Kidney transplant from HCV viremic donors to HCV-negative recipients and risk for de novo donor specific antibodies and acute rejection.

BACKGROUND: Kidney transplantation from HCV-viremic donors into uninfected recipients is associated with excellent short-term outcomes. However, concerns regarding an increased risk for the development of de novo donor specific antibodies (DSA) and acute rejection have been raised in single center reports. METHODS: A retrospective study of HCV-negative kidney-only transplant recipients between 2018 and 2020. Patients were grouped based on the donor HCV status into group 1; HCV-viremic donors, and group 2; HCV-negative donors. Inverse probability of treatment weighting (IPTW), with weights derived from the propensity score, were used to estimate the effect of donors' HCV-viremia on the recipients. The primary objective was to compare the 1-year incidence of de novo DSA. Secondary outcomes included group comparison of the incidence of biopsy proven acute rejection (BPAR), 1-year patient and allograft survival, and 1-year renal allograft function. RESULTS: A total of 71 patients were included in the HCV NAT+ group, and 440 in the HCV- negative group. One-year incidence of de novo DSA was higher in the HCV NAT+ group in the IPTW weighted analysis (19% vs. 9%, p = .02). In the unweighted analysis, BPAR occurred in 7% of recipients in the HCV NAT+ group, compared to 3% in the control group (p = .06). However, due to the low event rate in the in the IPTW weighted groups, a statistical significance test could not be performed. Average estimated GFR was higher in the HCV-viremic group at 3 months (61 vs. 53 ml/min/1.73 m2 p = .002), but comparable at 6 (59 vs. 56 ml/min/1.73 m2 , p = .31) and 12 months (60 vs. 55 ml/min/1.73 m2 , p = .07). Patient and allograft survival were comparable between the two groups. CONCLUSION: Kidney transplant from HCV-viremic donors was associated with an increased risk for the development of post-transplant de novo DSA in the first year after transplantation, but no difference in patient and graft survival.

Dynamic impact of liver allocation policy change on donor utilization.

Liver allocation policy was changed to reduce variance in median MELD scores at transplant (MMaT) in February 2020. "Acuity circles" replaced local allocation. Understanding the impact of policy change on donor utilization is important. Ideal (I), standard (S), and non-ideal (NI) donors were defined. NI donors include older, higher BMI donors with elevated transaminases or bilirubin, history of hepatitis B or C, and all DCD donors. Utilization of I, S, and NI donors was established before and after allocation change and compared between low MELD (LM) centers (MMaT ≤ 28 before allocation change) and high MELD (HM) centers (MMaT > 28). Following reallocation, transplant volume increased nationally (67 transplants/center/year pre, 74 post, p .0006) and increased for both HM and LM centers. LM centers significantly increased use of NI donors and HM centers significantly increased use of I and S donors. Centers further stratify based on donor utilization phenotype. A subset of centers increased transplant volume despite rising MMaT by broadening organ acceptance criteria, increasing use of all donor types including DCD donors (98% increase), increasing living donation, and transplanting more frequently for alcohol associated liver disease. Variance in donor utilization can undermine intended effects of allocation policy change.

Kidney transplant from hepatitis C viremic donors into aviremic recipients and risk for post-transplant BK and cytomegalovirus infection.

BACKGROUND: kidney transplantation from Hepatitis C virus (HCV) viremic donors to uninfected recipients is associated with excellent short-term outcomes. However, HCV viremia might be associated with an increased risk for post-transplant viral complications. METHODS: We designed a retrospective study of HCV-negative kidney-only transplant recipients between 2018 and 2020. Recipients were grouped into group 1; HCV-negative donors, and group 2; HCV-viremic donors. Patients were matched 1:1 using propensity score. The primary objectives were to compare the incidence of cytomegalovirus (CMV) viremia ≥ 200 ml/IU, and BK viremia ≥1000 copies/ml between the groups. Secondary outcomes included group comparison of CMV disease, BK viremia ≥10 000 copies/ml, and 1-year patient and allograft survival. RESULTS: The study included 634 patients in group 1, and 71 patients in group 2. Sixty-five pairs of patients were matched. Incidence of CMV viremia (33.3% vs. 40.0%, p = .4675), and BK viremia (15.9% vs. 27.7%, p = .1353) did not differ significantly between groups in the matched cohort. Incidence of CMV disease (81.0% vs. 76.9%, p = 1.000), and BK viremia ≥10 000 copies/ml (9.5% vs. 16.9%, p = .2987) were comparable between groups. There was no difference in the 1-year patient or allograft survival between groups. CONCLUSION: kidney transplant from HCV-viremic donors is not associated with increased risk for BK or CMV viremia.

The impact of donor and recipient diabetes on renal transplant outcomes.

The use of diabetic kidneys is increasing worldwide with better outcome than being on waitlist and possible reversal of diabetic changes in transplanted kidneys. But particular caution is warranted in diabetic donor-recipient combination. Total 1223 deceased donor kidney transplants were performed at our center between 2008 and 2018. 689 from non-diabetic donor (NDD) to non-diabetic recipient, 400 from non-diabetic donor to diabetic recipient, 97 from diabetic to non-diabetic recipient, and 32 from diabetic donor (DD) to diabetic recipient. The DD was older than NDDs (median age 48 vs 39 years, P < 0.0001). DD had higher BMI (35.6 vs 26.9, P < 0.0001), higher KDPI (74% vs 37%, P < 0.0001), and higher terminal creatinine (1.10 mg/dl vs 0.95 mg/dl, p 0.0046) than the NDD. Diabetes recipients were comparatively older (57 vs 54, P < 0.001). DD recipients had higher serum creatinine at 6 months (1.70 vs 1.50 mg/dl, p 0.00304) and 2 years post-transplant (1.70 vs 1.50 mg/dl P < 0.0002). DD recipients had more favorable end CPRA than NDD recipients (77.5% at 0% vs 67.4% at 0, P = 0.0074). Ten-year patient and graft survival was best in NDD-recipient pair and worse in DD-recipient pair. Diabetic donor kidneys to diabetic recipients have lower 1-, 3-, and 5-year graft survival.

Variation in DCD Liver Transplant Protocols Among Transplant Centers in the United States.

Background: Variation in donation after circulatory death (DCD) organ recovery and liver transplant practices exist among transplant centers. This study aimed to evaluate these practices among centers in the United States. Methods: Scientific Registry of Transplant Recipients data were accessed to identify centers that performed liver transplantation in 2021 and 2022. Surveys were sent to transplant centers that consistently performed ≥5 DCD liver transplants per year. Results: DCD liver transplants were performed by 95 centers (65.1%) of the 146 liver transplant centers in the United States. Survey results were recorded from 42 centers that consistently performed ≥5 DCD liver transplants per year, with a 59.5% response rate. Withdrawal-to-asystole and agonal time were used to define donor warm ischemia time (WIT) in 16% and 84% centers, respectively. Fifty-six percent of the centers did not use oxygen saturation to define donor WIT. Systolic blood pressure cutoffs used to define agonal time varied between 50 and 80 mm Hg, donor age cutoffs ranged between 55 and 75 y, and cold ischemia times varied between 4 and 10 h. Seventy-six percent of centers used normothermic machine perfusion for DCD liver transplantation. Conclusions: This study highlights the wide variation in use, recovery, and definition of donor WIT. Using national data to rigorously define best practices will encourage greater utilization of this important donor resource.

Textbook outcome: A novel metric in heart transplantation outcomes.

OBJECTIVE: Assessing heart transplant program quality using short-term survival is insufficient. We define and validate the composite metric textbook outcome and examine its association with overall survival. METHODS: We identified all primary, isolated adult heart transplants in the United Network for Organ Sharing/Organ Procurement and Transplantation Network Standard Transplant Analysis and Research files from May 1, 2005, to December 31, 2017. Textbook outcome was defined as length of stay 30 days or less; ejection fraction greater than 50% during 1-year follow-up; functional status 80% to 100% at 1 year; freedom from acute rejection, dialysis, and stroke during the index hospitalization; and freedom from graft failure, dialysis, rejection, retransplantation, and mortality during the first year post-transplant. Univariate and multivariate analyses were performed. Factors independently associated with textbook outcome were used to create a predictive nomogram. Conditional survival at 1 year was measured. RESULTS: A total of 24,620 patients were identified with 11,169 (45.4%, 95% confidence interval, 44.7-46.0) experiencing textbook outcome. Patients with textbook outcome were more likely free from preoperative mechanical support (odds ratio, 3.504, 95% confidence interval, 2.766 to 4.439, P < .001), free from preoperative dialysis (odds ratio, 2.295, 95% confidence interval, 1.868-2.819, P < .001), to be not hospitalized (odds ratio, 1.264, 95% confidence interval, 1.183-1.349, P < .001), to be nondiabetic (odds ratio, 1.187, 95% confidence interval, 1.113-1.266, P < .001), and to be nonsmokers (odds ratio, 1.160, 95% confidence interval,1.097-1.228, P < .001). Patients with textbook outcome have improved long-term survival relative to patients without textbook outcome who survive at least 1 year (hazard ratio for death, 0.547, 95% confidence interval, 0.504-0.593, P < .001). CONCLUSIONS: Textbook outcome is an alternative means of examining heart transplant outcomes and is associated with long-term survival. The use of textbook outcome as an adjunctive metric provides a holistic view of patient and center outcomes.

Outcomes After Deceased Donor Kidney Transplantation Using Kidney Allografts With Marginal Perfusion Parameters.

BACKGROUND: This study examines outcomes of deceased donor kidney transplantation (DDKT) in recipients of kidney allografts with marginal perfusion parameters. METHODS: Allografts with marginal perfusion parameters (resistance index [RI] >0.4 and pump flow rate [F] <70 mL/min; MP group) were compared with those with good parameters (RI <0.4 and F >70 mL/min; GP group) for DDKT recipients between January 1996 and November 2017 after hypothermic pulsatile perfusion. Demographics, creatinine, cold ischemia times (CIT), delayed graft function (DGF), and recipient glomerular filtration rate at pre- and post-transplant were noted. The primary outcome was graft survival post-transplant. RESULTS: In the MP (n = 31) versus GP (n = 1281) group, the median recipient was aged 57 years versus 51 years; the median donor was aged 47 versus 37 years; terminal creatinine was 0.9 versus 0.9 mg/dL; CIT was 10.2 versus 13 hours, and the RI and flow were 0.46 and 60 mL/min versus 0.21 and 120 mL/min. The DGF rate was 19% (MP) versus 8% (GP). The graft survival in the MP versus GP group was 81% versus 90% (1 year), 65% versus 79% (3 years), 65% versus 73% (4 years), and 45% versus 68% (5 years). CONCLUSION: Carefully selected kidney allografts after comprehensive donor and recipient evaluation may allow for the use of these routinely discarded kidneys with marginal perfusion parameters.

Textbook Outcome as a Quality Metric in Liver Transplantation.

Quality in liver transplantation (LT) is currently measured using 1-y patient and graft survival. Because patient and graft survival rates now exceed 90%, more informative metrics are needed. Textbook outcomes (TOs) describe ideal patient outcomes after surgery. This study critically evaluates TO as a quality metric in LT. Methods: United Network for Organ Sharing data for 25 887 adult LT recipients were used to define TO as patient and graft survival >1 y, length of stay ≤10 d, 0 readmissions within 6 mo, absence of rejection, and bilirubin <3 mg/dL between months 2 and 12 post-LT. Univariate analysis identified donor and recipient characteristics associated with TO. Covariates were analyzed using purposeful selection to construct a multivariable model, and impactful variables were incorporated as linear predictors into a nomogram. Five-year conditional survival was tested, and center TO rates were corrected for case complexity to allow for center-level comparisons. Results: The national average TO rate is 37.4% (95% confidence interval, 36.8%-38.0%). The hazard ratio for death at 5 y for patients who do not experience TO is 1.22 (95% confidence interval, 1.11-1.34; P ≤ 0.0001). Our nomogram predicts TO with a C-statistic of 0.68. Center-level comparisons identify 31% of centers as high performing and 21% of centers as below average. High rates of TO correlate only weakly with center volume. Conclusions: The composite quality metric of TO after LT incorporates holistic outcome measures and is an important measure of quality in addition to 1-y patient and graft survival.

Safely Expanding the Liver Donor Pool by Utilization of Organs from Donation after Circulatory Death with Comparable Results to Donation After Brain Death, a Large Single-Center Experience.

BACKGROUND: Use of livers donated after circulatory death (DCD) is one way to expand the donor pool. Our center has aggressively incorporated use of DCD liver grafts into practice. We examined our center and national outcomes as well as national DCD liver utilization. METHODS: Liver transplants performed at our center and nationally from 11/2016 through 9/2020 were compared. Primary outcomes were patient and graft survival, and national DCD liver utilization. RESULTS: For our center, DCD and donation after brain death (DBD) donors were similar except DCD donors were younger (37 vs 40 years; p < 0.05). Recipient Na-MELD (20 vs 24; p < 0.0001) and cold ischemia time (4.63 vs 5.18 h; p < 0.05) were lower in DCD recipients. There were no significant differences in 1-year patient and graft survival between DCD and DBD liver recipients locally. Nationally, there was a difference in 1-year graft survival year (89.4% vs 92.4%, p < 0.0001) but patient survival was similar between groups. The proportion of DCD livers recovered and transplanted widely varied among organ procurement organizations (OPOs) and transplant centers. CONCLUSIONS: Similar outcomes for DCD and DBD liver recipients should encourage centers and OPOs nationwide to expand utilization of DCD livers.

Machine perfusion of kidney allografts affects early but not late graft function.

BACKGROUND: Hypothermic machine perfusion (HMP) parameters are influenced by donor variables which further affect recipient outcome. Interplay between these parameters can help to predict kidney performance on pump and the long term outcome. METHODS: All the kidneys transplanted at our center between May 2013 through November 2017 were included in the study. Donor and recipient data was obtained from internal database. Multiple logistic regression models with backward selection were used to determine significant donor and pump variables. RESULTS: Donor BMI, KDPI, age and donor sex had a significant association with pump flow. Donor sex, donor type, KDPI and age had significant effect on RI. Diastolic pressure and KDPI were significantly associated with DGF. Duration on pump, KDPI, flow, donor creatinine and type of donor were significantly associated with day 5 creatinine. KDPI was significantly associated with Day 365 creatinine. CONCLUSION: HMP effects early graft function while the long term function depends on donor parameters.

Textbook Outcome as a Quality Metric in Living and Deceased Donor Kidney Transplantation.

BACKGROUND: Quality in kidney transplantation is measured using 1-year patient and graft survival. Because 1-year patient and graft survival exceed 95%, this metric fails to measure a spectrum of quality. Textbook outcomes (TO) are a composite quality metric offering greater depth and resolution. We studied TO after living donor (LD) and deceased donor (DD) kidney transplantation. STUDY DESIGN: United Network for Organ Sharing data for 69,165 transplant recipients between 2013 and 2017 were analyzed. TO was defined as patient and graft survival of 1 year or greater, 1-year glomerular filtration rate of greater than 40 mL/min, absence of delayed graft function, length of stay of 5 days or less, no readmissions during the first 6 months, and no episodes of rejection during the first year after transplantation. Bivariate analysis identified characteristics associated with TO, and covariates were incorporated into multivariable models. Five-year conditional survival was measured, and center TO rates were corrected for case complexity to allow center-level comparisons. RESULTS: The national average TO rates were 54.1% and 31.7% for LD and DD transplant recipients. The hazard ratio for death at 5 years for recipients who did not experience TO was 1.92 (95% CI 1.68 to 2.18, p ≤ 0.0001) for LD transplant recipients and 2.08 (95% CI 1.93 to 2.24, p ≤ 0.0001) for DD transplant recipients. Center-level comparisons identify 18% and 24% of centers under-performing in LD and DD transplantation. High rates of TO do not correlate with transplantation center volume. CONCLUSION: Kidney transplant recipients who experience TO have superior long-term survival. Textbook outcomes add value to the current standards of 1-year patient and graft survival.

Early Posttransplant Blood Transfusion and Risk for Worse Graft Outcomes.

INTRODUCTION: Blood transfusion is a risk factor for allosensitization. Nevertheless, blood transfusion posttransplant remains a common practice. We evaluated the effect of posttransplant blood transfusion on graft outcomes. METHODS: We included nonsensitized, first-time, kidney-alone recipients transplanted between 1 July 2015 and 31 December 2017. Patients were grouped based on receiving blood transfusion in the first 30 days posttransplant. The primary end point was a composite outcome of biopsy-proven acute rejection, death of any cause, or graft failure in the first year posttransplant. Secondary outcomes included the individual components of the primary outcome and the cumulative incidence of de novo donor-specific antibodies (DSAs). RESULTS: Two hundred seventy-three patients were included. One hundred twenty-seven (47%) received blood transfusion. Patients in the transfusion group were more likely to be older, have had a deceased donor, and have received induction with basiliximab. There was no difference between groups in the composite primary outcome (adjusted hazard ratio = [HR] 1.34; 95% confidence interval [CI], 0.83-2.17; P = 0.23). The cumulative incidence of de novo DSAs during the first year posttransplant was similar between groups (12.8% transfusion vs. 10.9% no transfusion, P = 0.48). CONCLUSION: Early transfusion of blood products in kidney transplant recipients receiving induction with lymphocyte depletion was not associated with an increased hazard of experiencing acute rejection, death from any cause, or graft loss.

Donation After Circulatory Death Yields Survival Rates Similar to Donation After Brain Death Liver Transplant, Which Effectively Expands the Donor Pool.

OBJECTIVES: Liver allograft shortage has necessitated greater use of donations after circulatory death. Limited data are available to compare recipients' health care utilization for donation after circulatory death versus brain death. MATERIALS AND METHODS: Liver transplant data for our center from November 2016 until May 2019 were obtained (208 donations after brain death and 39 after circulatory death). We excluded patients <18 years old and multiorgan transplants; for cost data only, we also excluded retransplants. Primary outcome was recipients' health care utilization in donation after circulatory death versus brain death and included index admission length of stay, readmissions, and charges from transplant to 6 months. Secondary outcomes were patient and graft survival. RESULTS: Donors from circulatory death were younger than donors from brain death (median age 32 vs 40 years; P < .01). Recipient body mass index (31.23 vs 29.38 kg/m2), Model for End-Stage Liver Disease score (17 vs 19), portal vein thrombosis (15.8% vs 18.0%), length of stay (7 vs 8 days), and 30-, 90-, and 180-day posttransplant index admissions were not significantly different. Charges for index admission were equivalent for donation after circulatory death ($370771) and brain death ($374272) (P = .01). Charges for readmissions at 30 and 180 days were not significantly different (P = .80 and P = .19, respectively). Rates for graft failure (10.3% vs 4.8%; P = .08) and recipient death (10.3% vs 3.8%; P = .17) at 6 months posttransplant were similar. CONCLUSIONS: Donation after circulatory death versus brain death liver transplant recipients had similar lengths of stay and equivalent index admission charges. Graft and patient survival and charges from transplant to 6 months were similar. Donation after circulatory death liver allografts provide a safe, costequivalent donor pool expansion after careful donorrecipient selection.