Faculty Bibliography

BACKGROUND/UNASSIGNED:Living kidney donation is possible for people living with HIV (PLWH) in the United States within research studies under the HIV Organ Policy Equity (HOPE) Act. There are concerns that donor nephrectomy may have an increased risk of end-stage renal disease (ESRD) in PLWH due to HIV-associated kidney disease and antiretroviral therapy (ART) nephrotoxicity. Here we report the first 3 cases of living kidney donors with HIV under the HOPE Act in the United States. METHODS/UNASSIGNED:Within the HOPE in Action Multicenter Consortium, we conducted a prospective study of living kidney donors with HIV. Pre-donation, we estimated the 9-year cumulative incidence of ESRD, performed genetic testing of apolipoprotein L1 (APOL1), excluding individuals with high-risk variants, and performed pre-donation kidney biopsies (HOPE Act requirement). The primary endpoint was ≥grade 3 nephrectomy-related adverse events (AEs) in year one. Post-donation, we monitored glomerular filtration rate (measured by iohexol/Tc-99m DTPA [mGFR] or estimated with serum creatinine [eGFR]), HIV RNA, CD4 count, and ART. FINDINGS/UNASSIGNED: at two years (eGFR) in donor 3. HIV RNA remained <20 copies/mL and CD4 count remained stable in all donors. INTERPRETATION/UNASSIGNED:The first three living kidney donors with HIV under the HOPE Act in the United States have had promising outcomes at two-four years, providing proof-of-concept to support living donation from PLWH to recipients with HIV. FUNDING/UNASSIGNED:National Institute of Allergy and Infectious Diseases, National Institutes of Health.

The latent viral reservoir(LVR) remains a major barrier to HIV-1 curative strategies. It is unknown whether receiving a liver transplant from a donor with HIV might lead to an increase in the LVR since the liver is a large lymphoid organ. We found no differences in intact provirus, defective provirus, or the ratio of intact to defective provirus between recipients with ART-supporesed HIV who received a liver from a donor with(n = 19) or without HIV(n = 10). All measures remained stable from baseline by one-year post transplant. These data demonstrate that the LVR is stable after liver transplantation in people living with HIV.

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

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.

UNLABELLED:Following the outbreak of coronavirus disease 2019 (COVID-19) in the United States, the number of kidney waitlist additions and living-donor and deceased-donor kidney transplants (LDKT/DDKT) decreased substantially but began recovering within a few months. Since then, there have been several additional waves of infection, most notably, the Delta and Omicron surges beginning in August and December 2021, respectively. METHODS/UNASSIGNED:Using SRTR data, we compared observed waitlist registrations, waitlist mortality, waitlist removal due to deteriorating condition, LDKT, and DDKT over 5 distinct pandemic periods to expected events based on calculations from preepidemic data while accounting for seasonality and secular trends. RESULTS/UNASSIGNED:). CONCLUSIONS/UNASSIGNED:Despite exceptionally high COVID-19 incidence during the Omicron wave, the transplant system responded similarly to prior waves that imposed a lesser disease burden, demonstrating the transplant system's growing adaptations and resilience to this now endemic disease.

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).

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:Tixagevimab and Cilgavimab (T + C) is authorized for pre-exposure prophylaxis (PrEP) against Coronavirus Disease 2019 (COVID-19) in solid organ transplant recipients (SOTRs), yet patient-reported outcomes after injection are not well described. Furthermore, changes in risk tolerance after T + C PrEP have not been reported, of interest given uncertain activity against emerging Omicron sublineages. METHODS:Within a national prospective observational study, SOTRs who reported receiving T + C were surveyed for 3 months to ascertain: (1) local and systemic reactogenicity, (2) severe adverse events with focus on cardiovascular and alloimmune complications, and (3) breakthrough COVID-19, contextualized through (4) changes in attitudes regarding COVID-19 risk and behaviors. RESULTS:At 7 days postinjection, the most common reactions were mild fatigue (29%), headache (20%), and pain at injection sites (18%). Severe adverse events were uncommon; over 3 months of follow-up, 4/392 (1%) reported acute rejection and one (.3%) reported a myocardial infarction. Breakthrough COVID-19 occurred in 9%, 16-129 days after receiving full dose (300/300 mg) T + C, including two non-ICU hospitalizations. Most surveyed SOTRs (65%) felt T + C PrEP was likely to reduce their COVID-19 risk, and 70% reported increased willingness to engage in social activities such as visiting friends. However, few felt safe to return to in-person work (20%) or cease public mask-wearing (15%). CONCLUSIONS:In this prospective study of patient-reported outcomes, T + C was well tolerated with few serious events. Several COVID-19 breakthroughs were reported, notable as most SOTRs reported changes in risk tolerance after T + C. These results aid counseling of SOTRs regarding real-world safety and effectiveness of T + C.

BACKGROUND AND AIMS/OBJECTIVE:Identifying international differences in utilization and outcomes of liver transplantation (LT) after donation after circulatory death (DCD) donation provides a unique opportunity for benchmarking and population-level insight. METHODS:Adult (≥18 years) LT data between 2008 and 2018 from the UK and US were used to assess mortality and graft failure after DCD LT. We used time-dependent Cox-regression methods to estimate hazard ratios (HR) for risk-adjusted short-term (0-90 days) and longer-term (90 days-5 years) outcomes. RESULTS:One-thousand five-hundred-and-sixty LT receipts from the UK and 3426 from the US were included. Over the study period, the use of DCD livers increased from 15.7% to 23.9% in the UK compared to 5.1% to 7.6% in the US. In the UK, DCD donors were older (UK:51 vs. US:33 years) with longer cold ischaemia time (UK: 437 vs. US: 333 min). Recipients in the US had higher Model for End-stage Liver Disease (MELD) scores, higher body mass index, higher proportions of ascites, encephalopathy, diabetes and previous abdominal surgeries. No difference in the risk-adjusted short-term mortality or graft failure was observed between the countries. In the longer-term (90 days-5 years), the UK had lower mortality and graft failure (adj.mortality HR:UK: 0.63 (95% CI: 0.49-0.80); graft failure HR: UK: 0.72, 95% CI: 0.58-0.91). The cumulative incidence of retransplantation was higher in the UK (5 years: UK: 11.9% vs. 4.6%; p < .001). CONCLUSIONS:For those receiving a DCD LT, longer-term post-transplant outcomes in the UK are superior to the US, however, significant differences in recipient illness, graft quality and access to retransplantation were seen between the two countries.