Association of Recipient APOL1 Kidney Risk Alleles With Kidney Transplant Outcomes

BACKGROUND

Kidney transplant survival in African American recipients is lower compared with non-African American transplant recipients. APOL1 risk alleles (RA) have been postulated as likely contributors. We examined the graft outcomes in kidney transplant recipients (KTRs) stratified by APOL1 RA status in a multicenter observational prospective study.

METHODS

The Renal Transplant Outcome Study recruited a cohort of incident KTRs at 3 transplant centers in the Philadelphia area from 1999-2004. KTRs were genotyped for APOL1 RA. Allograft and patient survival rates were compared by the presence and number of APOL1 RA.

RESULTS

Among 221 participants, approximately 43% carried 2 APOL1 RA. Recipients carrying 2 APOL1 RA demonstrated lower graft survival compared with recipients with only 1 or none of APOL1 RA at 1 y posttransplant, independently of other donor and recipient characteristics (adjusted hazard ratio 3.2 [95% confidence interval, 1.0-10.4], P  = 0.05). There was no significant difference in overall survival or graft survival after 3 y posttransplantation. There was no difference in death by APOL1 -risk status ( P  = 0.11).

CONCLUSIONS

Recipients with 2 APOL1 high-risk alleles exhibited lower graft survival 1 y posttransplantation compared with recipients with only 1 or 0 APOL1 RA. Further research is required to study the combined role of the recipient and donor APOL1 genotypes in kidney transplantation.

Changes in Body Composition, Muscle Strength, and Fat Distribution Following Kidney Transplantation

RATIONALE AND OBJECTIVE

Low muscle mass relative to fat mass (relative sarcopenia) has been associated with mortality and disability but has not been examined following transplantation. We studied how measures of body composition change after receipt of a kidney allograft.

STUDY DESIGN

Prospective longitudinal cohort study.

SETTING AND PARTICIPANTS

60 kidney transplant recipients (ages 20-60 years) at the University of Pennsylvania.

EXPOSURE

Kidney transplantation.

OUTCOMES

DXA measures of fat mass index (FMI) and appendicular lean mass index (ALMI; representing muscle mass), CT measures of muscle density (low density represents increased intramuscular adipose tissue), dynamometer measures of leg muscle strength, and physical activity. ALMI relative to FMI (ALM_FMI) is an established index of relative sarcopenia.

ANALYTICAL APPROACH

Measures expressed as age, sex, and race-specific Z-scores for transplant recipients were compared to 327 healthy controls. Regression models were used to identify correlates of change in outcome Z-scores and compare transplant recipients to controls.

RESULTS

At transplantation, ALMI, ALMI_FMI, muscle strength and muscle density Z-scores were lower vs. controls (all p≤0.001). Transplant recipients received glucocorticoids throughout. The prevalence of obesity increased from 18 to 45%. Although ALMI increased following transplantation (p<0.001) and was comparable to controls from 6 months onward, gains were outpaced by increases in FMI, resulting in persistent ALMI_FMI deficits (mean Z-score -0.31 at 24 months, p=0.02 vs controls). Muscle density improved following transplantation despite gains in FMI (p = 0.02). Muscle strength relative to ALMI also improved (p = 0.04) but remained low compared with controls (p=0.01). Exercise increased in the early months following transplantation (p<0.05) but remained lower than controls (p=0.02).

LIMITATIONS

Lack of muscle biopsies precluded assessment of muscle histology and metabolism.

CONCLUSIONS

The two-year interval following kidney transplantation was characterized by gains in muscle mass and strength that were outpaced by gains in fat mass resulting in persistent relative sarcopenia.

Current state of kidney transplantation in patients with HIV, hepatitis C, and hepatitis B infection

Human immunodeficiency virus (HIV), hepatitis C (HCV), and hepatitis B (HBV) are common chronic viral infections in the end-stage kidney disease (ESKD) patient population that were once considered relative contraindications to kidney transplantation. In this review, we will summarize the current state of kidney transplantation in patients with HIV, HCV, and HBV, which is rapidly evolving. HIV+ patients enjoy excellent outcomes in the modern transplant era and may have new transplant opportunities with the use of HIV+ donors. Direct-acting antivirals for HCV have substantially changed the landscape of care for patients with HCV infection. HBV+ patients now have excellent patient and allograft survival with HBV therapy. Currently, kidney transplantation is a safe and appropriate treatment for the majority of ESKD patients with HIV, HCV, and HBV.

Bariatric surgery before and after kidney transplantation: long-term weight loss and allograft outcomes

BACKGROUND

Severe obesity is frequently a barrier to kidney transplantation, and kidney transplant recipients often have significant weight gain following transplantation.

OBJECTIVES

The goals of this study were to evaluate the long-term risks and benefits of bariatric surgery before and after kidney transplantation.

SETTING

University Hospital, United States.

METHODS

We performed a retrospective cohort study of 43 patients who had pretransplantation bariatric surgery and 21 patients who had posttransplantation bariatric surgery from 1994 to 2017 with propensity-score matching to identify matched controls using national registry data.

RESULTS

Body mass index at the time of transplantation was similar in patients who underwent bariatric surgery before versus after transplantation (32 versus 34 kg/m², P = .172). There was no significant difference in body mass index in the 5 years after bariatric surgery among patients who underwent bariatric surgery before versus after kidney transplantation (36 versus 32 kg/m², P = 0.814). Compared with matched controls, bariatric surgery before (n = 38) and after (n = 18) kidney transplantation was associated with a decreased risk of allograft failure (hazard ratio .31 [95% confidence interval .29-0.33] and .85 [95% confidence interval .85-.86] for pre- and posttransplant, respectively) and mortality (hazard ratio .57 [95% confidence interval .53-.61] and .80 [95% confidence interval .79-.82] for pre- and posttransplant, respectively).

CONCLUSIONS

Bariatric surgery before and after kidney transplantation results in similar maintenance of weight loss and improved long-term allograft survival compared with matched controls. Bariatric surgery appears to be a safe and reasonable approach to weight loss both before and after transplantation.

Lupus Nephritis and Kidney Transplantation: Where Are We Today?

Lupus nephritis (LN) is the cause of end-stage kidney disease (ESKD) for 1.9% of the ESKD population in the United States. Although the incidence rates of ESKD from LN stopped rising in recent years, racial disparities in waiting time, pre-emptive kidney transplant, and transplant outcomes still exist. Patients with LN who progress to ESKD tend to be female, of African ancestry, and young. Kidney transplantation is safe in this population and associated with a substantial survival benefit, primarily due to reduced deaths from cardiovascular disease and infection. Transplant outcomes for patients with ESKD due to LN are similar to those without LN.

Adherence rates to ferric citrate as compared to active control in patients with end stage kidney disease on dialysis

INTRODUCTION

Oral phosphate binders are the main stay of treatment of hyperphosphatemia. Adherence rates to ferric citrate, a recently approved phosphate binder, are unknown.

METHODS

We conducted a post-hoc analysis to evaluate whether adherence rates were different for ferric citrate vs. active control in 412 subjects with end stage kidney disease (ESKD) who were randomized to ferric citrate vs. active control (sevelamer carbonate and/or calcium acetate). Adherence was defined as percent of actual number of pills taken to total number of pills prescribed.

FINDINGS

There were no significant differences in baseline characteristics including gender, race/ethnicity, and age between the ferric citrate and active control groups. Baseline phosphorus, calcium, and parathyroid hormone levels were similar. Mean (SD) adherence was 81.4% (17.4) and 81.7% (15.9) in the ferric citrate and active control groups, respectively (P = 0.88). Adherence remained similar between both groups after adjusting for gender, race/ethnicity, age, cardiovascular disease (CVD), and diabetic nephropathy (mean [95% CI]: 81.4% [78.2, 84.6] and 81.5% [77.7, 85.2] for ferric citrate and active control, respectively). Gender, race/ethnicity, age, and diagnosis of diabetic nephropathy did not influence adherence to the prescribed phosphate binder. Subjects with CVD had lower adherence rates to phosphate binder; this was significant only in the active control group.

DISCUSSION

Adherence rates to the phosphate binder, ferric citrate, were similar to adherence rates to active control. Similar adherence rates to ferric citrate are notable since tolerance to active control was an entry criteria and the study was open label. Gender, race/ethnicity, nor age influenced adherence.

Successful Treatment of Hepatitis C in Renal Transplant Recipients With Direct-Acting Antiviral Agents

The direct-acting antivirals (DAAs) constitute an emerging group of small molecule inhibitors that effectively treat hepatitis C virus (HCV) infection, a common comorbidity in end-stage renal disease patients. To date, there are no data to guide use of these agents in kidney transplant patients. The authors collected data from 20 consecutive kidney recipients treated with interferon-free treatment regimens for HCV at their center: 88% were infected with genotype 1; 50% had biopsy-proved advanced hepatic fibrosis on their most recent liver biopsy preceding treatment (Metavir stage 3 fibrosis [F3] or F4); and 60% had failed treatment pretransplantation with interferon-based therapy. DAA treatment was initiated a median of 888 days after renal transplantation. All patients cleared the virus while on therapy, and 100% have achieved a sustained virologic response at 12 weeks after completion of DAA therapy. The most commonly used regimen was sofosbuvir 400 mg daily in combination with simeprevir 150 mg daily. However, four different treatment approaches were used, with comparable results. The DAAs were well tolerated, and less than half of patients required calcineurin inhibitor dose adjustment during treatment. Eradication of HCV infection with DAAs is feasible after kidney transplantation with few treatment-related side effects.

The Phosphate Binder Ferric Citrate and Mineral Metabolism and Inflammatory Markers in Maintenance Dialysis Patients: Results From Prespecified Analyses of a Randomized Clinical Trial

BACKGROUND

Phosphate binders are the cornerstone of hyperphosphatemia management in dialysis patients. Ferric citrate is an iron-based oral phosphate binder that effectively lowers serum phosphorus levels.

STUDY DESIGN

52-week, open-label, phase 3, randomized, controlled trial for safety-profile assessment.

SETTING & PARTICIPANTS

Maintenance dialysis patients with serum phosphorus levels ≥6.0 mg/dL after washout of prior phosphate binders.

INTERVENTION

2:1 randomization to ferric citrate or active control (sevelamer carbonate and/or calcium acetate).

OUTCOMES

Changes in mineral bone disease, protein-energy wasting/inflammation, and occurrence of adverse events after 1 year.

MEASUREMENTS

Serum calcium, intact parathyroid hormone, phosphorus, aluminum, white blood cell count, percentage of lymphocytes, serum urea nitrogen, and bicarbonate.

RESULTS

There were 292 participants randomly assigned to ferric citrate, and 149, to active control. Groups were well matched. For mean changes from baseline, phosphorus levels decreased similarly in the ferric citrate and active control groups (-2.04±1.99 [SD] vs -2.18±2.25 mg/dL, respectively; P=0.9); serum calcium levels increased similarly in the ferric citrate and active control groups (0.22±0.90 vs 0.31±0.95 mg/dL; P=0.2). Hypercalcemia occurred in 4 participants receiving calcium acetate. Parathyroid hormone levels decreased similarly in the ferric citrate and active control groups (-167.1±399.8 vs -152.7±392.1 pg/mL; P=0.8). Serum albumin, bicarbonate, serum urea nitrogen, white blood cell count and percentage of lymphocytes, and aluminum values were similar between ferric citrate and active control. Total and low-density lipoprotein cholesterol levels were lower in participants receiving sevelamer than those receiving ferric citrate and calcium acetate. Fewer participants randomly assigned to ferric citrate had serious adverse events compared with active control.

LIMITATIONS

Open-label study, few peritoneal dialysis patients.

CONCLUSIONS

Ferric citrate was associated with similar phosphorus control compared to active control, with similar effects on markers of bone and mineral metabolism in dialysis patients. There was no evidence of protein-energy wasting/inflammation or aluminum toxicity, and fewer participants randomly assigned to ferric citrate had serious adverse events. Ferric citrate is an effective phosphate binder with a safety profile comparable to sevelamer and calcium acetate.

Transplant nephrectomy: histologic findings—a single center study

AIMS

To identify the histopathological features of transplant nephrectomy (TN) specimens.

METHODS

We performed retrospective analysis of 73 nephrectomies to review the histopathology in detail and correlate the Banff grading characteristics of TN specimens with time post engraftment and clinical features. Retrospective data on donor-specific antibodies (DSA) were also collected.

RESULTS

The majority of patients who had TN in less than 3 months posttransplant (n = 20; median time to TN: 4 days) had hemorrhagic infarction; 7 patients (35%) had grade 3 acute rejection (AR). Patients who had TN later than 3 months posttransplant (n = 53; median time to TN: 67 months) had AR, grade 2B (21%) and 3 (43%), coexisting with advanced vascular injury in the form of interstitial hemorrhage, extensive interstitial fibrosis and tubular atrophy (IF/TA) as well as the presence of DSAs. Overall, the majority of patients without DSA pre-TN developed DSA post-TN.

CONCLUSIONS

Our data revealed extensive inflammation and ongoing immunologic activity in a subset of patients with a failed graft. Careful and individualized approach based on clinical and laboratory data should guide the decision for transplant nephrectomy.

Persistent BK viremia does not increase intermediate-term graft loss but is associated with de novo donor-specific antibodies

There are limited data regarding intermediate-term outcomes in patients with persistent BK viremia. Other viral infections have been implicated in the development of allosensitization through heterologous immunity, but the relationship between BK viremia and donor-specific antibodies (DSAs) is unexplored. In 2008, we initiated routine post-transplant BK viremia and DSA screening at our center; 785 kidney or kidney-pancreas transplant recipients were included in our study. Of these recipients, 132 (17%) recipients developed BK viremia during the study period. The median duration of BK viremia was 140 days (interquartile range=40-393 days), and persistent BK viremia was defined as lasting ≥140 days. Kaplan-Meier curves were generated to assess differences in patient and allograft survival on the basis of BK viremia status; survival was modeled using Cox proportional hazard regression. After a median follow-up of 3 years, there was no significant difference in terms of patient (hazard ratio [HR], 0.83; 95% confidence interval [95% CI], 0.28 to 2.49) or allograft survival (HR, 0.80; 95% CI, 0.37 to 1.73) between patients with and without BK viremia, which was confirmed in a time-varying analysis. In our logistic regression model, persistent BK viremia was strongly associated with the development of class II (HR, 2.55; 95% CI, 1.30 to 4.98) but not class I (HR, 1.13; 95% CI, 0.46 to 2.77) DSAs. These data suggest that persistent BK viremia does not negatively affect intermediate-term patient or allograft survival but is associated with increased risk for de novo DSA, although the exact mechanism is unclear.

BK virus infection: an update on diagnosis and treatment

BK virus, first isolated in 1971, is a significant risk factor for renal transplant dysfunction and allograft loss. Unfortunately, treatment options for BK virus infection are limited, and there is no effective prophylaxis. Although overimmunosuppression remains the primary risk factor for BK infection after transplantation, male gender, older recipient age, prior rejection episodes, degree of human leukocyte antigen mismatching, prolonged cold ischemia time, BK serostatus and ureteral stent placement have all been implicated as risk factors. Routine screening for BK has been shown to be effective in preventing allograft loss in patients with BK viruria or viremia. Reduction of immunosuppression remains the mainstay of BK nephropathy treatment and is the best studied intervention. Laboratory-based methods such as ELISPOT assays have provided new insights into the immune response to BK and may help guide therapy in the future. In this review, we will discuss the epidemiology of BK virus infection, screening strategies, treatment options and future research directions.

Changes in vitamin D binding protein and vitamin D concentrations associated with liver transplantation

BACKGROUND

Vitamin D deficiency is associated with fractures, infections and death. Liver disease impairs vitamin D and vitamin D binding protein (DBP) metabolism.

AIMS

We aimed to determine the impact of liver transplantation on vitamin D, particularly on DBP and free vitamin D concentrations.

METHODS

Serum 25(OH)D, 1,25(OH)(2) D and DBP concentrations were measured in 202 adults before liver transplantation and 3 months later in 155. Free vitamin D concentrations were estimated from these values. Risk factors for 25(OH)D deficiency (<20 ng/ml) and low 1,25(OH)(2) D (<20 pg/ml) were examined with logistic regression, and changes in concentrations following transplantation with linear regression.

RESULTS

Pretransplant, 84% were 25(OH)D deficient, 13% had 25(OH)D concentrations <2.5 ng/ml, and 77% had low 1,25(OH)(2) D. Model for end-stage liver disease score ≥ 20 (P < 0.005) and hypoalbuminemia (P < 0.005) were associated with low 25(OH)D and 1,25(OH)(2) D concentrations. Following transplantation, 25(OH)D concentrations increased a median of 17.8 ng/ml (P < 0.001). Albumin increased from a median of 2.7 to 3.8 g/dl (P < 0.001) and DBP from 8.6 to 23.8 mg/dl (P < 0.001). Changes in total 25(OH)D were positively and independently associated with changes in DBP (P < 0.05) and albumin (P < 0.001). Free 25(OH)D concentrations rose from 6.0 to 9.7 pg/ml (P < 0.001). In contrast, total 1,25(OH)(2)D concentrations rose only by 4.3 pg/ml (P < 0.001) and free 1,25(OH)(2D concentrations declined (P < 0.001).

CONCLUSIONS

Serum total and free 25(OH)D and DBP concentrations rose substantially following transplantation, while 1,25(OH)(2) D concentrations showed modest changes and free 1,25(OH)(2) D decreased. Studies of the effects of vitamin D status on diverse transplant complications are needed.

The influence of induction therapy for kidney transplantation after a non-renal transplant

BACKGROUND AND OBJECTIVES

Non-renal transplant recipients who subsequently develop ESRD and undergo kidney transplantation are medically and immunologically complex due to comorbidities, high cumulative exposure to immunosuppressants, and sensitization to alloantigen from the prior transplant. Although prior non-renal transplant recipients are one of the fastest growing segments of the kidney wait list, minimal data exist to guide the use of antibody induction therapy (IT+) at the time of kidney after lung (KALu), heart (KAH), and liver (KALi) transplant.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective cohort study used national registry data to examine IT use and survival after kidney transplantation. Separate multivariate Cox regression models were constructed to assess patient survival for IT+ and IT- KALu (n=232), KAH (n=588), and KALi (n=736) recipients.

RESULTS

Use of IT increased during the study period. The percentage of patients considered highly sensitized (panel reactive antibody ≥20%) was not statistically significant between IT+ and IT- groups. IT+ was not associated with improvement in 1- and 10-year patient survival for KALu (P=0.20 and P=0.22, respectively) or for KAH (P=0.90 and P=0.14, respectively). However, IT+ among KALi was associated with inferior patient survival at 1 and 10 years (P=0.04 and P=0.02, respectively).

CONCLUSIONS

Use of IT for kidney transplantation among prior non-renal transplant recipients may not offer a survival advantage in KALu or KAH. However, due to limited power, these findings should be interpreted cautiously. IT+ was associated with inferior outcomes for KALi. Use of IT should be judicially reconsidered in this complex group of recipients.

Age, exclusion criteria, and generalizability of randomized trials enrolling kidney transplant recipients

BACKGROUND

The proportion of elderly (≥65 years) kidney transplant recipients (KTRs) doubled in the United States from 1999 to 2008. Given higher mortality, more medication side effects, and less rejection among elderly KTRs, optimal care of these patients may require tailored decisions about transplant therapeutics. It is unknown whether participants in transplant clinical trials-which generate the best evidence for patient care-are representative of the aging population of KTRs.

METHODS

Using PubMed, we identified randomized trials involving KTRs from 1999 to 2008 and determined age-exclusion criteria and the mean age of participants. The mean age of these trial participants was compared with the mean age of the overall population of incident KTRs in the United States.

RESULTS

The 87,222 participants in 573 trials were significantly younger than the US KTR population (P<0.05). This age discrepancy worsened over the study period (during the years 2006 to 2008, the mean age was 45 years for trial participants versus 50 years for US KTRs, P<0.05). Thirty percent of trials had an exclusion criterion based on older age, and 16% excluded recipients aged 65 years or older. In multivariable regression, immunosuppression trials (P<0.01) and trials in higher impact journals (P=0.03) were more likely to exclude the elderly, but there was no significant difference in exclusion of elderly patients based on a trial's geographic location.

CONCLUSIONS

Trial participants are younger than KTRs in the United States and many trials exclude older patients. Transplant investigators should make strong efforts to recruit patients across the total age spectrum.

Reduction of immunosuppression as initial therapy for posttransplantation lymphoproliferative disorder(★)

Reduction of immunosuppression (RI) is commonly used to treat posttransplant lymphoproliferative disorder (PTLD) in solid organ transplant recipients. We investigated the efficacy, safety and predictors of response to RI in adult patients with PTLD. Sixty-seven patients were managed with RI alone and 30 patients were treated with surgical excision followed by adjuvant RI. The response rate to RI alone was 45% (complete response-37%, partial response-8%). The relapse rate in complete responders was 17%. Adjuvant RI resulted in a 27% relapse rate. The acute rejection rate following RI-containing strategies was 32% and a second transplant was feasible without relapse of PTLD. The median survival was 44 months in patients treated with RI alone and 9.5 months in patients who remained on full immunosuppression (p = 0.07). Bulky disease, advanced stage and older age predicted lack of response to RI. Survival analysis demonstrated predictors of poor outcome-age, dyspnea, B symptoms, LDH level, hepatitis C, bone marrow and liver involvement. Patients with none or one of these factors had a 3-year overall survival of 100% and 79%, respectively. These findings support the use of RI alone in low-risk PTLD and suggest factors that predict response and survival.

Aortic calcification predicts cardiovascular events and all-cause mortality in renal transplantation

BACKGROUND

Cardiovascular disease is a leading cause of death among renal transplant recipients. Aortic calcification is associated with increased mortality in dialysis subjects. The significance of aortic calcification among renal transplant recipients is unknown. Our objective was to prospectively examine the association of aortic calcification with cardiovascular events and all-cause mortality among asymptomatic incident renal transplant recipients.

METHODS

One hundred and twelve renal transplant recipients underwent electron beam computed tomography. Aortic calcification was scored by the Agatston method. The mean follow-up time was 5.1 years. Cardiovascular events (heart failure, coronary artery disease, peripheral arterial disease and stroke) and all-cause mortality were recorded.

RESULTS

The cohort consisted of 62% Caucasians, 38% African Americans and 62% male gender. The mean age was 49.0 +/- 12.5 years. Thirty-four percent had aortic calcification. During follow-up, 12 cardiovascular events and 10 deaths were recorded. Subjects with aortic calcification had more cardiovascular events compared to those without aortic calcification (23.7 versus 4.1%, P = 0.001). Recipients with aortic calcification had higher mortality compared to those without aortic calcification but it did not reach statistical significance (15.8 versus 5.4%, P = 0.07). The univariate hazard ratio of aortic calcification score in a proportional hazard Cox model to assess event-free survival was 1.15 (1.04-1.27, P = 0.01). Diabetes and aortic calcification score were independently associated with survival. In addition to the predictors above, dialysis vintage was an independent predictor for combined future cardiovascular event and mortality.

CONCLUSIONS

In conclusion, aortic calcification is prevalent among renal transplant recipients and is predictive of future cardiovascular events. Aortic calcification is easily identified by non-invasive testing, and should be considered when assessing cardiovascular risk in asymptomatic renal transplant recipients.

Kidney transplantation at the University of Pennsylvania: 1998-2008

Kidney transplantation at the University of Pennsylvania has grown substantially over the past 11 years. Although our transplant volume has increased primarily as a consequence of multiorgan transplants as well as the utilization of historically "marginal" allografts, our post-transplantation outcomes remain excellent in both children and adults. We attribute these outcomes to technical improvements in tissue typing and donor-recipient crossmatching, modification of immunosuppression protocols, and rigorous donor and recipient selection. In the next decade, we hope to substantially expand our living donor program and refine our overall donor and recipient selection process such that we maintain excellent post-transplant outcomes in the face of aging and increasingly comorbid donors and recipients. We further predict significant changes in post-transplant management of kidney recipients with respect to immunosuppression regimens. In particular, we anticipate the modulation of immunosuppression regimens in recipients with high titers of donor-specific antibody and the integration of B-cell specific immunosuppression into post-transplant patient care. Only time will tell whether such therapies will 1) improve long-term outcomes, 2) allow us to diminish the degree of non-specific pharmacologic immunosuppression currently in use, 3) or even promote donor-specific tolerance in kidney transplant recipients.

Posttransplantation Anemia at 12 Months in Kidney Recipients Treated with Mycophenolate Mofetil: Risk Factors and Implications for Mortality

Although posttransplantation anemia (PTA) is common in the mycophenolate mofetil era, its impact on patient survival is unknown. This retrospective cohort study characterized factors that are associated with PTA 12 mo after transplantation in mycophenolate mofetil-treated kidney recipients and explored whether 12-mo PTA affects outcomes. The records of 626 kidney recipients were examined for presence of anemia (hemoglobin <12 g/dl). Multivariate regression models, fit with covariates that had unadjusted relationships, investigated both risk factors for 12-mo PTA and whether 12-mo PTA contributes to mortality. Anemia prevalence was 72, 40, and 20.3% at 1, 3, and 12 mo, respectively. By multivariate logistic regression, anemia at 3 mo (odds ratio [OR] 10.0; 95% confidence interval [CI] 5.3 to 17.1; P = 0.0001), donor age (OR 1.0; 95% CI 1.1 to 1.3; P = 0.005), and 3-mo creatinine (OR 2.0; 95% CI 1.2 to 3.3; P = 0.044) were associated with 12-mo PTA. The PTA cohort had inferior patient survival (P = 0.02, log rank) and a higher proportion of cardiovascular deaths (6.3 versus 2.2%; P = 0.017) than nonanemic patients. By Cox regression, 12-mo PTA (hazard ratio [HR] 3.0; 95% CI 1.3 to 6.7; P = 0.009), 12-mo creatinine (HR 1.3; 95% CI 1.1 to 1.4; P = 0.008), age at transplantation (HR 1.1; 95% CI 1.1 to 1.2; P = 0.004), and hepatitis C seropositivity (HR 2.8; 95% CI 1.1 to 7.0; P = 0.03) were associated with mortality. There was no interaction between 12-mo PTA and serum creatinine. In conclusion, 12-mo PTA is associated with an increased risk for patient death. The presence of anemia 3 mo after kidney transplantation is a major determinant of 12-mo PTA. PTA in kidney recipients therefore should be defined by its persistence or occurrence beyond the third posttransplantation month.

24-Week Oral Ganciclovir Prophylaxis in Kidney Recipients Is Associated with Reduced Symptomatic Cytomegalovirus Disease Compared to a 12-Week Course

BACKGROUND

Cytomegalovirus (CMV) infection is associated with reduced graft and patient survival among kidney recipients. The highest risk of CMV infection occurs in CMV-naive recipients of kidneys from seropositive donors (D+/R-). Optimal CMV prophylaxis is not established. This prospective cohort study compared the safety and efficacy of prophylaxis with 12 versus 24 weeks of oral ganciclovir.

METHODS

We prospectively administered 24 weeks ganciclovir to 31 D+/R- recipients. The control group comprised 39 patients transplanted in the immediately preceding era who received a 12-week course of prophylaxis. All patients received cytolytic therapy within the first month, as well as a tacrolimus-based maintenance regimen. A logistic regression model was fit to examine the relationship between 24 weeks ganciclovir prophylaxis and the odds of developing CMV infection by one year.

RESULTS

Groups were matched, though the 12-week cohort had more delayed graft function than their 24-week counterparts (45% vs. 29%, P=0.04). CMV infection occurred in 31% and 7% patients in the 12-week and 24-week groups, respectively (P<or=0.01). Mean time to development of CMV infection was 17.5+/-2.2 weeks in the 12-week, and 22.0+/-10.0 weeks in the 24-week, groups (P=0.79). Both 24 weeks ganciclovir prophylaxis (O.R. 0.15, 95% C.I. 0.03-0.91, P=0.04) and delayed graft function (O.R. 4.49, 95% C.I. 1.67-36.56, P<0.01) were associated with CMV infection.

CONCLUSIONS

Oral ganciclovir prophylaxis for 24 weeks is associated with a lower risk of symptomatic CMV disease than a 12-week course in high risk D+/R- kidney recipients.

Macroscopic Hematuria in a Kidney Transplant Recipient: A Rare Cause

Pseudoaneurysm formation in a renal transplant is an uncommon complication of such interventional procedures as percutaneous nephrostomy or renal biopsy; symptoms may be delayed for days or even years. Presentation may vary from incidental discovery to worsening renal insufficiency to life-threatening hemorrhage. We report a case of macroscopic hematuria from a pseudoaneurysm that developed in a kidney transplant recipient after placement of a percutaneous nephrostomy tube. This patient was treated with transcatheter embolization, which is highly effective. A high index of suspicion, along with early diagnosis and transcatheter embolization, are essential for the management of hematuria caused by pseudoaneurysm formation from percutaneous nephrostomy tube placement.

Experience with antibody-mediated rejection in kidney allograft recipients

In our case series, AMR occurred in patients who had DSA. Twelve of the 21 patients (57%) who developed de novo antibodies post-transplant had biopsy-proven episodes of either rejection (of any Banff classification) and/or chronic allograft nephropathy. Only one-third of these 12 patients with rejection episodes were classified as AMR. It is unclear when and how often measurements for DSA should be performed after transplantation. When AMR is suspected, the detection of anti-HLA antibodies should be done using very sensitive assays. An increase in PRA and/or the detection of anti-HLA antibodies specific to previous sensitization events may precede an episode of AMR, even in the absence of DSA. Prospective clinical trials are needed to assess the predictive value of the presence of DSA after transplant. It is uncertain which therapeutic response should follow after the detection of these antibody responses in the absence of clinical symptoms. AMR requires intensive therapy, but no standard treatment has been established. Three patients who had AMR at our center were treated with rituximab in addition to various combinations of plasmapheresis, methylprednisolone, OKT3, and intravenous immune globulin. Only one patient responded to this treatment. Well-controlled clinical trials would help to evaluate the efficacy and benefit of B-cell depletion in combination with other immunosuppressive agents.

Complications related to dapsone use for Pneumocystis jirovecii pneumonia prophylaxis in solid organ transplant recipients

Dapsone, used for prevention of Pneumocystis jirovecii infections, has been reported to cause hemolytic anemia and methemoglobinemia; its tolerability in solid organ transplant recipients is not well described. We investigated dapsone-related adverse events in patients undergoing solid organ transplantation from 1999 to 2004. Transplant providers identified patients for the investigators who then reviewed the patients' hospital and outpatient records. Sixteen solid organ transplant recipients fit case definitions for dapsone-related hemolytic anemia (n = 11) or methemoglobinemia (n = 5). Median time from event to dapsone discontinuation was 15 days; all patients improved after drug discontinuation. G6PD enzyme activity was normal in all patients whose test results were available. Dapsone may be associated with hemolytic anemia or methemoglobinemia, even with normal G6PD levels. These events are often not promptly recognized, and drug discontinuation is delayed. Dapsone-related hemolytic anemia or methemoglobinemia should be considered in solid organ transplant recipients with unexplained anemia or hypoxia.

Reproduction and transplantation: report on the AST Consensus Conference on Reproductive Issues and Transplantation

It has been almost 50 years since the first child was born to a female transplant recipient. Since that time pregnancy has become common after transplantation, but physicians have been left to rely on case reports, small series and data from voluntary registries to guide the care of their patients. Many uncertainties exist including the risks that pregnancy presents to the graft, the patient herself, and the long-term risks to the fetus. It is also unclear how to best modify immunosuppressive agents or treat rejection during pregnancy, especially in light of newer agents available where pregnancy safety has not been established. To begin to address uncertainties and define clinical practice guidelines for the transplant physician and obstetrical caregivers, a consensus conference was held in Bethesda, Md. The conferees summarized both what is known and important gaps in our knowledge. They also identified key areas of agreement, and posed a number of critical questions, the resolution of which is necessary in order to establish evidence-based guidelines. The manuscript summarizes the deliberations and conclusions of the conference as well as specific recommendations based on current knowledge in the field.

Screening asymptomatic diabetic patients for coronary artery disease prior to renal transplantation

BACKGROUND

Coronary artery disease (CAD) is a significant contributor to excess mortality in renal transplant candidates with diabetes mellitus (DM). Prior studies relating to risk stratification for significant CAD in diabetics are confined to Caucasian type 1 DM patients.

METHODS

To assess the prevalence of clinically silent CAD and to identify variables that are associated with CAD, we retrospectively analyzed the cardiac catheterization data of 97 asymptomatic type 1 and 2 DM kidney and kidney-pancreas transplant candidates.

RESULTS

Thirty-three percent of type 1 and 48% of type 2 DM patients had significant stenosis (> or = 70%) in 1 or more coronary arteries. On multivariate logistic regression analysis, body mass index (BMI) >25 was significantly associated with CAD (relative risk = 4.8, P = 0.002). The age of the patient (7% increase in risk/year, P = 0.01; or relative risk = 3.0 if age >47 years, P = 0.032) and smoking history (2% increase in risk/pack-year of smoking, P = 0.10) were also associated with CAD. African American patients, who comprised 30% of the sample, had a 71% lower risk compared with Caucasian patients (P = 0.03). Factors that were not significantly associated with CAD included gender, type of diabetes, and whether dialyzed for >6 months prior to catheterization.

CONCLUSIONS

We conclude that a notable proportion (approximately one-third to one-half) of asymptomatic type 1 and type 2 diabetic renal transplant candidates have significant CAD. Additionally, young African American DM patients with no smoking history and a BMI </=25 are at reduced risk, and invasive tests may not be necessary in this group.

A pilot protocol of a calcineurin-inhibitor free regimen for kidney transplant recipients of marginal donor kidneys or with delayed graft function

The worsening shortage of cadaver donor kidneys has prompted use of expanded or marginal donor kidneys (MDK), i.e. older age or donor history of hypertension or diabetes. MDK may be especially susceptible to calcineurin-inhibitor (CI) mediated vasoconstriction and nephrotoxicity. Similarly, early use of CI in patients with delayed graft function may prolong ischaemic injury. We developed a CI-free protocol of antibody induction, sirolimus, mycophenolate mofetil, and prednisone in recipients with MDK or DGF.

METHODS

Adult renal transplant recipients who received MDK or had DGF were treated with a CI-free protocol consisting of antibody induction (basiliximab or thymoglobulin), sirolimus, mycophenolate mofetil, and prednisone. Serial biopsies were performed for persistent DGF. Patients were followed prospectively with the primary endpoints being patient and graft survival, biopsy-proven acute rejection, and sirolimus-related toxicity.

RESULTS

Nineteen recipients were treated. Mean follow-up was 294 days. Actuarial 6- and 12-month patient survival was 100% and 100% and graft survival was 93% and 93%, respectively. The only graft loss was due to primary non-function (PNF). The incidence of AR was 16%. Mean serum creatinine at last follow-up was 1.6 mg/dL. Sirolimus-related toxicity included lymphocele (1), wound infection (2), thrombocytopenia (1). and interstitial pneumonitis (1).

CONCLUSION

A CI-free protocol with antibody induction and sirolimus results in low rates of AR and PNF and excellent early patient and graft survival in patients with MDK and DGF. CI-free protocols may allow expansion of the kidney donor pool by encouraging utilization of MDK at high risk for DGF or CI-mediated nephrotoxicity.

L-carnitine treatment of anemia

Recombinant human erythropoietin (rHuEPO) and iron supplementation have had a profoundly positive impact on the anemia of patients with chronic kidney disease. However, a significant number of patients remain hyporesponsive to rHuEPO, with hemoglobin values less than target levels. A suboptimal response to rHuEPO is associated with complications that can reduce quality of life and increase morbidity, mortality, and costs. There are a number of other metabolic derangements associated with uremia that can impact on the production and survival of red blood cells. Dialysis-related carnitine disorder is a functional metabolic deficiency, common in chronic dialysis patients, that can have a negative impact on erythrocyte production and survival. This article reviews the role of L-carnitine in the pathogenesis and adjunctive treatment of anemia associated with kidney failure. After a comprehensive database search, primary and secondary reports were analyzed. Laboratory studies examining the influence of carnitine on red blood cell function and clinical trials of L-carnitine in dialysis patients support the use of L-carnitine in the setting of rHuEPO hyporesponsiveness. Consensus groups, including the National Kidney Foundation-Kidney Disease Outcome Quality Initiative (K/DOQI), consider the use of L-carnitine for hyporesponsive rHuEPO-dependent anemia a promising application of this therapy, recommending an empiric trial of L-carnitine in these patients.

Recurrent lupus nephritis in renal transplant recipients revisited: it is not rare

BACKGROUND

Although recurrent lupus nephritis (RLN) after kidney transplantation is reported to be rare (1%-4%), recent studies suggest a higher incidence. The purpose of this study was to determine the incidence of RLN in a large cohort of renal transplant recipients with systemic lupus erythematosus (SLE).

METHODS

The records of 54 renal transplant recipients with SLE were reviewed. Thirty-one patients underwent biopsy because of worsening renal function and proteinuria. All biopsy specimens were evaluated by light microscopy, immunofluorescence (IF), and electron microscopy (EM).

RESULTS

Among the 50 patients with at least 3 months of follow-up, RLN was present in 15 (52% of patients who underwent biopsy, 30% of total patients): mesangial lupus nephritis (LN) (class II) in eight, focal proliferative LN (class III) in four, and membranous LN (class Vb) in three patients. One patient had graft loss because of RLN (class II) at 10.5 years. The duration of dialysis before transplantation was not different between patients with RLN compared to patients without RLN (P=0.40). Overall patient survival (n=50) was 96% at 1 year and 82% at 5 years, and graft survival was 87% at 1 year and 60% at 5 years. Graft survival was worse in patients who underwent biopsy compared with patients who never underwent biopsy (P<0.01).

CONCLUSIONS

RLN is more common than previously reported, but in our series, graft loss because of RLN was rare. Aggressive use of allograft biopsies and morphologic evaluation with IF and EM are important factors in the diagnosis of RLN. The impact of new immunosuppressive agents on the incidence of RLN remains to be seen.

Renal transplantation

Renal Transplantation has progressed from an experiment in surgery, nephrology, and immunology to the preferred means of renal replacement therapy for patients with end-stage renal disease. Patient and graft survival rates are spectacular in the short run and improving steadily in the long. The current state of the art reflects deepened understanding of the alloimmune response and the T lymphocyte activation cascade in part driving the discovery of ever more potent immunosuppressive agents. Important issues remain such as chronic allograft dysfunction, the organ shortage, and tolerance induction. In this review, we will look at the history, the expanding treatment options based on better understanding of the immunobiology of alloantigen response, and the persistent challenges awaiting.

Transplantation for the millennium: attaining tolerance in our time--the Holy Grail

Despite tremendous advances in organ transplantation over the past 40 years, life-long immunosuppression is still required to maintain the transplanted organ. The induction of human tolerance to defined foreign antigens while maintaining completely intact all the rest of the immune repertoire, in the absence of maintenance immunosuppression, continues to be the dream of the transplant scientist and clinician, the "Holy Grail," the quest which energizes much recent research. This article presents an overview on recent developments on transplantation tolerance.