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Bruce Kaplan

Publications and source records attributed to Bruce Kaplan.

At least 37 records · Page 2Linked to original sources
PubMed2005

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.

Cadaver↗
PubMed2005

Kidneys from deceased donors: maximizing the value of a scarce resource.

Donor age is a significant risk factor for graft loss after kidney transplantation. We investigated the question whether significant graft years were being lost through transplantation of younger donor kidneys into older recipients with potentially shorter lifespans than the organs they receive. We examined patient and graft survival for deceased donor kidney transplants performed in the United States between the years 1990 and 2002 by Kaplan-Meier plots. We categorized the distribution of deceased donor kidneys by donor and recipient age. Subsequently, we calculated the actual and projected graft survival of transplanted kidneys from younger donors with the patient survival of transplant recipients of varying ages. Over the study period, 16.4% (9250) transplants from donors aged 15-50 were transplanted to recipients over the age of 60. At the same time, 73.6% of donors above the age of 50 were allocated to recipients under the age of 60. The graft survival of grafts from younger donors significantly exceeded the patient survival of recipients over the age of 60. The overall projected improvement in graft survival, by excluding transplantation of younger kidneys to older recipients, was approximately 3 years per transplant. Avoiding the allocation of young donor kidneys to elderly recipients, could have significantly increased the overall graft life, by a total 27,500 graft years, between 1990 and 2002, with projected cost savings of about 1.5 billion dollars.

Adolescent↗
PubMed2005

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.

Adolescent↗
PubMed2004

Evaluation of drug interaction software to identify alerts for transplant medications.

BACKGROUND: The ability of computerized physician order entry (CPOE) systems to identify clinically significant drug interactions is dependent upon the integrity of the drug information populating the software. A CPOE system with incomplete or inaccurate drug information will fail to identify clinically important drug interactions and, therefore, fail to reduce preventable adverse drug events (pADEs). OBJECTIVE: To evaluate, from the prescribers' perspective, the ability of a common drug interaction database to identify clinically important drug interactions involving drugs used in transplantation. METHODS: The clinical significance of drug interactions involving 5 transplant drugs was evaluated by an expert panel to determine whether alerts should be generated for physicians not involved in the transplant at the time of order entry. Drug interactions included in the analysis were generated from the expert panel, a common drug interaction database, and 2 standard drug interaction references. Responses on the clinical significance were used to calculate the sensitivity, specificity, and positive and negative predictive values for each severity setting of a common electronic drug interaction database. RESULTS: Overall, the database failed to identify approximately 70% of interactions considered significant by the expert panel. Of the alerts that were generated, >85% were considered clinically significant. The database was most deficient in identifying interactions resulting from additive toxicity. CONCLUSIONS: To expect a decrease in pADEs caused by drug interactions, the information used to populate CPOE systems must be validated. Establishing consistency and integrity of this information may be a future role for pharmacists.

Databases as Topic↗
PubMed2004

Mycophenolate mofetil vs azathioprine in a large population of elderly renal transplant patients.

BACKGROUND: Mycophenolate mofetil (MMF) has been shown to decrease acute rejection episodes after kidney transplantation, and has been associated with better graft and patient survival vs azathioprine (AZA). Previous studies reported a higher risk of death due to infection in elderly recipients treated with MMF-based immunosuppression. METHODS: We analysed 5069 elderly ( > 65 years of age) primary renal allograft recipients treated with either MMF or AZA reported to the Scientific Registry of Transplant Recipients between 1988 and 2000, and compared rates of acute rejection, late acute rejection, graft survival, death-censored graft survival, patient survival and death with a functioning graft. RESULTS: In Cox proportional hazard models, MMF was associated with lower rates of late acute rejection with 12 (RR = 0.72, P = 0.11) and 24 months (RR = 0.50, P = 0.028) of continuous therapy. In univariate analysis (Kaplan-Meier), MMF was associated with improved patient (P = 0.0003) and graft (P<0.0001) survival vs AZA, and trends toward improved patient and graft survival in multivariate analyses. CONCLUSIONS: These findings demonstrate the efficacy of MMF-based immunosuppression in elderly transplant recipients and do not suggest an increased risk of death compared to treatment with AZA.

Aged↗
PubMed2004

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.

Graft Rejection↗
PubMed2004

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.

Aged↗
PubMed2004

Effect of sirolimus withdrawal in patients with deteriorating renal function.

Sirolimus has been an important addition to immunosuppressive regimens utilized in kidney transplantation. However, sirolimus can potentiate calcineurin inhibitor (CNI) nephrotoxicity by some still uncertain mechanisms. Studies have demonstrated that withdrawal of a CNI under sirolimus immunosuppression can improve renal function. However, it has yet to be demonstrated that withdrawal of sirolimus from such a regimen can also improve renal function and reverse progressive functional deterioration. We studied 17 patients who developed deterioration of renal function while on a CNI and sirolimus. Once an established deterioration in renal function was noted, sirolimus was withdrawn from the regimen and replaced with mycophenolate mofetil. Out of 17 patients with a negative slope in 1/cr, 15 demonstrated a positive treatment effect (change to a positive slope). On aggregate, renal function improved by 18% (creatinine 2.75-2.24 mg/dL), LDL cholesterol improved, as did hematocrit values after withdrawal. The majority of patients on a CNI and sirolimus regimen who experience deterioration in renal function demonstrate improvement in renal function after withdrawal of sirolimus. This strategy may be particularly useful in those patients where CNI withdrawal is considered to be of high immunologic or metabolic risk.

Adult↗
PubMed2004

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.

Adolescent↗
PubMed2004

Sirolimus with neoral versus mycophenolate mofetil with neoral is associated with decreased renal allograft survival.

To evaluate the association between a regimen of cyclosporine microemulsion (CsA) + sirolimus (Rapa) treatment versus CsA and mycophenolate mofetil (MMF) and renal allograft survival, we analyzed 23 016 primary recipients reported to the Scientific Registry of Transplant Recipients between January 1, 1998 and July 26, 2003. Univariate Kaplan-Meier analysis and multivariate Cox proportional hazard models correcting for demographic and clinical covariates were used to estimate the relative risks for CsA+Rapa versus CsA+MMF-treated patients reaching study endpoints. Subgroup analyses were conducted for recipient ethnicity and donor type. CsA+Rapa was associated with significantly lower graft survival (74.6% vs. 79.3% at 4 years, p = 0.002) and death-censored graft survival (83.7% vs. 87.2%, p = 0.003) compared to CsA+MMF. In multivariate analyses, CsA+Rapa was associated with a significantly increased risk for graft loss, death-censored graft loss and decline in renal function (HR = 1.22, p = 0.002; HR = 1.22, p = 0.018 and HR = 1.25, p < 0.001, respectively). Similar results were obtained in recipient ethnicity and donor type subgroups. In summary, CsA+Rapa was associated with significantly worse graft survival and death-censored graft survival compared to CsA+MMF, and likely reflects full-dose CsA +Rapa. Outcomes regarding alternative strategies of Rapa utilization with reduced CsA, with alternative agents or with no calcineurin inhibitor cannot be extrapolated from these data.

Adult↗
PubMed2003

A GH3-like domain in reaper is required for mitochondrial localization and induction of IAP degradation.

Reaper is a potent pro-apoptotic protein originally identified in a screen for Drosophila mutants defective in apoptotic induction. Multiple functions have been ascribed to this protein, including inhibition of IAPs (inhibitors of apoptosis); induction of IAP degradation; inhibition of protein translation; and when expressed in vertebrate cells, induction of mitochondrial cytochrome c release. Structure/function analysis of Reaper has identified an extreme N-terminal motif that appears to be sufficient for inhibition of IAP function. We report here that this domain, although required for IAP destabilization, is not sufficient. Moreover, we have identified a small region of Reaper, similar to the GH3 domain of Grim, that is required for localization of Reaper to mitochondria, induction of IAP degradation, and potent cell killing. Although a mutant Reaper protein lacking the GH3 domain was deficient in these properties, these defects could be fully rectified by appending either the C-terminal mitochondrial targeting sequence from Bcl-xL or a homologous region from the pro-apoptotic protein HID. Together, these data strongly suggest that IAP destabilization by Reaper in intact cells requires Reaper localization to mitochondria and that induction of IAP instability by Reaper is important for the potent induction of apoptosis in Drosophila cells.

Animals↗
PubMed2003

Decreased renal function is a strong risk factor for cardiovascular death after renal transplantation.

BACKGROUND: Chronic kidney disease is thought to be a potential risk factor for cardiovascular death. In renal-allograft recipients, cardiovascular disease is the most significant cause of death. The purpose of this study was to investigate if renal function has a significant role in determining the risk for cardiovascular death in renal-allograft recipients. METHODS: We analyzed 58,900 adult patients registered in the United States Renal Data System who received a primary renal transplant between 1988 and 1998 and who had at least 1 year of graft survival. The primary study endpoint was death from a cardiovascular event beyond 1 year of transplantation. Secondary endpoints were death caused by infections and malignancy-related deaths. Cox proportional-hazard models were used to estimate the effect of renal function on cardiovascular death, infectious death, and malignancy-related death while correcting for potential confounding variables, such as donor and recipient age, gender, race, cause of end-stage renal disease, length of dialysis before transplantation, year of transplantation, donor source and age, delayed graft function, and immunosuppressive regimen. RESULTS: Serum creatinine values at 1 year after transplantation were strongly associated with the risk for cardiovascular death. Above a serum creatinine value of 1.5 mg/dL, there was a significant and progressive increase in the risk for cardiovascular death. The risk of cardiovascular death was significantly higher when patients who lost allograft function were included in the analysis. There was an association between worsening renal function and infectious death, but there was no association between renal function and malignancy-related death. CONCLUSION: Serum creatinine at 1 year is strongly associated with the incidence of cardiovascular death independent of known risk factors.

Cardiovascular Diseases↗
PubMed2003

Mycophenolate mofetil versus azathioprine therapy is associated with a significant protection against long-term renal allograft function deterioration.

BACKGROUND: To evaluate the association of long-term continuous mycophenolate mofetil (MMF) versus azathioprine (AZA) therapy and renal allograft function, as measured by the slope of reciprocal creatinine, we analyzed 49,666 primary renal allograft recipients reported to the United States Renal Data System between October 31, 1988 and June 30, 1998. METHODS: The primary study endpoint was defined as a greater than 20% decrease below a 6-month baseline of 1/serum creatinine (SCr) (slope of reciprocal creatinine) at or beyond 1 year after transplantation. A secondary endpoint was defined as reaching an SCr value greater than 1.6 mg/dL. Univariate Kaplan-Meier analysis and multivariate Cox proportional hazard models were used to investigate the risk of reaching the study endpoints. Multivariate analyses were corrected for potential confounding covariates. RESULTS: According to the Cox proportional hazard model, 12-month continued therapy of MMF versus AZA was associated with a protective effect against declining renal function, as measured by the slope of reciprocal creatinine (relative risk [RR]=0.84, confidence interval 0.78-0.91, P<0.001). For 24-month continued therapy of MMF versus AZA, MMF was associated with a further decreased risk for a decline in renal function (RR=0.66, confidence interval=0.57-0.77, P<0.001). Furthermore, MMF was associated with a protective effect against reaching the SCr threshold of 1.6 mg/dL (RR=0.80, P<0.001) beyond 12 months posttransplantation. CONCLUSIONS: Continuous use of MMF versus AZA was associated with a protective effect against declining renal function beyond 1 year after transplantation. Further study is needed to confirm that continued MMF therapy is protective against long-term deterioration in renal function.

Adult↗
PubMed2003

Pharmacokinetics of an everolimus-cyclosporine immunosuppressive regimen over the first 6 months after kidney transplantation.

The pharmacokinetics of everolimus were characterized over the first 6 months post transplant in 731 patients receiving either 0.75 or 1.5 mg bid everolimus in addition to cyclosporine and corticosteroids. Pharmacokinetic data consisted of 4014 everolimus trough concentrations (Cmin) obtained in all patients and 659 area under the concentration-time curve (AUC) -profiles obtained at months 2, 3, and 6 in a subset of 261 patients. Cmins averaged 4.3 +/- 2.4 and 7.2 +/- 4.2 ng/mL at 0.75 and 1.5 mg bid, indicating a 20% under-proportionality at the upper dose level. Cmins were 19-34% lower in the first month compared with months 2 through 6-values. AUC was dose-proportional and stable over time, averaging 77 +/- 32 and 136 +/- 57 ng.h.mL-1 at the two dose levels. Within- and between-patient variability in AUC were 27% and 31%, respectively. There was no influence of sex, age (16-66 years), or weight (42-132 kg) on AUC. Everolimus exposure was significantly lower by an average 20% in blacks. Everolimus exposure was relatively stable over the first 6 months post transplant, with no major departure from dose-proportionality over the therapeutic dose range. Weight-adjusted dosing (mg/kg) does not appear warranted. Black patients may have lower bioavailability and/or higher clearance of everolimus compared with white patients.

Adult↗