Impact of CYP3A5 Status on the Clinical and Financial Outcomes Among African American Kidney Transplant Recipients.

Pharmacogenetic profiling of transplant recipients demonstrates that the marked variation in the metabolism of immunosuppressive medications, particularly tacrolimus, is related to genetic variants. Patients of African ancestry are less likely to carry loss-of-function (LoF) variants in the CYP3A5 gene and therefore retain a rapid metabolism phenotype and higher clearance of tacrolimus. Patients with this rapid metabolism typically require higher dosing to achieve therapeutic trough concentrations. This study aims to further characterize the impact of CYP3A5 genotype on clinical outcomes and financial expenditure. Methods: The CYP3A5 phenotype status was identified in 438 adult kidney transplant (KTx) recipients (96% were African American) using 3 LoF alleles (CYP3A5*3, *6 or *7). Individuals were categorized as rapid metabolism phenotype without LoF alleles' intermediate phenotype for 1 LoF allele' and slow phenotype for 2 LoF alleles. KTx outcomes (patient/kidney survival and Medicare spending) were determined using linked transplant registry and claims data. Results: Among the cohort, 23% had a rapid, 47% intermediate, and 30% a slow metabolism phenotype based on genotype. At 3 y, the rate of death censored graft failure and all cause graft failure was highest in the rapid metabolism phenotype and lowest in the intermediate metabolism phenotype group. First-year Medicare reimbursement differed significantly by genotype (rapid: $79 535, intermediate: $72 796, slow: $79 346, P = 0.03). After adjustment for donor and recipient characteristics, care for patients with intermediate metabolism was $4790 less expensive (P = 0.003). Conclusions: Pharmacogenomic assessment of African American KTx recipients may be useful to guide therapy when as CYP3A5 functional variants appear to be associated with differential outcome and spending after transplant.

Cost burden of post-transplant lymphoproliferative disease following kidney transplants in Medicare-eligible patients by survival status.

AIMS AND OBJECTIVES: Patients diagnosed with post-transplant lymphoproliferative disease (PTLD) experience high mortality within the first 2 years of diagnosis; however, few data exist on the economic burden of PTLD in these patients. We determined the healthcare resource utilization (HRU) and cost burden of post-kidney transplant PTLD and evaluated how these differ by survival status. MATERIALS AND METHODS: Utilizing data from the United States Renal Data System and the Scientific Registry of Transplant Recipients, we identified 83,818 Medicare-covered kidney transplant recipients between 2007 and 2016, of which 347 had at least one Medicare claim during the first year after diagnosis of PTLD. We tabulated Medicare Part A and Part B and calculated per patient-year (PPY) costs. RESULTS: Patients diagnosed with PTLD in the first year post-transplant had Part A + B costs of $222,336 PPY, in contrast with $83,546 PPY in all kidney transplants. Post-transplant costs in the first year of PTLD diagnosis were similar regardless of the year of diagnosis. Cost burden for PTLD patients who died within 2 years of diagnosis was >3.3 times higher than PTLD patients still alive after 2 years. Of those who died within 2 years, the majority died within 6 months and costs were highest for these patients, with almost 7 times higher costs than PTLD patients who were still alive after 2 years. LIMITATIONS: Medicare costs were the only costs examined in this study and may not be representative of other costs incurred, nor be generalizable to other insured populations. Patients were only Medicare eligible for 3 years after transplant unless aged ≥62 years, therefore any costs after this cut-off were not included. CONCLUSIONS: PTLD represents a considerable HRU and cost burden following kidney transplant, and the burden is most pronounced in patients who die within 6 months.

Economic impacts of alternative kidney transplant immunosuppression: A national cohort study.

Understanding the economic implications of induction and maintenance immunosuppression (ISx) is important in developing personalized kidney transplant (KTx) care. Using data from a novel integrated data set including financial records from the University Health System Consortium, Medicare, and pharmacy claims (2007-2014), we estimated the differences in the impact of induction and maintenance ISx regimens on transplant hospitalization costs and Medicare payments from KTx to 3 years. Use of thymoglobulin (TMG) significantly increased transplant hospitalization costs ($12 006; P = .02), compared with alemtuzumab and basiliximab. TMG resulted in lower Medicare payments in posttransplant years 1 (-$2058; P = .05) and 2 (-$1784; P = .048). Patients on steroid-sparing ISx incurred relatively lower total Medicare spending (-$10 880; P = .01) compared with patients on triple therapy (tacrolimus, antimetabolite, and steroids). MPA/AZA-sparing, mammalian target of rapamycin inhibitors-based, and cyclosporine-based maintenance ISx regimens were associated with significantly higher payments. Alternative ISx regimens were associated with different KTx hospitalization costs and longer-term payments. Future studies of clinical efficacy should also consider cost impacts to define the economic effectiveness of alternative ISx regimens.

Perceived barriers to medication adherence remain stable following solid organ transplantation.

Perceived barriers to adherence have previously been investigated in SOT to identify plausible intervention targets to improve adherence and transplant outcomes. Fifteen centers in CTOTC enrolled patients longitudinally. Patients >8 years completed Adolescent Scale(AMBS) at two visits at least 6 months apart in the first 17 months post-transplant while their guardians completed PMBS. Differences over time for pre-identified AMBS/PMBS factors were analyzed. Perceived barrier reporting impact on subsequent TAC levels was assessed. A total of 123 patients or their guardians completed PMBS or AMBS. Twenty-six were 6-11 years and 97 were ≥12. The final cohort consisted of kidney (66%), lung (19%), liver (8%), and heart (7%) recipients. Unadjusted analysis showed no statistically significant change in reported barriers from visit 1 (median 2.6 months, range 1.2-3.7 post-transplant) to visit 2 (median 12, range 8.9-16.5). Of 102 patients with TAC levels, 74 had a single level reported at both visits. The factor of "Disease frustration" was identified through the PMBS/AMBS questions about fatigue around medication and disease. Each point increase in "disease frustration" at visit 1 on the AMBS/PMBS doubled the odds of a lower-than-threshold TAC level at visit 2. No clear change in overall level of perceived barriers to medication adherence in the first year post-transplant was seen in pediatric SOT. However, disease frustration early post-transplant was associated with a single subtherapeutic TAC levels at 12 months. A brief screening measure may allow for early self-identification of risk.

Cannabis Dependence or Abuse in Kidney Transplantation: Implications for Posttransplant Outcomes.

BACKGROUND: Cannabis is categorized as an illicit drug in most US states, but legalization for medical indications is increasing. Policies and guidance on cannabis use in transplant patients remain controversial. METHODS: We examined a database linking national kidney transplant records (n = 52 689) with Medicare claims to identify diagnoses of cannabis dependence or abuse (CDOA) and associations [adjusted hazard ratio (aHR) with 95% upper and lower confidence limits (CLs)] with graft, patient, and other clinical outcomes. RESULTS: CDOA was diagnosed in only 0.5% (n = 254) and 0.3% (n = 163) of kidney transplant recipients in the years before and after transplant, respectively. Patients with pretransplant CDOA were more likely to be 19 to 30 years of age and of black race, and less likely to be obese, college-educated, and employed. After multivariate and propensity adjustment, CDOA in the year before transplant was not associated with death or graft failure in the year after transplant, but was associated with posttransplant psychosocial problems such as alcohol abuse, other drug abuse, noncompliance, schizophrenia, and depression. Furthermore, CDOA in the first year posttransplant was associated with an approximately 2-fold increased risk of death-censored graft failure (aHR, 2.29; 95% CL, 1.59-3.32), all-cause graft loss (aHR, 2.09; 95% CL, 1.50-2.91), and death (aHR, 1.79; 95% CL, 1.06-3.04) in the subsequent 2 years. Posttransplant CDOA was also associated with cardiovascular, pulmonary, and psychosocial problems, and with events such as accidents and fractures. CONCLUSIONS: Although associations likely, in part, reflect associated conditions or behaviors, clinical diagnosis of CDOA in the year after transplant appears to have prognostic implications for allograft and patient outcomes. Recipients with posttransplant CDOA warrant focused monitoring and support.

Clinical and Economic Consequences of Early Cancer After Kidney Transplantation in Contemporary Practice.

BACKGROUND: Current clinical and economic consequences of cancer after kidney transplantation are incompletely defined. METHODS: We examined United States Renal Data System records of Medicare-insured kidney transplant recipients in 2000 to 2011 to determine clinical and economic impacts of cancer diagnosed within the first 3 years posttransplantation. Cancer diagnoses were identified using Medicare billing codes and categorized as nonmelanoma skin cancer (NMSC), viral-linked and "other" cancers. Associations of cancers with mortality and graft loss were estimated by time-varying Cox regression. Impacts of cancer diagnoses on inpatient and outpatient costs within each year were quantified by multivariate linear regression modeling. RESULTS: Among 67 157 recipients, by 3 years posttransplant, NMSC was diagnosed in 5.7%, viral-linked cancer in 1.9%, and "other" cancers in 6.3%. Viral-linked cancer was associated with more than 3-fold increased risk in subsequent mortality until the third transplant anniversary, and nearly twice the mortality risk after year 3. "Other" cancers had similar associations with death and graft loss, whereas NMSC was associated with 33% higher mortality beyond the third year posttransplant. Viral-linked cancer had the largest inpatient and outpatient cost impacts per case, followed by "other" cancer, whereas NMSC impacted only outpatient costs. Care of new cancer diagnoses was generally more costly than care of previously established diagnoses. Cancer accounted for 3% to 5.5% of total inpatient Medicare expenditures and 1.5% to 3.3% of outpatient expenditures in the first 3 years posttransplant. CONCLUSIONS: Early posttransplant malignancy is an expensive and morbid condition that warrants attention in efforts to improve pretransplant screening and management protocols before and after transplant.

Pretransplant Midodrine Use: A Newly Identified Risk Marker for Complications After Kidney Transplantation.

BACKGROUND: Midodrine is prescribed to prevent symptomatic hypotension and decrease complications associated with hypotension during dialysis. We hypothesized that midodrine use before kidney transplantation may be a novel marker for posttransplant risk. METHODS: We analyzed integrated national US transplant registry, pharmacy records, and Medicare claims data for 16 308 kidney transplant recipients transplanted 2006 to 2008, of whom 308 (1.9%) had filled midodrine prescriptions in the year before transplantation. Delayed graft function (DGF), graft failure, and patient death were ascertained from the registry. Posttransplant cardiovascular complications were identified using diagnosis codes on Medicare billing claims. Adjusted associations of pretransplant midodrine use with complications at 3 and 12 months posttransplant were quantified by multivariate Cox or logistic regression, including propensity for midodrine exposure. RESULTS: At 3 months, patients who used midodrine pretransplant had significantly (P < 0.05) higher rates of DGF, 32% versus 19%; hypotension, 14% versus 4%; acute myocardial infarction, 4% versus 2%; cardiac arrest, 2% versus 0.9%, graft failure, 5% versus 2%; and death, 4% versus 1% than nonusers. After multivariate adjustment including recipient and donor factors, as well as for the propensity of midodrine exposure, pretransplant midodrine use was independently associated with risks of DGF (adjusted odds ratio, 1.78; 95% confidence interval [CI], 1.36-2.32), and 3 month death-censored graft failure (adjusted hazard ratio, 2.0; 95% CI, 1.18-3.39), and death (adjusted hazard ratio, 3.49; 95% CI, 1.95-6.24). Patterns were similar at 12 months. CONCLUSIONS: Although associations may in part reflect underlying conditions, the need for midodrine before kidney transplantation is a risk marker for complications including DGF, graft failure, and death.

Perceived barriers to medication adherence in pediatric and adolescent solid organ transplantation.

Comparisons of perceived barriers to adherence in pediatric and adolescent SOT have not been systematically conducted despite association between medication non-adherence and poor outcome. Fifteen centers in CTOT-C enrolled patients in a cross-sectional study. Subjects' guardians completed the PMBS and subjects over eight completed the Adolescent Scale (AMBS). Association of three identified PMBS factors and subject age was assessed. Secondary analyses assessed associations between PMBS, AMBS, and patient demographics. Three hundred sixty-eight subjects or their guardians completed PMBS or AMBS. A total of 107 subjects were 6-11 yr; 261 were ≥12. Unadjusted and propensity-adjusted analyses indicated higher perceived barriers in guardians of adolescents as compared to guardians of pre-adolescents medication scheduling and frustration domains regardless of organ (p < 0.05). PMBS and AMBS comparisons revealed that guardians reported fewer ingestion issues than patients (p = 0.018), and differences appeared more pronounced within younger responders for scheduling (p = 0.025) and frustration (p = 0.019). Screening revealed guardians of older patients report increased perceived barriers to adherence independent of socioeconomic status. Guardians of adolescents reported fewer perceived barriers to ingestion/side effects than patients themselves, particularly in pre-adolescents (8-11 yr). Brief screening measures to assess perceived barriers should be further studied in adherence improvement programs.

Clinical and economic consequences of first-year urinary tract infections, sepsis, and pneumonia in contemporary kidney transplantation practice.

We examined United States Renal Data System registry records for Medicare-insured kidney transplant recipients in 2000-2011 to study the clinical and cost impacts of urinary tract infections (UTI), pneumonia, and sepsis in the first year post-transplant among a contemporary, national cohort. Infections were identified by billing diagnostic codes. Among 60 702 recipients, 45% experienced at least one study infection in the first year post-transplant, including UTI in 32%, pneumonia in 13%, and sepsis in 12%. Older recipient age, female sex, diabetic kidney failure, nonstandard criteria organs, sirolimus-based immunosuppression, and steroids at discharge were associated with increased risk of first-year infections. By time-varying, multivariate Cox regression, all study infections predicted increased first-year mortality, ranging from 41% (aHR 1.41, 95% CI 1.25-1.56) for UTI alone, 6- to 12-fold risk for pneumonia or sepsis alone, to 34-fold risk (aHR 34.38, 95% CI 30.35-38.95) for those with all three infections. Infections also significantly increased first-year costs, from $17 691 (standard error (SE) $591) marginal cost increase for UTI alone, to approximately $40 000-$50 000 (SE $1054-1238) for pneumonia or sepsis alone, to $134 773 (SE $1876) for those with UTI, pneumonia, and sepsis. Clinical and economic impacts persisted in years 2-3 post-transplant. Early infections reflect important targets for management protocols to improve post-transplant outcomes and reduce costs of care.

Associations of pre-transplant prescription narcotic use with clinical complications after kidney transplantation.

BACKGROUND: The impact of narcotic use before kidney transplantation on post-transplant clinical outcomes is not well described. METHODS: We examined integrated national transplant registry, pharmacy records, and Medicare billing claims to follow 16,322 kidney transplant recipients, of whom 28.3% filled a narcotic prescription in the year before transplantation. Opioid analgesic fills were normalized to morphine equivalents (ME) and expressed as mg/kg exposures (approximate quartiles: 0.1-1.7, 1.8-5.4, 5.5-23.7, and ≥ 23.8 mg/kg, respectively). Post-transplant cardiovascular, respiratory, neurological, accidents, substance abuse, and noncompliance events were identified using diagnosis codes on Medicare billing claims. Adjusted associations of ME level with post-transplant complications were quantified by multivariate Cox regression. RESULTS: The incidence of complications at 3 years post-transplant among those with the highest pre-transplant ME exposure compared to no use included: ventricular arrhythmias, 1.1 vs. 0.2% (p < 0.001); cardiac arrest, 4.7 vs. 2.7% (p < 0.05); hypotension, 14 vs. 8% (p < 0.0001); hypercapnia, 1.6 vs. 0.9% (p < 0.05); mental status changes, 5.3 vs. 2.7% (p < 0.001); drug abuse/dependence, 7.0 vs. 1.7% (p < 0.0001); alcohol abuse, 1.8 vs. 0.6% (p = 0.0001); accidents, 0.9 vs. 0.3% (p < 0.05); and noncompliance, 3.5 vs. 2.3% (p < 0.05). In multivariate analyses, transplant recipients with the highest level of pre-transplant narcotic use had approximately 2 to 4 times the risks of post-transplant ventricular arrhythmias, mental status changes, drug abuse, alcohol abuse, and accidents compared with non-users, and 35-45% higher risks of cardiac arrest and hypotension. CONCLUSION: Although associations may reflect underlying conditions or behaviors, high-level prescription narcotic use before kidney transplantation predicts increased risk of clinical complications after transplantation.

Kidney transplant results in children: progress made, but blacks lag behind.

Early kidney transplant results in children lagged behind corresponding results in adults. Multiple advances over the past three decades have eliminated that gap. Most children now have equal or superior long-term allograft and patient survival compared with adult recipients. However, black children in the United States continue to have allograft survival results inferior to those of non-black children, even after extensive adjustments for socioeconomic status and access to transplantation.

Quantifying prognostic impact of prescription opioid use before kidney transplantation through linked registry and pharmaceutical claims data.

BACKGROUND: Limited data are available on the outcome implications of prescription narcotic use before kidney transplantation. METHODS: We examined a novel database wherein national transplant registry identifiers for kidney transplant recipients were linked to records from a large U.S. pharmaceutical claims clearinghouse (2005-2010). We selected recipients with 1 year of captured pretransplant pharmaceutical fill records (N=31,197). Opioid analgesic fills in the year before transplantation were normalized to morphine equivalents (ME) and expressed as mg/kg exposures. Adjusted associations of ME level with posttransplant graft and patient survival (adjusted hazards ratio, aHR) were quantified by multivariate Cox regression. RESULTS: Among the 29% of the sample who filled opioid prescriptions in the year before transplantation, the 25th, 50th, and 75th percentiles of annual ME were 1.8, 5.5, and 23.7 mg/kg, respectively. Three-year graft survival was 88.0% and 84.4% in live donor recipients with upper quartiles of ME use, compared with 92.0% among those who did not receive prescription narcotics (P<0.0001). Adjusted risks of posttransplant death and all-cause graft loss in live donor recipients with the highest quartile of narcotic use were 2.3 times (aHR, 2.27; 95% confidence interval, 1.66-3.10) and 1.8 times (aHR, 1.75; 95% confidence interval, 1.37-2.26), respectively, that of narcotic nonusers. Graded associations of pretransplant opioid exposure level with death and graft loss after deceased donor transplantation were also observed. CONCLUSIONS: Although associations may in part reflect underlying conditions or behaviors, high levels of prescription opioid use before kidney transplantation predict increased risk of posttransplant death and graft loss.

Early clinical complications after ABO-incompatible live-donor kidney transplantation: a national study of Medicare-insured recipients.

BACKGROUND: Descriptions of the sequelae of ABO-incompatible (ABOi) kidney transplantation are limited to single-center reports, which may lack power to detect important effects. METHODS: We examined U.S. Renal Data System registry data to study associations of ABOi live-donor kidney transplantation with clinical complications in a national cohort. Among 14,041 Medicare-insured transplants in 2000 to 2007, 119 non-donor-A2 ABOi transplants were identified. A2-incompatible (n=35) transplants were categorized separately. Infection and hemorrhage events were identified by diagnosis codes on billing claims. Associations of ABO incompatibility with complications were assessed by multivariate Cox regression. RESULTS: Recipients of ABOi transplants experienced significantly (P<0.05) higher incidence of wound infections (12.7% vs. 7.3%), pneumonia (7.6% vs. 3.8%), and urinary tract infections (UTIs) or pyelonephritis (24.5% vs. 15.3%) in the first 90 days compared with ABO-compatible recipients. In adjusted models, ABO incompatibility was associated with twice the risk of pneumonia (adjusted hazard ratio [aHR], 2.22; 95% confidence interval [CI], 1.14-4.33) and 56% higher risk of UTIs or pyelonephritis (aHR, 1.56; 95% CI, 1.05-2.30) in the first 90 posttransplantation days, and 3.5 times the relative risk of wound infections in days 91 to 365 (aHR, 3.55; 95% CI, 1.92-6.57). ABOi recipients, 19% of whom underwent pre- or peritransplant splenectomy, experienced twice the adjusted risk of early hemorrhage (aHR, 1.96; 95% CI, 1.19-3.24). A2-incompatible transplantation was associated only with early risk of UTIs or pyelonephritis. CONCLUSION: ABOi transplantation offers patients with potential live donors an additional transplant option but with higher risks of infectious and hemorrhagic complications. Awareness of these complications may help improve protocols for the management of ABOi transplantation.

Best allograft survival from share-35 kidney donors occurs in middle-aged adults and young children-an analysis of OPTN data.

BACKGROUND: On October 2005, the Organ Procurement and Transplant Network implemented a new allocation policy for kidney transplants (KTX) from deceased donors (DD) ages <35 years to increase an access to transplantation from young donors for pediatric (ages <18 years) recipients, which is known as Share-35 (S35). However, many of these kidneys were allocated to adult recipients. The intent of this study was to analyze the graft outcomes from S35 kidneys in pediatric and adult recipients, stratified further by recipient age, to assess if recipient age affects the outcome from these presumably ideal kidneys. METHODS: The Organ Procurement and Transplant Network database from October 2005 to November 2010 involving 18,461 S35-KTX was used to calculate cumulative graft survival (CGS), death-censored graft survival, and patient survival using Kaplan-Meier estimates. The differences between survival curves were tested for significance by log-rank method after adjusting for various donor, recipient, and transplant-associated variables. RESULTS: With S35 implementation, children received a higher proportion of DD ages <35 years. Within the pediatric age group, adolescents (ages 13-17 years) had the worst CGS. Among adults, the highest CGS was obtained in middle-aged adults, whereas young adults (ages 18-25 years) showed worse CGS. CGS in young children (ages <12 years) was comparable with those in middle-aged adults. In older adults (ages >55 years), CGS was lowered by higher patient death rates. CONCLUSIONS: Recipient age affects allograft survival from high-quality young DD kidneys, such as S35 kidneys. Best survival occurs in middle-aged adults and in children ages <12 years, whereas adolescents and young adults do not derive an optimal benefit.

Lymphoproliferative disorders after adult kidney transplant: epidemiology and comparison of registry report with claims-based diagnoses.

BACKGROUND: Posttransplant lymphoproliferative disorder (PTLD) is a major complication of kidney transplant. STUDY DESIGN: Retrospective cohort study comparing PTLD incidence rates using US Medicare claims and Organ Procurement and Transplantation Network (OPTN) data, examining risk factors for PTLD in OPTN data, and studying recipient and graft survival after PTLD diagnosis. SETTING & PARTICIPANTS: All adult first-transplant patients who underwent deceased or living donor kidney-only transplants in 2000-2006 (n = 89,485) followed up through 3 years posttransplant. PREDICTORS: Recipient and donor characteristics, HLA mismatches, viral serologic test results, and initial immunosuppression. OUTCOMES: OPTN-reported or Medicare claims-based PTLD diagnosis, recipient and graft survival after OPTN-reported PTLD diagnosis. MEASUREMENTS: Adjusted HRs for PTLD diagnosis estimated using a Cox proportional hazards model; probability of survival free of all-cause graft failure estimated using the Kaplan-Meier method. RESULTS: The incidence rate of PTLD during the first posttransplant year was 2-fold higher in Medicare claims (0.46/100 patient-years; 95% CI, 0.39-0.53) than in OPTN data (0.22/100 patient-years; 95% CI, 0.17-0.27). Factors associated with increased rates of PTLD included older age, white race (vs African American), induction with T-cell-depleting antibodies, Epstein-Barr virus seronegativity at the time of transplant, and cytomegalovirus seronegativity at the time of transplant. The adjusted risk of death with graft function was 17.5 (95% CI, 14.3-21.4) times higher after a report of PTLD, and the risk of death-censored graft failure was 5.5 (95% CI, 3.9-7.7) times higher. LIMITATIONS: Shortcomings inherent in large databases, including inconsistencies in patient follow-up, reporting, and coding practices by transplant centers; insufficient registry data to analyze acute rejection episodes and antirejection treatment; no available data for potential effects of different types of PTLD treatment on patient outcomes. CONCLUSIONS: Despite the limitations of data collected by registries, PTLD clearly is an important complication; both mortality and death-censored graft failure increase after PTLD.

Racial variation in the development of posttransplant lymphoproliferative disorders after renal transplantation.

BACKGROUND: We previously reported that posttransplant lymphoproliferative disorders (PTLD) occurred more frequently in non-African American (AF) kidney transplant recipients. An in-depth analysis of racial differences in the development of PTLD has not been reported. METHODS: We assessed Medicare claims for PTLD in a retrospective cohort of 53,719 patients who underwent transplantation from January 2000 to September 2006 and followed up through December 2007. RESULTS: There were 719 (1.3%) patients with claims for PTLD. Non-AF recipient race (including all races analyzed separately, adjusted hazard ratio [AHR] 1.38, 95% confidence interval [CI] 1.13-1.68), recipient Epstein-Barr virus (EBV) immunoglobulin G (IgG) seronegative status (AHR 1.88, 95% CI 1.53-2.34), and de novo sirolimus (AHR 1.22, 95% CI 1.03-1.45) were associated with an increased risk of PTLD. Furthermore, de novo sirolimus showed a significant interaction with EBV IgG; among EBV IgG-negative recipients, sirolimus use was significant (P = 0.003), but among EBV IgG-positive recipients, it was not significant (P = 0.18). EBV IgG-seronegative status was significant in all races except for AFs, and racial differences were a significant effect modifier for EBV IgG status and risk of PTLD. Mortality subsequent to PTLD did not differ by race. CONCLUSIONS.: AF kidney transplant recipients were at lower risk for PTLD, irrespective of the recipient EBV IgG serostatus. On the contrary, recipient EBV IgG-seronegative status was associated with a higher risk of PTLD in the non-AF population. De novo sirolimus therapy was associated with increased risk of PTLD in EBV IgG-negative recipients, regardless of race.

Comparison of generic tacrolimus and Prograf drug levels in a pediatric kidney transplant program: brief communication.

A generic version of tacrolimus was approved for use in the USA in August 2009. These narrow therapeutic index generics are tested for bioequivalence only in adults. No data are available on generic tacrolimus levels in children with allografts. Four patients with stable renal allografts in our pediatric program were inadvertently switched to generic tacrolimus. We retrospectively analyzed pre- and post-switch trough tacrolimus and serum creatinine levels. Twelve-h trough tacrolimus levels (mean ± s.e.) were (i) patient 1 (12-yr-old girl): 7.0 ± 0.69 and 9.7 ± 3.5 (p =NS); (ii) patient 2 (eight-yr-old boy): 4.7 ± 0.68 and 3.4 ± 0.84 (p = 0.04); (iii) patient 3 (22-yr-old woman): 6.8 ± 0.17 and 6.6 ± 0.4 (p = NS); (iv) patient 4 (20-yr-old woman): 5.4 ± 0.25 and 4.9 ± 1.4 (p = NS). Creatinine levels were similar pre- and post-switch (eGFR > 75 mL/min/1.73 m²) in the first three. Patient 4 experienced a biopsy proven acute rejection immediately after switching. Mean creatinine rose from 1.15 ± 0.05 to 2.168 ± 0.07 after switch (p < 0.001). Given our mixed picture with the early data, we suggest careful monitoring of pediatric patients who get switched to generic tacrolimus.

Progressive multifocal leukoencephalopathy and use of mycophenolate mofetil after kidney transplantation.

Mycophenolate mofetil (MMF) use may be associated with progressive multifocal leukoencephalopathy (PML). We conducted a retrospective cohort study of 32,757 renal transplant recipients using the United States Renal Data System kidney transplant files for the incidence, prognosis, and clinical features associated with PML occurring after kidney transplant. Subjects were transplanted from January 1, 2000 to July 31, 2004 and followed through December 31, 2004. The incidence density of PML in MMF users was 14.4 cases/100,000 person-years at risk versus 0 for non-MMF users (P=0.11) by log rank test. Factors significantly associated with PML were BK virus infection (22.2% vs. 1.1%), pretransplant transfusion (75% vs. 34%), panel reactive antibody more than 20% (56% vs. 14%), and use of antirejection medications in the first year (33% vs. 9.2%), all P less than 0.05. PML is rare in the renal transplant population. There was no significant association between PML and MMF, but MMF use in this cohort is too high to accurately assess an association.

Effects of urinary tract infection on outcomes after renal transplantation in children.

Urinary tract infection (UTI) is the most common infection after kidney transplantation. A previous analysis showed that late (>6 mo after transplantation) UTI is associated with earlier graft loss in adults. It was hypothesized that children who are younger than 18 yr would be at higher risk to develop UTI and develop graft loss after both early and late UTI. The US Renal Data System database was analyzed from 1996 to 2000 for Medicare claims (composite of inpatient and outpatient) for UTI up to 36 mo after transplantation. SPSS software and Cox regression models were used to determine association of UTI and age after adjustment for covariates. Early UTI was defined as occurring <6 mo after transplantation, and late UTI was defined as occurring > or =6 mo after transplantation. The risk for graft loss after early UTI was elevated in all children (adjusted hazard ratio [AHR] 5.47; 95% confidence interval [CI] 1.93 to 15.4; P < 0.001) but not after late UTI (AHR 2.09; 95% CI 0.56 to 7.80; P = 0.27). Risk for posttransplantation death was not increased significantly after either early UTI (AHR 1.23; 95% CI 0.37 to 4.08) or late UTI (relative risk 2.22; 95% CI 0.90 to 5.44). Boys aged 2 to 5 (versus age 13 to <18 years) were at significantly higher risk for UTI. In girls, only those in the youngest age category (0 to 1) had higher risk for UTI. Children are at greater risk for graft loss after early but not necessarily late UTI. UTI was not an independent predictor of death in this population.