Lack of improvement in renal allograft survival despite a marked decrease in acute rejection rates over the most recent era

Acute rejection is known to have a strong impact on graft survival. Many studies suggest that very low acute rejection rates can be achieved with current immunosuppressive protocols. We wanted to investigate how acute rejection rates have evolved on a national level in the U.S. and how this has impacted graft survival in the most recent era of kidney transplantation. For this purpose, we analyzed data provided by the Scientific Registry of Transplant Recipients regarding all adult first renal transplants between 1995 and 2000. We noted a significant decrease in overall acute rejection rates during the first 6 months, during the first year, and also in late rejections during the second year after transplantation. Despite this decrease in the rate of acute rejection, there was no significant improvement in overall graft survival; furthermore, we noted a statistically significant trend towards worse death-censored graft survival. There was also a trend for a greater proportion of rejection episodes to fail to recover to previous baseline function after treatment. Our data suggest that decreasing acute rejection rates between 1995 and 2000 have not led to an increase in long-term graft survival. Part of this discordance might be related to a higher proportion of acute rejections which have not resolved with full functional recovery in more recent years. However, the etiology of this concerning trend for worse death censored graft survival in recent years will warrant further investigation.

Acute kidney injury is associated with increased long-term mortality after cardiothoracic surgery

BACKGROUND

Long-term survival after acute kidney injury (AKI) is poorly studied. We report the relationship between long-term mortality and AKI with small changes in serum creatinine during hospitalization after various cardiothoracic surgery procedures.

METHODS AND RESULTS

This was a retrospective study of 2973 patients with no history of chronic kidney disease who were discharged from the hospital after cardiothoracic surgery between 1992 and 2002. AKI was defined by the RIFLE classification (Risk, Injury, Failure, Loss, and End stage), which requires at least a 50% increase in serum creatinine and stratifies patients into 3 grades of AKI: Risk, injury, and failure. Patient survival was determined through the National Social Security Death Index. Long-term survival was analyzed with a risk-adjusted Cox proportional hazards regression model. Survival was worse among patients with AKI and was proportional to its severity, with an adjusted hazard ratio of 1.23 (95% CI 1.06 to 1.42) for the least severe RIFLE risk class and 2.14 (95% CI 1.73 to 2.66) for the RIFLE failure class compared with patients without AKI. Survival was worse among all subgroups of cardiothoracic surgery with AKI except for valve surgery. Patients with complete renal recovery after AKI still had an increased adjusted hazard ratio for death of 1.28 (95% CI 1.11 to 1.48) compared with patients without AKI.

CONCLUSIONS

The risk of death associated with AKI after cardiothoracic surgery remains high for 10 years regardless of other risk factors, even for those patients with complete renal recovery. Improved renal protection and closer postdischarge follow-up of renal function may be warranted.

Long-term renal allograft survival: have we made significant progress or is it time to rethink our analytic and therapeutic strategies?

Impressive renal allograft survival improvement between 1988 and 1995 has been described using projections of half-lives based on limited actual follow up. We aimed, now with sufficient follow up available to calculate real half-lives. Real half-lives calculated from Kaplan-Meier curves for the overall population as well as subsets of repeat transplants and African Americans recipients were examined. Real half-lives were substantially shorter than projected half-lives. As a whole, half-lives have improved by about 2 years between 1988 and 1995 as compared to the earlier projected 6 years of improvement. The improvement seems to be driven primarily by the improvement in graft survival of re-transplants. First transplants showed a cumulative increase in graft survival of less than 6 months. Projected half-lives are a risky estimation of long-term survival especially when based on short actual follow up. First transplant survival has only marginally improved during the early years of post transplant follow up while no significant improvement in long-term survival could be detected between 1988 and 1995. Redirection of attention from early endpoints towards the process of long-term graft loss may be necessary to sustain early gains in the long term.

Kidney transplantation halts cardiovascular disease progression in patients with end-stage renal disease

Morbidity and mortality from cardiovascular disease have a devastating impact on patients with chronic kidney disease (CKD) and end-stage renal disease. Renal function decline in itself is thought to be a strong risk factor for cardiovascular disease (CVD). In this study, we investigated the hypothesis that the elevated CV mortality in kidney transplant patients is due to the preexisting CVD burden and that restoring renal function by a kidney transplant might over time lower the risk for CVD. We analyzed 60,141 first-kidney-transplant patients registered in the USRDS from 1995 to 2000 for the primary endpoint of cardiac death by transplant vintage and compared these rates to all 66813 adult kidney wait listed patients by wait listing vintage, covering the same time period. The CVD rates peaked during the first 3 months following transplantation and decreased subsequently by transplant vintage when censoring for transplant loss. This trend could be shown in living and deceased donor transplants and even in patients with end-stage renal disease secondary to diabetes. In contrast, the CVD rates on the transplant waiting list increased sharply and progressively by wait listing vintage. Despite the many mechanisms that may be in play, the enduring theme underlying rapid progression of atherosclerosis and cardiovascular disease in renal failure is the loss of renal function. The data presented in this paper thus suggest that the development or progression of these lesions could be ameliorated by restoring renal function with a transplant.

Vitamin D supplementation in chronic kidney disease: a systematic review and meta-analysis of observational studies and randomized controlled trials

BACKGROUND AND OBJECTIVES

Vitamin D deficiency is highly prevalent among patients with chronic kidney disease (CKD). The benefits and harms of vitamin D supplementation (ergocalciferol or cholecalciferol) were assessed in patients with nondialysis-dependent CKD, dialysis-dependent CKD, and renal transplant recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

MEDLINE (1966 to September 2009), SCOPUS (September 2009), and nephrology conference proceedings were searched for relevant observational and randomized controlled trials (RCTs). Treatment effects were summarized as mean differences (MDs) with 95% confidence intervals (CIs) using a random effects model. Separate analyses were conducted for observational studies and RCTs.

RESULTS

Twenty-two studies (17 observational and 5 RCTs) were included. There was a significant improvement in 25-hydroxyvitamin D (MD 24.1 ng/ml, 95% CI 19.6 to 28.6) and an associated decline in parathyroid hormone (PTH) levels (MD -41.7 pg/ml, 95% CI -55.8 to -27.7) among observational studies. PTH reduction was higher in dialysis patients. Among RCTs, there was a significant improvement in 25-hydroxyvitamin D (MD 14 ng/ml, 95% CI 5.6 to 22.4) and an associated decline in PTH levels (MD -31.5 pg/ml, 95% CI -57 to -6.1). A low incidence of hypercalcemia and hyperphosphatemia was reported with vitamin D supplementation. Cardiovascular and skeletal effects of vitamin D supplementation have not been studied. Included studies were mostly of low to moderate quality.

CONCLUSIONS

Available evidence from low-to-moderate quality observational studies and fewer RCTs suggests that vitamin D supplementation improves biochemical endpoints. However, whether such improvements translate into clinically significant outcomes is yet to be determined.

Barriers to evaluation and wait listing for kidney transplantation

BACKGROUND AND OBJECTIVES

Many factors have been shown to be associated with ESRD patient placement on the waiting list and receipt of kidney transplantation. Our study aim was to evaluate factors and assess the interplay of patient characteristics associated with progression to transplantation in a large cohort of referred patients from a single institution.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We examined 3029 consecutive adult patients referred for transplantation from 2003 to 2008. Uni- and multivariable logistic models were used to assess factors associated with progress to transplantation including receipt of evaluations, waiting list placement, and receipt of a transplant.

RESULTS

A total of 56%, 27%, and 17% of referred patients were evaluated, were placed on the waiting list, and received a transplant over the study period, respectively. Older age, lower median income, and noncommercial insurance were associated with decreased likelihood to ascend steps to receive a transplant. There was no difference in the proportion of evaluations between African Americans (57%) and Caucasians (56%). Age-adjusted differences in waiting list placement by race were attenuated with further adjustment for income and insurance. There was no difference in the likelihood of waiting list placement between African Americans and Caucasians with commercial insurance.

CONCLUSIONS

Race/ethnicity, age, insurance status, and income are predominant factors associated with patient progress to transplantation. Disparities by race/ethnicity may be largely explained by insurance status and income, potentially suggesting that variable insurance coverage exacerbates disparities in access to transplantation in the ESRD population, despite Medicare entitlement.

Consensus conference on best practices in live kidney donation: recommendations to optimize education, access, and care

Live donor kidney transplantation is the best treatment option for most patients with late-stage chronic kidney disease; however, the rate of living kidney donation has declined in the United States. A consensus conference was held June 5-6, 2014 to identify best practices and knowledge gaps pertaining to live donor kidney transplantation and living kidney donation. Transplant professionals, patients, and other key stakeholders discussed processes for educating transplant candidates and potential living donors about living kidney donation; efficiencies in the living donor evaluation process; disparities in living donation; and financial and systemic barriers to living donation. We summarize the consensus recommendations for best practices in these educational and clinical domains, future research priorities, and possible public policy initiatives to remove barriers to living kidney donation.

Which renal transplant candidates should accept marginal kidneys in exchange for a shorter waiting time on dialysis?

Renal transplantation has been established as a life-saving procedure for patients with ESRD. Deceased donor kidneys convey variable life expectancies for recipients. However, limited information is available to guide patients and patient advocates concerning the appropriateness to list for expanded criteria donations (ECD). Half-lives for wait-listed transplant candidates were estimated from the time of ESRD onset on the basis of recipient age, primary diagnosis, and organ quality using survival models. In addition, we evaluated the likelihood of candidates' receiving a transplant on the basis of age and other characteristics by duration of waiting time. Older patients (65+) had longer life expectancy when they accepted an ECD within 2 yr of ESRD onset (5.6 yr) compared with waiting for a standard kidney (5.3 yr) or a living donation (5.5 yr) after 4 yr of dialysis. Conversely, younger recipients (18 to 39 yr) had longer life expectancy with a living donation (27.6 yr) or standard kidney (26.4 yr) after 4 yr on dialysis compared with an ECD after 2 yr of dialysis (17.6 yr). Increased candidate age was associated with the likelihood of not receiving a transplant during the period on the waiting list as a result of mortality and separately related to morbidity and delisting. Older and frailer transplant candidates benefit from accepting lower quality organs early after ESRD, whereas younger and healthier patients benefit from receiving higher quality organs even with longer dialysis exposure. These findings are important for transplant candidates and advocates decision-making and for potential further implementation in allocation policy.

Are we frozen in time? Analysis of the utilization and efficacy of pulsatile perfusion in renal transplantation

Preservation techniques are crucial to deceased donor kidney transplantation (DDTx), but the efficacy of pulsatile perfusion (PP) versus cold storage (CS) remains uncertain. We describe patterns of PP use and explore four fundamental questions. What kidneys are selected for PP? How does PP affect utilization of donated kidneys? What effect does PP have on outcomes? When does PP appear to be most efficacious? We examined rates of PP in DDTx in the United States from 1994 to 2003. We generated models for organ utilization, delayed graft function (DGF) and for the use of PP. We analyzed the long-term effect of PP with multivariate Cox models. The utilization rates for non-expanded criteria donors (ECDs) were similar by storage type, but for ECDs there was a significantly higher utilization rate with PP (70% with PP vs. 59% with CS, p < 0.001). Use of PP was widely variable across transplant centers. DGF rates were significantly lower with PP (27.6% vs. 19.6%). PP was associated with a mild benefit on death censored graft survival (adjusted hazard ratio = 0.88, 95% CI 0.85-0.91). Reduced DGF and significantly lower discard rates of ECDs associated with PP suggest an important utility of PP in renal transplantation. Additional evidence of improvement in graft survival, particularly in more recent years, provides further encouraging evidence for the use of PP.

The broad spectrum of quality in deceased donor kidneys

The quality of the deceased donor organ clearly is one of the most crucial factors in determining graft survival and function in recipients of a kidney transplant. There has been considerable effort made towards evaluating these organs culminating in an amendment to allocation policy with the introduction of the expanded criteria donor (ECD) policy. Our study, from first solitary adult deceased donor transplant recipients from 1996 to 2002 in the National Scientific Transplant Registry database, presents a donor kidney risk grade based on significant donor characteristics, donor-recipient matches and cold ischemia time, generated directly from their risk for graft loss. We investigated the impact of our donor risk grade in a naive cohort on short- and long-term graft survival, as well as in subgroups of the population. The projected half-lives for overall graft survival in recipients by donor risk grade were I (10.7 years), II (10.0 years), III (7.9 years), IV (5.7 years) and V (4.5 years). This study indicates that there is great variability in the quality of deceased donor kidneys and that the assessment of risk might be enhanced by this scoring system as compared to the simple two-tiered system of the current ECD classification.

Long-term kidney transplant graft survival-Making progress when most needed

Current short-term kidney post-transplant survival rates are excellent, but longer-term outcomes have historically been unchanged. This study used data from the national Scientific Registry of Transplant Recipients (SRTR) and evaluated 1-year and 5-year graft survival and half-lives for kidney transplant recipients in the US. All adult (≥18 years) solitary kidney transplants (n = 331,216) from 1995 to 2017 were included in the analysis. Mean age was 49.4 years (SD +/-13.7), 60% male, and 25% Black. The overall (deceased and living donor) adjusted hazard of graft failure steadily decreased from 0.89 (95%CI: 0.88, 0.91) in era 2000-2004 to 0.46 (95%CI: 0.45, 0.47) for era 2014-2017 (1995-1999 as reference). Improvements in adjusted hazards of graft failure were more favorable for Blacks, diabetics and older recipients. Median survival for deceased donor transplants increased from 8.2 years in era 1995-1999 to an estimated 11.7 years in the most recent era. Living kidney donor transplant median survival increased from 12.1 years in 1995-1999 to an estimated 19.2 years for transplants in 2014-2017. In conclusion, these data show continuous improvement in long-term outcomes with more notable improvement among higher-risk subgroups, suggesting a narrowing in the gap for those disadvantaged after transplantation.

Evaluating Glomerular Filtration Rate Slope as a Surrogate End Point for ESKD in Clinical Trials: An Individual Participant Meta-Analysis of Observational Data

BACKGROUND

Decline in eGFR is a biologically plausible surrogate end point for the progression of CKD in clinical trials. However, it must first be tested to ensure strong associations with clinical outcomes in diverse populations, including patients with higher eGFR.

METHODS

To investigate the association between 1-, 2-, and 3-year changes in eGFR (slope) with clinical outcomes over the long term, we conducted a random effects meta-analysis of 3,758,551 participants with baseline eGFR≥60 ml/min per 1.73 m² and 122,664 participants with eGFR<60 ml/min per 1.73 m² from 14 cohorts followed for an average of 4.2 years.

RESULTS

Slower eGFR decline by 0.75 ml/min per 1.73 m² per year over 2 years was associated with lower risk of ESKD in participants with baseline eGFR≥60 ml/min per 1.73 m² (adjusted hazard ratio, 0.70; 95% CI, 0.68 to 0.72) and eGFR<60 ml/min per 1.73 m² (0.71; 95% CI, 0.68 to 0.74). The relationship was stronger with 3-year slope. For a rapidly progressing population with predicted 5-year risk of ESKD of 8.3%, an intervention that reduced eGFR decline by 0.75 ml/min per 1.73 m² per year over 2 years would reduce the ESKD risk by 1.6%. For a hypothetical low-risk population with a predicted 5-year ESKD risk of 0.58%, the same intervention would reduce the risk by only 0.13%.

CONCLUSIONS

Slower decline in eGFR was associated with lower risk of subsequent ESKD, even in participants with eGFR≥60 ml/min per 1.73 m², but those with the highest risk would be expected to benefit the most.

Treatment for BK virus: incidence, risk factors and outcomes for kidney transplant recipients in the United States

There has been a notable rise of BK virus among kidney transplant recipients. Single-center reports have identified risk factors for development of BK virus. However, there has not been an assessment of risk factors and incidence of this complication at a national level. This study utilized newly collected follow-up information from the national SRTR database to investigate incidence, risk factors and outcomes for solitary kidney transplant recipients associated with treatment for BK virus (TBKV) from 2004 to 2006. Logistic and Cox models were utilized to assess risk factors and evaluate graft survival associated with TBKV. Incidence of TBKV was 1.6% at 6 months and 2.6% at 1 year following transplantation. Patients with and without TBKV at 6 months had 79% and 90% 3-year overall graft survival respectively. Risk factors included advanced donor age, pediatric, African American and male recipients, human leukocyte antigen-mismatching and tacrolimus and thymoglobulin induction as baseline immunosuppression. Acute rejection episodes were more frequent prior to and following TBKV. TBKV is a common and rising incidence, varies based on transplant characteristics and should be included as a safety endpoint in studies investigating immunosuppressive protocols. Careful monitoring and further understanding of disease etiology and treatment strategies are needed.

Serum bicarbonate and mortality in stage 3 and stage 4 chronic kidney disease

BACKGROUND AND OBJECTIVES

The incidence and prevalence of metabolic acidosis increase with declining kidney function. We studied the associations of both low and high serum bicarbonate levels with all-cause mortality among stage 3 and 4 chronic kidney disease (CKD) patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We examined factors associated with low (<23 mmol/L) and high (>32 mmol/L) serum bicarbonate levels using logistic regression models and associations between bicarbonate and all-cause mortality using Cox-proportional hazard models, Kaplan-Meier survival curves, and time-dependent analysis.

RESULTS

Out of 41,749 patients, 13.9% (n = 5796) had low and 1.6% (n = 652) had high serum bicarbonate levels. After adjusting for relevant covariates, there was a significant association between low serum bicarbonate and all-cause mortality (hazard ratio [HR] 1.23, 95% CI 1.16, 1.31). This association was not statistically significant among patients with stage 4 CKD and diabetes. The time-dependent analysis demonstrated a significant mortality risk associated with a decline from normal to low bicarbonate level (HR 1.59, 95% CI 1.49, 1.69). High serum bicarbonate levels were associated with death irrespective of the level of kidney function (HR 1.74, 95% CI 1.52, 2.00). When serum bicarbonate was examined as a continuous variable, a J-shaped relationship was noted between serum bicarbonate and mortality.

CONCLUSIONS

Low serum bicarbonate levels are associated with increased mortality among stage 3 CKD patients and patients without diabetes. High serum bicarbonate levels are associated with mortality in both stage 3 and stage 4 CKD patients.

Impact of cold ischemia time on graft survival among ECD transplant recipients: a paired kidney analysis

Delays in expanded criteria donor (ECD) kidney placement increases cold ischemia times (CIT) potentially leading to discard. The effect of increased CIT on ECD kidney transplant outcomes is unknown. We evaluated paired ECD kidneys (derived from the same donor transplanted to different recipients) from the SRTR registry transplanted between 1995 and 2009 (n = 17,514). To test the effect of CIT, we excluded paired transplants with the same CIT (n = 3286). Of 14,230 recipients (7115 donors) the median difference in CIT was 5 h (Q1 = 3 h, Q3 = 9 h). Delayed graft function (DGF) was significantly more likely between pairs with greater CIT (35% vs. 31%, p < 0.001) including substantially higher rates for CIT differences ≥ 15 h (42%). Overall graft loss was not significantly different between recipients with higher CIT relative to paired donor recipients with lower CIT (p = 0.47) or for pairs with differences of 1-3 h (p = 0.90), 4-9 h (p = 0.41), 10-14 h (p = 0.36) or ≥ 15 h (p = 0.10). Results were consistent in multivariable models adjusted for recipient factors. Although increasing cold ischemia time is a risk factor for DGF among ECD kidney transplants, there is no effect on graft survival which may suggest an important utility for donor kidneys that may not currently be considered viable.

Influence of CIT-induced DGF on kidney transplant outcomes

Increased cold ischemia time (CIT) predisposes to delayed graft function (DGF). DGF is considered a risk factor for graft failure after kidney transplantation, but DGF has multiple etiologies. To analyze the risk of CIT-induced DGF on graft survival, we evaluated paired deceased-donor kidneys (derived from the same donor transplanted to different recipients) in which one donor resulted in DGF and the other did not, using national Scientific Registry of Transplant Recipients data between 2000 and 2009. Of 54 565 kidney donors, 15 833 were excluded for mate kidney non-transplantation, 27 340 because both or neither kidney developed DGF and 2310 for same/unknown CIT. The remaining 9082 donors (18 164 recipients) were analyzed. The adjusted odds (aOR) of DGF were significantly higher when CIT was longer by ≥ 1 h (aOR 1.81, 95% CI 1.7-2.0), ≥ 5 h (aOR 2.5, 95% CI 2.3-2.9), ≥ 10 h (aOR 3.3, 95% CI 2.7-2.9) and ≥ 15 h (aOR 4.4, 95% CI 3.4-5.8) compared to shorter CIT transplants. In the multivariable models adjusted for recipient characteristics, graft survival between paired donor transplants, with and without DGF, were similar. These results suggest that DGF, specifically induced by prolonged CIT, has limited bearing on long-term outcomes, which may have important implications for kidney utilization.

Serum Potassium, End-Stage Renal Disease and Mortality in Chronic Kidney Disease

BACKGROUND/AIMS

Hypokalemia and hyperkalemia are often noted in chronic kidney disease (CKD) patients, but their impact on mortality and end-stage renal disease (ESRD) is less well understood. We aimed at studying the associations between potassium disorders, and mortality and progression to ESRD in a CKD population.

METHODS

Using our electronic health record-based CKD registry, 36,359 patients with eGFR <60 ml/min/1.73 m(2) and potassium levels measured from January 1, 2005 to September 15, 2009 were identified. We examined factors associated with hypokalemia (<3.5 mmol/l) and hyperkalemia (>5.0 mmol/l) using logistic regression models and associations between serum potassium levels (both as continuous and categorical variables) and all-cause mortality or ESRD using Cox-proportional hazards models.

RESULTS

Serum potassium <3.5 mmol/l was noted among 3% and >5.0 mmol/l among 11% of the study population. In the multivariable logistic regression analysis, lower eGFR, diabetes and use of ACE inhibitors or Angiotensin-Receptor Blockers were associated with higher odds of having hyperkalemia. Heart failure and African American race were factors associated with higher odds of hypokalemia. After adjustment for covariates including kidney function, serum potassium <4.0 and >5.0 mmol/l were significantly associated with increased mortality risk, but there was no increased risk for progression to ESRD. Time-dependent repeated measures analysis confirmed these findings. When potassium was examined as a continuous variable, there was a U-shaped association between serum potassium levels and mortality.

CONCLUSION

In patients with stage 3-4 CKD, serum potassium levels <4.0 and >5.0 mmol/l are associated with higher mortality but not with ESRD.

Development and validation of an electronic health record-based chronic kidney disease registry

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) is increasing, and outcomes-related research from diverse health care settings is needed to target appropriate efforts and interventions. We developed an electronic health record (EHR)-based CKD registry at the Cleveland Clinic and validated comorbid conditions.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients who had at least one face-to-face outpatient encounter with a Cleveland Clinic health care provider and (1) had two estimated GFR values <60 ml/min per 1.73 m(2) >90 days apart as of January 1, 2005 and/or (2) were patients with International Classification of Diseases-9 (ICD-9) diagnosis codes for kidney disease were included.

RESULTS

Our registry includes 57,276 patients (53,399 patients met estimated GFR criteria and 3877 patients met ICD-9 diagnosis code criteria) as of March 2010. Mean age was 69.5 ± 13.4 years, with 55% women and 12% African Americans. Medicare is the primary insurer for more than one half of the study cohort. The κ statistics to assess the extent of agreement between the administrative dataset extracted from the EHR and actual EHR chart review showed substantial agreement (>0.80) for all conditions except for coronary artery disease and hypertension, which had moderate agreement (<0.60).

CONCLUSIONS

Development of an EHR-based CKD registry is feasible in a large health system, and the comorbid conditions included in the registry are reliable. In addition to conducting research studies, such a registry could help to improve the quality of care delivered to CKD patients and complement the ongoing nationwide efforts to develop a CKD surveillance project.

The association of center performance evaluations and kidney transplant volume in the United States

Report cards evaluating transplant center performance have received significant attention in recent years corresponding with the Centers for Medicare and Medicaid Services issue of the 2007 Conditions of Participation. Our primary aim was to evaluate the association of report card evaluations with transplant center volume. We utilized data from the Scientific Registry of Transplant Recipients (SRTR) along with six consecutive program-specific reports from January 2007 to July 2009 for adult kidney transplant centers. Among 203 centers, 46 (23%) were low performing (LP) with statistically significantly lower than expected 1-year graft or patient survival at least once during the study period. Among LP centers, there was a mean decline in transplant volume of 22.4 cases compared to a mean increase of 7.8 transplants among other centers (p = 0.001). Changes in volume between LP and other centers were significant for living, standard and expanded criteria deceased donor (ECD) transplants. LPs had a reduction in use of donors with extended cold ischemia time (p = 0.04) and private pay recipients (p = 0.03). Centers without low performance evaluations were more likely to increase the proportion of overall transplants that were ECDs relative to other centers (p = 0.04). Findings indicate a significant association between reduced kidney transplant volume and low performance report card evaluations.

Outcomes and utilization of kidneys from deceased donors with acute kidney injury

Utilization and long-term outcomes of kidneys from donors with elevated terminal serum creatinine (sCr) levels have not been reported. Using data from the Scientific Registry of Transplant Recipients from 1995 to 2007, recipient outcomes of kidneys from adult donors were evaluated stratified by standard criteria (SCD; n = 82 262) and expanded criteria (ECD; n = 16 978) donor type and by sCr </=1.5, 1.6-2.0 and >2.0 mg/dL. Discard rates for SCDs were ascertained. The relative risk of graft loss was similar for recipients of SCD kidneys with sCr of 1.6-2.0 and >2.0 mg/dL, compared to </=1.5 mg/dL. For ECD recipients, the relative risk of graft failure significantly increased with increasing sCr. Of potential SCDs, the adjusted risk of discard was higher with sCr >2.0 mg/dL (adjusted odds ratio [AOR] 7.04, 95% confidence interval [CI] 6.5-7.6) and 1.6-2.0 mg/dL (AOR 2.7; CI 2.5-2.9) relative to sCr </=1.5 mg/dL. Among potential SCDs, elevated terminal creatinine is a strong independent risk factor for kidney discard; yet, when kidney transplantation is performed elevated donor terminal creatinine is not a risk factor for graft loss. Further research is needed to identify safe practices for the optimal utilization of SCD kidneys from donors with acute kidney injury.

Sirolimus in combination with tacrolimus is associated with worse renal allograft survival compared to mycophenolate mofetil combined with tacrolimus

Cyclosporine (CsA) nephrotoxicity is enhanced by sirolimus (SRL). Tacrolimus is perceived to be less nephrotoxic than CsA, and therefore, CsA has been largely replaced by tacrolimus (TAC) when calcineurin inhibitors are used with SRL. We analyzed 44 915 adult renal transplants in the Scientific Renal Transplant Registry (SRTR) from 2000 to 2004. Three thousand five hundred twenty-four (7.8%) patients received a baseline immunosuppressive regimen of TAC/SRL, with an inferior overall (log-rank p<0.001) and death-censored graft survival (p<0.001) as compared to TAC/MMF (N=27 007). This effect was confirmed in multivariate Cox models; the adjusted hazard ratio (AHR) for overall graft loss with TAC/SRL was 1.47 (95% CI=1.32, 1.63) and for CsA/SRL 1.38 (95% CI=1.20, 1.59) relative to TAC/MMF. These effects were most apparent in high-risk transplants. Six-month acute rejection rates were low (11.5-12.6%) and not different between groups. In summary, national data indicate that TAC/SRL as compared to TAC/MMF is associated with significantly worse renal allograft survival in all subgroups of patients and, in particular, higher-risk transplants. These results have to be interpreted in the context of the inherent limitations of any retrospective database analysis and evaluated in context with data from prospective clinical trials.

Long-term graft survival with neoral and tacrolimus: a paired kidney analysis

Calcineurin inhibitors (CNI) are an important component of most immunosuppressive protocols utilized in renal transplantation. Both CNI available (cyclosporine and tacrolimus) have been used for many years. Studies comparing the efficacy of these two agents in terms of long-term graft or patient survival have thus far failed to show an advantage for either agent. This failure to show a difference could possibly be due to underpowering of clinical trials. The authors used the SRTR database to analyze 5-yr graft survival of the microemulsion formulation of cyclosporine (Neoral) as compared with tacrolimus. To minimize the donor variability and bias, a paired kidney analysis was used. Deceased donors from the years 1995-2002 were analyzed from the SRTR database. All paired kidneys during this period, where one kidney was allocated to a patient receiving initial Neoral therapy and its mate allocated to a patient receiving initial tacrolimus therapy were evaluated. Multivariate and univariate analysis were performed. Univariate analysis demonstrated equivalent graft survival for Neoral compared with tacrolimus (66.9% versus 65.9%, respectively). Multivariate analysis could not demonstrate a difference in risk for 5-yr patient survival or graft loss. Renal function was superior for tacrolimus at all time points, whereas the slope of 1/Cr over time did not differ for the two agents. In this paired kidney analysis, no difference in 5-yr renal allograft survival could be found between the two agents. Renal function was superior in the patients receiving initial tacrolimus therapy; however, slope of 1/Cr did not differ between the agents.

Determinants of breastfeeding initiation and cessation among employed mothers: a prospective cohort study

Background

The U.S. continues to have one of the lowest breastfeeding rates in the industrialized world. Studies have shown that full-time employment and early return to work decreased breastfeeding duration, but little is known about the relationship between leave policies and breastfeeding initiation and cessation. This study aimed to identify workplace-related barriers and facilitators associated with breastfeeding initiation and cessation in the first 6 months postpartum.

Methods

A prospective cohort study design was utilized to recruit 817 Minnesota women aged 18 and older while hospitalized for childbirth. Selection criteria included English-speaking, employed mothers with a healthy, singleton birth. These women were followed up using telephone interviews at 6 weeks, 12 weeks, and 6 months after childbirth. The main study outcomes were breastfeeding initiation, measured during hospital enrollment, and breastfeeding cessation by 6 months postpartum.

Results

Women were 30 years old; 86 % were White, and 73 % were married. Breastfeeding rates were 81 % at childbirth, 67 % at 6 weeks, 49 % at 12 weeks, and 33 % at 6 months postpartum. Logistic regression revealed the odds of breastfeeding initiation were higher for women who: held professional jobs, were primiparae, had graduate degree, did not smoke prenatally, had no breastfeeding problems, and had family or friends who breastfeed. Survival analyses showed the hazard for breastfeeding cessation by 6 months was: higher for women who returned to work at any time during the 6 months postpartum versus those who did not return, lower for professional workers, higher among single than married women, higher for every educational category compared to graduate school, and higher for those with no family or friends who breastfeed.

Conclusions

While employer paid leave policy did not affect breastfeeding initiation or cessation, women who took shorter leaves were more likely to stop breastfeeding in the first 6 months postpartum. Future research should examine women’s awareness of employer policies regarding paid and unpaid leave.

Mycophenolate mofetil/sirolimus compared to other common immunosuppressive regimens in kidney transplantation

We evaluated outcomes with the sirolimus (SRL) and mycophenolate mofetil (MMF) combination regimen (SRL/MMF) in solitary kidney transplant recipients transplanted between 2000 and 2005 reported to the Scientific Registry of Renal Transplant Recipients. Three-and-a-half percent received SRL/MMF (n = 2040). Six-month acute rejection rates were higher with SRL/MMF (SRL/MMF: 16.0% vs. other regimens: 11.2%, p < 0.001). Overall graft survival was significantly lower on SRL/MMF. SRL/MMF was associated with twice the hazard for graft loss (AHR = 2.0, 95% C.I., 1.8, 2.2) relative to TAC/MMF, also consistent in both living donor transplants (AHR = 2.4, 95% C.I., 1.9, 2.9) and expanded criteria donor transplants (AHR = 2.1, 95% C.I., 1.7-2.5). Among deceased donor transplants, DGF rates were higher in the SRL/MMF cohort (47% vs. 27%, p < 0.001). However, adjusted graft survival was also significantly inferior with SRL/MMF in DGF-free patients (AHR = 1.9, 95% C.I., 1.6-2.3). In analyses restricted to patients who remained on the discharge regimen at 6 months posttransplant, conditional graft survival in deceased donor transplants was significantly lower with SRL/MMF compared to patients on TAC/MMF or CsA/MMF regimens at 5 years posttransplant (64%, 78%, 78%, respectively, p = 0.001) and across all patient subgroups. In conclusion, SRL/MMF is associated with inferior renal transplant outcomes compared with other commonly used regimens.

Comorbidity burden and perioperative complications for living kidney donors in the United States

BACKGROUND AND OBJECTIVES

Since 1998, 35% of kidney transplants in the United States have been derived from living donors. Research suggests minimal long-term health consequences after donation, but comprehensive studies are limited. The primary objective was to evaluate trends in comorbidity burden and complications among living donors.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The National Inpatient Sample (NIS) was used to identify donors from 1998 to 2010 (n=69,117). Comorbid conditions, complications, and length of stay during hospitalization were evaluated. Outcomes among cohorts undergoing appendectomies, cholecystectomies and nephrectomy for nonmetastatic carcinoma were compared, and sample characteristics were validated with the Scientific Registry of Transplant Recipients (SRTR). Survey regression models were used to identify risk factors for outcomes.

RESULTS

The NIS captured 89% (69,117 of 77,702) of living donors in the United States. Donor characteristics were relatively concordant with those noted in SRTR (mean age, 40.1 versus 40.3 years [P=0.18]; female donors, 59.0% versus 59.1% [P=0.13]; white donors, 68.4% versus 69.8% [P<0.001] for NIS versus SRTR). Incidence of perioperative complications was 7.9% and decreased from 1998 to 2010 (from 10.1% to 7.6%). Men (adjusted odds ratio [AOR], 1.37; 95% confidence interval [CI], 1.20 to 1.56) and donors with hypertension (AOR, 3.35; 95% CI, 2.24 to 5.01) were more likely to have perioperative complications. Median length of stay declined over time (from 3.7 days to 2.5 days), with longer length of stay associated with obesity, depression, hypertension, and pulmonary disorders. Presence of depression (AOR, 1.08; 95% CI, 1.04 to 1.12), hypothyroidism (AOR, 1.07; 95% CI, 1.04 to 1.11), hypertension (AOR, 1.38; 95% CI, 1.27 to 1.49), and obesity (AOR, 1.07; 95% CI, 1.03 to 1.11) increased over time. Complication rates and length of stay were similar for patients undergoing appendectomies and cholecystectomies but were less than those with nephrectomies for carcinoma.

CONCLUSIONS

The NIS is a representative sample of living donors. Complications and length of stay after donation have declined over time, while presence of documented comorbid conditions has increased. Patients undergoing appendectomy and cholecystectomy have similar outcomes during hospitalization. Monitoring the health of living donors remains critically important.