Should children receive a kidney transplant before 2 years of age?

BACKGROUND: The optimal age of kidney transplantation for infants and toddlers with kidney failure is unclear. We aimed to evaluate the patient survival associated with kidney transplantation before 2 years of age versus remaining on the waitlist until ≥2 years. METHOD: We used the Scientific Registry of Transplant Recipients to identify all children added to the deceased-donor waitlist before 2 years of age between 1/1/2000 and 4/30/2020. For each case aged <2 years at transplant, we created a control group comprising all candidates on the waitlist on the case's transplant date. Patient survival was evaluated using sequential Cox regression. Dialysis-free time was defined as graft survival time for cases and the sum of dialysis-free time on the waitlist and graft survival time for controls. RESULTS: We observed similar patient survival for posttransplant periods 0-3 and 4-12 months but higher survival for period >12 months for <2-year decreased-donor recipients (aHR: 0.32; 95% CI: 0.13-0.78; p = .01) compared with controls. Similarly, patient survival was higher for <2-year living-donor recipients for posttransplant period >12 months (aHR: 0.21; 95% CI: 0.06-0.73; p = .01). The 5-year dialysis-free survival was higher for <2-year deceased- (difference: 0.59 years; 95% CI: 0.23-0.93) and living-donor (difference: 1.84 years; 95% CI: 1.31-2.25) recipients. CONCLUSION: Kidney transplantation in children <2 years of age is associated with improved patient survival and reduced dialysis exposure compared with remaining on the waitlist until ≥2 years.

Prevention and management of CMV infection in pediatric solid organ transplant recipients.

Human cytomegalovirus (CMV) remains one of the most common opportunistic infections following solid organ transplantation in children. CMV causes morbidity and mortality through direct tissue-invasive disease and indirect immunomodulatory effects. In recent years, several new agents have emerged for the prevention and treatment of CMV disease in solid organ transplant recipients. However, pediatric data remain scarce, and many of the treatments are extrapolated from the adult literature. Controversies exist about the type and duration of prophylactic therapies and the optimal dosing of antiviral agents. This review provides an up-to-date overview of treatment modalities used to prevent and treat CMV disease in solid organ transplant (SOT) recipients.

Language barriers and kidney transplantation in children.

BACKGROUND: Understanding disparities in pediatric kidney transplants is important to provide equitable care. We compared transplant outcomes between English-speaking (ES) and interpreter-needing (IN) pediatric kidney transplant recipients. METHODS: Through retrospective review, primary kidney transplant recipients, 0-21 years transplanted between 2005 and 2019, were divided into ES and IN cohorts. Continuous and categorical variables were compared using Wilcoxon rank-sum, Welch two-sample t-test, and chi-squared analyses. Patient survival, graft survival, and rejection-free survival were evaluated using Kaplan-Meier methods and Cox regression. Days hospitalized were evaluated using negative binomial regression. RESULTS: Our sample included 211 ES and 37 IN transplant recipients. Compared with the ES, the IN cohort was older at transplant (14.56 vs. 11.03 years; p < 0.01), had more time between kidney failure and transplant (0.9 vs. 0.3 years; p < 0.01), and more often received deceased over living donor transplants (78.4% vs. 30.4%; p < 0.01). Multivariate Cox proportional-hazard models evaluating adjusted 5-year patient survival demonstrated decreased 5-year post-transplant survival in the IN cohort (aHR = 10.10, 95% CI: 1.5, 66.8; p = 0.02). We did not identify differences in 5-year death-censored graft survival (aHR = 0.57; 95% CI: 0.14, 2.4; p = 0.4) nor rejection-free survival (aHR = 0.8; 95% CI: 0.4, 1.5; p = 0.5). We found significantly fewer hospitalization events in the IN cohort during the first year post-transplant (aRR: 0.62; 95% CI: 0.4, 0.9; p = 0.01) but no difference 5-year post-transplant. The IN cohort had more missed outpatient appointments (10.4% vs. 2.8%; p = 0.03) and undetectable serum immunosuppressant levels (mean: 3.8% vs. 1.3%; p = 0.02) 5 years post-transplant. CONCLUSIONS: Pediatric kidney transplant recipients requiring interpreter services for healthcare delivery demonstrate fewer post-transplant interactions with their healthcare team (fewer hospitalizations and more no-show visits) and lower 5-year patient survival compared with recipients not requiring interpreters. A higher resolution version of the Graphical abstract is available as Supplementary information.

BK DNAemia in pediatric kidney transplant recipients: Predictors and outcomes.

BACKGROUND: Pediatric data on risk factors and the clinical course of BK DNAemia are limited. We aimed to determine the effects of BK DNAemia on transplant outcomes and delineate the safety and efficacy of various treatment approaches. METHODS: This retrospective-cohort study included 161 transplants (age ≤ 21 years) performed at a single center between 1/1/2012 and 1/1/2020. We used Cox proportional models to evaluate the effects of BK DNAemia on patient survival (PS), graft survival (GS), and acute rejection (AR), using BK as a time-dependent covariate. We also assessed the effects of pharmacological intervention on BK DNAemia duration using intervention as a time-dependent covariate. RESULTS: BK-free survival was 69.1% at 1-year and 54.6% at 3-year posttransplant. After multivariate adjustment, BK DNAemia was associated with young age at transplant (aHR, age 5-<12 vs. ≥12 (years): 2.5 (1.4-4.5); p = .001) and steroid-based immunosuppression (IS) (aHR: 2.2 [1.1-4.5]; p = .03). We found no effect of DNAemia on AR (aHR: 1.25; p = .5), PS (aHR: 2.85; p = .22), and GS (aHR: 0.56; p = .41). Of 70 patients with DNAemia, 22 (31.4%) received no treatment, 20 (28.6%) received IS reduction alone, and 28 patients (40%) received treatment with at least one pharmacological agent (leflunomide, IVIG, ciprofloxacin, cidofovir). Sixty-three patients (90%) cleared DNAemia with median time to resolution of 2.4 months (IQR:1.4-5.6). We found no significant effect of BK-directed pharmacological treatment on time to resolution (aHR: 0.64;p = .13). BK-directed agents were well tolerated. CONCLUSIONS: BK DNAemia is associated with a young age at transplant and steroid-based maintenance IS. We found no effect of BK DNAemia on AR, GS, and PS.

Survival Benefit of Donation After Circulatory Death Kidney Transplantation in Children Compared With Remaining on the Waiting List for a Kidney Donated After Brain Death.

BACKGROUND: Kidneys donated after circulatory death (DCD) are increasingly being used for transplantation in adults to alleviate organ shortage. Pediatric data on survival benefits of DCD transplantation compared with remaining on the waitlist for a kidney donated after brain death (DBD) offer are lacking. METHODS: We used Scientific Registry of Transplant Recipients to identify 285 pediatric (<18 y) DCD kidney transplants performed between 1987 and 2017. Propensity score matching was used to create a comparison group of 1132 DBD transplants. We used sequential Cox analysis to evaluate survival benefit of DCD transplantation versus remaining on the waitlist and Cox regression to evaluate patient and graft survival. RESULTS: DCD transplantation was associated with a higher incidence of delayed graft function (adjusted odds ratio: 3.0; P < 0.001). The risks of graft failure (adjusted hazard ratio [aHR], 0.89; P = 0.46) and death (aHR, 1.2; P = 0.67) were similar between DCD and DBD recipients. We found a significant survival benefit of DCD transplantation compared with remaining on the waitlist awaiting a DBD kidney (aHR, 0.44; P = 0.03). CONCLUSIONS: Despite a higher incidence of delayed graft function, long-term patient and graft survival are similar between pediatric DCD and DBD kidney transplant recipients. DCD transplantation in children is associated with a survival benefit, despite pediatric priority for organ allocation, compared with remaining on the waitlist.

Racial disparities and trends in kidney transplant outcomes in patients with Alport syndrome.

BACKGROUND: Registry data from Europe has shown an increase in age at end-stage kidney disease for patients with Alport syndrome in recent years. Whether a similar delay in transplant age has occurred in the United States for Alport patients across all racial/ethnic groups is unknown. MATERIALS AND METHODS: We used data from the Scientific Registry of Transplant Recipients (SRTR) to identify 3,794 Alport patients transplanted between 12/1987 and 12/2017. We divided the study period into five equal eras to assess temporal trends in age at transplant, graft survival, and patient survival across racial groups using linear regression and Cox regression models. RESULTS: The mean age at transplant for Blacks (28.3 years; difference (Black vs. White): 8.9 years; p < 0.0001) and Hispanics (28.7 years; difference (Hispanics vs. White): 8.7 years; p < 0.0001) was significantly younger compared with that of Whites. We observed a temporal increase in age at transplant for Whites but not for Blacks and Hispanics (p-value for interaction: 0.001). Black recipients were at a higher risk of graft loss (aHR: 1.78; 95% CI: 1.47, 2.15; p < 0.0001) and death (aHR: 1.73; 95% CI: 1.11, 2.69; p = 0.02) compared with White recipients. We observed significant improvements in graft survival with each successive era (p < 0.01). Temporal trends in graft survival (interaction p = 0.46) were not modified by race. CONCLUSION: We found racial disparities in age at transplant and long-term graft survival for patients with Alport syndrome in the United States. The age at transplant increased over time for Whites but not Black and Hispanic patients.

Steroid avoidance/withdrawal and maintenance immunosuppression in pediatric kidney transplantation.

BACKGROUND: Corticosteroids have been an integral part of maintenance immunosuppression for pediatric kidney transplantation. However, prolonged steroid therapy is associated with significant toxicities resulting in several SW/avoidance strategies in recent years. METHOD/OBJECTIVE: This comprehensive review aims to discuss steroid-related toxicities and the safety, efficacy, and benefit of steroid avoidance/withdrawal immunosuppression in pediatric kidney transplant recipients. RESULTS: Initial studies of SW/avoidance conducted in the setting of CSA and AZA showed an increased incidence of AR but no increase in graft loss or mortality with SW/avoidance maintenance immunosuppression. Studies performed under modern immunosuppression (induction therapy, Tac, and MMF) show no significant increase in AR or graft loss with SW/avoidance immunosuppression. Furthermore, SW/avoidance immunosuppression is associated with significant improvement in growth, BMI, BP control, and lipid profile in pediatric kidney transplant recipients. Despite these data, SW/avoidance remains controversial, and only 40% of pediatric kidney transplant recipients in the United States are currently on SW/avoidance maintenance immunosuppression. CONCLUSION: SW/avoidance maintenance immunosuppression is safe and associated with fewer side effects compared with steroid-inclusive maintenance immunosuppression in pediatric kidney transplant recipients.

Antineutrophilic cytoplasmic antibody-associated vasculitis and the kidney.

PURPOSE OF REVIEW: The purpose of this review is to highlight recent studies that have emerged on the topic of ANCA-associated vasculitis with some historical context. The review also discusses how the adult data is relevant to pediatric patients. RECENT FINDINGS: Pediatric studies on AAV are lacking. Therapies targeted to the inflammatory cascade specifically implicated in AAV, such as MPO inhibitors and complement mediators, are emerging. The PEXIVAS study recently called into question the routine use of plasma exchange (PLEX) in severe AAV, with no difference in ESKD or mortality found between patients who did or did not receive PLEX. Longer maintenance duration of nearly 48 months is preferred as compared with shorter duration in patients who are not on dialysis because of higher relapse rates in children with AAV. SUMMARY: Current treatment in AAV includes corticosteroids, rituximab, and cyclophosphamide for induction. Maintenance therapy commonly consists of azathioprine or rituximab. Plasma exchange (PLEX) is no longer recommended for induction therapy for AAV but some experts still consider this as an option for patients who are not responding to therapy or have severe disease at presentation. However, emerging novel therapies may be on the horizon.

Induction and maintenance immunosuppression in pediatric kidney transplantation-Advances and controversies.

Advances in immunosuppression have improved graft survival in pediatric kidney transplant recipients; however, treatment-related toxicities need to be balanced against the possibility of graft rejection. Several immunosuppressive agents are available for use in transplant recipients; however, the optimal combinations of agents remain unclear, resulting in variations in institutional protocols. Lymphocyte-depleting antibodies, specifically ATG, are the most common induction agent used for pediatric kidney transplantation in the US. Basiliximab may be used for induction in immunologically low-risk children; however, pediatric data are scarce. CNIs and antiproliferative agents (mostly Tac and mycophenolate in recent years) constitute the backbone of maintenance immunosuppression. Steroid-avoidance maintenance regimens remain controversial. Belatacept and mTOR inhibitors are used in children under specific circumstances such as non-adherence or CNI toxicity. This article reviews the indications, mechanism of action, efficacy, dosing, and side effect profiles of various immunosuppressive agents available for pediatric kidney transplantation.

Eculizumab exposure in children and young adults: indications, practice patterns, and outcomes-a Pediatric Nephrology Research Consortium study.

BACKGROUND: Eculizumab is approved for the treatment of atypical hemolytic uremic syndrome (aHUS). Its use off-label is frequently reported. The aim of this study was to describe the broader use and outcomes of a cohort of pediatric patients exposed to eculizumab. METHODS: A retrospective, cohort analysis was performed on the clinical and biomarker characteristics of eculizumab-exposed patients < 25 years of age seen across 21 centers of the Pediatric Nephrology Research Consortium. Patients were included if they received at least one dose of eculizumab between 2008 and 2015. Traditional summary statistics were applied to demographic and clinical data. RESULTS: A total of 152 patients were identified, mean age 9.1 (+/-6.8) years. Eculizumab was used "off-label" in 44% of cases. The most common diagnoses were aHUS (47.4%), Shiga toxin-producing Escherichia coli HUS (12%), unspecified thrombotic microangiopathies (9%), and glomerulonephritis (9%). Genetic testing was available for 60% of patients; 20% had gene variants. Dosing regimens were variable. Kidney outcomes tended to vary according to diagnosis. Infectious adverse events were the most common adverse event (33.5%). No cases of meningitis were reported. Nine patients died of noninfectious causes while on therapy. CONCLUSIONS: This multi-center retrospective cohort analysis indicates that a significant number of children and young adults are being exposed to C5 blockade for off-label indications. Dosing schedules were highly variable, limiting outcome conclusions. Attributable adverse events appeared to be low. Cohort mortality (6.6%) was not insignificant. Prospective studies in homogenous disease cohorts are needed to support the role of C5 blockade in kidney outcomes.

Early detection of SARS-CoV-2 and other infections in solid organ transplant recipients and household members using wearable devices.

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.

Timing of native nephrectomy and kidney transplant outcomes in children.

BACKGROUND: No consensus exists on the optimal timing for native nephrectomy in pediatric kidney transplant recipients. Data comparing outcomes between recipients undergoing pretransplant nephrectomy (staged nephrectomy with subsequent transplant) and those undergoing nephrectomy simultaneously with the transplant are lacking. METHOD: We studied 32 pediatric kidney transplant recipients who underwent native nephrectomy at a single center from 01/01/2011 to 12/31/2016. We divided recipients into two groups based on the nephrectomy timing (simultaneous nephrectomy/transplant and staged nephrectomy). We used Wilcoxon rank-sum test, Fisher's exact test, and Kaplan-Meier methods to compare outcomes. RESULTS: Of 32 recipients, 20 underwent simultaneous and 12 underwent staged nephrectomy. Simultaneous recipients were younger (median (years): 2.0 vs 7.0; P = .049). Staged recipients were more likely to have proteinuria/hypoalbuminemia, whereas simultaneous recipients were more likely to have hydronephrosis/vesicoureteral reflux/urinary infections as nephrectomy indications (P = .06). Median prenephrectomy albumin for patients with nephrotic syndrome was significantly lower in staged recipients (median g/dL: 1.9 vs 3.8; P = .02). Total number of hospital days (including both procedures) was higher for staged recipients compared with simultaneous (one procedure) recipients (median (days): 17.0 vs 11.5; P = .05). We observed no difference in 5-year graft survival between the groups (95.0% vs 91.7%, P = .73). Patient survival was 100% in both groups over a median follow-up of 44.2 months. Surgical complications were similar between the groups. CONCLUSION: Staged and simultaneous native nephrectomy in pediatric kidney transplant recipients are associated with comparable outcomes.

Use of expanded-criteria donors and > 85 KDPI kidneys for pediatric kidney transplantation in the United States.

Pediatric kidney transplant outcomes associated with expanded-criteria donors (ECD) and high Kidney Donor Profile Index (KDPI) kidneys are unknown. We reviewed the Scientific Registry of Transplant Recipients data from 1987-2017 to identify 96 ECD and 92 > 85 KDPI kidney recipients (<18 years). Using propensity scores, we created comparison groups of 375 non-ECD and 357 ≤ 85 KDPI recipients for comparisons with ECD and > 85 KDPI transplants, respectively. We used Cox regression for patient/graft survival and sequential Cox approach for survival benefit of ECD and > 85 KDPI transplantationvs remaining on the waitlist. After adjustment, ECD recipients were at significantly increased risk of graft failure (adjusted hazard ratio [aHR] = 1.6; P = .001) but not of mortality (aHR = 1.33; P = .15) compared with non-ECD recipients. We observed no survival benefit of ECD transplants vs remaining on the waitlist (aHR = 1.05; P = .83). We found no significant difference in graft failure (aHR = 1.27; P = .12) and mortality (aHR = 1.41; P = .13) risks between > 85 KDPI and ≤ 85 KDPI recipients. However, > 85 KDPI transplants were associated with a survival benefit vs remaining on the waitlist (aHR = 0.41; P = .01). ECD transplantation in children is associated with a high graft loss risk and no survival benefit, whereas > 85 KDPI transplantation is associated with a survival benefit for children vs remaining on the waitlist.

Survival Benefit of En Bloc Transplantation of Small Pediatric Kidneys in Children.

BACKGROUND: En bloc transplantation of small pediatric kidneys in children may help expand the existing deceased donor pool; however, studies examining the long-term outcomes of en bloc transplantation in children are few. METHODS: We used the Scientific Registry of Transplant Recipients to identify 149 pediatric en bloc recipients transplanted from October 1, 1987 to December 31, 2017. We used propensity scores to match 148 en bloc with 581 non-en bloc deceased donor recipients (matching variables: transplant age, gender, race, pretransplant dialysis, transplant center, and year). We evaluated patient and graft survival using Kaplan-Meier and Fleming-Harrington weighted log-rank test and examined survival benefit of en bloc transplantation versus remaining on the waiting list using the sequential Cox approach. We divided the study period into three 10-y intervals to assess the effect of era on outcomes. RESULTS: Compared with non-en bloc recipients, en bloc recipients had lower 1-y graft survival (78.9% versus 88.9%; P = 0.007); however, when stratified by transplant era, lower 1-y survival was only observed in the oldest era (1987-1997). En bloc recipients had superior 10-y patient (89.0% versus 80.4%; P = 0.04) and graft survival (51.6% versus 39.9%; P = 0.04) compared with non-en bloc recipients. After multivariate adjustment, en bloc transplantation was associated with superior patient survival compared with remaining on the waiting list (adjusted hazard ratio: 0.58; 95% confidence interval: 0.36-0.95; P = 0.03). CONCLUSIONS: En bloc transplantation of small pediatric kidneys in children is associated with superior long-term patient and graft survival. The increased risk of 1-y graft loss among en bloc recipients only appeared in the oldest era.

Use of oral immunoglobulins to treat diarrhea in pediatric kidney transplant recipients-Single-center experience and review of the literature.

Effective treatment modalities for diarrhea in solid organ transplant recipients are lacking. We evaluated the effect of oral IgG on clinical course of diarrhea in pediatric kidney transplant recipients. We retrospectively studied all pediatric kidney transplant recipients who required hospitalization for diarrhea between January 1, 2015, and December 31, 2017. We divided the recipients into two groups based on whether they had received oral IgG to treat diarrhea. Sixteen pediatric kidney transplant recipients required hospitalization for diarrhea over 3 years. Median age at admission was 9.25 years (IQR:12.54). Fifty-six percent of recipients were male, and 81% were white. Four patients received oral IgG for prolonged diarrhea. Oral IgG recipients had longer diarrheal duration before admission (median (days) 14.5 vs1; P .02), a trend for greater weight loss at admission (median (kilogram) 1.4 vs 0.2; P .3), and a trend for higher acute kidney injury (>75% reduction in glomerular filtration rate: 100% vs 42%; P .36). Diarrhea resolved completely in 3 (75%) oral IgG recipients and 7 (58%) non-oral IgG patients by discharge (P .99). One oral IgG recipient showed partial improvement but also had biopsy evidence of mycophenolate-induced colitis. All patients tolerated oral IgG well. No patients required re-hospitalization within 30 days of discharge. Oral IgG may be used safely and effectively to treat prolonged diarrhea in pediatric kidney transplant recipients. A larger, randomized, prospective study is needed to further assess the efficacy of oral IgG in the treatment of diarrhea.

Trends in kidney transplant outcomes in children and young adults with cystinosis.

Temporal changes in kidney transplant outcomes for cystinosis are unknown. We used the SRTR to identify all kidney transplants performed for cystinosis in patients younger than 31 years between 1987 and 2017. We divided time into three equal eras (1987-1997, 1998-2007, and 2008-2017) to assess changes in outcomes using Cox proportional and linear regression models. We examined 441 transplants in 362 patients. Age at ESRD progressively increased (12.1 vs 13.3 vs 13.4; P = .046). Eras 2 and 3 had lower risk of acute rejection (aHR 2 vs 1:0.45; P < .001) (aHR 3 vs 1:0.26; P < .001) and higher 5-year mean GFR (difference 2 vs 1:9.2 mL/min/1.73 m2 ; P = .005) (difference 3 vs 1:12.9 mL/min/1.73 m2 ; P = .002) compared with era 1. Five-year graft survival was similar across eras, but 5-year patient survival was higher for era 2 (aHR: 0.25; P = .01). Seventy-nine patients underwent retransplantation. Five-year patient (94.2% vs 92.5%; P = .57) and graft survival (79.1% vs 74.1%; P = .52) were similar between primary and subsequent transplants. Age at ESRD, acute rejection, GFR at 5 years, and patient survival improved over time. Kidney retransplantation is associated with excellent outcomes in children and young adults with cystinosis.

Kidney transplant outcomes associated with the use of increased risk donors in children.

Increased risk donors (IRDs) may inadvertently transmit blood-borne viruses to organ recipients through transplant. Rates of IRD kidney transplants in children and the associated outcomes are unknown. We used the Scientific Registry of Transplant Recipients to identify pediatric deceased donor kidney transplants that were performed in the United States between January 1, 2005 and December 31, 2015. We used the Cox regression analysis to compare patient and graft survival between IRD and non-IRD recipients, and a sequential Cox approach to evaluate survival benefit after IRD transplants compared with remaining on the waitlist and never accepting an IRD kidney. We studied 328 recipients with and 4850 without IRD transplants. The annual IRD transplant rates ranged from 3.4% to 13.2%. IRDs were more likely to be male (P = .04), black (P < .001), and die from head trauma (P = .006). IRD recipients had higher mean cPRA (0.085 vs 0.065, P = .02). After multivariate adjustment, patient survival after IRD transplants was significantly higher compared with remaining on the waitlist (adjusted hazard ratio [aHR]: 0.48, 95% CI: 0.26-0.88, P = .018); however, patient (aHR: 0.93, 95% CI: 0.54-1.59, P = .79) and graft survival (aHR: 0.89, 95% CI: 0.70-1.13, P = .32) were similar between IRD and non-IRD recipients. We recommend that IRDs be considered for transplant in children.

Infection rates in tacrolimus versus cyclosporine-treated pediatric kidney transplant recipients on a rapid discontinuation of prednisone protocol: 1-year analysis.

AR is lower in pKTx recipients on Tac vs CsA. Data comparing infection outcomes for children treated with these agents are limited. We retrospectively studied infection outcomes in 96 pKTx recipients on a RDP. PS, DCGS, AR, and infection-free survival were assessed using Kaplan-Meier/log-rank tests and proportional hazards models. There were no differences in 1-year PS, DCGS, or AR between Tac and CsA recipients. After adjusting for AR, the hazard of CMV viremia was 4.0 times higher (95%CI: 1.04, 15.5; P = .044) and that of BK viremia was 3.8 times higher (95%CI: 1.5, 10.2; P = .007) in Tac recipients. The incidence of EBV viremia was similar between the groups (P = .56). PostTx lymphoproliferative disease was only observed in Tac recipients (3%). There was no difference in the incidence of pneumonia, urinary tract, or Clostridium difficile infections between Tac and CsA recipients. Among KTx recipients on RDP, the hazards of CMV and BK viremia within 1 year post-KTx were significantly higher in Tac recipients compared to CsA. Regular assessment for infections and lower Tac trough levels may be warranted in Tac recipients.