First Year Renal Function as a Predictor of Kidney Allograft Outcome

Background

Several factors are known to have detrimental effects on kidney allograft function in the first year posttransplantation, which has been reported to be an important factor influencing long-term graft survival.

Objectives

The objectives of this study were to evaluate risk factors for lower estimated glomerular filtration rate (eGFR) at 3 and 12 months posttransplantation and analyze the influence of first year allograft function on graft and patient survivals.

Patients

We performed a retrospective review of the clinical data from 433 cadaveric donor kidney transplantations in adults performed in our unit from May 1989 to May 2007.

Results

Donor female gender and nontraumatic cause of death, panel-reactive antibody (PRA) titer ≥50%, acute rejection episodes, and delayed graft function (DGF) were significant risk factors for a decreased eGFR at one year posttransplantation. Recipient and donor age showed negative correlations with eGFR at 3 and 12 months. A logistic regression model showed acute rejection episodes, DGF, donor age ≥55 years, donor female gender, and nontraumatic cause of donor death to be independent adverse risk factors for eGFR <60 mL/min at 3 and 12 months. Lower eGFRs at 3 and 12 months were associated with poorer allograft survival when data were censored for death with a functioning graft and patient survival. Multivariate analysis revealed that PRA titer ≥50%, acute rejection episodes, and eGFR <30mL/min at 12 months had adverse effects on allograft survival.

Conclusion

Several factors influence kidney allograft function in the first year after transplantation. Kidney allograft function at 12 months predicted long-term graft survival.     

Arteriolar Hyalinization in Implantation Kidney Biopsies as a Predictor of Graft Function

The shortage of organs suitable for transplantation has caused a constant evolution of donor acceptance criteria, making an implantation biopsy a valuable tool to predict kidney allograft survival. Preimplantation vascular changes may be divided into sclerosis or intimal fibrous thickening or arteriolar hyalinization. Increasing evidence has indicated their impact on graft function. The aim of this study was to evaluate the significance of preimplantation arteriolar hyalinization for the stability of kidney allograft function. Among a prospective cohort study of 53 kidney recipients (implantation: 2006–2007) who showed serum creatinine values between 1 and 2 mg/dL at 3 months after engraftment, the mean observation time was 24 ± 8.7 months. At the end of the observation, kidney function as defined by the estimated glomerular filtration rate by the Cockcroft-Gault formula (eGFR C-G) was significantly diminished in individuals with preimplantation evidences of arteriolar hyalinization (mean values: 51.2 ± 14.8 and 62.0 ± 16.7, respectively; P < .03) or serum creatinine concentrations (1.76 ± 0.36 vs 1.51 ± 0.48 mg/dL; P < .09). The negative influence of arteriolar hyalinosis on allograft function was time-dependent; an early satisfactory filtration rate did not preclude progressive kidney dysfunction.     

Diabetes Mellitus as Predictor of Patient and Graft Survival After Kidney Transplantation

Background

In this study, we used a single-center database to examine the risks of renal transplantation in patients with diabetes mellitus (DM). We aimed to compare 1-year outcomes of survival and morbidity after renal transplantation among recipients with and without DM.

Methods

We reviewed retrospectively 1211 adult patients who underwent renal transplantation from January 2001 to December 2010. The patients were divided into 2 groups: Those with (33%) and those without (67%) pretransplant diabetes. Unpaired Student's t tests and χ² tests were used to compare outcomes between diabetic and nondiabetic renal transplant recipients. We analyzed survival, renal function, development of proteinuria, rejection, and infection (requiring hospitalization).

Results

Patients with diabetes were older, had a greater body mass index (mean, 29.5 vs 25.3 kg/m²; P < .05), and had lower creatinine clearance (44.2 ± 11.4 vs 56.0 ± 18.2; P = .01). Forty-one patients died in hospital (3.4%; P = nonsignificant). Furthermore, survival rates were similar between these 2 groups. However, we found a trend toward decreased survival for those with DM at 1 year (80.4% vs 88.7%; P = .20). Mean follow-up time was 3.2 years. Infection rate within 6 months was greater among those with DM (19% vs 5%; odds ratio, 6.25). Freedom from rejection at 3 years was similar (75.2% vs 76.8%; P = .57). Multivariate analysis showed increased baseline creatinine level as a significant risk factor for survival. Body mass index >30 kg/m² was a significant risk factor for survival among patients with DM.

Conclusion

We found an increased risk of serious infections in patients with DM, particularly within the first 6 months. However, our data suggest that diabetes is not associated with worse 1-year survival or higher morbidity in renal transplant patients, as long as good blood glucose control is maintained.     

Post-Transplant HLA class II Antibodies and High Soluble CD30 Levels are Independently Associated with Poor Kidney Graft Survival

HLA-specific antibodies (HSA) and soluble CD30 (sCD30) were measured in 208 renal transplant recipients with functioning grafts at least 1 year after transplantation (median 8.2 years) to investigate the predictive value of HSA and sCD30 on subsequent graft outcome. HSA (class I and class II) were detected by both ELISA LAT-M and Luminex LabScreen assays. Data on graft outcome was collected with a median follow-up time of 3.5 years after antibody and sCD30 measurement. Recipients with post-transplant HLA class II antibodies had particularly poor graft outcome with a hazard ratio (HR) of 7.8 (p < 0.0001) when detected by ELISA, and a HR of 6.0 (p < 0.0001) when detected by Luminex. A high post-transplant sCD30 level >or=100 U/mL was associated with increased risk of subsequent graft failure (HR 2.7, p = 0.03). sCD30 and HSA had an independent and additive association with graft outcome. Recipients with HLA class II antibody and high sCD30 had the highest risk of subsequent graft failure (HR 43.4, p < 0.0001 and HR 18.1, p = 0.0008 for ELISA and Luminex, respectively). These data show that detection of HSA and serum sCD30 measured at least 1-year post-transplant provides valuable and predictive information regarding subsequent graft outcome.     

High Serum Level of the Soluble CD30 Identifies Chinese Kidney Transplant Recipients at High Risk of Unfavorable Outcome

Background

We sought investigate the relationship between serum level of sCD30 and recipient/graft survival rates, rejection types, as well as other prognostic factors among Chinese kidney transplant patients.

Materials and methods

We performed enzyme-linked immunosorbent assays of serum sCD30 levels in duplicate among retrospective cohort of 707 renal transplant patients.

Results

The incidences of rejection increased in relation to the pretransplant sCD30 level. The reversal rates of rejection were 100%, 90.6%, and 78.6% for the low, intermediate, and high sCD30 groups. This observation suggested that high levels of sCD30 and pretransplant panel-reactive antibody (PRA)-positive patients are risk factors for acute rejection with odds ratios of 6.862 and 1.756. High sCD30 was an independent risk factor for functional graft survival. The 5-year graft survival rates were 99.39% ± 6.1%, 93.11% ± 1.93%, and 82.07% ± 3.97% among the low, intermediate, and high sCD30 groups, while the 5-year recipient survival rates were 89.25% ± 2.41%, 91.82% ± 1.64%, and 88.85% ± 2.36%, respectively. Increased sCD30 levels were observed among patients who were PRA-positive, cytomegalovirus antigens or antibodies positive, on long-term dialysis, and ≤ 20 years old.

Conclusions

Pretransplant sCD30 serum levels reflect immune status.     

The First Year Renal Function as a Predictor of Long-Term Graft Survival After Kidney Transplantation

This study examined the impact of graft function at the end of the first year after kidney transplantation on long-term graft survival. We analyzed the roles of serum creatinine (Scr) and other variables as predictors of graft survival among 235 adult kidney transplant patients. The subjects were divided into 3 groups according to their Scr at the end of the first year: group 1, Scr < 100 μmol/L; group 2, 100 μmol/L ≤ Scr ≤ 150 μmol/L; and group 3, Scr >150 μmol/L. The annual rate of graft loss of 0.7% (95% confidence interval [CI], 0.63-0.77) in group 1, was lower than those in group 2 (2.1%; 95% CI, 2.02-2.18; P < .0001) and group 3 (6%; 5.74-6.26; P < .0001). Regression analysis showed the role of recipient age at the time of operation, and Scr level at the end of the first year to be independent predictors of graft loss. Graft survival was not influenced by any other studied parameter, including donor age, year of procedure, warm ischemia time, history of acute tubular necrosis, and occurrence of an acute rejection episode. We conclude that the 1-year Scr value predicts long-term renal graft survival, representing a simple, practical tool to identify recipients with an high risk for late graft failure.     

Resistance Index Measured by Doppler Ultrasound as a Predictor of Graft Function After Kidney Transplantation

IntroductionDoppler ultrasound (US) has become the primary imaging technique for the evaluation of renal transplants. It provides information about the intrarenal resistance index (RI). A high RI is seen in every form of graft dysfunction. In this article, we review the utility of sonography, particularly the intrarenal RI measured early after renal transplant, as a predictor of acute and chronic clinical outcome in patients.ResultsRI is a valuable marker to determine graft function and related vascular complications. It reveals a strong correlation with serum creatinine levels measured days after transplant. Its elevation is typical for acute tubular necrosis and can be used to predict its duration. An RI >1 (absent end-diastolic flow) seen in the first weeks after transplant is associated with impaired renal graft recovery. In addition, it is an early predictor of chronic allograft nephropathy (even correlated with biopsy results), which will allow a change in therapy.ConclusionsRI measured serially in the early period after kidney transplantation is a valuable marker for determining renal graft function. It is also useful for demonstrating various types of graft dysfunction; however, it cannot differentiate between them. In recent studies, extrarenal factors in kidney transplantation (eg, recipient's age) may significantly influence RI in the recipient, demonstrating that RI depends on the vascular characteristics of the recipient and not on the graft itself.     

Soluble CD30 as a predictor of kidney graft outcome.

BACKGROUND: In the present study, we investigated whether the soluble form of CD30 (sCD30), a marker for T helper 2-type cytokine-producing T cells, is increased in sera of potential kidney graft recipients. We also investigated whether the pretransplantation serum sCD30 content is related to kidney graft survival. METHODS: Pretransplantation sera of 844 cadaver kidney recipients from three transplant centers in Germany were tested for serum sCD30 content using a commercially available ELISA kit. RESULTS: Kidney graft recipients showed a significantly higher serum sCD30 content than healthy controls (P<0.0001). High sCD30 serum content was associated with graft rejection. The 2-year graft survival rate in recipients with a high pretransplantation serum sCD30 was 68+/-6%, significantly lower than the 86+/-1% rate in recipients with a low sCD30 (P<0.0001). Importantly, high sCD30 was indicative of an increased risk of graft loss even in recipients without lymphocytotoxic alloantibodies. CONCLUSION: These data show that an elevated pretransplantation serum sCD30 reflects an immune state that is detrimental for kidney graft survival.     

Level of Soluble CD30 After Kidney Transplantation Correlates With Acute Rejection Episodes

Measurement of soluble CD30 (sCD30) levels may predict acute rejection episodes (ARE). To explore the value of sCD30 after transplantation, we tested serum sCD30 levels in 58 kidney transplant cases at 1 day before and 7 and 28 days after transplantation by enzyme-linked immunosorbent assay (ELISA). The incidences of ARE after kidney transplantation were recorded simultaneously. Meanwhile, 31 healthy individuals were selected as a control group. The results showed a relationship between sCD30 level in serum before kidney transplantation and the incidence of ARE. However, the relationship was more significant between serum sCD30 levels at day 7 after kidney transplantation and the incidence of ARE. There was no obvious relationship between serum sCD30 levels at day 28 after kidney transplantation and the incidence of ARE. These results suggested that the level of sCD30 at day 7 posttransplantation provides valuable data to predict ARE.     

Lower Time in Therapeutic Range Relates to a Worse Kidney Graft Outcome

Tacrolimus has a narrow therapeutic margin. Maintaining tacrolimus blood levels in the appropriate range is difficult because of its intrapatient variability. In fact, greater blood level variability has been related to worse kidney graft outcome, but only measuring variability does not consider the therapeutic range goal. Determining the time in therapeutic range (TTR) using the Rosendaal method allows dose optimization by considering the adverse events associated with both supratherapeutic and subtherapeutic doses. Some previous studies in kidney and lung transplantation have shown that the measurement of TTR has been related to the subsequent graft outcome.We performed a single-center, observational study including 215 consecutive kidney transplants performed in our center. The percentage of time that the patient remained with levels above 6 ng/mL between months 3 and 12 (%TTR3-12) was calculated using the Rosendaal method.A lower %TTR3-12 was associated with a higher risk of acute rejection (area under the receiver operating characteristic curve, 0.614; 95% confidence interval [CI], 0.513-0.714; P = .018) and with a higher risk of having a 1-year glomerular filtration rate < 30 mL/min/1.73 m² (area under the receiver operating characteristic curve, 0.676; 95% CI, 0.542-0.811; P = .014). The lowest tertile of %TTR3-12 was independently associated with a higher risk of death-censored graft loss (hazard ratio, 10.773; 95% CI, 1.315-88.264; P = .027) after adjusting by 1-year glomerular filtration rate, expanded criteria donation, and acute rejection throughout the first year.To conclude, measuring TTR after kidney transplant is an easy way to estimate the time of exposure to adequate levels of tacrolimus and relates to kidney graft outcome.     

Presence of Vesicoureteral Reflux in the Graft Kidney Does Not Adversely Affect Long-Term Graft Outcome in Kidney Transplant Recipients

Introduction

We studied the incidence of vesicoureteral reflux (VUR) in the graft kidney and its effect on the occurrence of urinary tract infection (UTI) and long-term graft function.

Methods

We performed a retrospective analysis of 64 adult kidney transplant recipients based upon voiding cystourethrography at 12 months post-transplantation. Patients underwent analysis of survival, incidence of UTIs beyond 1 year, and graft function.

Results

Thirty-seven male and 27 female patients in the study populations showed a mean age 42 years. VUR in the transplanted kidney at 12 months post-transplant occurred among 78.1% (50/64) of subjects: grade I (n = 6), grade II (n = 30), or grade III (n = 14) reflux. Patients followed for a median 61 months (range 44–74s) showed 11 cases of UTIs in 9 subjects. There were no significant differences in clinical characteristics or incidence of, UTIs according to the presence or severity of VUR (P = .81) or the Serum creatinine and estimated glomerular filtration rate values at 12, 36, 48, or 60 months post-transplantation.

Conclusions

VUR present in 78.1% of patients after kidney transplantation affected neither graft functions or graft survival. The incidence of UTI did not differ according to the presence of VUR.     

Is External Jugular Venous Pressure a Good Predictor of Volume Status in Kidney Graft Recipients?

To ensure appropriate function of the transplanted organ, it is necessary to adequately maintain vascular volume during the kidney transplantation procedure. For this purpose, central venous pressure (CVP) is monitored through a catheter inserted into the superior vena cava (SVC). Central venous cannulation is associated with a risk of serious complications. An objective of this study was to investigate whether there was a correlation between pressures measured in the SVC and in the external jugular vein (EJV). We studied 33 chronically dialyzed patients who had a short catheter placed in the EJV because of difficulties in peripheral vein cannulation in the limbs. In each case, general anesthesia was induced and a central catheter inserted into the SVC. Every 10 minutes venous pressure measurements were obtained simultaneously at both sites. A significant (P < .001) correlation was observed between external jugular vein pressure (EJVP) and CVP. CVP could be described as a function of EJVP by the equation CVP = {0.90299 × EJVP} − 0.8361. The results of this study indicated that monitoring the EJVP allows equally efficient evaluation of vascular volume as the CVP. In our opinion, EJVP is sufficient to evaluate vascular volume during kidney transplantation in patients with difficult vascular access.     

Head Injury as a Predictor of Psychological Outcome in Combat Veterans

Although it is recognized that psychosocial variables influence the expression of psychopathology following trauma exposure, physiological variables have received less attention as potential mediators of psychological outcome in trauma victims. The purpose of this study was to examine the relationship of head injury to psychological outcome in 171 combat veterans seeking compensation for service-connected disabilities for mental disorders attributed to etiologies other than head injury. Veterans underwent structured psychiatric diagnostic interview and completed self-report measures of combat exposure, posttraumatic stress disorder (PTSD), depression, and occurrence of head injury. Comparisons between veterans with and without history of head injury indicated that head injury was associated with more severe depression. Regression analysis suggested that head injury predicted depression, but not PTSD, severity.     

Soluble CD30 levels as a diagnostic marker for bronchiolitis obliterans syndrome following human lung transplantation

The long term survival of human lung allograft is hampered by the occurrence of chronic rejection, Bronchiolitis Obliterans Syndrome (BOS). This end-stage disease is normally diagnosed clinically by using the pulmonary function tests. This results in delay of BOS diagnosis and consequently prevents early intervention. It is generally accepted that alloimmunity plays an important role in chronic rejection of the allograft. In this study we analyzed serial serum samples from BOS+ and BOS- patients for sCD30 levels to determine the role of sCD30 to predict the onset of BOS. In contrast to BOS negative patients and normal subjects, 6 out of 9 BOS+ patients (p<0.05) studied had an increase in the sCD30 levels. Significantly, the rise was noted 7.57+/-2.63 months before the clinical diagnosis was evident. Therefore, we propose that the rise in serum sCD30 levels can be used as a marker for the detection of patients who are at risk of development of BOS.     

Graft Outcome and Mycophenolic Acid Trough Level Monitoring in Kidney Transplantation

Background

Large inter- and intrapatient variabilities have been observed in the pharmacokinetics of mycophenolic acid (MPA). As a consequence, the efficacy and safety of mycophenolate mofetil (MMF) may be optimized with individualized doses based on therapeutic drug monitoring.

Materials and Methods

In this retrospective study we analyzed; 7536 12-hour trough MPA samples obtained during the first year posttransplantation among 314 kidney recipients treated with tacrolimus, MMF, and corticosteroids.

Results

Despite taking similar MMF doses, patients with delayed graft function (DGF) showed lower 12-hour trough MPA levels than patients without DGF 1.4 ± 0.1 vs 2.1 ± 0.1 μg/mL; P = .001). There was a significant correlation between 12-hour trough MPA levels and creatinine clearance (r = .32; P < .001). Logistic regression analysis showed that creatinine clearance was a predictive factor of adequate 12-hour trough MPA levels (>1.6 μg/mL) at 7 days posttransplantation. Twelve-hour trough MPA levels at 7 days posttransplantation were lower among patients who developed an acute rejecton episode (1.5 ± 0.1 vs 2.1 ± 0.1 μg/mL; P < .001), whereas those with gastrointestinal side effects showed high levels (4.1 ± 0.5 μg/mL).

Conclusions

In patients with delayed or poor graft function, MMF doses greater than 2 g/d may be necessary to achieve adequate MPA levels. Therapeutic drug monitoring of MPA may be useful to prevent acute rejection episodes or toxicity.     

Pay Status as a Predictor of Outcome in Surgical Treatment of Obesity

Background: Higher complication rates and lower success in surgery for severe obesity have been reported for patients with government pay status. We examined the effect of pay status upon outcome in surgical treatment of obesity. Methods: This was an observational study from an aggregate data set of individual patient information. Government pay status (G) was defined as full or partial medical care payment through Medicare, Medicaid, or Veterans Administration. Payment entirely by private insurance was defined as private (P). Operations were classified as either simple (S, gastric restriction) or complex (C, gastric restriction with small bowel bypass). Two measures of outcome, perioperative complication rate and weight loss success (≤50% excess weight), were examined to determine pay status effect. Results: More G than P patients were treated with simple procedures (79% vs 51%, p < 0.05). Perioperative complication rates were more common for G than P patients (14.4% vs 9.1%, p < 0.05). One-year weight loss success was higher for P than G, regardless of operation type. Conclusion: Pay status should be included in characterization of patient groups and in the analysis of results when effectiveness of surgical treatment for severe obesity is reported.