Cardiac troponin levels in asymptomatic patients on the renal transplant waiting list

AIMS: Cardiac troponin levels predict mortality and cardiovascular events in asymptomatic patients receiving dialysis and may be a useful clinical tool to stratify high-risk asymptomatic individuals. METHODS: The present study examined levels of troponins I (cTnI) and T (cTnT) in patients with chronic renal impairment, patients receiving dialysis and renal transplant recipients. Patients receiving dialysis on the renal transplant waiting list were compared with those excluded from the list based on medical criteria. Median levels were compared using the Kruskal-Wallis test and proportions compared by chi-squared. RESULTS: Median troponin levels were higher in patients on dialysis than transplant recipients. Comparing patients receiving dialysis not listed compared with those listed for renal transplant, median cTnI levels were significantly higher (0.03 versus 0.02 microg/L, P < 0.01) whereas median cTnT levels were not. Patients listed for transplantation were younger, had less clinical cardiovascular disease and lower C-reactive protein than those awaiting renal transplantation. The proportion of patients with elevated cTnT was not substantially different between patients awaiting renal transplantation (38%) and those excluded (52%). Levels of cTnI and cTnT were inversely related to renal function in predialysis and transplant patients, but were not related to time on dialysis for those receiving dialysis therapy. CONCLUSION: As patients awaiting renal transplantation are clinically screened for cardiovascular disease but have frequently elevated cardiac troponin levels, troponin may be a useful clinical tool to identify high-risk asymptomatic patients on dialysis prior to renal transplantation. The influence of renal function on the interpretation of cardiac troponin and risk prediction requires further evaluation.     

Pericardial Effusion Associated With Sirolimus Use After Renal Transplantation: A Single-Center Case Series

Pericardial effusion and cardiac tamponade following renal transplantation have been recognized as a potentially serious complications associated with the use of sirolimus for immunosuppression. Our study aims to analyze the development of sirolimus-associated pericardial effusion.Patients who underwent renal transplantation at our institution between 2001 and 2014 were reviewed and the correlation between sirolimus exposure and pericardial effusion was determined. Nineteen out of 792 patients who received a renal transplant over this 14-year period (incidence 2.4%) developed symptomatic pericardial effusion (determined by the need for pericardiocentesis or a pericardial window). All patients had a pre-transplantation cardiac workup, including echocardiogram, which did not reveal the presence of pericardial effusion. Our cohort of patients is mostly male (57.9%) and Caucasian (73.7%), which is consistent with the makeup of transplant recipients at our center. The mean age was 52.42 years at the time of transplantation. The development of symptomatic pericardial effusions occurred at a mean of 5.06 (.5–9.8) years after renal transplant while on sirolimus therapy. Sirolimus levels at diagnosis were 5.19–7.47 ng/mL. No significant pericardial effusion (resulting in tamponade physiology) recurred after therapeutic intervention, including cessation of sirolimus with or without pericardial drainage. This study is the largest single-center report of the possible association between pericardial effusion in renal transplant recipients who received sirolimus. Due to the widespread use of sirolimus in organ transplantation, clinicians must remain vigilant for this potential cardiac complication.     

Waiting time on dialysis as the strongest modifiable risk factor for renal transplant outcomes: a paired donor kidney analysis

BACKGROUND: Waiting time on dialysis has been shown to be associated with worse outcomes after living and cadaveric transplantation. To validate and quantify end-stage renal disease (ESRD) time as an independent risk factor for kidney transplantation, we compared the outcome of paired donor kidneys, destined to patients who had ESRD more than 2 years compared to patients who had ESRD less than 6 months. METHODS: We analyzed data available from the U.S. Renal Data System database between 1988 and 1998 by Kaplan-Meier estimates and Cox proportional hazards models to quantify the effect of ESRD time on paired cadaveric kidneys and on all cadaveric kidneys compared to living-donated kidneys. RESULTS: Five- and 10-year unadjusted graft survival rates were significantly worse in paired kidney recipients who had undergone more than 24 months of dialysis (58% and 29%, respectively) compared to paired kidney recipients who had undergone less than 6 months of dialysis (78% and 63%, respectively; P<0.001 each). Ten-year overall adjusted graft survival for cadaveric transplants was 69% for preemptive transplants versus 39% for transplants after 24 months on dialysis. For living transplants, 10-year overall adjusted graft survival was 75% for preemptive transplants versus 49% for transplants after 24 month on dialysis. CONCLUSIONS: ESRD time is arguably the strongest independent modifiable risk factor for renal transplant outcomes. Part of the advantage of living-donor versus cadaveric-donor transplantation may be explained by waiting time. This effect is dominant enough that a cadaveric renal transplant recipient with an ESRD time less than 6 months has the equivalent graft survival of living donor transplant recipients who wait on dialysis for more than 2 years.     

Deterioration of renal function after replacement of cyclosporine with sirolimus in five patients with severe renal impairment late after heart transplantation

A retrospective analysis of all cases when cyclosporine (CyA) was replaced with sirolimus (SIR) to avoid the renal toxicity of CyA late after heart transplant (OHT) was discontinued due to advanced renal impairment in all five heart transplant recipients (four men, 1 women; age 41 years, range 38-45; time after OHT 5 years, range 4-14). The serum creatinine level at the time of SIR introduction, which was 298 micromol/L (range 217-676), had remained stable for the 6 months prior to conversion. Target SIR trough levels were 12-20 ng/mL. In four patients the last dose of CyA was immediately followed by the first dose of SIR, whereas in one patient CyA was tapered gradually in the presence of low-dose SIR. Deterioration of renal function with signs of fluid overload and increased serum creatinine levels (Delta: 77, 33-150 micromol/L) was observed in all patients. Two patients required dialysis during SIR treatment including one case of pulmonary edema requiring emergency hemodialysis. None of four biopsies showed significant rejection. Four patients were converted back to low-dose CyA (including the two patients requiring dialysis during SIR therapy); one was maintained on mycophenolate mofetil. The creatinine level at the time of SIR discontinuation was (range 250-753) micromol/L, 448. Eventually, all patients required dialysis. In conclusion, replacement of cyclosporine with sirolimus in heart transplant recipients with severe renal impairment late after transplantation may accelerate renal failure.     

Sirolimus experience in heart transplantation

INTRODUCTION: Sirolimus is a potent, nonnephrotoxic immunosuppressant with antiproliferative activity in nonimmune cells. Recent data support the conversion in late renal failure secondary to calcineurin inhibitors (CNIs), with limited experience in de novo regimens in patients with predictive factors of postoperative renal impairment. OBJECTIVE: We evaluated our experience of sirolimus-based immunosuppression administered to 25 heart transplant recipients. METHODS: A retrospective analysis of 25 heart transplant recipients who received sirolimus included 17 conversions due to late CNI-related chronic renal dysfunction, six patients with a de novo regimen, and two patients who developed posttransplant pulmonary neoplasms. The conversion from CNI to sirolimus was started with 2 mg, with an average time after transplantation of 78 +/- 43 months and a mean baseline serum creatinine level of 2.1 +/- 0.45 mg/dL. The mean clinical follow-up was 17 +/- 9 months postconversion, and included echocardiography and laboratory studies. In the de novo group successive endomyocardial biopsies were performed during the first semester. RESULTS: Serum creatinine fell from 2.1 +/- 0.45 mg/dL to 1.8 +/- 0.51 mg/dL (P = .012). Mean sirolimus levels were 15 +/- 9 ng/mL (doses 2.2 +/- 0.4 mg). This improvement continued until 3 months (creatinine 1.5 +/- 0.35 P < .01)/sirolimus levels 11.7 +/- 5 ng/mL [1.9 +/- 0.7 mg]), with maintenance at 6 months (1.58 +/- 0.3 mg/dL/14 +/- 4 ng/mL [1.85 +/- 0.7 mg]) and 1-year postconversion (1.53 +/- 0.39 mg/dL; P = .019/10.7 +/- 2.5 ng/mL [1.5 +/- 0.7 mg]). De novo, after a mean follow-up of 13 months (range 3 to 35), sirolimus appeared to increase the incidence of a moderate histological grade of rejection without hemodynamic compromise. Side effects were common (63%), including peripheral edema, skin eruptions, and pericardial effusion. Only one patient discontinued treatment, due to intestinal intolerance. Four patients died during follow-up: two because of lung neoplasms and two because of progressive graft vessel disease. CONCLUSION: Sirolimus improved late CNI-related chronic renal dysfunction. Kidney function was preserved using a de novo CNI-free immunosuppressive regimen for recent cardiac transplant recipients.     

The effect of coronary angiography on renal function in preemptive renal transplant candidates

Lorenz EC, Stegall MD, Cosio FG, Gloor JM, Larson TS, Taler SJ. The effect of coronary angiography on renal function in preemptive renal transplant candidates.
Clin Transplant 2011: 25: 594–599. © 2010 John Wiley & Sons A/S. Abstract: Background: Increasing numbers of patients undergo preemptive renal transplantation. Obtaining cardiac catheterizations prior to transplantation to screen for coronary artery disease is controversial because of the perceived risk of inducing contrast nephropathy and the need for dialysis in patients with marginal renal function. We sought to examine the true impact of cardiac catheterization on time to dialysis in a cohort of preemptive renal transplant candidates. Methods: From a cohort of 376 transplant candidates evaluated preemptively at our program between 2/2001 and 4/2005, 34 patients had positive dobutamine stress echocardiograms. We reviewed the subsequent need for dialysis in these patients. Results: Among candidates undergoing angiography, 8.7% required dialysis within 14 d of contrast administration and 26% eventually needed dialysis prior to transplantation at 5.3 ± 3.7 months after their pre‐transplant evaluation. Among patients who did not undergo angiography, 27% needed dialysis prior to transplantation at 2.4 ± 1.8 months after pre‐transplant evaluation. Conclusions: Our results demonstrate a low risk of hastening the need for dialysis after coronary angiography in preemptive renal transplant candidates. Undergoing angiography had no effect on the ultimate need for or timing of dialysis initiation. These findings support completion of full cardiac evaluation as indicated for high‐risk preemptive renal transplant candidates.     

Serologic evidence of Chlamydia pneumoniae infection as a long-term predictor of cardiovascular death in renal transplant recipients

BACKGROUND: Cardiovascular disease is the main cause of death with a functioning graft in renal transplant recipients. Elevated levels of C-reactive protein (CRP) and evidence of chronic Chlamydia pneumoniae infection have been linked to cardiovascular disease and survival in patients with normal renal function and patients with end-stage renal disease on dialysis. So far, no such data have been available in renal transplant recipients. METHODS: CRP, immunoglobulin (Ig)G and IgA antibodies to C. pneumoniae, and classic risk factors were compiled in 143 patients who underwent renal transplantation between January 1989 and April 1991. Samples were collected at transplantation, 1 year later, and at study end. Cardiovascular disease, death, and graft loss were documented during follow-up. RESULTS: A total of 44 patients died during a mean follow-up of 10 years. Cardiac events were responsible for 37% of deaths. Age, gender, number of antihypertensive drugs, and seropositivity for IgG and IgA antibodies to C. pneumoniae, but not CRP levels, were significantly associated with cardiac death. C. pneumoniae serology and CRP levels, however, did not influence graft survival. Age, presence of diabetes, calcium phosphorus ion product, number of antihypertensive drugs, serum creatinine at 1 year, and presence of chronic rejection were all negatively correlated with graft survival. CONCLUSIONS: Serologic evidence of chronic C. pneumoniae infection is associated with mortality as the result of cardiovascular disease in renal transplant recipients. CRP serum levels do not predict cardiac death in renal transplant recipients, in contrast with patients with normal renal function and patients on dialysis.     

Posttransplant complications in cardiac transplant recipients at National Cardiovascular Center

We have performed 21 cases of heart transplantation at our institution. We retrospectively reviewed the complications and its incidence in those post transplant course. METHODS: Twenty-one heart transplant recipients (aged at transplant 14 to 61 year old, 16 male and 5 female, observation period: 4 to 99 months) were retrospectively reviewed. Transplant coronary artery disease (TxCAD) was defined as existence of severer than Stanford class IV maximum intimal thickness seen by intra-coronary ultrasound at their annual evaluation. The incidence of hypertension, diabetes, hyperlipidemia, renal dysfunction and malignancy were also reviewed. RESULT: One patient died after 4.3 year posttransplant due to systemic infections. Eight patients (38.1%) developed TxCAD, 4 patients (19%) developed hypertension, 2 patients (9.5%) developed diabetes, 1 patient (4.8%) developed hyperlipidemia. Renal insufficiency defined as serum creatinine level of greater than 1.5 mg/dl was seen in 2 patients (9.5%), however none of them showed severe renal dysfunction such as serum creatinine level of greater than 2.0 mg/dl or requiring dialysis. No malignancy was seen in our patients. Cellular rejection episodes requiring admission for treatment were seen in 3.1% of all biopsies performed. CONCLUSIONS: Survival rate of our cardiac transplant recipients was 95.2% at 8.3 years. TxCADs and renal insufficiency were seen in 38% and 9.5% of our patients respectively, however the incidences of these complications were lower than those in ISHLT 2006 registry. Even in Japan, long-term survivors after cardiac transplantation are increasing. Maintenance of not only the cardiac function but also other organ function is required in post transplant care.     

Prognostic importance of renal function 1 year after heart transplantation for all-cause and cardiac mortality and development of allograft vasculopathy

BACKGROUND: Impaired renal function is associated with increased mortality among heart failure patients. Although a significant proportion of heart transplant (HTx) recipients have reduced renal function at 1 year post-HTx, no previous study has evaluated the associated risk for both all-cause and cardiac mortality. Hence, we assessed the relationship between glomerular filtration rate (GFR) at 1 year post-HTx and all-cause and cardiac mortality and development of cardiac allograft vasculopathy (CAV). METHODS: We evaluated 381 patients with a minimum survival of 1 year post-HTx and the Modification of Diet in Renal Disease Study formula was used to calculate estimated GFR. Mortality and angiographic CAV were defined as separate endpoints, and median follow-up was 7.4 and 4.0 years, respectively. RESULTS: During the follow-up period, 122 patients died and 154 patients developed CAV. Reduced GFR pre-HTx was not a risk factor for either endpoint. Overall, 193 (51%) patients had GFR <60 ml/min/1.73 m at one year post-HTx and this was an independent predictor of all-cause mortality with an adjusted hazard ratio of 1.7 (P=0.01) for a GFR between 30-60 and 3.2 (P=0.006) for GFR <30 ml/min/1.73 m. GFR <60 ml/min/1.73 m at 1 year post-HTx was also associated with a higher risk of cardiac mortality (HR=1.9; P=0.04) but did not predict the development of CAV. CONCLUSIONS: Renal impairment is evident in a majority of HTx recipients at 1 year post-HTx. It is an important risk factor for both all-cause and cardiac mortality but does not predict the development of angiographic CAV.     

Beneficial effect of early initiation of lipid-lowering therapy following renal transplantation.

BACKGROUND: Renal transplant recipients have a significantly reduced life expectancy, largely due to premature cardiovascular disease. The aim of the current analysis was to investigate the importance of time of initiation of therapy after transplantation, on the benefits of statin therapy. METHODS: 2102 renal transplant recipients with total cholesterol levels of 4.0-9.0 mmol/l were randomly assigned to treatment with fluvastatin (n = 1050) or placebo (n = 1052) and followed for a mean time of 5.1 years. The end-points were major cardiac events. The average median time from transplantation to randomization was 4.5 years (range: 0.5-29 years). RESULTS: In patients starting treatment with fluvastatin <4.5 years after renal transplantation, the incidence of cardiac events was 4.6% over 5.1 years vs 9.2% in those on placebo (P = 0.007). Fluvastatin significantly reduced the risk of cardiac death and non-fatal myocardial infarction by 56% [risk ratio (RR): 0.44; 95% confidence interval (95% CI): 0.26-0.74; P = 0.002]. In a more detailed analysis patients were grouped into 2-year intervals (since the last transplantation). The frequency of cardiac death and non-fatal myocardial infarction was reduced by 3.2%, 5.1%, 9.6% and 8.2% with fluvastatin treatment as compared to 6%, 10.4%, 13.4% and 9.6% with placebo when treatment was initiated at 0-2, 2-4, 4-6 and >6 years, respectively. The risk reduction for patients initiating therapy with fluvastatin at years 0-2 (compared with >6 years) following transplantation was 59% (RR: 0.41; 95% CI: 0.18-0.92; P = 0.0328). This is also reflected in total time on renal replacement therapy: in patients in the first quartile (<47 months) fluvastatin use was associated with a risk reduction of 64% compared with 19% for patients in the fourth quartile (>120 months) (P = 0.033). CONCLUSIONS: Our data support an early introduction of fluvastatin therapy in a population of transplant recipients at high risk of premature coronary heart disease.     

Tolerability of sirolimus: a decade of experience at a single cardiac transplant center

Sirolimus is used in cardiac transplant recipients to prevent rejection, progression of cardiac allograft vasculopathy, and renal dysfunction. However, sirolimus has many potential side effects and its tolerability when used outside of clinical trials is not well established. We describe a decade of experience with sirolimus in cardiac transplant recipients at our institution. We retrospectively reviewed records of all adult cardiac transplant recipients living between September 1999 and February 2010 (n = 329) and identified 67 patients (20%) who received sirolimus. The indications for sirolimus were cardiac allograft vasculopathy (67%), renal dysfunction (25%), rejection (4%), and intolerability of tacrolimus (3%). One‐third of patients discontinued sirolimus at a median (25th, 75th percentiles) of 0.9 (0.2, 1.6) yr of duration. Over 70% of subjects experienced an adverse event attributed to sirolimus. Adverse events were associated with higher average sirolimus levels (9.1 ng/mL vs. 7.1 ng/mL, p = 0.004). We conclude that sirolimus is frequently used in cardiac transplant recipients (20%) and commonly causes side effects, often necessitating discontinuation. Higher average sirolimus levels were associated with adverse events, suggesting that tolerability may improve if levels are maintained within the lower end of the current therapeutic range; however, the improvement in tolerability would need to be balanced with the potential for decreased efficacy.     

Does pre‐emptive kidney transplantation with a deceased donor improve outcomes? Results from a French transplant network

Large analyses have demonstrated that pre‐emptive kidney transplantation (PKT) leads to significant improvements in patient and graft survival when compared with transplantation performed after a period of dialysis. We analysed 1585 patients who received a first renal transplantation from a deceased donor between 2000 and 2004 in four French transplantation centres. The objective was to compare the characteristics of the deceased donor transplantations with or without previous dialysis and to evaluate the impact of PKT and length of dialysis on patient and graft outcomes. Mean age of recipients was 48.1 ± 13.4 years, 62% were men, and 118 (7.4%) of them received a pre‐emptive transplantation. For the nonpre‐emptive patients, mean time on pretransplant dialysis was 3.4 ± 3.2 years. Pretransplant factors independently related to pre‐emptive transplantation were year of transplantation, centre and recipients characteristics: gender, diabetes history, blood group and donor age. Patients with pretransplant dialysis were three times more likely to have delayed graft function than pre‐emptive transplant patients, and were 10 times more likely to receive post‐transplant dialysis. Five‐year patient survival was 92.9%. Five‐year graft survival was 89.0%. Neither pre‐emptive transplantation nor time on dialysis was significantly associated with patient and/or graft survival.     

Sirolimus use and incidence of venous thromboembolism in cardiac transplant recipients

Sirolimus is an immunosuppressive agent increasingly used in cardiac transplant recipients in the setting of allograft vasculopathy or worsening renal function. Recently, sirolimus has been associated with increased risk of venous thromboembolism (VTE) in lung transplant recipients. To investigate whether this association is also present in cardiac transplant recipients, we retrospectively reviewed the charts of 67 cardiac transplant recipients whose immunosuppressive regimen included sirolimus and 134 matched cardiac transplant recipients whose regimen did not include sirolimus. Rates of VTE were compared. Multivariable Cox proportional hazards models tested the association of sirolimus use with VTE. A higher incidence of VTE was seen in patients treated with vs. without sirolimus (8/67 [12%] vs. 9/134 [7%], log‐rank statistic: 4.66, p = 0.03). Lower body mass index (BMI) and total cholesterol levels were also associated with VTE (p < 0.05). The association of sirolimus with VTE persisted when adjusting for BMI (hazard ratio [95% confidence interval]: 2.96 [1.13, 7.75], p = 0.03) but not when adjusting for total cholesterol (p = 0.08). These data suggest that sirolimus is associated with an increased risk of VTE in cardiac transplant recipients, a risk possibly mediated through comorbid conditions. Larger, more conclusive studies are needed. Until such studies are completed, a heightened level of awareness for VTE in cardiac transplant recipients treated with sirolimus appears warranted.     

Neurocognitive Functions in Pediatric Renal Transplant Patients

Neurocognitive dysfunction is one of the major complications of chronic renal failure (CRF). Uremic state during CRF encompasses a wide spectrum of neurobehavioral and neurological disturbances. Recent studies showed that the pathophysiology of neurocognitive dysfunction in CRF is related to plasma levels of uremic solutes. Successful renal transplantation improves renal, metabolic, and endocrine functions and the quality of life. The aim of our study was to determine the state of neurocognitive function in pediatric renal transplant recipients. We prospectively performed a neurological examination and neuropsychological test battery (Bender-Gestalt Test, Cancellation Test, and Visual and Auditory Number Assay Test) in 20 pediatric renal transplant recipients between 6 and 16 years of age. Twenty healthy children and 20 children with CRF were included in the study as the control groups. Mean age of the renal transplant recipients was 13.50 ± 3.40 years old. Mean evaluation time after transplantation was 2.0 ± 0.5 years. Bender-Gestalt Test result was abnormal in 40% of patients. The results of the Cancellation Test and the Visual and Auditory Number Assay Test showed significant decline in pediatric renal transplant patients when compared with the control. We found that neurocognitive dysfunction was frequent in pediatric renal transplantation patients. Awareness of this potential problem may be helpful for early recognition and treatment. Our findings suggest that periodic neurocognitive assessments may be indicated in transplant recipients.     

Observations regarding the use of sirolimus and tacrolimus in high-risk cadaveric renal transplantation

BACKGROUND: Balancing the risk of acute rejection (AR) with drug-induced toxicities complicates the selection of the optimal immunosuppressive regimen, especially in the high-risk renal transplant recipient. This study was designed to determine the optimal dosage combinations of tacrolimus and sirolimus in a high-risk cadaveric renal transplant population. METHODS: Primary cadaveric renal transplant recipients were randomly assigned to receive either standard tacrolimus (trough levels of 10-15 ng/mL) plus reduced sirolimus (trough levels of 5-10 ng,mL) (Group I) or to receive reduced tacrolimus (trough levels of 5-10 ng,mL) plus standard sirolimus (trough levels of 10-15 ng/mL) (Group II). All patients received Thymoglobulin induction and steroids. RESULTS: Thirty-nine (16 in Group I and 23 in Group II) high-risk renal transplant recipients (100% cadaveric donors, 79% African-American recipients, and 59% delayed graft function) are the subjects of this report. At 6 months, the patient survival rate was 94 and 100% and the graft survival rate was 94 and 83% in Groups I and II, respectively. The incidence of biopsy-proven AR was 6 and 5% in Groups I and II, respectively. Eight patients (50%) in Group I required discontinuation of tacrolimus, seven because of biopsy-proven tacrolimus nephrotoxicity and one secondarily to interstitial pneumonitis. Wound complications were the most frequent adverse event reported in both groups. CONCLUSIONS: The combination of tacrolimus and sirolimus was associated with a low risk of AR in this cohort of high-risk renal transplant recipients. However, 50% of patients who received standard tacrolimus and reduced sirolimus combination had to be discontinued from the regimen because of biopsy-proven nephrotoxicity. These preliminary results provide evidence that sirolimus should not be added to tacrolimus without dosage adjustments. We have discontinued recruitment of patients to the standard tacrolimus and reduced sirolimus combination and we have tightened our criteria for selection of marginal donor kidneys with our high-risk renal transplant recipients.     

The prevalence of peripheral arterial disease and medial arterial calcification in patients with chronic renal failure: requirements for diagnostics

BACKGROUND: Knowledge of the prevalence of peripheral arterial disease (PAD) in patients with chronic renal failure (CRF) is limited because of a lack of uniformity in disease definition and recognition. Furthermore, little is known of the prevalence of medial arterial calcification (MAC) in patients with CRF. Our goal is to study the prevalence of PAD and MAC defined by ankle brachial index (ABI) or toe brachial index (TBI) measurements in a Finnish population of patients with CRF consisting of predialysis and dialysis patients, as well as renal transplant recipients. METHODS: We examined 136 patients with CRF and 59 control subjects. Fifty-nine of the patients with CRF had moderate to severe predialysis CRF, 36 patients were on dialysis treatment, and 41 were renal transplant recipients. Mean age of patients was 51.9 +/- 11.5 years, and 39 patients (29%) had diabetes. ABI and TBI were measured by means of photoplethysmography. The definition of PAD required an ABI value of 0.90 or less, a TBI value of 0.60 or less, or a previous positive lower-extremity angiogram result. ABI values of 1.3 or greater or incompressible arteries at ankle level indicated MAC. The presence of claudication was determined by an interview. RESULTS: Prevalences of PAD on this study were 22.0% in patients with predialysis CRF, 30.6% in patients on dialysis treatment, 14.6% in renal transplant recipients, and 1.7% in the control group (P = 0.001). Prevalences of MAC were 23.7%, 41.7%, 23.1%, and 3.4% (P < 0.001), respectively. Only 9 patients had claudication, and 6 of those patients had PAD. CONCLUSION: Both asymptomatic PAD and MAC are common in patients with CRF. Therefore, we recommend the use of both ABI and TBI measurements in the evaluation of PAD in patients with CRF.     

Renal transplantation reverses functional deficiencies in circulating dendritic cell subsets in chronic renal failure patients

BACKGROUND: Dendritic cell (DC) subsets play critical roles in regulation of innate and adaptive immune responses. These important antigen-presenting cells have not been extensively analyzed in chronic renal failure (CRF), during dialysis, or before and after renal transplantation. METHODS: The incidence of circulating precursor (pre)-DC subsets relative to total peripheral blood mononuclear cells was analyzed in healthy controls, haemodialysis patients, peritoneal dialysis patients, CRF patients, and renal transplant (RT) recipients. DC subsets were identified and characterized phenotypically by multicolour flow cytometric analysis and purified by immunomagnetic bead isolation respectively. Cytokine production and circulating DC mobilizing cytokines were determined by ELISA. RESULTS: The incidence of circulating prePDC was reduced in all patients, but the incidence of circulating preMDC was comparable in RT and dialysis patients compared to healthy controls. CRF patients exhibited the lowest incidence of circulating preMDC and prePDC. Immunomagnetic bead-isolated preMDC and prePDC from haemodialysis patients were functionally impaired (reduced expression of surface costimulatory molecules and interleukin-12p70 production following bacterial lipopolysaccharide stimulation, and reduced interferon-alpha production following herpes simplex virus stimulation respectively, compared to healthy controls and RT recipients. Glomerular filtration rate correlated significantly with the incidence of circulating preMDC, but not prePDC. CONCLUSIONS: Deficiencies in the incidence and function of precursor DC can be reversed with successful renal transplantation achieving normal renal function. However, the finding of reduced incidence of circulating prePDC in the peripheral blood in RT recipients may be of significance in the pathogenesis of infections and malignancies.     

A Randomized Controlled Trial of Late Conversion from CNI-Based to Sirolimus-Based Immunosuppression Following Renal Transplantation

Maintenance immunosuppression with calcineurin inhibitors (CNIs) following renal transplantation is associated with nephrotoxicity and accelerated graft loss. We aimed to assess whether conversion to sirolimus-based immunosuppression would affect the progression of renal impairment. In this single center, randomized controlled trial, 40 renal transplant recipients between 6 months and 8 years post-transplant were randomly assigned to remain on their CNI (cyclosporin or tacrolimus) or to switch to sirolimus. The primary outcome measure was change in glomerular filtration rate (GFR) measurement at 12 months. Analysis was by intention-to-treat. Of the 40 patients randomized, 2 patients never took the study drugs and were excluded, leaving 19 patients per group. There was a significant change in GFR at 12 months following conversion to sirolimus (12.9 mL/min, 95% CI 6.1-19.7; p < 0.001). Following conversion, the principal adverse events were the development of rashes (68%), particularly acne, and mouth ulcers (32%). No patient in either group experienced an acute rejection episode. In renal transplant recipients, a change in maintenance therapy from CNIs to sirolimus is associated with significant improvement in GFR at 12 months.     

Renal Histopathological Lesions After Orthotopic Liver Transplantation (OLT)

Liver transplant recipients are at risk of chronic renal failure (CRF), customarily considered to be secondary to CsA/FK506 nephrotoxicity. We have examined renal biopsies from 26 liver transplant recipients with CRF. Before OLT, 5 patients had CRF, 8 were diabetic and 9 hypertensive. Renal biopsies were performed at a mean of 5 years after liver transplantation. Mean SCr was then 212 micromol/L, proteinuria was 1 g/24 h. Twelve patients were diabetic and 25 hypertensive. Histology revealed impressive renal destruction, with a mean of 45% interstitial fibrosis and 45% glomerular sclerosis. All biopsies showed severe arteriosclerosis. CRF can be attributed to four associated primary lesions: (i) specific chronic CsA/FK506 arteriolopathy; (ii) typical diabetic nephropathy; (iii) acute or chronic thrombotic microangiopathy attributed to CsA/FK506 or alpha-IFN and (iv) tubular changes related to administration of hydroxyethylstarch. At the end of the follow-up, after a mean of 6.4 years, 12 patients required dialysis, 13 had CRF and only 1 had normal renal function. Thus, CRF in OLT recipients is more complex than originally thought and should not be classified as anti-calcineurin nephrotoxicity without further investigations, including renal histology. These investigations have therapeutic potential, that is, they may lead to a more aggressive treatment of hypertension and/or diabetes.     

Randomized Controlled Trial of Sirolimus Conversion in Cardiac Transplant Recipients With Renal Insufficiency

This randomized, comparative, multinational phase 3b/4 study of patients 1–8 years postcardiac transplantation (mean 3.9 years) evaluated the effect of conversion from a calcineurin inhibitor (CNI) to sirolimus on renal function in patients with renal insufficiency. In total, 116 patients on CNI therapy with GFR 40–90 mL/min/1.73m² were randomized (1:1) to sirolimus (n = 57) or CNI (n = 59). Intent‐to‐treat analysis showed the 1‐year adjusted mean change from baseline in creatinine clearance (Cockcroft‐Gault) was significantly higher with sirolimus versus CNI treatment (+3.0 vs. ?1.4 mL/min/1.73 m², respectively; p = 0.004). By on‐therapy analysis, values were +4.7 and –2.1, respectively (p < 0.001). Acute rejection (AR) rates were numerically higher in the sirolimus group; 1 AR with hemodynamic compromise occurred in each group. A significantly higher treatment discontinuation rate due to adverse events (AEs; 33.3% vs. 0%; p < 0.001) occurred in the sirolimus group. Most common treatment‐emergent AEs significantly higher in the sirolimus group were diarrhea (28.1%), rash (28.1%) and infection (47.4%). Conversion to sirolimus from CNI therapy improved renal function in cardiac transplant recipients with renal impairment, but was associated with an attendant AR risk and higher discontinuation rate attributable to AEs.