Faculty Bibliography

Donor/recipient incompatibility in kidney transplantation classically refers to ABO/HLA-incompatibility. Kidney paired donation (KPD) was historically established to circumvent ABO/HLA-incompatibility, with the goal of identifying ABO/HLA-compatible matches. However, there is a broad range of donor factors known to impact recipient outcomes beyond ABO/HLA-incompatibility, such as age and weight, and quantitative tools are now available to empirically compare potential living donors across many of these factors, such as the living donor kidney donor profile index (LKDPI). Moreover, the detrimental impact of mismatch at other HLA antigens (such as DQ) and epitope mismatching on posttransplant outcomes has become increasingly recognized. Thus, it is time for a new paradigm of incompatibility that considers all of these risks factors together in assessing donor/recipient compatibility and the potential utility for KPD. Under this new paradigm of incompatibility, we show how the LKDPI and other tools can be used to identify donor/recipient incompatibilities that could be improved through KPD, even for those with a traditionally "compatible" living donor.

Background/UNASSIGNED:Posttransplant diabetes (PTD), a major complication after kidney transplantation (KT), is often attributable to immunosuppression. The risk of PTD may increase with more potent steroid maintenance and older recipient age. Methods/UNASSIGNED:Using United States Renal Data System data, we studied 12 488 adult first-time KT recipients (2010-2015) with no known pre-KT diabetes. We compared the risk of PTD among recipients who underwent early steroid withdrawal (ESW) versus continued steroid maintenance (CSM) using Cox regression with inverse probability weighting to adjust for confounding. We tested whether the risk of PTD resulting from ESW differed by recipient age (18-29, 30-54, and ≥55 y). Results/UNASSIGNED:). Conclusions/UNASSIGNED:The beneficial association of ESW with decreased PTD was more pronounced among recipients aged ≥55, supporting an age-specific assessment of the risk-benefit balance regarding ESW.

Patient and graft survival are similar following whole versus split liver transplants (SLT) among pediatric and adult recipients, yet SLTs are rarely used. We sought to determine the survival benefit associated with accepting a splittable offer for SLT versus declining and waiting for a subsequent offer using 2010-2018 SRTR data on 928 pediatric and 1814 adult LT candidates who were ever offered a splittable graft. We compared eventual mortality, regardless of subsequent transplants, between those who accepted versus declined a splittable liver offer with adjustment for PELD/MELD, diagnosis, and weight among pediatric candidates, and matching for MELD, height, and offer among adult candidates. Among pediatric candidates ≤7kg, splittable offer acceptance versus decline was associated with a 63% reduction in mortality (aHR _0.17 0.37_0.80 , p=0.01; 93.1% versus 84.0% one-year survival post-decision). Within one year of decline for those ≤7kg, 6.4% died and 31.1% received a whole liver transplant. Among pediatric candidates >7kg, there was no significant difference associated with acceptance of a splittable offer (aHR _0.63 1.07_1.82 , p=0.81; 91.7% vs 94.4% one-year survival post-decision). Within one year of decline for those >7kg, 1.8% died and 45.8% received a whole liver. Among adult candidates, splittable offer acceptance was associated with a 43% reduction in mortality (aHR _0.39 0.57_0.83, p=0.005; 92.2% vs 84.4% one-year survival post-decision). Within one year of decline for adult candidates, 7.9% died and 39.3% received a whole liver. Conclusion: Accepting splittable offers for SLT could significantly improve survival for small children and adults on the waitlist.

OBJECTIVES:The COVID-19 pandemic significantly affected the provisions of health services to necessary but deprioritised fields, such as transplantation. Many programmes had to ramp-down their activity, which may significantly affect transplant volumes. We aimed to pragmatically analyse measures of transplant activity and compare them by a country's income level and cumulative COVID-19 incidence (CCI). DESIGN, SETTING AND PARTICIPANTS:From June to September 2020, we surveyed transplant physicians identified as key informants in their programmes. Of the 1267 eligible physicians, 40.5% from 71 countries participated. OUTCOME:Four pragmatic measures of transplant activity. RESULTS:Overall, 46.5% of the programmes from high-income countries anticipate being able to maintain >75% of their transplant volume compared with 31.6% of the programmes from upper-middle-income countries, and with 21.7% from low/lower-middle-income countries (p<0.001). This could be because more programmes in high-income countries reported being able to perform transplantation/s (86.8%%-58.5%-67.9%, p<0.001), maintain prepandemic deceased donor offers (31.0%%-14.2%-26.4%, p<0.01) and avoid a ramp down phase (30.9%%-19.7%-8.3%, p<0.001), respectively. In a multivariable analysis that adjusted for CCI, programmes in upper-middle-income countries (adjusted OR, aOR=0.47, 95% CI 0.27 to 0.81) and low/lower-middle-income countries (aOR 0.33, 95% CI 0.16 to 0.67) had lower odds of being able to maintain >75% of their transplant volume, compared with programmes in high-income countries. Again, this could be attributed to lower-income being associated with 3.3-3.9 higher odds of performing no transplantation/s, 66%-68% lower odds of maintaining prepandemic donor offers and 37%-76% lower odds of avoiding ramp-down of transplantation. Overall, CCI was not associated with these measures. CONCLUSIONS:The impact of the pandemic on transplantation was more in lower-income countries, independent of the COVID-19 burden. Given the lag of 1-2 years in objective data being reported by global registries, our findings may inform practice and policy. Transplant programmes in lower-income countries may need more effort to rebuild disrupted services and recuperate from the pandemic even if their COVID-19 burden was low.

Background/UNASSIGNED:Few reports have focused on newer coronavirus disease 2019 (COVID-19) therapies (remdesivir, dexamethasone, and convalescent plasma) in solid organ transplant recipients; concerns had been raised regarding possible adverse impact on allograft function or secondary infections. Methods/UNASSIGNED:We studied 77 solid organ transplant inpatients with COVID-19 during 2 therapeutic eras (Era 1: March-May 2020, 21 patients; and Era 2: June-November 2020, 56 patients) and 52 solid organ transplant outpatients. Results/UNASSIGNED:In Era 1, no patients received remdesivir or dexamethasone, and 4 of 21 (19.4%) received convalescent plasma, whereas in Era 2, remdesivir (24/56, 42.9%), dexamethasone (24/56, 42.9%), and convalescent plasma (40/56, 71.4%) were commonly used. Mortality was low across both eras, 4 of 77 (5.6%), and rejection occurred in only 2 of 77 (2.8%) inpatients; infections were similar in hypoxemic patients with or without dexamethasone. Preexisting graft dysfunction was associated with greater need for hospitalization, higher severity score, and lower survival. Acute kidney injury was present in 37.3% of inpatients; renal function improved more rapidly in patients who received remdesivir and convalescent plasma. Post-COVID-19 renal and liver function were comparable between eras, out to 90 d. Conclusions/UNASSIGNED:Newer COVID-19 therapies did not appear to have a deleterious effect on allograft function, and infectious complications were comparable.

Physical frailty and impaired cognition are common in patients with cirrhosis. Physical frailty can be assessed using performance-based tests, but the extent to which impaired cognition may impact performance is not well characterized. We assessed the relationship between impaired cognition and physical frailty in patients with cirrhosis. We enrolled 1,623 ambulatory adult patients with cirrhosis waiting for liver transplantation at 10 sites. Frailty was assessed with the liver frailty index (LFI; "frail," LFI ≥ 4.4). Cognition was assessed at the same visit with the number connection test (NCT); continuous "impaired cognition" was examined in primary analysis, with longer NCT (more seconds) indicating worse impaired cognition. For descriptive statistics, "impaired cognition" was NCT ≥ 45 seconds. Linear regression associated frailty and impaired cognition; competing risk regression estimated subhazard ratios (sHRs) of wait-list mortality (i.e., death/delisting for sickness). Median NCT was 41 seconds, and 42% had impaired cognition. Median LFI (4.2 vs. 3.8) and rates of frailty (38% vs. 20%) differed between those with and without impaired cognition. In adjusted analysis, every 10-second NCT increase associated with a 0.08-LFI increase (95% confidence interval [CI], 0.07-0.10). In univariable analysis, both frailty (sHR, 1.63; 95% CI, 1.43-1.87) and impaired cognition (sHR, 1.07; 95% CI, 1.04-1.10) associated with wait-list mortality. After adjustment, frailty but not impaired cognition remained significantly associated with wait-list mortality (sHR, 1.55; 95% CI, 1.33-1.79). Impaired cognition mediated 7.4% (95% CI, 2.0%-16.4%) of the total effect of frailty on 1-year wait-list mortality. Conclusion: Patients with cirrhosis with higher impaired cognition displayed higher rates of physical frailty, yet frailty independently associated with wait-list mortality while impaired cognition did not. Our data provide evidence for using the LFI to understand mortality risk in patients with cirrhosis, even when concurrent impaired cognition varies.