Faculty Bibliography

Purpose: Blood type B candidates on the deceased donor kidney waitlist have a lower transplantation rate and longer wait time than candidates of other blood types. The new national kidney allocation system (KAS), implemented in December 2014, prioritizes the allocation of kidneys from blood type A2 and A2B deceased donors to blood type B candidates to mitigate this disparity in access to transplantation. We analyzed our center's data to determine whether blood type A2/A2B to B transplantation is clinically feasible without the need for additional immunosuppression.
Method(s): We conducted a single-center retrospective cohort study to analyze the utilization and outcomes in A2/A2B to B deceased donor renal transplants. Data on adult, kidney-only recipients were extracted with custom reports from the United Network for Organ transplantation (UNOS) portal. We used multivariable Coxproportional hazards models to compare graft and patient survival in blood type A2/A2B to B deceased donor renal transplants to survival in blood type B to B transplants. We estimated Kaplan-Meier (KM) graft and patient survival functions.
Result(s): Since 2015, our center has performed 44 A2/A2B to B and 65 B to B kidney transplants. We followed the patients for a median of 712 days (IQR 343-1143). Recipients of A2/A2B to B and B to B kidney transplants were similar with respect to age, gender, estimated post-transplant survival (EPTS), calculated panel reactive antibody (CPRA), HLA ABDR mismatch, kidney donor profile index (KDPI), and the incidence of delayed graft function (DGF). A higher percentage of A2/A2B to B transplant recipients were Black/African American (22/44, 50%) than B to B transplant recipients (14/65, 21.5%). Blood type A2/A2B to B and B to B transplant recipients had similar 1-year graft (97.7% vs. 93.8%, p=0.34) and 1-year patient survival (97.7% vs. 98.5%, p=0.78) rates. Multivariable models adjusted for race/ ethnicity showed that death censored graft survival (adjusted HR=1.45, p=0.70, 95% CI=0.21 to 9.82) and patient survival (4.22, p=0.14, 95% CI=0.64 to 27.92) in A2/A2B to B transplant recipients were similar to the traditionally ABO blood type compatible B to B transplants.
Conclusion(s): The NYU Langone blood type A2/A2B to B transplantation adds to the body of evidence suggesting that blood type A2/A2B to B transplantation is clinically feasible. This provision of the KAS appears to be having its intended effect of increasing access to transplantation in blood type B candidates with no attendant compromise in overall patient or death censored graft survival

Purpose: Utilization of HCV viremic donor kidneys for transplant into HCV naive recipients has become more widespread, yet best practices governing the initiation, timing or duration of direct acting antiviral (DAA) therapy are lacking. Most published series describe DAA initiation weeks to months after transplant. However, fibrosing cholestatic hepatitis has been reported with delayed DAA initiation. Herein we report our center practice utilizing donor blood for HCV genotyping to expedite DAA insurance approval and minimize the duration of recipient viremia.
Method(s): Patients received education and DAA insurance benefits were ensured prior to listing for HCV+ organs. At the time of transplant, donor blood accompanying the kidney was used for HCV genotyping. Results were received within one week of transplant. Recipients were screened for HCV RNA by POD#4, and weekly for 12 weeks. Insurance authorization for DAA coverage was sought after both recipient viremia and donor HCV genotyping resulted. In 3 cases, donor viral load was insufficient for genotyping, and these recipients were genotyped once viremic.
Result(s): 80 hepatitis C naive patients received hepatitis C positive donor kidneys between July, 2018 and October, 2020. 17 donors were HCV Ab+/NAT-and 63 donors were HCV Ab+/NAT+. All recipients of NAT+ donor organs became viremic; 89% were genotype 1a or 3. The median time to DAA initiation was 10 days for cases with donor genotyping (IQR 8-13). In contrast, the median time to DAA initiation was 20 days for the 3 cases with recipient genotyping (IQR 18-24). Median time from transplant to clearance of HCV viremia was 38 days (IQR 30-47) (Table 1). SVR12 was achieved in all patients, and no cases of fibrosing cholestatic hepatitis have been observed. There were 2 needlestick exposures of patient family members, though no HCV transmission occurred.
Conclusion(s): Early HCV genotyping using donor blood results in expedited initiation of DAA therapy for recipients of HCV+ kidneys. Compared to published reports, our patients are clearing viremia at the time that most other centers' patients are initiating DAA therapy. Whether duration of viremia or peak viral load are associated with adverse allograft events such as acute rejection is not known. The advantages to a shortened duration of HCV viremia remain to be characterized, but may include a lower risk of fibrosing cholestatic hepatitis and lower risk of HCV exposure to family members and caregivers. Our practice of expedited genotyping using donor blood is immediately implementable at all centers performing these transplants. (Table Presented)

The increasing global prevalence of SARS-CoV-2 and the resulting COVID-19 disease pandemic pose significant concerns for clinical management of solid organ transplant recipients (SOTR). Wearable devices that can measure physiologic changes in biometrics including heart rate, heart rate variability, body temperature, respiratory, activity (such as steps taken per day) and sleep patterns, and blood oxygen saturation show utility for the early detection of infection before clinical presentation of symptoms. Recent algorithms developed using preliminary wearable datasets show that SARS-CoV-2 is detectable before clinical symptoms in >80% of adults. Early detection of SARS-CoV-2, influenza, and other pathogens in SOTR, and their household members, could facilitate early interventions such as self-isolation and early clinical management of relevant infection(s). Ongoing studies testing the utility of wearable devices such as smartwatches for early detection of SARS-CoV-2 and other infections in the general population are reviewed here, along with the practical challenges to implementing these processes at scale in pediatric and adult SOTR, and their household members. The resources and logistics, including transplant-specific analyses pipelines to account for confounders such as polypharmacy and comorbidities, required in studies of pediatric and adult SOTR for the robust early detection of SARS-CoV-2, and other infections are also reviewed.

Despite utilization of hepatitis C viremic organs for hepatitis C naïve recipients (HCV D+/R-) in other solid organ transplants, HCV viremic pancreata remain an unexplored source of donor organs. This study reports the first series of HCV D+/R- pancreas transplants. HCV D+/R- had shorter wait list times compared to HCV D-/R-, waiting a mean of 16 days from listing for HCV positive organs. HCV D+/R- had a lower match allocation sequence than HCV D-/R-, and this correlated to receipt of organs with a lower Pancreas Donor Risk Index (PDRI) score. All HCV D+R- had excellent graft function with a mean follow up of 438 days and had undetectable HCV RNA levels by a mean of 23 days after initiation of HCV-directed therapy. The rates of infectious complications, re-operation, readmission, rejection, and length of stay were not impacted by donor HCV status. A national review of potential ideal pancreas donors found that 37% of ideal HCV negative pancreas allografts were transplanted, compared to only 5% of ideal HCV positive pancreas allografts. The results of the current study demonstrate the safety of accepting HCV positive pancreata for HCV naïve recipients and advocates for increased utilization of ideal HCV positive pancreas allografts.

Desensitization has enabled incompatible living donor kidney transplantation (ILDKT) across HLA/ABO barriers, but added immunomodulation might put patients at increased risk of infections. We studied 475 recipients from our center from 2010 to 2015, categorized by desensitization intensity: none/compatible (n = 260), low (0-4 plasmaphereses, n = 47), moderate (5-9, n = 74), and high (≥10, n = 94). The 1-year cumulative incidence of infection was 50.1%, 49.8%, 66.0%, and 73.5% for recipients who received none, low, moderate, and high-intensity desensitization (P < .001). The most common infections were UTI (33.5% of ILDKT vs. 21.5% compatible), opportunistic (21.9% vs. 10.8%), and bloodstream (19.1% vs. 5.4%) (P < .001). In weighted models, a trend toward increased risk was seen in low (wIRR = _0.77 1.40_2.56 ,P = .3) and moderately (wIRR = _0.88 1.35_2.06 ,P = .2) desensitized recipients, with a statistically significant 2.22-fold (wIRR = _1.33 2.22_3.72 ,P = .002) increased risk in highly desensitized recipients. Recipients with ≥4 infections were at higher risk of prolonged hospitalization (wIRR = _2.62 3.57_4.88 , P < .001) and death-censored graft loss (wHR = _1.15 4.01_13.95 ,P = .03). Post-KT infections are more common in desensitized ILDKT recipients. A subset of highly desensitized patients is at ultra-high risk for infections. Strategies should be designed to protect patients from the morbidity of recurrent infections, and to extend the survival benefit of ILDKT across the spectrum of recipients.

Incompatible living donor kidney transplant recipients (ILDKTr) have pre-existing donor-specific antibody (DSA) that, despite desensitization, may persist or reappear with resulting consequences, including delayed graft function (DGF) and acute rejection (AR). To quantify the risk of DGF and AR in ILDKT and downstream effects, we compared 1406 ILDKTr to 17 542 compatible LDKT recipients (CLDKTr) using a 25-center cohort with novel SRTR linkage. We characterized DSA strength as positive Luminex, negative flow crossmatch (PLNF); positive flow, negative cytotoxic crossmatch (PFNC); or positive cytotoxic crossmatch (PCC). DGF occurred in 3.1% of CLDKT, 3.5% of PLNF, 5.7% of PFNC, and 7.6% of PCC recipients, which translated to higher DGF for PCC recipients (aOR = _1.03 1.68_2.72 ). However, the impact of DGF on mortality and DCGF risk was no higher for ILDKT than CLDKT (p interaction > .1). AR developed in 8.4% of CLDKT, 18.2% of PLNF, 21.3% of PFNC, and 21.7% of PCC recipients, which translated to higher AR (aOR PLNF = _1.45 2.09_3.02 ; PFNC = _1.67 2.40_3.46 ; PCC = _1.48 2.24_3.37 ). Although the impact of AR on mortality was no higher for ILDKT than CLDKT (p interaction = .1), its impact on DCGF risk was less consequential for ILDKT (aHR = _1.34 1.62_1.95 ) than CLDKT (aHR = _1.96 2.29_2.67 ) (p interaction = .004). Providers should consider these risks during preoperative counseling, and strategies to mitigate them should be considered.

BACKGROUND:Desensitization protocols for HLA-incompatible living donor kidney transplantation (ILDKT) vary across centers. The impact of these, as well as other practice variations, on ILDKT outcomes remain unknown. METHODS:We sought to quantify center-level variation in mortality and graft loss following ILDKT using a 25-center cohort of 1358 ILDKT recipients with linkage to SRTR for accurate outcome ascertainment. We used multilevel Cox regression with shared frailty to determine the variation in post-ILDKT outcomes attributable to between-center differences, and to identify any center-level characteristics associated with improved post-ILDKT outcomes. RESULTS:After adjusting for patient-level characteristics, only 6 centers (24%) had lower mortality and 1 (4%) had higher mortality than average. Similarly, only 5 centers (20%) had higher graft loss and 2 had lower graft loss than average. Only 4.7% of the differences in mortality (p<0.01) and 4.4% of the differences in graft loss (p<0.01) were attributable to between-center variation. These translated to a median hazard ratio of 1.36 for mortality and 1.34 of graft loss for similar candidates at different centers. Post-ILDKT outcomes were not associated with the following center-level characteristics: ILDKT volume and transplanting a higher proportion of highly sensitized, prior transplant, preemptive, or minority candidates. CONCLUSION/CONCLUSIONS:Unlike most aspects of transplantation where center-level variation and volume impact outcomes, we did not find substantial evidence for this in ILDKT. Our findings support the continued practice of ILDKT across these diverse centers.

BACKGROUND:The Lung Allocation Score (LAS) significantly improved outcomes and waitlist mortality in lung transplantation. However, mortality remains high for the sickest waitlist candidates despite additional changes to allocation distance. Regulatory considerations of overhauling the current lung allocation system has met significant resistance, and would require years to implement. This study evaluates if a modest change to the current system by prioritization of only high-LAS lung transplant candidates would result in lowered waitlist mortality. METHODS:The Thoracic Simulated Allocation Model was used to evaluate all lung transplant candidates and donor lungs recovered between July 1, 2009 and June 30, 2011. Current lung allocation rules (initial offer within 250 nautical-mile radius for ABO-identical then compatible offers) were run. Allocation was then changed for only patients with an LAS≥50 (high-LAS) to be prioritized within a 500 nautical-mile radius with no stratification between ABO-identical and compatible offers. Ten iterations of each model were run. Primary endpoints were waitlist mortality and post-transplant 1-year survival. RESULTS:6,538 waitlist candidates and transplant recipients were evaluated per iteration, for a total of 130,760 simulated patients. Compared with current allocation, the adjusted model had a 23.3% decrease in waitlist mortality. Post-transplant 1-year survival was minimally affected. CONCLUSIONS:Without overhauling the entire system, simple prioritization changes to the allocation system for high-LAS candidates may lead to decreased waitlist mortality and increased organ utilization. Importantly, these changes do not appear to lead to clinically significant changes in post-transplant 1-year survival.

BACKGROUND:Coronavirus disease 2019 (Covid-19) remains a worldwide pandemic with a high mortality rate among patients requiring mechanical ventilation. The limited data that exists regarding the utility of extracorporeal membrane oxygenation (ECMO) in these critically ill patients shows poor overall outcomes. This paper describes our institutional practice regarding the application and management of ECMO support for patients with Covid-19 and reports promising early outcomes. METHODS:>60 mmHg with no life-limiting comorbidities. Patients were cannulated at bedside and were managed with protective lung ventilation, early tracheostomy, bronchoscopies and proning as clinically indicated. RESULTS:Of 321 patients intubated for Covid-19, 77 (24%) patients were evaluated for ECMO support with 27 (8.4%) patients placed on ECMO. All patients were placed on veno-venous ECMO. Current survival is 96.3%, with only one mortality to date in over 350 days of total ECMO support. Thirteen patients (48.1%) remain on ECMO support, while 13 patients (48.1%) have been successfully decannulated. Seven patients (25.9%) have been discharged from the hospital. Six patients (22.2%) remain in the hospital of which four are on room-air. No healthcare workers that participated in ECMO cannulation developed symptoms of or tested positive for Covid-19. CONCLUSIONS:The early outcomes presented here suggest that the judicious use of ECMO support in severe Covid-19 may be clinically beneficial.