Experience with everolimus

Everolimus is a novel macrolide immunosuppressant that acts as a T-lymphocyte proliferation signal inhibitor. Its actions are complementary to and synergistic with those of the calcineurin inhibitors. Compared with sirolimus, everolimus has unique pharmacokinetic characteristics including greater bioavailability and a shorter half-life, allowing more rapid achievement of a steady state. Clinical experience to date, largely limited to use in kidney transplant patients receiving cyclosporine-based immunosuppression, indicates that administration of everolimus is associated with low rates of acute rejection and a tolerable safety profile. Recent observations in heart transplant patients suggest that the antiproliferative effects of everolimus may prevent allograft vasculopathy.

Withdrawal of steroid therapy in African American kidney transplant recipients receiving sirolimus and tacrolimus

BACKGROUND

Withdrawal of corticosteroids from the immunosuppressive regimens of kidney transplant recipients has been associated with an increased risk of acute and chronic allograft rejection. Previous studies indicate that the risk of rejection is particularly high in African Americans.

METHODS

We prospectively enrolled 44 African American kidney transplant recipients to participate in an uncontrolled trial in which they were initially treated with sirolimus, tacrolimus, and corticosteroids. No patient received antibody induction therapy. Prednisone was withdrawn from eligible patients free of acute rejection beginning as early as 3 months posttransplant, and followed for a minimum of 9 months posttransplant. Patients were followed for acute rejection and for changes in blood pressure, body weight, and serum creatinine concentrations before and after withdrawal of steroids.

RESULTS

Thirty of 44 patients (68%) were weaned off of prednisone. Follow-up after withdrawal of prednisone ranged from 3 to 26 months (mean, 14.3+/-7.7 months). Two of 30 patients (6.7%) developed acute rejection. At last follow-up, 27 of 30 patients (90%) remain steroid-free. Steroid withdrawal was associated with significant reductions in blood pressure.

CONCLUSIONS

Use of sirolimus and tacrolimus, without the use of induction antibody therapy, allows withdrawal of prednisone as early as 3 months posttransplant with low rates of subsequent acute rejection in African American kidney transplant recipients. Withdrawal of prednisone was associated with lower blood pressures and the need for fewer antihypertensive medications.

Determinants of quality of life changes among long-term cardiac transplant survivors: results from longitudinal data

BACKGROUND

Cross-sectional analyses have identified significant associations between quality of life (QOL), and comorbidities and adverse effects in cardiac transplant recipients. However, little is known about factors that influence changes in QOL over time. This study examines both cross-sectional and longitudinal data from long-term survivors to identify factors that affect differences in QOL among recipients and individual changes in QOL during a 1-year period.

METHODS

Self-selected enrollees completed questionnaires, including QOL scales, at 3-month intervals. Repeated measures multiple regression analysis was used to examine the association between the QOL scales and comorbidities, adverse effects, and compliance measures, controlling for other factors.

RESULTS

We included 569 participants in the analysis, with a mean time since transplantation of 8.6 years. Cross-sectional results showed that the number of comorbidities, treatment non-compliance, and several adverse effects were associated with low QOL. In longitudinal results, waiting to take medications and taking less medication because of lifestyle restrictions were associated with decreases in QOL over time. Hair loss, changes in face shape, and decreased sexual interest or ability also had the largest adverse effects on changes in QOL.

CONCLUSIONS

These findings provide new opportunities for interventions to address factors related to decreases in QOL. Clinicians should actively solicit information about compliance with medication regimens. In addition, information about the adverse effects of medications should be considered when making therapeutic decisions.

Enzyme linked immunosorbent spot (ELISPOT) assay for interferon-gamma independently predicts renal function in kidney transplant recipients

Post-transplant monitoring of cellular immunity might be useful in predicting long-term outcomes of kidney transplant recipients. We used an enzyme linked immunoabsorbent spot (ELISPOT) assay to serially measure the frequency of peripheral blood lymphocytes producing interferon-gamma in response to stimulator cells from donors or third parties in 55 primary kidney transplant recipients. Mean frequencies measured during the first 6 months after transplantation correlated significantly with the serum creatinine concentration at both 6 and 12 months following transplantation. The mean frequencies were higher in patients with acute rejection than in those without acute rejection. Multiple regression analyses indicated that the correlations between the early ELISPOT measurements of interferon-gamma and serum creatinine were independent of acute rejection, delayed graft function, or the presence of panel reactive antibodies before transplantation. Patients with low mean frequencies of interferon-producing cells in the early post-transplant period were generally free from acute rejection and exhibited excellent renal function at 6 and 12 months post-transplant. In conclusion, using the ELISPOT assay, we show an independent correlation between early cellular alloreactivity and long-term renal function. Increased levels of early alloreactivity measured with this assay may serve as a surrogate for chronic allograft dysfunction.

Use of sirolimus to facilitate cyclosporine avoidance or steroid withdrawal in kidney transplant recipients

Sirolimus is a non-nephrotoxic cell-cycle progression antagonist that has proven to be highly effective in preventing renal allograft rejection when used in combination with cyclosporine and corticosteroids. On the basis of its immunosuppressive potency alone, sirolimus has emerged as an agent with the potential for facilitating the elimination of calcineurin inhibitors or corticosteroids from the maintenance regimens administered to kidney transplant recipients. The results of three randomized trials suggest that use of sirolimus as a substitute for cyclosporine in patients receiving steroids and either azathioprine or mycophenolate mofetil results in comparable rates of acute rejection and better renal function than in patients maintained on cyclosporine. Preliminary results from uncontrolled trials indicate that use of sirolimus in combination with either cyclosporine or tacrolimus allows withdrawal of steroid therapy with low rates of subsequent acute rejection compared to historical controls. Larger, controlled studies with longer durations of follow-up are warranted to verify the favorable results of these early experiences with the use of sirolimus as a calcineurin inhibitor or steroid-sparing agent.

Improved renal function in sirolimus-treated renal transplant patients after early cyclosporine elimination

BACKGROUND

Sirolimus (Rapamune; SRL) in combination with cyclosporine (CsA) reduces the incidence of acute rejection episodes in renal allograft recipients. This study evaluated whether renal function could be improved by elimination of CsA from an SRL-based regimen.

METHODS

This phase 2, open-label, controlled, randomized study was conducted at 17 centers in the United States and Europe. Two hundred forty-six first cadaveric renal allograft recipients were enrolled, and 197 were randomized to full-dose CsA (microemulsion) plus fixed-dose SRL (2 mg/day; group A, n=97) or reduced-dose CsA plus concentration-controlled SRL (troughs 10-20 ng/mL; group B, n=100). Most patients with acute tubular necrosis-delayed graft function that resolved later than posttransplantation day 7 were not randomized but were assigned to a third group (nonrandomized, n=49) and received up to 5 mg per day of SRL as part of their individualized treatment regimen. All patients received standard doses of corticosteroids. At the end of posttransplantation month 2, eligible patients (those not treated for rejection within 3 weeks) in group B had CsA tapered and eliminated over the subsequent 4 to 6 weeks.

RESULTS

At 12 months after transplantation, renal function was significantly better in the CsA-elimination arm. In patients who were on therapy and who had not experienced an acute rejection episode before month 6, serum creatinine level was significantly lower (1.38 mg/dL vs. 1.82 mg/dL, P < 0.001) and calculated glomerular filtration rate (Nankivell method) was significantly higher (73.5 mL/min vs. 57.1 mL/min, P < 0.001) in group B than in group A. In the intention-to-treat population, rates of biopsy-confirmed acute rejection at 12 months were similar between groups A and B (18.6% vs. 22.0%, respectively; P = 0.598). In addition, graft survival (92.8% and 95.0%) and patient survival (96.9% and 96.0%) rates at 12 months were not significantly different between groups A and B, respectively. Furthermore, there were no significant differences between black and nonblack recipients within treatment groups in terms of rejection rates and graft survival at 12 months. Black recipients in group B had better serum creatinine levels at 12 months compared with black recipients in group A (1.55 mg/dL vs. 2.69 mg/dL, respectively, P = 0.011), as did nonblack recipients in group B compared with nonblack recipients in group A (1.53 mg/dL vs. 1.75 mg/dL, respectively, P = 0.055). Black patients in group A had higher mean serum creatinine levels (2.69 mg/dL) than nonblack patients in group A (1.75 mg/dL, P = 0.028). Hypertension, edema, hypomagnesemia, and dyspnea were reported significantly less frequently in patients randomly assigned to undergo CsA elimination compared with patients in group A (P < 0.05); group B patients had a significantly greater (P < 0.05) incidence of abnormal liver function tests, diarrhea, hypokalemia, and thrombocytopenia.

CONCLUSION

Concentration-controlled SRL with early elimination of CsA is safe and results in improved renal function. Reduced exposure to CsA does not result in a clinically significant increase in the incidence of acute rejection episodes. This is true for both black and nonblack recipients. SRL may be used to reduce the exposure of renal allograft recipients to the nephrotoxic effects of CsA.

Improved renal function in sirolimus-treated renal transplant patients after early cyclosporine elimination

BACKGROUND

Sirolimus (Rapamune; SRL) in combination with cyclosporine (CsA) reduces the incidence of acute rejection episodes in renal allograft recipients. This study evaluated whether renal function could be improved by elimination of CsA from an SRL-based regimen.

METHODS

This phase 2, open-label, controlled, randomized study was conducted at 17 centers in the United States and Europe. Two hundred forty-six first cadaveric renal allograft recipients were enrolled, and 197 were randomized to full-dose CsA (microemulsion) plus fixed-dose SRL (2 mg/day; group A, n=97) or reduced-dose CsA plus concentration-controlled SRL (troughs 10-20 ng/mL; group B, n=100). Most patients with acute tubular necrosis-delayed graft function that resolved later than posttransplantation day 7 were not randomized but were assigned to a third group (nonrandomized, n=49) and received up to 5 mg per day of SRL as part of their individualized treatment regimen. All patients received standard doses of corticosteroids. At the end of posttransplantation month 2, eligible patients (those not treated for rejection within 3 weeks) in group B had CsA tapered and eliminated over the subsequent 4 to 6 weeks.

RESULTS

At 12 months after transplantation, renal function was significantly better in the CsA-elimination arm. In patients who were on therapy and who had not experienced an acute rejection episode before month 6, serum creatinine level was significantly lower (1.38 mg/dL vs. 1.82 mg/dL, P < 0.001) and calculated glomerular filtration rate (Nankivell method) was significantly higher (73.5 mL/min vs. 57.1 mL/min, P < 0.001) in group B than in group A. In the intention-to-treat population, rates of biopsy-confirmed acute rejection at 12 months were similar between groups A and B (18.6% vs. 22.0%, respectively; P = 0.598). In addition, graft survival (92.8% and 95.0%) and patient survival (96.9% and 96.0%) rates at 12 months were not significantly different between groups A and B, respectively. Furthermore, there were no significant differences between black and nonblack recipients within treatment groups in terms of rejection rates and graft survival at 12 months. Black recipients in group B had better serum creatinine levels at 12 months compared with black recipients in group A (1.55 mg/dL vs. 2.69 mg/dL, respectively, P = 0.011), as did nonblack recipients in group B compared with nonblack recipients in group A (1.53 mg/dL vs. 1.75 mg/dL, respectively, P = 0.055). Black patients in group A had higher mean serum creatinine levels (2.69 mg/dL) than nonblack patients in group A (1.75 mg/dL, P = 0.028). Hypertension, edema, hypomagnesemia, and dyspnea were reported significantly less frequently in patients randomly assigned to undergo CsA elimination compared with patients in group A (P < 0.05); group B patients had a significantly greater (P < 0.05) incidence of abnormal liver function tests, diarrhea, hypokalemia, and thrombocytopenia.

CONCLUSION

Concentration-controlled SRL with early elimination of CsA is safe and results in improved renal function. Reduced exposure to CsA does not result in a clinically significant increase in the incidence of acute rejection episodes. This is true for both black and nonblack recipients. SRL may be used to reduce the exposure of renal allograft recipients to the nephrotoxic effects of CsA.

Evolution of the enzyme-linked immunosorbent spot assay for post-transplant alloreactivity as a potentially useful immune monitoring tool

Post-transplant monitoring of cellular immunity has the potential to guide alterations in medical therapy. To this end, our laboratory has developed an enzyme-linked immunosorbent spot (ELISPOT) assay for detection of peripheral blood alloimmunity. Peripheral blood lymphocytes (PBLs) from normal volunteers and from renal allograft recipients were tested against donor stimulator cells for their ability to respond in 'one-way' cytokine ELISPOT assays. T cell depletion of donor spleen or PBLs eliminated donor cell cytokine secretion while preserving the ability of these cells to present allo-antigen to responding T cells. Alloreactive IFN-gamma-producing PBLs derive from the memory T cell pool and are readily detectable in recipients of renal allografts taking immunosuppressant medications. A significant expansion of IFN-gamma-producing donor-reactive memory PBLs was detectable at 4-6 months post-transplant in those who had experienced an acute rejection episode compared with those with a stable post-transplant course. The data demonstrate the feasibility of repeated post-transplant monitoring of allograft recipients, and provide the foundation for improving the care of human transplant recipients through rational clinical decision-making based on measures of immune function.

Outcomes of African American kidney transplant recipients treated with sirolimus, tacrolimus, and corticosteroids

BACKGROUND

African American kidney transplant recipients generally exhibit poor long-term graft survival compared with other ethnic groups. The combination of sirolimus, tacrolimus, and corticosteroids has proven to be effective in reducing rejection episodes in high-risk organ and islet cell transplant recipients but has not yet been tested in a large number of African American patients.

METHODS

The outcomes of 56 African American adult, primary kidney transplant recipients treated with corticosteroids, sirolimus, and tacrolimus targeted to relatively low trough blood levels were compared with those of a concurrent group of 65 white patients treated with steroids, mycophenolate mofetil, and tacrolimus targeted to relatively high blood levels. Induction antibody therapy was not routinely used in either group.

RESULTS

The incidence of acute rejection in the first 3 posttransplantation months was 7.1% in African Americans and 16.9% in whites (P=NS). Actuarial 2-year patient, graft, and rejection-free graft survival rates were equivalent in the two groups. Posttransplantation diabetes mellitus occurred in 36% of the African American patients, despite similar doses of corticosteroids and lower trough levels of tacrolimus, compared with 15% of white patients (P=0.024).

CONCLUSIONS

The combination of corticosteroids, sirolimus, and relatively low doses of tacrolimus results in acute rejection, graft survival, and patient survival rates equivalent to those achieved in white patients receiving steroids, mycophenolate mofetil, and relatively high doses of tacrolimus, even without the routine use of induction antibody therapy. Posttransplantation diabetes mellitus remains a problem for African Americans receiving this combination of immunosuppressants, despite relatively low tacrolimus blood levels.

Inhibition of endothelin-1 improves survival and vasculopathy in rat cardiac transplants treated with cyclosporine

BACKGROUND

In animal models, endothelin-1 (ET-1) blockade attenuates transplant vasculopathy and chronic allograft dysfunction even in the absence of cyclosporine (CsA). As CsA has side effects and ET-1 antagonism alone has significant benefits, we postulated that allograft survival could be significantly improved by combining an endothelin-converting enzyme inhibitor with low-dose CsA.

METHODS

Survival of Lewis to Fisher 344 rat heterotopic cardiac allografts was determined in untreated animals and compared with those treated with high-dose CsA (62 mg/kg i.m. on day 2), low-dose CsA (25 mg/kg), an endothelin-converting enzyme inhibitor, phosphoramidon (PA, 10 mg/kg/day), or low-dose CsA + PA.

RESULTS

Untreated allografts had a median survival of 16 days compared with 20 days for low-dose CsA. Grafts treated with PA survived for 28 days, and combination of PA and low-dose CsA improved median survival to 47 days (P<0.01). Median survival with combination therapy was similar to that for high-dose CsA (42 days). To explore mechanisms underlying the benefits of combination therapy, cardiac allografts treated as above (n=4 each group) were explanted at 20 d and analyzed for parenchymal rejection, neointimal vasculopathy, myocardial fibrosis, and macrophage infiltration. Low-dose CsA alone but not PA improved parenchymal rejection; in contrast, PA alone but not low-dose CsA improved vasculopathy. Both parenchymal rejection and vasculopathy were improved by combination therapy with low-dose CsA and PA. Unlike CsA, inhibition of ET-1 biosynthesis significantly reduced myocardial fibrosis in allografts.

CONCLUSIONS

These results suggest that the combination of low-dose CsA and endothelin-converting enzyme inhibition may prove useful to improve long-term graft survival while minimizing potential side effects of CsA.

Life satisfaction and adverse effects in renal transplant recipients: a longitudinal analysis

INTRODUCTION

Previous cross-sectional analyses have identified significant associations between quality of life (QOL), comorbidities and adverse effects in renal transplant recipients. This report examines the longitudinal relationship between adverse effects and QOL, with particular attention to the relative impact of adverse effects associated with immunosuppression.

METHODS

The Transplant Learning Center (TLC) is a program designed to improve QOL and preserve graft function in transplant recipients. Self-selected enrollees filled out questionnaires at roughly 3-month intervals. Each questionnaire included QOL scales developed for the program. Repeated measures multiple regression analysis was used to examine the relationship between the QOL scales, comorbidities, adverse effects, adjusting for other factors.

RESULTS

A total of 4247 TLC enrollees were included in the analysis, with a mean time since transplant of 5.1 yr. Comorbidities and adverse effects were common, with high blood pressure reported by 87% of respondents and unusual hair growth reported by 69.6%. In bivariate analysis, emotional/psychological problems and headaches had the largest impact on QOL. In multivariate analysis, emotional/psychological problems decreased sexual interest or ability, and headache had the largest adverse QOL effect.

CONCLUSIONS

We have identified QOL issues that have been previously underemphasized in transplant recipients. These findings open new areas of research to further explore and define these issues. They provide new opportunities for interventions to address factors adversely impacting QOL and to develop strategies to improve QOL in these patients. Clinicians should actively solicit information about adverse effects of medications, particularly information about sexual and relationship issues, when evaluating renal recipients. These issues should be taken into account when making therapeutic decisions.

Safety and efficacy of TOR inhibitors and other immunosuppressive regimens in African-American renal transplant recipients

African-American renal transplant recipients have higher rates of acute allograft rejection and lower rates of allograft survival compared with Caucasian patients, and these differences have not been eliminated by a new generation of potent immunosuppressive drugs. In particular, African-Americans tend to exhibit higher rejection rates after withdrawal of corticosteroid therapy. Based on promising early results using the combination of sirolimus and low-dose tacrolimus in liver, kidney-pancreas, and islet-cell transplant recipients, our center is conducting a pilot study of this immunosuppression regimen in African-American patients. As of April 2001, there has been only 1 acute rejection episode (2.8%) in this cohort. Long-term follow-up of these patients will be necessary to assess the benefits and risks of this regimen.

Life satisfaction in renal transplant recipients: preliminary results from the transplant learning center

The Transplant Learning Center (TLC) was designed to improve quality of life (QOL) and preserve graft function in solid-organ transplant recipients. To meet the specific goals of the program, the Life Satisfaction Index and Transplant Care Index were designed to serve as composite measures for measuring transplant-specific QOL and the ability to care for a transplant, respectively. In this study, we analyzed self-reported health information to examine relationships between comorbidities and individual posttransplantation side effects, life satisfaction, and transplant care, defined by renal transplant recipients. Patients entered the TLC through self-referral or referral by a health professional. Included in the analysis were 3,676 TLC enrollees with a mean time since transplantation of 4.8 years. Comorbidities and adverse effects were common, with high blood pressure reported by 89% of respondents and unusual hair growth reported by 70%. Sexual dysfunction and headache had a greater impact on QOL than more common adverse effects, such as changes in body and facial shape, hirsutism, and tremor. Regression modeling was used to identify the most significant associations between QOL indices and structural (nonmedical), medical, and psychosocial factors. Greater life satisfaction was most strongly associated with being in control of one's health and living a normally active life with satisfying emotional relationships. Management of such clinical problems as adverse effects of medication and nonadherence should be informed by the patient's perspective. Clinicians should actively solicit information about physical activity, appearance concerns, side effects of medications, nonadherence, and sexual and relationship issues when evaluating renal transplant recipients.