Antibody-mediated rejection: New approaches in prevention and management.

Despite the success of desensitization protocols, antibody-mediated rejection (AMR) remains a significant contributor to renal allograft failure in patients with donor-specific antibodies. Plasmapheresis and high-dose intravenous immunoglobulin have proved to be effective treatments to prevent and treat AMR, but irreversible injury in the form of transplant glomerulopathy can commonly manifest months to years later. There is an unmet need to improve the outcomes for patients at risk for AMR. Updated Banff criteria now take into account the increasing understanding of the complex and heterogeneous nature of AMR phenotypes, including the timing of rejection, subclinical and chronic AMR, C4d-negative AMR, and antibody-mediated vascular rejection. Treatment for AMR is not standardized, and there is little in the way of evidence-based treatment guidelines. Refining more precisely the mechanisms of injury responsible for different AMR phenotypes and establishing relevant surrogate endpoints to facilitate more informative studies will likely allow for more accurate determination of prognosis and efficacious intervention using new therapeutic approaches. In addition to plasma exchange and intravenous immunoglobulin, a number of other add-on therapies have been tried in small studies without consistent benefit, including anti-CD20, proteasome inhibitors, complement inhibitors, anti-interleukin-6 receptor blockers, and immunoglobulin G-degrading enzyme of Streptococcus pyogenes (called IdeS).

Pre-Kidney Transplant Lower Extremity Impairment and Post-Kidney Transplant Mortality.

Prediction models for post-kidney transplantation mortality have had limited success (C-statistics ≤0.70). Adding objective measures of potentially modifiable factors may improve prediction and, consequently, kidney transplant (KT) survival through intervention. The Short Physical Performance Battery (SPPB) is an easily administered objective test of lower extremity function consisting of three parts (balance, walking speed, chair stands), each with scores of 0-4, for a composite score of 0-12, with higher scores indicating better function. SPPB performance and frailty (Fried frailty phenotype) were assessed at admission for KT in a prospective cohort of 719 KT recipients at Johns Hopkins Hospital (8/2009 to 6/2016) and University of Michigan (2/2013 to 12/2016). The independent associations between SPPB impairment (SPPB composite score ≤10) and composite score with post-KT mortality were tested using adjusted competing risks models treating graft failure as a competing risk. The 5-year posttransplantation mortality for impaired recipients was 20.6% compared to 4.5% for unimpaired recipients (p < 0.001). Impaired recipients had a 2.30-fold (adjusted hazard ratio [aHR] 2.30, 95% confidence interval [CI] 1.12-4.74, p = 0.02) increased risk of postkidney transplantation mortality compared to unimpaired recipients. Each one-point decrease in SPPB score was independently associated with a 1.19-fold (95% CI 1.09-1.30, p < 0.001) higher risk of post-KT mortality. SPPB-derived lower extremity function is a potentially highly useful and modifiable objective measure for pre-KT risk prediction.

Prescription opioid use before and after kidney transplant: Implications for posttransplant outcomes.

Evolving literature suggests that the epidemic of prescription opioid use affects the transplant population. We examined a novel database wherein national U.S. transplant registry records were linked to a large pharmaceutical claims warehouse (2007-2015) to characterize prescription opioid use before and after kidney transplant, and associations (adjusted hazard ratio, 95%LCL aHR95%UCL ) with death and graft loss. Among 75 430 eligible patients, 43.1% filled opioids in the year before transplant. Use was more common among recipients who were women, white, unemployed, publicly insured, and with longer pretransplant dialysis. Of those with the highest level of pretransplant opioid use, 60% continued high-level use posttransplant. Pretransplant opioid use had graded associations with one-year posttransplant outcomes; the highest-level use predicted 46% increased risk of death (aHR 1.28 1.461.66 ) and 28% increased risk of all-cause graft failure (aHR 1.17 1.281.41 ). Effects of high-level opioid use in the first year after transplant were stronger, predicting twice the risk of death (aHR 1.93 2.242.60 ) and 68% higher all-cause graft failure risk (aHR 1.50 1.681.89 ) over the subsequent year; increased risk persisted over five years. While associations may, in part, reflect underlying conditions or behaviors, opioid use history is relevant in assessing and providing care to transplant candidates and recipients.

The impact of direct-acting antiviral agents on liver and kidney transplant costs and outcomes.

Direct-acting antiviral medications (DAAs) have revolutionized care for hepatitis C positive (HCV+) liver (LT) and kidney (KT) transplant recipients. Scientific Registry of Transplant Recipients registry data were integrated with national pharmaceutical claims (2007-2016) to identify HCV treatments before January 2014 (pre-DAA) and after (post-DAA), stratified by donor (D) and recipient (R) serostatus and payer. Pre-DAA, 18% of HCV+ LT recipients were treated within 3 years and without differences by donor serostatus or payer. Post-DAA, only 6% of D-/R+ recipients, 19.8% of D+/R+ recipients with public insurance, and 11.3% with private insurance were treated within 3 years (P < .0001). LT recipients treated for HCV pre-DAA experienced higher rates of graft loss (adjusted hazard ratio [aHR] 1.34 1.852.10 , P < .0001) and death (aHR 1.47 1.681.91 , P < .0001). Post-DAA, HCV treatment was not associated with death (aHR 0.34 0.671.32 , P = .25) or graft failure (aHR 0.32 0.641.26 , P = .20) in D+R+ LT recipients. Treatment increased in D+R+ KT recipients (5.5% pre-DAA vs 12.9% post-DAA), but did not differ by payer status. DAAs reduced the risk of death after D+/R+ KT by 57% (0.19 0.430.95 , P = .04) and graft loss by 46% (0.27 0.541.07 , P = .08). HCV treatment with DAAs appears to improve HCV+ LT and KT outcomes; however, access to these medications appears limited in both LT and KT recipients.

The Banff 2017 Kidney Meeting Report: Revised diagnostic criteria for chronic active T cell-mediated rejection, antibody-mediated rejection, and prospects for integrative endpoints for next-generation clinical trials.

The kidney sessions of the 2017 Banff Conference focused on 2 areas: clinical implications of inflammation in areas of interstitial fibrosis and tubular atrophy (i-IFTA) and its relationship to T cell-mediated rejection (TCMR), and the continued evolution of molecular diagnostics, particularly in the diagnosis of antibody-mediated rejection (ABMR). In confirmation of previous studies, it was independently demonstrated by 2 groups that i-IFTA is associated with reduced graft survival. Furthermore, these groups presented that i-IFTA, particularly when involving >25% of sclerotic cortex in association with tubulitis, is often a sequela of acute TCMR in association with underimmunosuppression. The classification was thus revised to include moderate i-IFTA plus moderate or severe tubulitis as diagnostic of chronic active TCMR. Other studies demonstrated that certain molecular classifiers improve diagnosis of ABMR beyond what is possible with histology, C4d, and detection of donor-specific antibodies (DSAs) and that both C4d and validated molecular assays can serve as potential alternatives and/or complements to DSAs in the diagnosis of ABMR. The Banff ABMR criteria are thus updated to include these alternatives. Finally, the present report paves the way for the Banff scheme to be part of an integrative approach for defining surrogate endpoints in next-generation clinical trials.

Considering Tangible Benefit for Interdependent Donors: Extending a Risk-Benefit Framework in Donor Selection.

From its infancy, live donor transplantation has operated within a framework of acceptable risk to donors. Such a framework presumes that risks of living donation are experienced by the donor while all benefits are realized by the recipient, creating an inequitable distribution that demands minimization of donor risk. We suggest that this risk-tolerance framework ignores tangible benefits to the donor. A previously proposed framework more fully considers potential benefits to the donor and argues that risks and benefits must be balanced. We expand on this approach, and posit that donors sharing a household with and/or caring for a potential transplant patient may realize tangible benefits that are absent in a more distantly related donation (e.g. cousin, nondirected). We term these donors, whose well-being is closely tied to their recipient, "interdependent donors." A flexible risk-benefit model that combines risk assessment with benefits to interdependent donors will contribute to donor evaluation and selection that more accurately reflects what is at stake for donors. In so doing, a risk-benefit framework may allow some donors to accept greater risk in donation decisions.

The National Landscape of Living Kidney Donor Follow-Up in the United States.

In 2013, the Organ Procurement and Transplantation Network (OPTN)/ United Network for Organ Sharing (UNOS) mandated that transplant centers collect data on living kidney donors (LKDs) at 6 months, 1 year, and 2 years postdonation, with policy-defined thresholds for the proportion of complete living donor follow-up (LDF) data submitted in a timely manner (60 days before or after the expected visit date). While mandated, it was unclear how centers across the country would perform in meeting thresholds, given potential donor and center-level challenges of LDF. To better understand the impact of this policy, we studied Scientific Registry of Transplant Recipients data for 31,615 LKDs between January 2010 and June 2015, comparing proportions of complete and timely LDF form submissions before and after policy implementation. We also used multilevel logistic regression to assess donor- and center-level characteristics associated with complete and timely LDF submissions. Complete and timely 2-year LDF increased from 33% prepolicy (January 2010 through January 2013) to 54% postpolicy (February 2013 through June 2015) (p < 0.001). In an adjusted model, the odds of 2-year LDF increased by 22% per year prepolicy (p < 0.001) and 23% per year postpolicy (p < 0.001). Despite these annual increases in LDF, only 43% (87/202) of centers met the OPTN/UNOS-required 6-month, 1-year, and 2-year LDF thresholds for LKDs who donated in 2013. These findings motivate further evaluation of LDF barriers and the optimal approaches to capturing outcomes after living donation.

Increased Mortality and Graft Loss With Kidney Retransplantation Among Human Immunodeficiency Virus (HIV)-Infected Recipients.

Excellent outcomes have been demonstrated in primary human immunodeficiency virus (HIV)-positive (HIV+) kidney transplant recipients, but a subset will lose their graft and seek retransplantation (re-KT). To date, no study has examined outcomes among HIV+ re-KT recipients. We studied risk for death and graft loss among 4149 (22 HIV+ vs. 4127 HIV-negative [HIV-]) adult re-KT recipients reported to the Scientific Registry of Transplant Recipients (SRTR) (2004-2013). Compared to HIV- re-KT recipients, HIV+ re-KT recipients were more commonly African American (63.6% vs. 26.7%, p < 0.001), infected with hepatitis C (31.8% vs. 5.0%, p < 0.001) and had longer median time on dialysis (4.8 years vs. 2.1 years, p = 0.02). There were no significant differences in length of time between the primary and re-KT events by HIV status (1.5 years vs. 1.4 years, p = 0.52). HIV+ re-KT recipients experienced a 3.11-fold increased risk of death (adjusted hazard ratio [aHR]: 3.11, 95% confidence interval [CI]: 1.82-5.34, p < 0.001) and a 1.96-fold increased risk of graft loss (aHR: 1.96, 95% CI: 1.14-3.36, p = 0.01) compared to HIV- re-KT recipients. Re-KT among HIV+ recipients was associated with increased risk for mortality and graft loss. Future research is needed to determine if a survival benefit is achieved with re-KT in this vulnerable population.

Impact of Protease Inhibitor-Based Anti-Retroviral Therapy on Outcomes for HIV+ Kidney Transplant Recipients.

Excellent outcomes have been demonstrated among select HIV-positive kidney transplant (KT) recipients with well-controlled infection, but to date, no national study has explored outcomes among HIV+ KT recipients by antiretroviral therapy (ART) regimen. Intercontinental Marketing Services (IMS) pharmacy fills (1/1/01-10/1/12) were linked with Scientific Registry of Transplant Recipients (SRTR) data. A total of 332 recipients with pre- and posttransplantation fills were characterized by ART at the time of transplantation as protease inhibitor (PI) or non-PI-based ART (88 PI vs. 244 non-PI). Cox proportional hazards models were adjusted for recipient and donor characteristics. Comparing recipients by ART regimen, there were no significant differences in age, race, or HCV status. Recipients on PI-based regimens were significantly more likely to have an Estimated Post Transplant Survival (EPTS) score of >20% (70.9% vs. 56.3%, p = 0.02) than those on non-PI regimens. On adjusted analyses, PI-based regimens were associated with a 1.8-fold increased risk of allograft loss (adjusted hazard ratio [aHR] 1.84, 95% confidence interval [CI] 1.22-2.77, p = 0.003), with the greatest risk observed in the first posttransplantation year (aHR 4.48, 95% CI 1.75-11.48, p = 0.002), and a 1.9-fold increased risk of death as compared to non-PI regimens (aHR 1.91, 95% CI 1.02-3.59, p = 0.05). These results suggest that whenever possible, recipients should be converted to a non-PI regimen prior to kidney transplantation.

Waitlist Outcomes of Liver Transplant Candidates Who Were Reprioritized Under Share 35.

Under Share 35, deceased donor (DD) livers are offered regionally to candidates with Model for End-Stage Liver Disease (MELD) scores ≥35 before being offered locally to candidates with MELD scores <35. Using Scientific Registry of Transplant Recipients data from June 2013 to June 2015, we identified 1768 DD livers exported to regional candidates with MELD scores ≥35 who were transplanted at a median MELD score of 39 (interquartile range [IQR] 37-40) with 30-day posttransplant survival of 96%. In total, 1764 (99.8%) exports had an ABO-compatible candidate in the recovering organ procurement organization (OPO), representing 1219 unique reprioritized candidates who would have had priority over the regional candidate under pre-Share 35 allocation. Reprioritized candidates had a median waitlist MELD score of 31 (IQR 27-34) when the liver was exported. Overall, 291 (24%) reprioritized candidates had a comparable MELD score (within 3 points of the regional recipient), and 209 (72%) were eventually transplanted in 11 days (IQR 3-38 days) using a local (50%), regional (50%) or national (<1%) liver; 60 (21%) died, 13 (4.5%) remained on the waitlist and nine (3.1%) were removed for other reasons. Of those eventually transplanted, MELD score did not increase in 57%; it increased by 1-3 points in 37% and by ≥4 points in 5.7% after the export. In three cases, OPOs exchanged regional exports within a 24-h window. The majority of comparable reprioritized candidates were not disadvantaged; however, 21% died after an export.

The Changing Financial Landscape of Renal Transplant Practice: A National Cohort Analysis.

Kidney transplantation has become more resource intensive as recipient complexity has increased and average donor quality has diminished over time. A national retrospective cohort study was performed to assess the impact of kidney donor and recipient characteristics on transplant center cost (exclusive of organ acquisition) and Medicare reimbursement. Data from the national transplant registry, University HealthSystem Consortium hospital costs, and Medicare payments for deceased donor (N = 53 862) and living donor (N = 36 715) transplants from 2002 to 2013 were linked and analyzed using multivariate linear regression modeling. Deceased donor kidney transplant costs were correlated with recipient (Expected Post Transplant Survival Score, degree of allosensitization, obesity, cause of renal failure), donor (age, cause of death, donation after cardiac death, terminal creatinine), and transplant (histocompatibility matching) characteristics. Living donor costs rose sharply with higher degrees of allosensitization, and were also associated with obesity, cause of renal failure, recipient work status, and 0-ABDR mismatching. Analysis of Medicare payments for a subsample of 24 809 transplants demonstrated minimal correlation with patient and donor characteristics. In conclusion, the complexity in the landscape of kidney transplantation increases center costs, posing financial disincentives that may reduce organ utilization and limit access for higher-risk populations.

Changes in Utilization and Discard of Hepatitis C-Infected Donor Livers in the Recent Era.

The impact of interferon (IFN)-free direct-acting antiviral (DAA) hepatitis C virus (HCV) treatments on utilization and outcomes associated with HCV-positive deceased donor liver transplantation (DDLT) is largely unknown. Using the Scientific Registry of Transplant Recipients, we identified 25 566 HCV-positive DDLT recipients from 2005 to 2015 and compared practices according to the introduction of DAA therapies using modified Poisson regression. The proportion of HCV-positive recipients who received HCV-positive livers increased from 6.9% in 2010 to 16.9% in 2015. HCV-positive recipients were 61% more likely to receive an HCV-positive liver after 2010 (early DAA/IFN era) (aRR:1.45 1.611.79 , p < 0.001) and almost three times more likely to receive one after 2013 (IFN-free DAA era) (aRR:2.58 2.853.16 , p < 0.001). Compared to HCV-negative livers, HCV-positive livers were 3 times more likely to be discarded from 2005 to 2010 (aRR:2.69 2.993.34 , p < 0.001), 2.2 times more likely after 2010 (aRR:1.80 2.162.58 , p < 0.001) and 1.7 times more likely after 2013 (aRR:1.37 1.682.04 , p < 0.001). Donor HCV status was not associated with increased risk of all-cause graft loss (p = 0.1), and this did not change over time (p = 0.8). Use of HCV-positive livers has increased dramatically, coinciding with the advent of DAAs. However, the discard rate remains nearly double that of HCV-negative livers. Further optimization of HCV-positive liver utilization is necessary to improve access for all candidates.

PROviding Better ACcess To ORgans: A comprehensive overview of organ-access initiatives from the ASTS PROACTOR Task Force.

The American Society of Transplant Surgeons (ASTS) PROviding better Access To Organs (PROACTOR) Task Force was created to inform ongoing ASTS organ access efforts. Task force members were charged with comprehensively cataloguing current organ access activities and organizing them according to stakeholder type. This white paper summarizes the task force findings and makes recommendations for future ASTS organ access initiatives.

Predonation Prescription Opioid Use: A Novel Risk Factor for Readmission After Living Kidney Donation.

Implications of opioid use in living kidney donors for key outcomes, including readmission rates after nephrectomy, are unknown. We integrated Scientific Registry of Transplant Recipients data with records from a nationwide pharmacy claims warehouse and administrative records from an academic hospital consortium to quantify predonation prescription opioid use and postdonation readmission events. Associations of predonation opioid use (adjusted odds ratio [aOR]) in the year before donation and other baseline clinical, procedural, and center factors with readmission within 90 days postdonation were examined by using multivariate logistic regression. Among 14 959 living donors, 11.3% filled one or more opioid prescriptions in the year before donation. Donors with the highest level of predonation opioid use (>305 mg/year) were more than twice as likely as nonusers to be readmitted (6.8% vs. 2.6%; aOR 2.49, 95% confidence interval 1.74-3.58). Adjusted readmission risk was also significantly (p < 0.05) higher for women (aOR = 1.25), African Americans (aOR = 1.45), spouses (aOR = 1.42), exchange participants (aOR = 1.46), uninsured donors (aOR = 1.40), donors with predonation estimated glomerular filtration rate <60 mL/min/1.73 m2 (aOR = 2.68), donors with predonation pulmonary conditions (aOR = 1.54), and after robotic nephrectomy (aOR = 1.68). Predonation opioid use is independently associated with readmission after donor nephrectomy. Future research should examine underlying mechanisms and approaches to reducing risks of postdonation complications.

Risk of End-Stage Renal Disease in HIV-Positive Potential Live Kidney Donors.

New federal regulations allow HIV-positive individuals to be live kidney donors; however, potential candidacy for donation is poorly understood given the increased risk of end-stage renal disease (ESRD) associated with HIV infection. To better understand this risk, we compared the incidence of ESRD among 41 968 HIV-positive participants of North America AIDS Cohort Collaboration on Research and Design followed for a median of 5 years with the incidence of ESRD among comparable HIV-negative participants of National Health and Nutrition Examination III followed for a median of 14 years. We used risk associations from multivariable Cox proportional hazards regression to derive cumulative incidence estimates for selected HIV-positive scenarios (no history of diabetes, hypertension, AIDS, or hepatitis C virus coinfection) and compared these estimates with those from similarly selected HIV-negative scenarios. For 40-year-old HIV-positive individuals with health characteristics that were similar to those of age-matched kidney donors, viral load <400 copies/mL, and CD4+ count ≥500 cells/µL, the 9-year cumulative incidence of ESRD was higher than that of their HIV-negative peers, yet still low: 2.5 versus 1.1 per 10 000 among white women, 3.0 versus 1.3 per 10 000 among white men, 13.2 versus 3.6 per 10 000 among black women, and 15.8 versus 4.4 per 10 000 among black men. HIV-positive individuals with no comorbidities and well-controlled disease may be considered low-risk kidney donor candidates.

The Incremental Cost of Incompatible Living Donor Kidney Transplantation: A National Cohort Analysis.

Incompatible living donor kidney transplantation (ILDKT) has been established as an effective option for end-stage renal disease patients with willing but HLA-incompatible living donors, reducing mortality and improving quality of life. Depending on antibody titer, ILDKT can require highly resource-intensive procedures, including intravenous immunoglobulin, plasma exchange, and/or cell-depleting antibody treatment, as well as protocol biopsies and donor-specific antibody testing. This study sought to compare the cost and Medicare reimbursement, exclusive of organ acquisition payment, for ILDKT (n = 926) with varying antibody titers to matched compatible transplants (n = 2762) performed between 2002 and 2011. Data were assembled from a national cohort study of ILDKT and a unique data set linking hospital cost accounting data and Medicare claims. ILDKT was more expensive than matched compatible transplantation, ranging from 20% higher adjusted costs for positive on Luminex assay but negative flow cytometric crossmatch, 26% higher for positive flow cytometric crossmatch but negative cytotoxic crossmatch, and 39% higher for positive cytotoxic crossmatch (p < 0.0001 for all). ILDKT was associated with longer median length of stay (12.9 vs. 7.8 days), higher Medicare payments ($91 330 vs. $63 782 p < 0.0001), and greater outlier payments. In conclusion, ILDKT increases the cost of and payments for kidney transplantation.

Extraction Time of Kidneys From Deceased Donors and Impact on Outcomes.

Cold ischemia time (from flush to out-of-ice) and warm ischemia time (from out-of-ice to reperfusion) are known to impact delayed graft function (DGF) rates and long-term allograft survival following deceased donor kidney transplantation. We propose an additional ischemia time, extraction time, beginning with aortic cross-clamp and perfusion/cooling of the kidneys, and ending with removal of the kidneys and placement on ice on the backtable. During this time the kidneys rewarm, suffering an additional ischemic insult, which may impair transplant function. We measured extraction times of 576 kidneys recovered and transplanted locally between January 2006 and December 2008, then linked to Scientific Registry of Transplant Recipients (SRTR) data for outcomes. Extraction time ranged from 14 to 123 min, with a mean of 44.7 min. In SRTR-adjusted analyses, longer extraction time and DGF were statistically associated (odds ratio [OR] = 1.19 per 5 min beyond 60 min, 95% confidence interval [CI] 1.02-1.39, p = 0.03). Up to 60 min of extraction time, DGF incidence was 27.8%; by 120 min it doubled to nearly 60%. Although not statistically significant (OR = 1.19, 95% CI 0.96-1.49, p = 0.11), primary nonfunction rate also rose dramatically to nearly 20% by 120 min extraction time. Extraction time is a novel and important factor to consider when evaluating a deceased donor kidney offer and when strategizing personnel for kidney recovery.

Effects of High-Risk Kidneys on Scientific Registry of Transplant Recipients Program Quality Reports.

There is a perception that transplanting high-risk kidneys causes programs to be identified as underperforming, thereby increasing the frequency of discards and diminishing access to transplant. Thus, the Organ Procurement and Transplantation Network (OPTN) has considered excluding transplants using kidneys from donors with high Kidney Donor Profile Index (KDPI) scores (≥0.85) when assessing program performance. We examined whether accepting high-risk kidneys (KDPI ≥0.85) for transplant yields worse outcome evaluations. Despite a clear relationship between KDPI and graft failure and mortality, there was no relationship between a program's use of high-KDPI kidneys and poor performance evaluations after risk adjustment. Excluding high-KDPI donor transplants from the June 2015 evaluations did not alter the programs identified as underperforming, because in every case underperforming programs also had worse-than-expected outcomes among lower-risk donor transplants. Finally, we found that hypothetically accepting and transplanting additional kidneys with KDPI similar to that of kidneys currently discarded would not adversely affect program evaluations. Based on the study findings, there is no evidence that programs that accept higher-KDPI kidneys are at greater risk for low performance evaluations, and risk aversion may limit access to transplant for candidates while providing no measurable benefit to program evaluations.

Changes in Discard Rate After the Introduction of the Kidney Donor Profile Index (KDPI).

Since March 26, 2012, the Kidney Donor Profile Index (KDPI) has been provided with all deceased-donor kidney offers, with the goal of improving the expanded criteria donor (ECD) indicator. Although an improved risk index may facilitate identification and transplantation of marginal yet viable kidneys, a granular percentile system may reduce provider-patient communication flexibility, paradoxically leading to more discards ("labeling effect"). We studied the discard rates of the kidneys recovered for transplantation between March 26, 2010 and March 25, 2012 ("ECD era," N = 28 636) and March 26, 2012 and March 25, 2014 ("KDPI era," N = 29 021) using Scientific Registry of Transplant Recipients (SRTR) data. There was no significant change in discard rate from ECD era (18.1%) to KDPI era (18.3%) among the entire population (adjusted odds ratio [aOR] = 0.97 1.041.10 , p = 0.3), or in any KDPI stratum. However, among kidneys in which ECD and KDPI indicators were discordant, "high risk" standard criteria donor (SCD) kidneys (with KDPI > 85) were at increased risk of discard in the KDPI era (aOR = 1.07 1.421.89 , p = 0.02). Yet, recipients of these kidneys were at much lower risk of death (adjusted Risk Ratio [aRR] = 0.56 0.770.94 at 2 years posttransplant) compared to those remaining on dialysis waiting for low-KDPI kidneys. Our findings suggest that there might be an unexpected, harmful labeling effect of reporting a high KDPI for SCD kidneys, without the expected advantage of providing a more granular risk index.

Identification of Optimal Donor-Recipient Combinations Among Human Immunodeficiency Virus (HIV)-Positive Kidney Transplant Recipients.

For some patient subgroups, human immunodeficiency virus (HIV) infection has been associated with worse outcomes after kidney transplantation (KT); potentially modifiable factors may be responsible. The study goal was to identify factors that predict a higher risk of graft loss among HIV-positive KT recipients compared with a similar transplant among HIV-negative recipients. In this study, 82 762 deceased donor KT recipients (HIV positive: 526; HIV negative: 82 236) reported to the Scientific Registry of Transplant Recipients (SRTR) (2001-2013) were studied by interaction term analysis. Compared to HIV-negative recipients, the hepatitis C virus (HCV) amplified risk 2.72-fold among HIV-positive KT recipients (adjusted hazard ratio [aHR]: 2.72, 95% confidence interval [CI]: 1.75-4.22, p < 0.001). Forty-three percent of the excess risk was attributable to the interaction between HIV and HCV (attributable proportion of risk due to the interaction [AP]: 0.43, 95% CI: 0.23-0.63, p = 0.02). Among HIV-positive recipients with more than three HLA mismatches (MMs), risk was amplified 1.80-fold compared to HIV-negative (aHR: 1.80, 95% CI: 1.31-2.47, p < 0.001); 42% of the excess risk was attributable to the interaction between HIV and more than three HLA MMs (AP: 0.42, 95% CI: 0.24-0.60, p = 0.01). High-HIV-risk (HIV-positive/HCV-positive HLAwith more than three MMs) recipients had a 3.86-fold increased risk compared to low-HIV-risk (HIV-positive/HCV-negative HLA with three or fewer MMs)) recipients (aHR: 3.86, 95% CI: 2.37-6.30, p < 0.001). Avoidance of more than three HLA MMs in HIV-positive KT recipients, particularly among coinfected patients, may mitigate the increased risk of graft loss associated with HIV infection.