lambda chosen by means of 10-fold cross-validation. Cox proportional hazards models were used to quantify associations with post-LT mortality. Model discrimination was quantified using the Harrell C-statistic. Results A total of 454 recipients (median age, 57 years [IQR, 50-62 years]; 294 men) were evaluated. In the adjusted model, pre-LT sarcopenia was associated with a higher hazard ratio (HR) of post-LT mortality (HR, 1.6 [95% CI: 1.1, 2.4]; C-statistic, 0.64; P = .02). SMI was significantly negatively associated with survival after adjustment for covariates. There was no evidence that myosteatosis was associated with mortality (HR, 1.3 [95% CI: 0.86, 2.1]; C-statistic, 0.64; P = .21). There was no evidence that BMI (HR, 1.2 [95% CI: 0.95, 1.4]), VAT (HR, 1.0 [95% CI: 0.98, 1.1]), SAT (HR, 1.0 [95% CI: 0.97, 1.0]), and VAT/SAT ratio (HR, 1.1 [95% CI: 0.90, 1.4]) were associated with mortality (P = .15-.77). Conclusions Sarcopenia, as assessed on routine pre-liver transplant (LT) abdominal CT scans, was the only factor significantly associated with post-LT mortality. © RSNA, 2022 See also the editorial by Ruehm in this issue.