Search

Introduction: Living liver donation improves survival of end‐stage liver disease (ESLD) patients. Yet, it continues to represent a small proportion of United States (U.S.) liver transplantation with existing racial disparities. We investigated the interplay of donor–recipient relationship and donor race to understand donor subgroups with no significant increase. Methods: We studied 4407 living liver donors in the U.S. from January 1, 2012, to December 31, 2022 (median age = 36 years, and 59% were biologically related to the recipient). We quantified the change in the number of donors per 3‐year increment using negative binomial regression (incidence rate ratio [IRR]), stratified by donor–recipient relationship and race/ethnicity. Results: Among biologically related donors, the observed annual number of White donors increased from 146 to 253, Hispanic donors from 18 to 53, and Black donors decreased from 11 to 10. Among unrelated donors, White donors increased from 65 to 221, Hispanic donors from 4 to 25, and Black donors from 3 to 11. For the IRR of biologically related donors aged <40 and ≥40 years, White donors increased by 18% and 22%; Hispanic donors increased by 25% and 54%; and Black donors did not change. Likewise, the IRR of unrelated donors aged <40 and ≥40 years, White donors increased by 48% and 55%; Hispanic donors increased by 52% and 65%; and Black donors did not change. Conclusions: While biologically related donors represent the majority of donors, unrelated donors have substantially risen in recent years, primarily driven by White donors. Although the rate of unrelated donations increased among Hispanic donors, the absolute number remains very small (≤25 donors/year). Interventions are needed to increase education among Hispanic and Black communities to grow unrelated living liver donations across race/ethnicity. [ABSTRACT FROM AUTHOR]

Introduction: Medication use in living kidney donor (LKD) candidates may have important implications for evaluation and donation care. We sought to characterize LKD candidate medication use through medication histories conducted at nephrologist evaluation and transplant pharmacist preoperative visits. Methods: This retrospective single‐center cohort study included adult LKD candidates evaluated for donation between October 1, 2019 and October 1, 2021. Scheduled and as‐needed medications for each candidate were abstracted from pre‐donation medication histories collected at the evaluation visit with the nephrologist and the preoperative visit with the transplant pharmacist, if approved for donation. Medication histories from each visit were compared with each other and evaluated by therapeutic class frequency. Results: Among 213 LKD candidates (112 approved for donation and 101 declined for donation), 198 (93.0%) candidates were taking at least one prescription medication, over‐the‐counter agent, or dietary supplement. Antidepressants and antihypertensives were the most common prescription agents used among candidates, with antihypertensives more common among declined donors (20.8% vs. 10.7%, p = 0.042). Nonsteroidal anti‐inflammatory drugs were more commonly identified at the evaluation visit of approved candidates compared to the preoperative visit (29.5% vs. 0.9%, p < 0.001) and dietary supplements were more commonly identified at the preoperative visit compared to the evaluation visit (49.1% vs. 59.8%, p = 0.023). Conclusions: The frequency of nonsteroidal anti‐inflammatory drugs decreased greatly between the evaluation and preoperative visit, likely reflective of discontinuation pre‐donation. Characterizing medication use among candidates evaluated for LKD donation may assist donor programs with developing more targeted patient medication education. Nearly all LKD candidates were taking a medication or dietary supplement pre‐donation. Transplant pharmacists are uniquely positioned to perform medication reconciliations and can also offer guidance to other team providers on best practices for this process. A better understanding of medication patterns in this population may also aid with further developing care guidelines for LKD evaluation and pre‐/postoperative LKD care. [ABSTRACT FROM AUTHOR]

Introduction: Racial/ethnic disparities in living donor kidney transplantation (LDKT) are a persistent challenge. Although nearly all directed donations are from members of patients' social networks, little is known about which social network members take steps toward living kidney donation, which do not, and what mechanisms contribute to racial/ethnic LDKT disparities. Methods: We describe the design and rationale of the Friends and Family of Kidney Transplant Patients Study, a factorial experimental fielding two interventions designed to promote LKD discussions. Participants are kidney transplant candidates at two centers who are interviewed and delivered an intervention by trained center research coordinators. The search intervention advises patients on which social network members are most likely to be LKD contraindication‐free; the script intervention advises patients on how to initiate effective LKD discussions. Participants are randomized into four conditions: no intervention, search only, script only, or both search and script. Patients also complete a survey and optionally provide social network member contact information so they can be surveyed directly. This study will seek to enroll 200 transplant candidates. The primary outcome is LDKT receipt. Secondary outcomes include live donor screening and medical evaluations and outcomes. Tertiary outcomes include LDKT self‐efficacy, concerns, knowledge, and willingness, measured before and after the interventions. Conclusion: This study will assess the effectiveness of two interventions to promote LKD and ameliorate Black‐White disparities. It will also collect unprecedented information on transplant candidates' social network members, enabling future work to address network member structural barriers to LKD. [ABSTRACT FROM AUTHOR]

Background: Despite the institution of a new Kidney Allocation System in 2014, A2/A2B to B transplantation has not increased as expected. The current Organ Procurement and Transplantation Network policy requires subtyping on two separate occasions, and in the setting of discrepant results, defaulting to the A1 subtype. However, there is significant inherent variability in the serologic assays used for blood group subtyping and genotyping is rarely done. Methods: The National Kidney Registry, a kidney paired donation (KPD) program, performs serological typing on all A/AB donors, and in cases of non‐A1/non‐A1B donors, confirmatory genotyping is performed. Results: Between 2/18/2018 and 9/15/2020, 13.0% (145) of 1,111 type A donors registered with the NKR were ultimately subtyped as A2 via genotyping. Notably, 49.6% (72) of these were subtyped as A1 at their donor center, and in accordance with OPTN policy, ineligible for allocation as A2. Conclusion: Inaccurate A2 subtyping represents a significant lost opportunity in transplantation, especially in KPD where A2 donors can not only facilitate living donor transplantation for O and highly sensitized candidates, but can also facilitate additional living donor transplants. This study highlights the need for improved accuracy of subtyping technique, and the need for policy changes encouraging optimal utilization of A2 donor kidneys. [ABSTRACT FROM AUTHOR]

Cytomegalovirus (CMV) infection is one of the most common and significant complications after solid organ transplant (SOT). Severe acute respiratory coronavirus 2 (SARS‐CoV‐2), which causes the novel betacoronavirus 2019 disease (COVID‐19), has become the first global pandemic in 100 years. The world's attention has turned to address this unanticipated development; however, the viral infection that has long plagued outcomes after solid organ transplantation still requires vigilance. With physical distancing as the key intervention to reduce the healthcare burden, and the unease related to healthcare contact within the transplant population given the associated morbidity and mortality of COVID‐19 in transplant recipients, providers have struggled to evaluate and streamline essential in‐person healthcare contact, including laboratory visits. Owing to this, the COVID‐19 pandemic has placed a significant strain on the delivery of CMV prophylaxis and treatment after solid organ transplantation. In this piece, we will describe issues our CMV antiviral stewardship service has encountered in the care of the transplant recipient with CMV during the this unprecedented time and share our expert opinion to approaches to providing optimal, evidenced based care during a pandemic associated with a seemingly unrelated viral infection. [ABSTRACT FROM AUTHOR]

Background: Primary cytomegalovirus (CMV) disease in high‐risk (D+/R‐) abdominal solid organ transplant recipients (aSOTRs) is well described, however, little is known of primary CMV disease in low‐risk (D‐/R‐) patients. Methods: Observational study of adult aSOTRs between 1/1/2009 and 9/1/2019 screened based on serostatus at transplant; D‐/R‐ and D+/R‐ patients were included. Primary objective: Describe epidemiology of primary CMV in D‐/R‐ aSOTRs. Secondary objective: Compare infectious and transplant‐related outcomes of primary CMV disease in the first 90 days (early CMV) between D‐/R‐ and D+/R‐. Results: Of 782 D‐/R‐ aSOTRs in the study period, 13 developed CMV at any time after transplant to last follow‐up. Of 671 D+/R‐ patients, 186 developed CMV. Early CMV disease was significantly more common in the D‐/R‐ group (54% vs 15.6%, P =.0005) despite populations being similar demographically, including allograft subtype. D‐/R‐ patients with early CMV disease had median viral load >100 000 IU/mL and 42.9% had end‐organ manifestations; 71.4% required hospital admission. Immunosuppressive therapy was adjusted in 100% of patients, there was an approximately 14.3% rate of antiviral resistance and 28.6% had concomitant opportunistic infection. These findings were similar to D+/R‐ patients. There was no difference in risk of rejection or all‐cause mortality associated with early CMV disease, however, graft loss was significantly higher in D‐/R‐. Conclusion: D‐/R‐ aSOTRs infrequently develop CMV, however, when it occurs, they present with disease manifestations similar to and graft outcomes inferior to D+/R‐ with CMV. Additionally, the majority of CMV disease in D‐/R‐ occurs in the first 90 days after transplant, suggesting possible donor subclinical infection or transfusion source. The complicated course in D‐/R‐ is likely caused by low clinical suspicion. Awareness of disease severity and aggressive upfront management may promote positive outcomes. [ABSTRACT FROM AUTHOR]

Study Objective: To evaluate the clinical course and long‐term impact of high‐dose acyclovir (HD‐A, 800 mg 4 times/day) cytomegalovirus (CMV) prophylaxis failure in a CMV‐seropositive abdominal solid organ transplant population. Design: Retrospective cohort study. Setting: Tertiary academic medical center. Patients: A total of 691 adults who received solid organ transplants between January 1, 2008, and June 30, 2013, without lymphocyte‐depleting induction and were prescribed 3 months of HD‐A prophylaxis at the time of hospital discharge. Of those patients, 54 experienced prophylaxis failure, defined as CMV detected via molecular diagnostics or on biopsy while receiving HD‐A (prophylaxis failure group), and 637 did not (comparator group). Measurements and Main Results: Mean ± SD time to failure was 64 ± 23 days; 98% (53/54 patients) was attributable to viremia diagnosed via positive polymerase chain reaction (PCR). Of these 53 patients, 34% (18 patients) were below the quantifiable range when detected. Median initial and peak CMV PCR for quantifiable readings were 1531 IU/ml (interquartile range [IQR] less than 250–2947) and 4442 IU/ml (IQR less than 250–32,500); 19 (36%) had a single detectable CMV PCR. Treatment was required in 56% (30/54 patients), with a median duration of 63 days; 40% (12 patients) were treated with valganciclovir alone, and the remainder received intravenous ganciclovir. CMV disease resulted in hospitalization in 28% (15 patients). Immunosuppression was modified in 52% (28 patients). The rate of CMV recurrence after 100 days was significantly higher in the prophylaxis failure group (59% vs 13%, p<0.0001). Higher rates of rejection; higher rates of 1‐, 3‐, and 5‐year graft failure; and higher rates of 1‐, 3‐, and 5‐year mortality were noted in the prophylaxis failure group on univariate analysis (43% vs 30%, p=0.045; 8%, 17%, and 34% vs 4%, 12%, and 17%, p=0.006; and 6%, 17%, and 26% vs 1%, 6%, and 10%, p=0.003, respectively). Multivariate analysis demonstrated an increased risk of graft failure in the prophylaxis failure group (hazard ratio [HR] 1.76, 95% confidence interval [CI] 1–3.1, p=0.0499) and a trend to increased mortality (HR 1.6, 95% CI 0.83–3.1, p=0.16). Conclusion: Prophylaxis failure with HD‐A was mostly limited to mild viremia; however, it was associated with significantly reduced long‐term graft survival, likely reflecting the negative impact of CMV viremia. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Renal transplant outcomes result from a combination of factors. Traditionally, donor factors were summarized by classifying kidneys as extended criteria or standard criteria. In 2014, the nomenclature changed to describe donor factors with the kidney donor profile index (KDPI). We aim to evaluate the relationship between KDPI and delayed graft function (DGF), and the impact KDPI on transplant outcomes for both donor after cardiac death (DCD) and donor after brain death (DBD). Methods: An IRB‐approved single‐center retrospective chart review was performed from January 1999 to July 2013. The patients were divided into six groups: DBD KDPI ≤60, DBD KPDI 61‐84, DBD KDPI ≥85, DCD KDPI ≤60, DCD KPDI 61‐84, and DCD KDPI ≥85. Rates of DGF, patient survival, and graft survival were examined among groups. Results: A total of 2161 kidney transplants were included. DGF rates increased, and graft and patient survival decreased with increasing KDPI (P < .001). DCD kidneys had higher DGF rates than their DBD counterparts (P < .001). In DCD kidneys, a higher KDPI score did not significantly affect the DGF rates (P > .302). There was no significant difference in graft or patient survival in all‐comers when comparing DCD and DBD kidneys with equivalent KDPIs (P > .317). Patients with DGF across all categories demonstrated worse graft half‐lives. Conclusion: The KDPI system is an accurate predictor of donor contributions to transplant outcomes. Recipients of DBD kidneys experience an increase in the rate of DGF as their KDPI increases. DCD kidneys have higher DGF rates than their DBD counterparts with similar KDPIs. Patients with documented post‐transplant DGF had between 3‐ and 5‐year shorter graft half‐lives when compared to recipients that did not experience DGF. Initiatives to reduce the rate of DGF could provide a significant impact on graft survival and result in a reduction in the number of patients requiring retransplant. [ABSTRACT FROM AUTHOR]

Ganciclovir-resistant cytomegalovirus ( GR- CMV) is emerging as a significant infection in the abdominal transplant population. GR- CMV is difficult to manage, and treatment options are limited. We report a descriptive case series of 15 patients who had documented GR- CMV at our center and review the literature on treatment of GR- CMV. The first case in this series was detected in 2012; the majority of cases occurred after January 1, 2014, with approximately 50% occurring in 2015. UL97 and UL54 viral genome mutations were present in 100% and 40% of CMV-infected patients, respectively. GR- CMV infection occurred ≤ 1 year posttransplantation in 11 patients (73%). All patients experienced dose reduction of valganciclovir (the oral prodrug of ganciclovir) before the development of GR- CMV. Initial treatment for GR- CMV included a variety of regimens, all including reduction in maintenance immunosuppression. Of the 6 patients with detectable GR- CMV by polymerase chain reaction ( PCR) who were discharged without GR- CMV treatment and had a length of stay ( LOS) less than 14 days, 83% were subsequently readmitted for treatment of GR- CMV within 2 months (60% in < 20 days); none received leflunomide. Of six patients with a LOS ≥ 14 days, 80% had CMV PCR below quantification on hospital discharge, and only one patient was readmitted in less than 20 days; 83% received leflunomide. Following GR- CMV, there was a 50% rejection incidence, 27% graft loss, and 20% mortality. For patients with more than three admissions for GR- CMV treatment, 100% had a major complication: 60% rejection, 20% graft loss, and 40% mortality. Common clinical characteristics of patients with GR- CMV included high-risk serostatus, lymphocyte depletion, and history of valganciclovir dose reduction. Overall, outcomes were poor. It appears that hospital readmission rate was reduced when CMV was treated to negativity with an initial treatment regimen of reduced immunosuppression, foscarnet, intravenous immunoglobulins, and leflunomide. [ABSTRACT FROM AUTHOR]

Since the institution of the new kidney allocation system in December 2014, kidney transplant candidates with the highest calculated panel reactive antibodies ( cPRA) of 99-100 have been transplanted at much higher rates. However, concerns have been raised that outcomes in these patients might be impaired due to higher immunological risk and longer cold ischemia times resulting from long-distance sharing of kidneys. Here, we compare outcomes at the University of Wisconsin between study patients with cPRA 99-100 and all other recipients of deceased donor kidneys transplanted between 12/04/2014 and 12/31/2015. All patients had at least 6 months post-transplant follow-up. The mean follow-up was 13.9±3 months in cPRA ≥99% and 12.3±3.5 months in cPRA ≤98%. There was a total of 152 transplants, 25 study patients, and 127 controls. No statistically significant differences were found between the two groups in delayed graft function, rejection, kidney function, graft and patient survival, or infections. We conclude that transplanting the most highly sensitized patients with kidneys shared outside their local donation service areas is associated with excellent short-term outcomes that are comparable to controls. [ABSTRACT FROM AUTHOR]

Copyright of Tropical Medicine & International Health is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: There is a paucity of data stratifying by age the incidence of antibody-mediated rejection (AMR) in kidney transplant patients. Methods: We performed a retrospective study of all adult, renal transplant recipients at a single institution between December 12, 2009, and March 16, 2011. Mildly and moderately sensitized patients were defined as patients with positive donor-specific antibody (DSA) and negative flow cross-match. Results: One hundred and forty-six patients were determined to have mild to moderate pre-transplantation sensitization. Thirty percent of patients younger than 40 yr of age experienced AMR vs. 15% in the older group (p = 0.04). There was a disproportionate increase in DSA for younger patients at 12 months, particularly for antibodies to class II. Histologic presence of C4d deposition was independently associated with AMR on multivariate analysis. Conclusions: Following renal transplantation, moderately sensitized patients aged 40 yr old and older were less likely to develop AMR when compared with younger patients. [ABSTRACT FROM AUTHOR]

Suramin has been reported to inhibit the reverse transcriptase activity of a number of retroviruses and to reduce the in vitro infectivity and cytopathic effect of HTLV-III/LAV, the etiologic agent of acquired immune deficiency syndrome (AIDS). The clinical pharmacokinetics of suramin were investigated as part of a pilot study to evaluate the safety and efficacy of this drug for the treatment of patients with diseases caused by HTLV-III/LAV. A dose of suramin 6.2 g was given intravenously over a five-week period to four patients. After the last dose, the plasma half-life of suramin was 44 to 54 days. This is among the longest half-lives reported for any therapeutic substance given to humans. Total plasma levels of suramin were greater than 100 μg/mL for several weeks. In vitro activity of suramin was found at concentrations as low as 50 μg/mL. Metabolites were not found in plasma, and urinary excretion accounts for elimination of most of the drug. Suramin is approximately 99.7% bound to plasma proteins. The results from these initial clinical pharmacokinetic studies might assist the design of further therapeutic trials of suramin, especially the selection of frequency of dosing and adjustments for renal impairment. [ABSTRACT FROM AUTHOR]

Background: HIV-1 natural viral suppressors (NVS) are individuals that control HIV replication without antiretrovirals (also know as HIV elite controllers). We have recently shown that these individuals have an elevated rate of hepatitis C virus (HCV) clearance. Given the association of IL28B genotype, specifically the rs12979860 single nucleotide polymorphism (SNP) based CC genotype, with HCV clearance, we studied its association with HIV control in 172 African American HIV subjects and 173 race-matched controls. Findings: The frequency of the CC genotype was 12.5% in the NVS, 14.7% in the LVL ('low viral load' cohort with 400-20,000 HIV-1 RNA copies/mL), 17.8% in the MHVL ('medium/high viral load' cohort with >20,000 HIV-1 RNA copies/mL), and 11.6% in an HIV-negative cohort. There was no statistical significance in the CC genotype distribution between these cohorts ( p= 0.48 between the NVS and non-NVS HIV positive controls, p= 0.85 between NVS and HIV-negatives). We also did not observe any association between CC genotype distribution and HIV RNA viral load, as a continuous measure. Conclusions: The IL28B CC genotype does not account for the noted HIV control in our specific NVS cohort. Further studies will be needed to determine if a common genetic factor can primarily account for any joint clearance of HCV and control of HIV. Clin Trans Sci 2011; Volume 4: 282-284 [ABSTRACT FROM AUTHOR]

Simultaneous pancreas and kidney (SPK) and pancreas after kidney (PAK) transplant are both potential options for diabetic ESRD patients. Historically, PAK pancreas graft outcomes were felt to be inferior to SPK pancreas graft outcomes. Little is known about outcomes in the modern era of transplantation. We analyzed our SPK and PAK recipients transplanted between 01/2000 and 12/2016. There were a total of 635 pancreas and kidney transplant recipients during the study period, 611 SPK and 24 PAK. Twelve of the PAK patients received a living donor kidney. There were no significant differences between the two groups in kidney or pancreas graft rejection at 1 year. Similarly, 1‐year graft survival for both organs was not different. At last follow‐up, uncensored and death‐censored graft survival was not statistically different for kidney or pancreas grafts. In addition, in Cox regression analysis SPK and PAK were associated with similar graft survival. Although the majority of pancreas transplants are in the form of SPK, PAK is an acceptable alternative. Simultaneous pancreas and kidney avoids donor risks associated with live donation, so may be preferable in regions with short wait times, but PAK with a living donor kidney may be the best alternative in regions with long SPK wait times. [ABSTRACT FROM AUTHOR]

Background: Hmong ethnicity has been associated with infection, particularly fungal. The risk of infection after transplant in the Hmong population is unknown. Methods: Observational study of adult renal transplant (RTX) recipients between 1/1/1994 and 12/31/2015. Primary objective was to identify infectious risk in the Hmong RTX population as compared to non‐Hispanic whites (NHW). Secondary objective was to evaluate transplant outcomes. Results: There was a total of 2599 patients in the study window; 95 Hmong, 2504 NHW. The Hmong population had significantly fewer bacterial and fungal infections at 1 and 3 years (Bacterial: Hmong 21.7%, 32.4% vs NHW 36.9%, 46.7%, P = .004; Fungal: Hmong 3.3%, 5.7% vs NHW 12.7%, 16.6%, P = .0005) and improved graft and patient survival at 1, 5, and 10 years (Graft: Hmong 92.6%, 78.4%, 61.9% vs NHW 90.7%, 72.2%, 48.5%, P = .006; Patient: Hmong 97.8%, 94.5%, 83.3% vs NHW 95.3%, 82.1%, 62.1% P < .001). Spectrum of bacterial infection was similar, but with significantly more Staphylococcal infection in the NHW population. Blastomycoses were the major fungal pathogen in Hmong (2/3, 67%) vs Candida in NWH (77%). When minimally adjusted for PRA and age, rates of bacterial infection (HR 0.69, 95% CI 0.48‐0.99, P = .047), fungal infection (HR 0.39, 95% CI 0.17‐0.87, P = .02), and mortality (HR 0.5, 95% CI 0.28‐0.88, P = .02) were more favorable in the Hmong population. When analyzed in a stepwise Cox proportional hazards model; Hmong ethnicity was not a significant risk factor for graft failure, rejection, CMV, BK, or fungal infection after RTX and was associated with reduced risk of bacterial infection (HR 0.61, 95% CI 0.4‐0.9, P = .02) and mortality (HR 0.51, 95% CI 0.27‐0.96, P = .04). Conclusions: Despite concern regarding infective risk in the Hmong population, infection after RTX is no higher than NHW comparator. In all analyses, the Hmong population has equal or better outcomes. It does not appear variance in standard infection prophylaxis is necessary for the Hmong population after RTX. [ABSTRACT FROM AUTHOR]

Transplant surgical workforce concerns have arisen in the last 5 years as reflected in challenges securing job opportunities for new fellows. The present survey was designed by the ASTS Membership and Workforce Committee to describe the current practice characteristics of transplant centers in order to estimate changes in the workforce. The survey questionnaire requested information about the transplant programs, the transplant surgeons involved in the program, and the estimated changes in the staffing of the program over the next 3 years. Seventy‐one transplant centers responded from a total of 235 identified and queried (30.2% response rate), with median responding centers per UNOS region of 7 (IQR 4.5‐8.5). The recruitment outlook for the next 3 years forecasts a positive inflow of surgeons at a 2:1 rate (incoming:leaving). The new female transplant workforce within the responding cohort has increased from 3.7% in 1980 to 18.4% in 2010. Currently, 13.1% of practicing US transplant surgeons in this survey are female which is higher than many other surgical specialties. This report represents the most up‐to‐date view into the abdominal transplant surgical workforce. The positive job recruitment outlook for transplant surgeons and the narrowing gender gap are new findings from this study. [ABSTRACT FROM AUTHOR]

Redfield RR, Parsons RF, Rodriguez E, Mustafa M, Cassuto J, Vivek K, Noorchashm H, Naji A, Levine MH, Abt PL. Underutilization of A2 ABO incompatible kidney transplantation. Clin Transplant 2011 DOI: 10.1111/j.1399-0012.2011.01543.x. © 2011 John Wiley & Sons A/S. Abstract: Background: ABO compatibility creates a disadvantage for O and B renal allograft candidates. A2 ABO incompatible transplant may decrease waiting times and generate equivalent graft survival to an ABO compatible transplant. Methods: Death-censored graft survival was compared between A recipients and O, B, and AB recipients of an A2 allograft with multivariate Cox regression models utilizing data from the United Network of Organ Sharing (UNOS) between 1997 and 2007. Results: Eighty-five percent of A2 kidneys were transplanted into ABO compatible recipients vs. 15% into ABO incompatible recipients. Rates of A2 incompatible kidney transplants did not increase over the study period (14.8% to 14.6%). Mean wait time for A2→O kidneys was 337 vs. 684 d for O→O and for A2→B kidneys, 542 vs. 734 d for B→B. Adjusted relative risk of graft loss at five-yr was similar between O, B, and AB recipients compared to A recipients of an A2 allograft, corresponding to a five-yr graft survival of 84%, 86.2%, 86.1%, and 86.1%, respectively. Conclusion: A2 incompatible kidney transplantation is underutilized. Graft outcomes are similar among A2 compatible and incompatible recipients. Shorter waiting time and improved access might be achieved if A2 kidneys are considered in all blood groups. [ABSTRACT FROM AUTHOR]