How Should We Manage Renal Transplant Patients with Failed Allografts Who Return to Dialysis?

Patients with failing renal allografts often progress to end-stage renal disease, unlike transplant-naive chronic kidney disease patients, in an accelerated and unpredictable manner. The variability of this population renders decisions regarding placement of permanent dialysis access more difficult. Since patients with failed allografts who return to dialysis experience higher rates of morbidity and mortality, recognition and optimization of factors that will improve survival outcomes and quality of life are tantamount to longer term success. We provide guidelines on several topics such as immunosuppression withdrawal and determination of nephrectomy need versus retaining the allograft based on the current literature and our copious single-center experience.

Cell-Free DNA and Active Rejection in Kidney Allografts.

Histologic analysis of the allograft biopsy specimen is the standard method used to differentiate rejection from other injury in kidney transplants. Donor-derived cell-free DNA (dd-cfDNA) is a noninvasive test of allograft injury that may enable more frequent, quantitative, and safer assessment of allograft rejection and injury status. To investigate this possibility, we prospectively collected blood specimens at scheduled intervals and at the time of clinically indicated biopsies. In 102 kidney recipients, we measured plasma levels of dd-cfDNA and correlated the levels with allograft rejection status ascertained by histology in 107 biopsy specimens. The dd-cfDNA level discriminated between biopsy specimens showing any rejection (T cell-mediated rejection or antibody-mediated rejection [ABMR]) and controls (no rejection histologically), P<0.001 (receiver operating characteristic area under the curve [AUC], 0.74; 95% confidence interval [95% CI], 0.61 to 0.86). Positive and negative predictive values for active rejection at a cutoff of 1.0% dd-cfDNA were 61% and 84%, respectively. The AUC for discriminating ABMR from samples without ABMR was 0.87 (95% CI, 0.75 to 0.97). Positive and negative predictive values for ABMR at a cutoff of 1.0% dd-cfDNA were 44% and 96%, respectively. Median dd-cfDNA was 2.9% (ABMR), 1.2% (T cell-mediated types ≥IB), 0.2% (T cell-mediated type IA), and 0.3% in controls (P=0.05 for T cell-mediated rejection types ≥IB versus controls). Thus, dd-cfDNA may be used to assess allograft rejection and injury; dd-cfDNA levels <1% reflect the absence of active rejection (T cell-mediated type ≥IB or ABMR) and levels >1% indicate a probability of active rejection.

Donor-derived Cell-free DNA Identifies Antibody-mediated Rejection in Donor Specific Antibody Positive Kidney Transplant Recipients.

BACKGROUND: Elevated levels of donor-derived cell-free DNA (dd-cfDNA) in the plasma of renal allograft recipients indicates organ injury and an increased probability of active rejection. Donor-specific antibodies (DSA) to HLA antigens are associated with risk of antibody-mediated rejection (ABMR). This study assessed the combined use of dd-cfDNA and DSA testing to diagnose active ABMR. METHODS: Donor-derived cell-free DNA was assayed in 90 blood samples with paired DSA and clinically indicated biopsies from 87 kidney transplant patients. Sixteen cases met criteria for active ABMR. Performance characteristics of dd-cfDNA for diagnosis of active ABMR were determined for samples with prior or current positive DSA (DSA+, n = 33). RESULTS: The median level of dd-cfDNA (2.9%) in DSA+ patients with active ABMR was significantly higher than the median level (0.34%) in DSA+ patients without ABMR (P < 0.001). The median level of dd-cfDNA in DSA- patients was 0.29%. The positive predictive value of dd-cfDNA (at 1%) to detect active ABMR in DSA+ patients was 81%, whereas the negative predictive value was 83%. The positive predictive value for DSA+ alone was 48%. CONCLUSIONS: The combined use of dd-cfDNA and DSA testing may improve the noninvasive diagnosis of active ABMR in kidney transplant patients. Patients with dd-cfDNA+/ DSA+ results have a high probability of active ABMR.

Improvement in 3-month patient-reported gastrointestinal symptoms after conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in renal transplant patients.

BACKGROUND: The benefit of conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) in terms of gastrointestinal symptom burden has been evaluated previously using patient-reported outcomes. However, data are lacking concerning the sustained effect of conversion over time, and the potential impact of concomitant calcineurin inhibitor. METHODS: In this 3-month, prospective, multicenter, longitudinal, open-label trial, MMF-treated renal transplant patients with gastrointestinal symptoms receiving cyclosporine or tacrolimus were converted to equimolar doses of EC-MPS. Change in gastrointestinal symptom burden was evaluated using a validated Gastrointestinal Symptom Rating Scale (GSRS). RESULTS: A significant improvement in GSRS score was observed from baseline (2.61, 95% CI 2.54-2.68) to month 1 (1.87, 95% CI 1.81-1.93) after conversion to EC-MPS and was sustained to month 3 (1.81, 95% CI 1.74-188; both P<0.0001 versus baseline). The mean change in overall GSRS score from baseline to month 1 was -0.74 overall (cyclosporine: -0.73 and tacrolimus: -0.74; all P<0.0001 versus baseline), with a slight further improvement (-0.79) at month 3 (cyclosporine: -0.82 and tacrolimus: -0.78; all P<0.0001 versus baseline). A significant improvement in GSRS subscale scores was also observed in the total population regardless of calcineurin inhibitor at month 1, sustained to month 3 (all P<0.0001 versus baseline). The improvement in GSRS score postconversion was similar in African-American and non-African-American patients, and in diabetic and nondiabetic patients. CONCLUSIONS: This exploratory study in 728 patients demonstrates that following conversion from MMF to EC-MPS, regardless of concomitant calcineurin inhibitor, GSRS is improved and sustained over 3 months.

Ezetimibe in renal transplant patients with hyperlipidemia resistant to HMG-CoA reductase inhibitors.

Hyperlipidemia affects the majority of renal transplant patients. Multiple risk factors contribute to elevated serum cholesterol including the use of certain immunosuppressant agents. HMG-Co A reductase inhibitors have become the preferred class of cholesterol-lowering medication with an increasing body of evidence to support their safety, efficacy, and outcomes in both the normal and renal transplant populations. New guidelines recommend lowering previous LDL-c goals as outcomes appears to continually improve. As a result, ezetimibe has been added to patients with persistently elevated triglycerides and/or LDL-c in individuals who possessed a renal transplant and were deemed to be on a maximum safe dose of statin agent. After the addition of ezetimibe, total cholesterol, LDL-c, and triglycerides fell by 21%, 31%, and 13%, respectively. Creatinine phosphokinase, liver enzyme serum levels, and renal function were not affected to any level of clinical significance with the addition of ezetimibe. Large interpatient variability of measurable immunosuppressant levels was seen but no serious adverse events were attributed to a change in levels.

Polyclonal antibody-induced serum sickness in renal transplant recipients: treatment with therapeutic plasma exchange.

Serum sickness is an immune-complex mediated illness that frequently occurs in patients after polyclonal antibody therapy (ATGAM or thymoglobulin). Serum sickness presents with significant morbidity but is self-limited and resolves with prolonged steroid therapy. We present five renal transplant patients who developed serum sickness after polyclonal antibody treatment with severe symptoms that persisted after being started on systemic steroids. These patients underwent one or two courses of therapeutic plasma exchange (TPE) with subsequent complete resolution of their symptoms. Renal transplant recipients with serum sickness after polyclonal antibody therapy may benefit from TPE by accelerating their time to recovery and thereby reducing overall morbidity.

Living donor kidney transplantation in a Veterans Administration medical center.

BACKGROUND: A shortage of organ donors remains the major limiting factor in kidney transplantation. Living donor renal transplantation, especially living-unrelated donors, may expand the donor pool by providing another source of excellent grafts. METHODS: Between 1983 and 2003, 109 living donor kidney transplants were performed. Potential donors were assessed with a standardized routine. Antithymocyte serum (N-ATS) and Basiliximab were used as induction agents. Sandimmune, Gengraf, Neoral, and Prograf were the main immunosuppressants with Immuran, Mycophenolate Mofetil, and steroids. Eighty-two percent of the recipients were from out of state. RESULTS: Seventy-eight percent of the living donors were from living-related donors and 22% were from living-unrelated donors. One- and three-year patient survival rates were 97.6% and 93.2% with 1- and 3-year graft survival rates of 93.2% and 88.3%, respectively. There were 6 delayed graft functions (5.5%), 16 acute cellular rejections (10%), and 10 chronic rejections (9%). Twelve patients died, 7 of them with a functioning graft. In the past 6 years (1997-2003), the number of living donor kidney transplants surpassed deceased donor kidney transplants. CONCLUSIONS: Because of the limited number of cadaveric kidneys available for transplant, living donors represent a valuable source, and the use of living-unrelated donors has produced an additional supply of organs. In our program, the proportion of living donors used for kidney transplant is comparable with other non-Veterans Administration programs and the survival of these allografts appears to be superior to deceased donor kidney transplants.

Effects of diabetes and cadaveric organs on functional performance and health-related quality of life after kidney transplantation.

BACKGROUND: The current study was undertaken to identify factors specific to kidney transplantation that are associated with posttransplant functional performance (FP) and health-related quality of life (HRQOL). METHODS: Karnofsky FP status was assessed longitudinally in 86 adult kidney transplant recipients. Patients reported HRQOL using the Short Form-36 (SF-36) health survey and the Psychosocial Adjustment to Illness Scale (PAIS). RESULTS: FP improved (P <0.001) after kidney transplantation (from 75 +/- 1 to 77 +/- 1, 81 +/- 1, and 82 +/- 1 at 0, 3, 6, and 12 months, respectively). Patients receiving organs from living donors showed continued improvement through posttransplant year 1 while those receiving cadaveric organs stabilized at month 6 (simple interaction contrast, year 1 versus pretransplant; P <0.05). Patients receiving dialysis therapy for 6 months or more prior to transplantation demonstrated lower SF-36 posttransplant physical component scores in comparison with patients who were transplanted preemptively (38 +/- 1 versus 45 +/- 2, P <0.05). Path analysis demonstrated the positive direct effect of time on FP with kidney transplantation (beta = 0.23, P <0.05), and the negative direct effects on FP of diabetes (beta = -0.22) and cadaveric organs (beta = -0.22, both P <0.05). In turn, FP had a positive direct effect on HRQOL (beta = 0.40, P <0.001). CONCLUSIONS: Overall improvement in FP is attenuated 1 year after kidney transplantation in recipients of organs from cadaveric donors. The positive effect of time after transplantation, and the negative effects of cadaveric organs and diabetes on posttransplant HRQOL, are indirect and are mediated by the direct effects of these variables on posttransplant FP.

Mammalian target of rapamycin inhibitors in organ transplantation: an unkept promise.

The initial enthusiasm for the advent of a potentially nonnephrotoxic immunosuppressant has been muted by data unmasking nephrotoxicity of mammalian target of rapamycin inhibitors, including renal podocyte injury resulting in proteinuria. Adverse reactions, including anemia, thrombocytopenia, hyperlipidemia, and especially diabetogenesis, have limited its use to niche indications such as prevention or amelioration of malignancy in organ transplant. The class seems to be best used to address malignancy in organ allograft recipients and as a first-line therapy in lymphangioleiomyomatosis.

Enteric-coated mycophenolate sodium versus mycophenolate mofetil in renal transplant recipients experiencing gastrointestinal intolerance: a multicenter, double-blind, randomized study.

BACKGROUND: Two open-label studies demonstrated that conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) significantly reduces gastrointestinal (GI) symptom burden and improves GI-specific health-related quality of life. Using a randomized design, this study evaluated changes in GI symptoms and health-related quality of life in patients converted from MMF to EC-MPS versus patients who continued with MMF-based treatment. METHODS: In this 4-week, multicenter, randomized, prospective, double-blind, parallel-group trial, renal transplant recipients with GI symptoms receiving MMF plus a calcineurin inhibitor ± corticosteroids were randomized to an equimolar dose of EC-MPS+MMF placebo or continue on their MMF-based regimen+EC-MPS placebo. The primary efficacy outcome was a change from baseline in total Gastrointestinal Symptom Rating Scale score of a minimally important difference of more than or equal to 0.3. RESULTS: Three hundred ninety-six patients (EC-MPS group: n=199; MMF group: n=197) were included. A greater proportion of EC-MPS patients (62%) reached the primary efficacy outcome compared with MMF patients (55%); however, the difference was not statistically significant (P=0.15). EC-MPS patients had a significantly greater decrease in the Gastrointestinal Symptom Rating Scale indigestion syndrome dimension versus MMF patients. Within the subgroups of patients with diabetes, patients transplanted 6 to 12 months of study enrollment, and patients on steroids, a statistically significant greater proportion of EC-MPS versus MMF patients reached the primary efficacy outcome. CONCLUSIONS: Conversion from MMF to EC-MPS may be associated with improvements in presence and severity of GI symptoms, particularly in patients with indigestion, diabetes, on steroids, and in patients converted between 6 and 12 months posttransplantation.

Ezetimibe reduces low-density lipoprotein cholesterol (LDL-C) in renal transplant patients resistant to HMG-CoA reductase inhibitors.

Hyperlipidemia is common after renal transplantation. On the basis of current lipid guidelines, the majority of renal transplant recipients should have plasma low-density lipoprotein cholesterol (LDL-C) levels <100 mg/dL. Even with statin (HMG-CoA [3-hydroxy-3-methylglutaryl CoA] reductase inhibitor) therapy, a significant number of renal transplant recipients have LDL-C levels >100 mg/dL. We report that ezetimibe, a novel inhibitor of intestinal cholesterol absorption, was well tolerated and effectively reduced the LDL-C level to <100 mg/dL in our cohort of renal transplant recipients with persistently elevated LDL-C levels during treatment with maximally tolerated statin medications.

The management of the failed renal allograft: an enigma with potential consequences.

The number of patients returning to dialysis after their renal allograft fails is increasing in absolute numbers year after year. The management of the failed allograft that is not immediately symptomatic remains controversial. Surgical mortality and morbidity, a rising number of circulating antibodies, reduced erythropoietin, and diuresis are among the arguments to support simply observing the failed allograft. Chronic inflammation, potential for malignancy, infection, and the need for low-dose immunosuppression are concerns that might goad one into performing a preemptive nephrectomy. Based on the current literature and our own clinical experience, we believe allograft nephrectomies should not be routinely performed. They should be reserved for those patients who develop particular symptoms attributable to the allograft or those who require space for retransplantation. Future studies that address this issue in addition to testing various immunosuppression attrition rates may be able to discern a protocol that minimizes drug exposure while leading to reduced nephrectomy rates after returning to dialysis.