Inferior outcome of two-haplotype matched renal transplants in blacks: role of early rejection

MyKidneyCoach, Patient Activation, and Clinical Outcomes in Diverse Kidney Transplant Recipients: A Randomized Control Pilot Trial

Kidney transplant (KT) recipients who are not actively engaged in their care and lack self-management skills have poor transplant outcomes, which are disproportionately observed among Black KT recipients. This pilot study aimed to determine whether the MyKidneyCoach app, an mHealth intervention that provides self-management monitoring and coaching, improved patient activation, engagement, and nutritional behaviors in a diverse KT population.

Methods

This was a randomized, age-stratified, parallel-group, attention-control, pilot study in post-KT patients. Participants were randomized into the attention-control with access to MyKidneyCoach for education and self-management (n = 9) or the intervention with additional tailored nurse coaching (n = 7). Feasibility, acceptability, and clinical outcomes were assessed.

Results

The acceptability of MyKidneyCoach by System Usability Scale was 67.5 (95% confidence interval [CI], 59.1-75.9). Completion rates based on actively using MyKidneyCoach were 81% (95% CI, 57%-93%) and study retention rate of 73%. Patient activation measure significantly increased overall by a mean of 11 points (95% CI, 3.2-18.8). Additionally, Black patients (n = 7) had higher nutrition self-efficacy scores of 80.5 (95% CI, 74.4-86.7) compared with 75.6 (95% CI, 71.1-80.1) in non-Black patients (n = 9) but lower patient activation measure scores of 69.3 (95% CI, 56.3-82.3) compared with 71.8 (95% CI, 62.5-81) in non-Black patients after 3 mo.

Conclusions

MyKidneyCoach was easy to use and readily accepted with low attrition, and improvements were demonstrated in patient-reported outcomes. Both Black and non-Black participants using MyKidneyCoach showed improvement in self-management competencies; thus, this intervention may help reduce healthcare inequities in KT.

A Contemporary Analysis of Outcomes and Modifiable Risk Factors of Ethnic Disparities in Kidney Transplantation

OBJECTIVE

The aim of this study was to provide a contemporary analysis of longitudinal kidney transplant outcomes and to evaluate potential causes of ethnic disparities among African American (AA) and Caucasian American (CA) patients undergoing kidney transplantation at our institution.

PATIENTS AND METHODS

1400 patients were identified who underwent kidney transplantation from 2003 to 2013 from a large, academic institution in Cleveland, OH. Relevant recipient and donor demographic and clinical covariates were obtained from an institutional transplant database. Simple descriptive statistics and comparative survival analyses were performed to assess overall survival and graft survival.

RESULTS

The final cohort was comprised of 341 AA and 1059 CA patients. AAs were less likely to receive a living donor transplant (27.6% vs. 57.2%, p < 0.001) compared to CAs. Overall patient survival did not significantly differ between the two groups even when stratified by ethnicity. However, AAs had a significantly lower rate of graft survival (p < 0.001). On stratified analysis, there was no difference in the rate of graft survival among AAs and CAs who received living donor grafts. On univariate analysis, AAs demonstrated higher rates of immunosuppression non-compliance and chronic rejection (both p < 0.05). On multivariate analysis, AA recipient ethnicity (HR 1.56, p = 0.047), recipient history of diabetes (HR 1.67, p < 0.001), and AA donor ethnicity (HR 1.56, p = 0.047) were significantly associated with graft failure.

CONCLUSION

AAs undergoing deceased donor renal transplantation demonstrated lower graft survival compared to CAs. Conversely, this disparity did not exist among AAs undergoing living donor transplantation. AAs had higher rates of deceased donor transplantation, immunosuppression non-compliance, chronic rejection, and diabetes. Opportunities exist to use patient education, alternative immunosuppression regimens, and living transplantation to close the ethnic disparity in renal allograft survival.

The Privilege of Induction Avoidance and Calcineurin Inhibitors Withdrawal in 2 Haplotype HLA Matched White Kidney Transplantation

Background

White recipients of 2-haplotype HLA-matched living kidney transplants are perceived to be of low immunologic risk. Little is known about the safety of induction avoidance and calcineurin inhibitor withdrawal in these patients.

Methods

We reviewed our experience at a single center and compared it to Organ Procurement and Transplantation Network (OPTN) registry data and only included 2-haplotype HLA-matched white living kidney transplants recipients between 2000 and 2013.

Results

There were 56 recipients in a single center (where no induction was given) and 2976 recipients in the OPTN. Among the OPTN recipients, 1285 received no induction, 903 basiliximab, 608 thymoglobulin, and 180 alemtuzumab. First-year acute rejection rates were similar after induction-free transplantation among the center and induced groups nationally. Compared with induction-free transplantation in the national data, there was no decrease in graft failure risk over 13 years with use of basiliximab (adjusted hazard ratio [aHR], 0.86; confidence interval [CI], 0.68-1.08), Thymoglobulin (aHR, 0.92; CI, 0.7-1.21) or alemtuzumab (aHR, 1.18; CI, 0.72-1.93). Among induction-free recipients at the center, calcineurin inhibitor withdrawal at 1 year (n = 27) did not significantly impact graft failure risk (HR,1.62; CI, 0.38-6.89).

Conclusions

This study may serve as a foundation for further studies to provide personalized, tailored, immunosuppression for this very low-risk population of kidney transplant patients.

Racial and Ethnic Disparities in Graft and Recipient Survival in Elderly Kidney Transplant Recipients

OBJECTIVES

To investigate racial and ethnic differences in graft and recipient survival in elderly kidney transplant recipients.

DESIGN

Retrospective cohort.

SETTING

First-time, kidney-only transplant recipients aged 60 and older of age at transplantation transplanted between July 1996 and October 2010 (N = 44,013).

PARTICIPANTS

United Network for Organ Sharing (UNOS) database.

MEASUREMENTS

Time to graft failure and death obtained from the UNOS database and linkage to the Social Security Death Index. Neighborhood poverty from 2000 U.S. Census geographic data.

RESULTS

Of the 44,013 recipients in the sample, 20% were black, 63% non-Hispanic white, 11% Hispanic, 5% Asian, and the rest "other racial groups." In adjusted Cox models, blacks were more likely than whites to experience graft failure (hazard ratio (HR) = 1.23, 95% confidence interval (CI) = 1.15-1.32), whereas Hispanics (HR = 0.77, 95% CI = 0.70-0.85) and Asians (HR = 0.70, 95% CI = 0.61-0.81) were less likely to experience graft failure. Blacks (HR = 0.84, 95% CI = 0.80-0.88), Hispanics (HR = 0.68, 95% CI = 0.64-0.72), and Asians (HR = 0.62, 95% CI = 0.57-0.68) were less likely than whites to die after renal transplantation.

CONCLUSION

Elderly blacks are at greater risk of graft failure than white transplant recipients but survive longer after transplantation. Asians have the highest recipient and graft survival, followed by Hispanics. Further studies are needed to assess additional factors affecting graft and recipient survival in elderly adults and to investigate outcomes such as quality of life.

The Impact of Medicare's lifetime immunosuppression coverage on racial disparities in kidney graft survival

Beginning January 1, 2000, Medicare effectively extended its coverage of immunosuppression medications from 3 years to lifetime for patients eligible for Medicare on the basis of age or disability status. We examined the impact of this policy on racial disparities in kidney transplant outcomes at 5 years. Using data from the US Renal Data System, we identified cohorts of Medicare-insured kidney transplant recipients according to patient characteristics defining eligibility for lifetime immunosuppression coverage according to the year 2000 policy. We compared racial disparities in graft survival among those eligible for lifetime coverage with the Kaplan-Meier method. We modeled adjusted associations of patient race, patient income, benefits eligibility category and policy exposure with graft loss by multivariable Cox's regression. The racial disparity in graft survival between African American and non-African American among transplant recipients eligible for the lifetime benefit persisted. The graft survival disparity between high- and low-income African American recipients was insignificantly reduced among those eligible for the lifetime benefit. The results of the study suggest that insurance coverage of medication did not eliminate or reduce the racial disparity in graft survival.

Donor ethnicity influences outcomes following deceased-donor kidney transplantation in black recipients

Although the majority of deceased-donor kidneys are donated after brain death, increased recovery of kidneys donated after cardiac death could reduce the organ shortage and is now a national priority. Racial disparities in donations after brain death have been well described for renal transplantation, but it is unknown whether similar disparities occur in donations after cardiac death. In this study, outcomes of adult deceased-donor renal transplant recipients included in the United Network for Organ Sharing database (1993 through 2006) were analyzed. Among black recipients of kidneys obtained after cardiac death, those who received kidneys from black donors had better long-term graft and patient survival than those who received kidneys from white donors. In addition, compared with standard-criteria kidneys from white donors after brain death, kidneys from black donors after cardiac death conferred a 70% reduction in the risk for graft loss (adjusted hazard ratio 0.30; 95% confidence interval 0.14 to 0.65; P = 0.002) and a 59% reduction in risk for death (adjusted hazard ratio 0.41; 95% confidence interval 0.2 to 0.87; P = 0.02) among black recipients. These findings suggest that kidneys obtained from black donors after cardiac death may afford the best long-term survival for black recipients.

Racial Disparities in Renal Allograft Survival: A Public Health Issue?

BACKGROUND

Racial disparities in renal transplantation outcomes have been documented with inferior allograft survival among African Americans compared with non-African Americans. These differences have been attributed to a variety of factors, including immunologic hyperresponsiveness, socioeconomic status, compliance, HLA matching, and access to care. The purpose of this study was to examine both immunologic and nonimmunologic risk factors for allograft loss with a goal of defining targeted strategies to improve outcomes among African Americans.

STUDY DESIGN

We retrospectively analyzed all primary deceased-donor adult renal transplants (n = 2,453) at our center between May 1987 and December 2004. Analysis included the impact of recipient and donor characteristics, HLA typing, and immunosuppressive regimen on graft outcomes. Data were analyzed using standard Kaplan-Meier actuarial techniques and were explored with nonparametric and parametric methods. Multivariable analyses in the hazard-function domain were done to identify specific risk factors associated with graft loss.

RESULTS

The 1-year allograft survival in recipients improved substantially throughout the study period, and 3-year allograft survival also improved. Risk factor analyses are shown by type of allograft and according to specific time periods. Risk of immunologic graft loss (acute rejection) was most prominent during the early phase. During late-phase, immunologic risk persists (chronic rejection), but recurrent disease, graft quality, and recipient's comorbidities have an increasingly greater role.

CONCLUSIONS

Advances in immunosuppression regimens have contributed to allograft survival in both early and late (constant) phases throughout all eras, but improvement in longterm outcomes for African Americans continues to lag behind non-African Americans. The disparity in renal allograft loss between African Americans and non-African Americans over time indicates that beyond immunologic risk, the impact of nonimmunologic variables, such as time on dialysis pretransplantation, diabetes, and access to medical care, can be key issues.

Assessment of differences in HLA-A, -B, and -DRB1 allele mismatches among African-American and non-African-American recipients of deceased kidney transplants

Among recipients of deceased donor kidney transplants, African-Americans experience a more rapid rate of kidney allograft loss than non-African-Americans. The purpose of this study was to characterize and quantify the HLA-A, -B, and -DRB1 allele mismatches and amino acid substitutions at antigen recognition sites among African-American and non-African-American recipients of deceased donor kidney transplants matched at the antigen level. In recipients with zero HLA antigen mismatches, the degree of one or two HLA allele mismatches for both racial groups combined was 47%, 29%, and 11% at HLA-DRB1, HLA-B, and HLA-A, respectively. There was a greater number of allele mismatches in African-Americans than non-African-Americans at HLA-A (P < .0001), -B (P = .096), and -DRB1 loci (P < .0001). For both racial groups, the HLA allele mismatches were predominantly at A2 for HLA-A; B35 and B44 for HLA-B; but multiple specificities for HLA-DRB1. The observed amino acid mismatches were concentrated at a few functional positions in the antigen binding site of HLA-A and -B and -DRB1 molecules. Future studies are ongoing to assess the impact of these HLA mismatches on kidney allograft loss.

Tacrolimus versus cyclosporin as primary immunosuppression for kidney transplant recipients

BACKGROUND

Kidney transplantation is the treatment of choice for most patients with end-stage renal disease (ESRD). Standard protocols in use typically involve three drug groups each directed to a site in the T-cell activation or proliferation cascade which are central to the rejection process: calcineurin inhibitors (e.g. cyclosporin, tacrolimus), anti-proliferative agents (e.g. azathioprine, mycophenolate mofetil) and steroids (prednisolone). It remains unclear whether new regimens are more specific or simply more potent immunosuppressants.

OBJECTIVES

To compare the effects of tacrolimus with cyclosporin as primary therapy for kidney transplant recipients.

SEARCH STRATEGY

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Cochrane Renal Group's specialist register and conference proceedings were searched to identify relevant reports of randomised controlled trials (RCTs). Two reviewers assessed trials for eligibility, quality and extracted data independently.

SELECTION CRITERIA

All RCTs where tacrolimus was compared with cyclosporin for the initial treatment of kidney transplant recipients

DATA COLLECTION AND ANALYSIS

Data were synthesised (random effects model) and results expressed as relative risk (RR), values <1 favouring tacrolimus, with 95% confidence intervals (CI). Subgroup analysis and meta-regression were used to examine potential effect modification by differences in trial design and immunosuppressive co-interventions.

MAIN RESULTS

123 reports from 30 trials (4102 patients) were included. At six months graft loss was significantly reduced in tacrolimus-treated recipients (RR 0.56, 95% CI 0.36 to 0.86), and this effect was persistent up to three years. Meta-regression showed that this benefit diminished as higher trough levels of tacrolimus were targeted (P = 0.04), after allowing for differences in cyclosporin formulation (P = 0.97) and cyclosporin target trough level (P = 0.38). At one year, tacrolimus patients suffered less acute rejection (RR 0.69, 95% CI 0.60 to 0.79), and less steroid-resistant rejection (RR 0.49, 95% CI 0.37 to 0.64), but more insulin-requiring diabetes mellitus (RR 1.86, 1.11 to 3.09), tremor, headache, diarrhoea, dyspepsia and vomiting. Cyclosporin-treated recipients experienced significantly more constipation and cosmetic side-effects. We demonstrated no differences in infection or malignancy.

AUTHORS' CONCLUSIONS

Tacrolimus is superior to cyclosporin in improving graft survival and preventing acute rejection after kidney transplantation, but increases post-transplant diabetes, neurological and gastrointestinal side effects. Treating 100 recipients with tacrolimus instead of cyclosporin would avoid 12 suffering acute rejection, two losing their graft but cause an extra five to become insulin-requiring diabetics.

Tacrolimus versus ciclosporin as primary immunosuppression for kidney transplant recipients: meta-analysis and meta-regression of randomised trial data

OBJECTIVE

To compare the positive and negative effects of tacrolimus and ciclosporin as initial treatment for renal transplant recipients.

DESIGN

Systematic review.

DATA SOURCES AND STUDY SELECTION

Reports of comparative randomised trials of tacrolimus and ciclosporin identified by searches of Medline, Embase, the Cochrane Register of Controlled Trials, the Cochrane Renal Group Specialist Register, and conference proceedings.

DATA EXTRACTION AND SYNTHESIS

Two reviewers assessed trials for eligibility and quality and extracted data independently. Data were synthesised (random effects model) and results expressed as relative risk (RR), with values < 1 favouring tacrolimus. Subgroup analysis and meta-regression were used to examine potential effect modification by differences in trial design and immunosuppressive co-interventions.

RESULTS

123 reports from 30 trials (4102 patients) were included. At six months, graft loss was significantly reduced in tacrolimus treated recipients (RR = 0.56, 95% confidence interval 0.36 to 0.86), and this effect persisted up to three years. The relative reduction in graft loss with tacrolimus diminished with higher concentrations of tacrolimus (P = 0.04) but did not vary with ciclosporin formulation (P = 0.97) or ciclosporin concentration (P = 0.38). At one year, tacrolimus treated patients had less acute rejection (RR = 0.69, 0.60 to 0.79) and less steroid resistant rejection (RR = 0.49, 0.37 to 0.64) but more diabetes mellitus requiring insulin (RR = 1.86, 1.11 to 3.09), tremor, headache, diarrhoea, dyspepsia, and vomiting. The relative excess of diabetes increased with higher concentrations of tacrolimus (P = 0.003). Ciclosporin treated recipients had significantly more constipation and cosmetic side effects. No differences were seen in infection or malignancy.

CONCLUSIONS

Treating 100 recipients with tacrolimus instead of ciclosporin for the first year after transplantation avoids 12 patients having acute rejection and two losing their graft but causes an extra five patients to develop insulin dependent diabetes. Optimal drug choice may vary between patients.

Characterization of waiting times in a simulation of kidney paired donation

A national kidney paired donation (KPD) program will substantially increase transplant opportunities for recipients with blood type incompatible or cross-match positive donors. It seems likely that donor-recipient pairs with certain blood types, races or restrictions will wait longer than others for a match, although no data exist to confirm this assumption. We simulated patients and characterized the predicted waiting times for different blood type sub-groups, as well as the effects of patient-imposed restrictions on waiting time. We also compared waiting times of different racial sub-groups. Almost all patients with panel-reactive antibody (PRA) less than 80% match within a few months in a national KPD program, with the longest waiting time seen by O recipients with AB donors. Highly sensitized patients wait considerably longer, especially those unwilling to travel or accept older donors, and those with AB or B donors may not match in a timely manner. Although patients are better served by matching in a combined pool than within their own race, racial inequalities exist and bonus points can offset some of these differences. These data provide the first waiting time predictions that can aid patients with incompatible donors in choosing between KPD and desensitization, and can also facilitate planning for a national KPD program.

Effects of race on survival after stem cell transplantation

Effects of race or ethnicity on survival after high-dose chemoradiation followed by stem cell transplantation (SCT) have not been thoroughly evaluated. We analyzed survival according to racial/ethnic categories for 3587 consecutive patients who had SCT at a single US institution between July 1992 and December 2000. Among 1366 patients who received autologous SCT, race or ethnicity was not significantly associated with survival. In contrast, among 2221 patients who received allogeneic SCT from HLA-matched unrelated or sibling donors, blacks had a significantly greater mortality than whites (unadjusted hazard ratio, 1.65; 95% confidence interval, 1.21-2.25). Mortality among other racial or ethnic groups was not significantly different from that among whites. The greater mortality hazard among blacks persisted after controlling for donor type, pretransplantation risk category, patient age, donor/patient sex, and cytomegalovirus exposure (hazard ratio, 1.71; 95% confidence interval, 1.25-2.34). SCT from both HLA-matched unrelated and HLA-identical sibling donors was associated with more severe acute graft-versus-host disease and higher nonrelapse mortality among blacks compared with whites. Furthermore, blacks who received SCT for chronic myeloid leukemia had longer diagnosis-to-transplantation intervals than whites. A matched-cohort analysis showed that the higher mortality among blacks could not be explained by obvious socioeconomic differences. The higher incidence of severe graft-versus-host disease among blacks compared with whites, both with HLA-identical sibling donors, might be related to yet-unidentified "immune-enhancing" genetic polymorphisms. We cannot exclude the possibility that the increased mortality risk among blacks after discharge from the transplant center might in part be related to unidentified sociocultural differences that influence medical care.

Health disparities in transplantation: focus on the complexity and challenge of renal transplantation in African Americans

The field of renal transplantation has grown exponentially as a result of a greater understanding of the immune system and the advent of numerous immunosuppressive agents. Although African Americans and whites have benefited from these advances, equivalent long-term success eludes African Americans who are disadvantaged in gaining access to renal transplantation. This review summarizes the obstacles for African Americans to end-stage renal disease(ESRD) care, focusing on transplantation. Factors that predispose African Americans for ESRD, impede this ethnic group from timely transplantation, and negatively influence graft survival are examined. Possible solutions to these persistent problems are offered.

Consequences of eliminating HLA-B in deceased donor kidney allocation to increase minority transplantation

HLA matching contributes to the disparity in Caucasian compared to minority kidney transplantation. HLA-B locus matching was eliminated from kidney allocation to shift a projected 166 organs from Caucasians to minorities annually. This study estimated the economic and quality-of-life impact of this policy. Cost-effectiveness analysis was performed using a Markov model. Data from the United States Renal Data System (USRDS) were used to estimate race-specific outcomes, patient and graft survival, quality-adjusted life years (QALYs) and medical costs in U.S. dollars. The greatest benefit is expected in African Americans, with expected savings of US 7.5 million dollars and 243 QALYs. Smaller cost and QALY benefits are seen in other minority groups. In Caucasians, a loss of 7.0 million dollars and a decrease of 967 QALYs are expected with the shift of organs. Overall, this policy is expected to save US 5400 dollars for each QALY that is lost. The same increase in minority transplantation would be expected from increasing Caucasian donation rates by 5.5%, or African-American donation by 29.0%, each producing large cost savings and QALY gains. Policies to increase minority transplants by increasing donation rates may prove more cost effective than the elimination of HLA-B matching from deceased donor kidney allocation.

The differential effect of race among pediatric kidney transplant recipients with focal segmental glomerulosclerosis

BACKGROUND

Given the differential effect of race on focal segmental glomerulosclerosis (FSGS) progression in native kidneys, recurrence of FSGS in the transplanted kidney, and allograft source, the authors conducted this study to evaluate the influence of FSGS by race and allograft source.

METHODS

Data from 8,065 pediatric renal transplant recipients (n = 620 FSGS) between 1987 and 1997 from the United Network for Organ Sharing registry were used for this study. Stratified analysis by race and allograft source allowed independent assessment of the effect of FSGS on transplant survival.

RESULTS

Among black children, allograft survival was not different between FSGS and non-FSGS patients adjusted for recipient age, recurrent disease, allograft source, zero antigen mismatch, and acute rejection (hazard ratio [HR], 1.15; 95% confidence interval [95% CI], 0.93 to 1.42; P = 0.22). Among nonblack children, the risk of allograft failure in children with FSGS was 1.31 times higher than other causes of end-stage renal disease (ESRD) in multivariate analysis (95% CI, 1.04 to 1.64; P = 0.02). Despite the impact of disease recurrence in the nonblack children with FSGS, the risk of graft failure was less for living donor recipients (HR, 1.51; 95% CI, 1.08 to 2.10) than for cadaveric recipients (HR, 1.80; 95% CI, 1.32 to 2.44) compared with the lowest risk group (nonblack, non-FSGS, living donor).

CONCLUSION

The effect of FSGS on renal allograft survival in children differs between racial groups. Children of nonblack races with FSGS have a worse allograft survival rate compared with other causes of ESRD. Within nonblack children with FSGS, living donor transplants convey a better allograft survival than cadaveric transplants.

A DECADE OF PROGRESS IN KIDNEY TRANSPLANTATION

Kidney transplantation has become the treatment of choice for patients with end-stage renal disease because of better surgical techniques and the availability of more powerful immunosuppressive drugs. Regimens of immunosuppression should combine both short-term outcomes and predictors of long-term safety and survival. The value of tacrolimus for immunosuppression protocols lies in its ability to reduce the immunologic risk to the allograft and its excellent safety profile. Outcomes for kidney-transplant recipients can be further optimized by individualizing therapy to address each patient's risk profile.

The use of daclizumab, tacrolimus and mycophenolate mofetil in african-american and Hispanic first renal transplant recipients

Limited data are available on the use of tacrolimus and mycophenolate mofetil in conjunction with anti-IL-2 receptor antibody, in groups of kidney transplant recipients considered to be at higher risk. This study compared the incidence of acute rejection between African-American (AA), Hispanic (H), and non-African-American, non-Hispanics (non-AA, non-H) first renal transplant recipients. We studied 233 sequential first renal transplants. Of the 233, 37 recipients (16%) were AA, 85 (36.5%) were H and 111 (47.5%) were non-AA, non-H. All received daclizumab induction therapy (1 mg/kg) on the day of surgery, and every other week for a total of 5 doses, as well as mycophenolate mofetil, tacrolimus, and steroids. At 1 year, patient and graft survival were 97% and 95% in AA, 98% and 98% in H, and 96% and 95% in non-AA, non-H, respectively (not statistically different). Biopsy-proven acute rejection episodes were 8.1% in AA, 4.7% in H, and 4.5% in non-AA, non-H (also not statistically different). This immunosuppressive protocol appears to be safe and effective in helping to minimize biopsy-proven acute rejection and optimize renal allograft survival in African-American and Hispanic renal transplant recipients in the first year post transplantation.

Effect of cyclosporin pharmacokinetics on renal allograft outcome in African-Americans

African-Americans (A-As) experience inferior outcome after transplantation compared with other ethnic groups. Bioavailability of cyclosporin (CsA) has been implicated as a possible contributing factor. This paper describes the outcome of 32 A-A recipients of de novo renal allograft who received CsA-based triple immunotherapy according to individual pharmacokinetic profiles. Patients received CsA-microemulsion q 12 h, dosed initially at 3.5 mg/kg (8 am) and 3.0 mg/kg (8 pm). The am and pm doses were independently adjusted to achieve a 12-h area under the concentration-time curve (AUC0-12) of 6600-7200 nghr/mL and morning trough level (C0) of 250-325 ng/mL, respectively. Mean age was 43 +/- 12 yr, 37% (12) female. Mean AUC0-12 in 1 wk, 1, 3, 6, and 12 months were 7810 +/- 1880 nghr/mL, 9057 +/- 2097 nghr/mL, 7674 +/- 1912 nghr/mL, 7132 +/- 2040 nghr/mL, and 6503 +/- 1410 ngl/h with corresponding C0 of 301 +/- 79 ng/mL, 316 +/- 66 ng/mL, 275 +/- 59 ng/mL, 273 +/- 66 ng/mL, and 224 +/- 49 ng/mL, respectively. Acute rejection occurred in two patients (6%) 1 yr after transplantation. Prospective use of CsA pharmocokinetic profiles improves renal allograft outcome in A-As.

The influence of Duffy blood group on renal allograft outcome in African Americans

BACKGROUND

African American patients demonstrate higher rates of acute allograft rejection and lower kidney-graft survival compared with white patients. Duffy antigen receptor for chemokines (DARC) on red blood cells has been suggested to have an anti-inflammatory role by acting as a "chemokine sink." We investigated the relationship of Duffy blood group type to renal allograft outcome in African American patient population.

METHODS

A total of 163 African American kidney-transplant recipients were studied for Duffy blood group status. Patient outcomes were assessed at 6 to 42 months after transplantation and monitored for acute rejection episodes, graft function, and graft survival.

RESULTS

A total of 117 (71.8%) patients were Duffy (a-b-), 14 (8.6%) Duffy (a+b-), 21 (12.9%) Duffy (a-b+), and 11 (6.8%) Duffy (a+b+). No significant differences were observed among the groups with respect to median serum-creatinine values or the incidence of biopsy-confirmed acute-rejection episodes. Although only 15.4% of the patients had Duffy (a+) antigen, none lost their allograft during the study period, and Kaplan-Meier graft survival was not significantly different compared to Duffy (a-) group (log-rank test, P=0.12). Duffy (a-b-) patients demonstrated lower allograft survival compared with the other three groups, although statistical significance was not reached (log-rank test P=0.15). Delayed graft function (DGF) was strongly associated with graft failure for only Duffy (a-b-) patients (log-rank test P=0.003).

CONCLUSIONS

Duffy (a-b-) patients have lower allograft survival in the presence of DGF. DARC may attenuate the inflammatory effects of DGF by acting as a "chemokine sink," and DARC-negative patients may be more vulnerable to DGF.

Two-year results of multicenter phase III trials on the effect of the addition of sirolimus to cyclosporine-based immunosuppressive regimens in renal transplantation

Randomized clinical trials conducted over 24 months and including nearly 1300 renal transplant patients compared the efficacy and safety of two dose levels of sirolimus versus azathioprine (United States) or placebo (Global) comparators administered with a cyclosporine (CsA) and prednisone (Pred) baseline regimen. Analysis of 24-month data revealed that patients in the 5 mg/d sirolimus groups experienced a significant delay in the onset and reduction in the incidence of acute rejection episodes compared with azathioprine (Aza) or placebo groups (P =.02/P =.001). Graft and patient survival rates and also the occurrence of transplant-related infections, lymphoproliferative disorders, or malignancies were similar among all treatment arms. Between 12 and 24 months, patients treated with 2 mg/d sirolimus displayed relatively stable mean serum creatinine values, namely 1.9-1.8 mg/dL for the US and 1.8-1.8 mg/dL for the Global (P = NS) studies, which remained higher than those of the comparators. Both 5 mg/d groups showed an increase in mean serum creatinine during this interval, which was significantly higher than the value in both comparators at 24 months. Both sirolimus groups showed persistently elevated triglyceride levels compared with Aza-treated patients at month 24. The Global trial showed a less-pronounced difference in mean fasting triglyceride values compared with placebo. Data from both trials demonstrate that the addition of sirolimus to a CsA-Pred treatment regimen yielded a durable immunosuppressive effect associated with a progressive resolution of adverse side effects over time except for hyperlipidemia, which required continued countermeasure therapy.

Can a pharmacokinetic approach to immunosuppression eliminate ethnic disparities in renal allograft outcome?

Although renal allograft outcome correlates more closely with area under the concentration time curve (AUC) for cyclosporin (CsA) compared with the 12-h trough level (C0), few studies have prospectively evaluated pharmacokinetic monitoring in kidney transplantation. This paper describes a study designed to evaluate the impact of a novel approach to CsA-based immunosuppression on ethnic differences in renal allograft outcome. Sixty (32 African Americans and 28 Caucasians) renal transplant recipients were treated with cyclosporin-based triple therapy. Morning and evening doses were independently adjusted to reach an AUC0-12 of 6600-7200 ng h/mL and a C0 of 250-325 ng/mL, respectively. AUCs were measured within 48 h of starting CsA, and as often as necessary to maintain target levels. Only two patients experienced significant adverse events related to immunosuppression. One (Caucasian) developed haemolytic uremic syndrome and was converted to tacrolimus, while another (African American) developed acute vascular rejection. One graft was lost (Caucasian) due to death with a functioning graft. An average of 8 AUCs (range 5-13) were measured in the first 3 months. AUCs were significantly higher in African Americans compared with Caucasians only in the first and second month. C0 values were similar in both groups throughout the study period. A pharmacokinetic approach to immunosuppression allows individualization of CsA exposure, and appears to reduce ethnic disparities in renal allograft outcome.

Mechanisms of clinically relevant drug interactions associated with tacrolimus

The clinical management of tacrolimus, a macrolide used as immunosuppressant after transplantation, is complicated by its narrow therapeutic index in combination with inter- and intraindividually variable pharmacokinetics. As a substrate of cytochrome P450 (CYP) 3A enzymes and P-glycoprotein, tacrolimus interacts with several other drugs used in transplantation medicine, which also are known CYP3A and/or P-glycoprotein inhibitors and/or inducers. In clinical studies, CYP3A/P-glycoprotein inhibitors and inducers primarily affect oral bioavailability of tacrolimus rather than its clearance, indicating a key role of intestinal P-glycoprotein and CYP3A. There is an almost complete overlap between the reported clinical drug interactions of tacrolimus and those of cyclosporin. However, in comparison with cyclosporin, only few controlled drug interaction studies have been carried out, but tacrolimus drug interactions have been extensively studied in vitro. These results are inconsistent and are of poor predictive value for clinical drug interactions because of false negative results. P-glycoprotein regulates distribution of tacrolimus through the blood-brain barrier into the brain as well as distribution into lymphocytes. Interaction of other drugs with P-glycoprotein may change tacrolimus tissue distribution and modify its toxicity and immunosuppressive activity. There is evidence that ethnic and gender differences exist for tacrolimus drug interactions. Therapeutic drug monitoring to guide dosage adjustments of tacrolimus is an efficient tool to manage drug interactions. In the near future, progress can be expected from studies evaluating potential pharmacokinetic interactions caused by herbal preparations and food components, the exact biochemical mechanism underlying tacrolimus toxicity, and the potential of inhibition of CYP3A and P-glycoprotein to improve oral bioavailability and to decrease intraindividual variability of tacrolimus pharmacokinetics.

Diurnal cyclosporine dosing optimizes exposure and reduces the risk of acute rejection after kidney transplantation

Acute rejection (AR) following transplantation may be due to episodic subtherapeutic cyclosporine (CsA) levels related to diurnal variation of hepatic drug metabolism. We postulated that asymmetrical dosing of CsA based on individualized pharmacokinetic profiles would optimize drug exposure and decrease the risk of AR. We prospectively treated all patients undergoing kidney transplantation with a diurnally split dose of CsA microemulsion given q 12 hours (3.5 mg/kg q a.m., 3.0 mg/kg qPM). Morning doses were adjusted to reach a day-time area under the concentration curve (AUC) of 7,800 ng hour/ml (utilizing 2 hour and 6 hour levels) and evening doses were adjusted to a morning trough of 300 ng/ml. Patients received high-dose steroids tapered to 20 mg prednisone by day 6. CsA was started within 36 hours and mycophenolate mofetil (1000 mg q 12 hour) was added on day 3 in most patients and continued for 3 months. Only one patient received antibody induction. Thirty kidneys (67% cadaveric) were transplanted into 28 adult patients (50% African American, 57% men). Therapeutic targets were reached in all patients prior to discharge and maintained during the study period. At 3 months follow-up, there was not a single episode of documented AR and mean creatinine was 1.5 +/- 0.1 mg/ml. Twelve patients required biopsy for allograft dysfunction; however no histological evidence of AR or CsA-toxicity was identified and the creatinine normalized in each case without altering immunosuppression. Patients continued to require increased CsA doses in the AM compared to the PM (P<0.05) throughout the study to maintain target levels. Diurnal dosing of CsA based on individual pharmacokinetic profiles optimizes CsA exposure and reduces the risk of AR during the first 3 months after transplantation.

Declining influence of race on the outcome of living-donor renal transplantation

A racial disparity in graft survival for renal transplant recipients has been documented for both cadaveric and living-donor transplants. In the present single-center study we analyzed graft survival by race for recipients of living-donor kidney transplants in three eras: 1985-89, 1990-94, and 1995-2000. There was an intensification of the immunosuppressant regimen beginning in 1996, such that all patients received cyclosporine or tacrolimus with mycophenolate and prednisone. Graft survival was analyzed using the Cox proportional hazards model. There were 79 black recipients and 210 white recipients with no difference in mean age, degree of HLA matching, or proportion of recipients with diabetes as the cause of end-stage renal disease. Using all data from 1985 to 2000, graft survival was significantly better for whites vs. blacks adjusted for age, gender, diabetes, era of the transplant, and haplotype match (p = 0.05). However, when analyzed by era, there was a temporal trend for a progressive decrease in the racial disparity in graft survival. In confirmation of this effect, there was a significant race-era interaction (p = 0.01) on multivariable Cox proportional hazards analysis. The most recent data from the United States Renal Data System (USRDS) show a similar decrease in the racial difference in 1-year graft survival. We conclude that the influence of race on living-donor graft survival is diminishing over time.

African Americans and renal transplantation: disproportionate need, limited access, and impaired outcomes

BACKGROUND

Renal transplantation is the therapy of choice for patients with end-stage renal disease (ESRD). However, African Americans' (AA) access to this modality is not commensurate with that of other races. This imbalance, coupled with AA disproportionately representing those with ESRD, has kept AA disadvantaged compared with other races, especially whites.

METHODS

We reviewed published reports that examined the connection between race and the incidence of chronic renal failure, access to optimal therapy, and outcomes of renal transplantation.

RESULTS

The incidence of ESRD in AA is 4 times greater than in whites, but AA remain less likely than whites to be referred for or undergo renal transplantation. Also, AA are at greater risk than whites to experience premature graft failure.

CONCLUSIONS

ESRD management has improved dramatically with the advent of successful renal transplantation. However, AA remain significantly disadvantaged in both access and outcomes compared with whites. Further evaluation of underlying causes and development of specific remedies is warranted.

Effect of race on outcome of orthotopic liver transplantation: a cohort study

BACKGROUND

There is significant evidence to suggest that long-term survival after renal transplantation is significantly lower in African Americans than in other races. We aimed to establish whether there was a difference in survival in African Americans compared with other races after orthotopic liver transplantation (OLT) and whether race was an independent predictor of survival.

METHODS

We collected data from the United Network of Organ Sharing transplant registry for all liver transplants done between 1988 and 1996 in the USA. We also recorded information on age, sex, race, blood group, and cause of death for the donors and recipients.

FINDINGS

2-year graft survival was significantly lower for African Americans (601 of 884, 68%) and Asians (266 of 416, 64%) compared with white Americans (8703 of 11762, 74%) and Hispanics (878 of 1220, 72%). 2-year and 5-year patient survival were significantly lower for African Americans (654 of 884 [74%], 270 of 565 [48%]) and Asians (287 of 416 [69%], 92 of 252 [37%]) compared with white Americans (9786 of 11762 [83%], 4357 of 7514 [58%]) and Hispanics (964 of 1220 [79%], 341 of 657 [52%]). Compared with white Americans, African American (hazard ratio 1.36, 95% CI 1.16-1.60, p<0.0001) and Asian (1.25, 1.01-1.56, p=0.03) race were independent predictors of poor survival at 2 years.

INTERPRETATION

African Americans and Asians have a worse outcome after OLT compared with white Americans and Hispanics. The higher rate of chronic rejection in African Americans and a relatively worse outcome in other minority races merits further examination.

Donor platelet and leukocyte load identify renal allografts at an increased risk of acute rejection

BACKGROUND

A reduction in acute rejection may reduce graft losses from chronic rejection, benefiting the recipient and helping ease the huge donor organ shortfall in the UK. The prediction of recipients at greater risk of acute rejection might justify the administration to them of more potent immunosuppression, but defining this group on clinical parameters has been largely unsuccessful. Events impacting on the kidney by the time of donation may, if detectable histologically, predict those kidneys more likely to undergo rejection.

METHODS

A prospective immunohistochemical analysis was undertaken to detect P-Selectin (PS), E-Selectin (ES), platelets, leukocyte common antigen, macrophages, T cells, and neutrophils in the pretransplant biopsies of 77 adult renal transplant recipients. Twenty-nine (38%) of this group rejected.

RESULTS

A significantly increased number of recipients rejected if the donor biopsy was PS positive (63 vs. 24%, P=0.0007), contained five or more leukocytes/glomerulus (48 vs. 21%, P=0.03), contained >9.3 leukocytes/high power field (46.5 vs. 10.5%, P=0.006) or was both PS positive and contained >9.3 leukocytes/high power field (61.9 vs. 0.0%, P=0.0001). The PS was mostly of platelet origin and the majority of leukocytes were macrophages. Only previous CMV or any current infection in the donor correlated with the immunohistochemical changes.

CONCLUSIONS

These immuno-histochemical changes are present before transplantation, which allows the prediction of recipients at both a higher and a lower risk of acute rejection, enabling the administration of recipient tailored immunosuppression, and supports the use of additional therapeutic intervention to reduce the injury response both within the recipient and the donor.

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.

The contribution of adhesion molecule expression in donor kidney biopsies to early allograft dysfunction

BACKGROUND

Renal allograft rejection is associated with the expression of adhesion molecules on vascular endothelial and tubular epithelial cells.

METHODS

To assess whether the number of cell adhesion molecules expressed in donor kidneys can predict early rejection or delayed graft function, kidney biopsies from 20 living and 53 cadaveric kidney donors were obtained before engraftment into the recipients and the expression of the cell adhesion molecules intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and endothelial leukocyte adhesion molecule (E-selectin) were determined by immunohistochemistry.

RESULTS

All biopsies from living donors showed significantly lower expression of ICAM-1 and VCAM-1 compared to biopsies from cadaveric donors. There was no difference in the expression of adhesion molecules on tubular cells between transplants with primary function compared to allografts with early rejection in living donated kidneys (ICAM-1: 2+/-8 vs. 3+/-8%; VCAM-1: 9+/-7 vs. 1+/-1%), as well as in cadaveric kidneys (ICAM-1: 38+/-29 vs. 39+/-38%; VCAM-1: 55+/-27 vs. 48+/-29%). The expression of ICAM-1 molecules on tubular cells was determined to be a predictor for the occurrence of delayed graft function in cadaveric kidneys (ICAM-1: 65+/-24* vs. 38+/-29% delayed graft versus primary graft function). No delayed graft function occurred in recipients of living donated kidneys.

CONCLUSIONS

These data suggest that adhesion molecule expression in donor biopsies is not a predictor for early allograft rejection, but can be used as a marker for the development of postischemic acute renal allograft failure.

Review of select transplant subpopulations at high risk of failure from standard immunosuppressive therapy

Despite improvements in short-term graft and patient survival rates for solid organ transplants, certain subgroups of transplant recipients experience poorer clinical outcome compared to the general population. Groups including pediatrics, African-Americans, diabetics, cystic fibrosis patients, and pregnant women require special considerations when designing immunosuppressive regimens that optimize transplant outcomes. Problems specific to pediatric transplant recipients include altered pharmacokinetics of immunosuppressive drugs, such as cyclosporine (CsA) and tacrolimus (poor absorption, increased metabolism, rapid clearance), the need to restore growth post-transplantation, and a high incidence of drug-related adverse effects. African-Americans have decreased drug absorption and bioavailability, high immunologic responsiveness, and a high incidence of post-transplant diabetes mellitus. Diabetics and cystic fibrosis patients exhibit poor absorption of immunosuppressive agents, which may lead to underimmunosuppression and subsequent graft rejection. Pregnant women undergo physiologic changes that can alter the pharmacokinetics of immunosuppressives, thus requiring careful clinical management to minimize the risks of either under- or overimmunosuppression to mother and child. To achieve an optimal post-transplant outcome in these high-risk patients, the problems specific to each group must be addressed, and immunosuppressive therapy individualized accordingly. Drug formulation greatly impacts upon pharmacokinetics and the resultant level of immunosuppression. Thus, a formulation with improved absorption (e.g., CsA for microemulsion), higher bioavailability, and less pharmacokinetic variability may facilitate patient management and lead to more favorable outcomes, especially in groups demonstrating low and variable bioavailability. Other strategies aimed at improving transplant outcome include the use of higher immunosuppressive doses, different combinations of immunosuppressive agents, more frequent monitoring, and management of concurrent disease states.

African-American renal transplant recipients experience decreased risk of death due to infection: possible implications for immunosuppressive strategies

INTRODUCTION

African-American renal transplant recipients tend to experience more acute rejection episodes and have shorter graft survival than Caucasian renal transplant recipients. Various factors have been posited to be responsible for this difference, including relative under immunosuppression. We reasoned that by looking at the balance of acute rejections versus death due to infection, we could ascertain whether African-American renal recipients might have more reserve to tolerate an increase in pharmacological immunosuppression.

METHODS

We analyzed the United States Renal Data System (USRDS) data from 1987 to 1997 regarding acute rejection episodes and infectious deaths. All other pertinent factors were gathered for a multivariate analysis. A total number of 68,885 adult renal transplant recipients were analyzed.

RESULTS

When corrected for all covariates, the relative risk for acute rejection (1.3) was higher although the relative risk for infectious death was lower (0.7) in African-Americans as compared with Caucasians (P<0.01).

CONCLUSION

Our study would indicate that relative to Caucasians, African-American renal transplant recipients are at decreased risk for infectious death and therefore may tolerate the more intensive immunosuppression that may be necessary to narrow the gap in acute rejection rates between African-Americans and Caucasian renal transplant recipients.

Efficacy of sirolimus compared with azathioprine for reduction of acute renal allograft rejection: a randomised multicentre study. The Rapamune US Study Group

BACKGROUND

Acute rejection episodes after renal transplantation are an important clinical challenge, despite use of multidrug immunosuppressive regimens. We did a prospective, multicentre, randomised, double-blind trial to investigate the impact of the addition of sirolimus, compared with azathioprine, to a cyclosporin and prednisone regimen.

METHODS

719 recipients of primary HLA-mismatched cadaveric or living-donor renal allografts who displayed initial graft function were randomly assigned, after transplantation, sirolimus 2 mg daily (n=284) or 5 mg daily (n=274), or azathioprine (n=161). We assessed the primary composite endpoint of efficacy failure, occurrence of biopsy-confirmed acute rejection episodes, graft loss, or death, and various secondary endpoints that characterise these episodes at 6 months and 12 months. Analyses were done by intention to treat.

FINDINGS

The rate of efficacy failure at 6 months was lower in the two sirolimus groups (2 mg 18.7%, p=0.002; 5 mg 16.8%, p<0.001) than in the azathioprine group (32.3%). The frequency of biopsy-confirmed acute rejection episodes was also lower (2 mg 16.9%, p=0.002; 5 mg 12.0%, p<0.001; azathioprine 29.8%). At 12 months, survival was similar in all groups for grafts (97.2%, 96.0%, and 98.1%) and patients (94.7%, 92.7%, and 93.8%). Patients on sirolimus showed a delay in the time to first acute rejection episode and decreased frequency of moderate and severe histological grades of rejection episodes and related antibody treatment, compared with the azathioprine group. Rates of infection and malignant disorders were similar in all groups.

INTERPRETATION

Use of sirolimus reduced occurrence and severity of biopsy-confirmed acute rejection episodes with no increase in complications. Further studies are needed to establish the optimum doses for the combined regimen.

HLA-identical sibling renal transplantation--a 21-yr single-center experience

Human lymphocyte antigen (HLA)-identical sibling organs offer the best long-term outcomes for recipients of a renal transplant apart from an identical twin. Unlike cadaveric transplants, however, factors that affect long-term survival of these immunologically privileged grafts are not well described. We reviewed 108 HLA-identical transplants performed at our institution between January 1977 and February 1993. Variables chosen for graft survival analysis were: gender, age and ABO blood type of donors and recipients, panel reactivity antibodies (PRA), blood transfusions prior to transplant, pregnancies, and the underlying renal disease. Additionally, incidence of acute rejection (AR), timing of AR, serum creatinine levels at 1 wk and at 1 yr, and presence of hypertension were included in the analysis. Mean follow-up was 130.9 +/- 58.2 months (range 38-250 months). Actual 5-yr patient and graft survivals were 92 and 88%, respectively. Thirty-eight grafts were lost, and 22 recipients died during the observation period. Death was the main cause of graft failure. Cardiac events accounted for the majority of deaths. AR occurred in 46% and repeated rejections in 11% of recipients. Actuarial graft survival at 10 yr was poorer for patients with any AR (69%), and significantly worse with repeated AR (33%), compared to patients without AR (86%), p = 0.001). Sixty percent of all rejections and 88% of the first rejections occurred in the first 60 d post-transplantation. The first AR that occurred after 60 d was associated with poor graft survival (49 vs. 70%, p = 0.04). Recipients with renal diseases with potential to recur (membranous glomerulonephritis (MGN), membrano-proliferative glomerulonephritis (MPGN), focal and segmental glomerulonephritis (FSGN), polyarteritis nodosa (PAN), rapid progressive glomerulonephritis (RPGN), Henoch-Schoenlein purpura (HSP), diabetes mellitus (DM), interstitial nephritis, systemic lupus erythematosus (SLE) and chronic glomerulonephritis (CGN)) faired worse as a group than recipients with hypertensive nephrosclerosis (HTN), autosomal dominant polycystic kidney disease (ADPKD), Alport's, reflux or congenital dysplasia (68 vs. 96% at 10 yr, p = 0.0009). Poor patient survival was seen in diabetics (71 vs. 88% at 10 yr, p = 0.01). There was a trend to poorer graft survival in diabetic recipients when compared to non-diabetics (65 vs. 81% at 10 yr, p = 0.054). Elevated creatinine at 1 yr was associated with worse graft survival. Likewise, the magnitude of creatinine increase during the first year directly correlated with the risk of graft loss. Hypertensive patients were more likely to lose their grafts than normotensive recipients (72 vs. 86%, p = 0.04). Pre-transplant blood transfusion, pregnancy, and PRA level were not associated with increased graft failure or AR. Graft survival was not affected by gender, age, or ABO blood type of donors or recipients. In conclusion, better prevention and treatment of AR, hypertension, and cardiac disease should improve graft and patient survival. Close attention to recurrence of disease and subtle changes in the creatinine level during the first year might dictate early diagnostic and, hopefully, therapeutic interventions.

Dialysis modality and delayed graft function after cadaveric renal transplantation

The purpose of this investigation was to compare outcomes in the immediate posttransplant period for hemodialysis (HD) and peritoneal (PD) dialysis patients who received cadaveric renal transplantation. Data were obtained from the United Network of Organ Sharing on all cadaveric graft recipients who were dialysis-dependent at the time of transplantation between April 1994 and December 1995. Baseline characteristics were compared between groups, and multivariate logistic regression was performed with outcome measures including urine production in the first 24 h posttransplantation (U24), requirement for dialysis in the first week posttransplant (FWDIAL), and treatment for acute rejection during the initial hospitalization. The odds of oliguria (not producing urine in the first 24 h) were 1.49 (1.28 to 1.74) times higher in HD versus PD patients. After adjustment for other comorbid conditions including age, gender, race, HLA mismatch, time on dialysis, panel-reactive antibodies, and cold and warm ischemia time, the odds of oliguria were 1.60 (1.14 to 2.25) times higher in black HD patients compared with PD patients and 1.29 (1.06 to 1.57) times higher in white HD patients. In a similar manner, after adjustment for significant comorbid conditions, the odds of requiring dialysis in the first week were 1.56 (1.22 to 2.0) times higher in black HD patients versus PD patients and 1.40 (1.21 to 1.60) times higher in white HD patients. The rate of acute rejection was similar during the first hospitalization. These results suggest that there is an association between hemodialysis and delayed graft function. Differences in biocompatibility between the two modalities could potentially be responsible.

Immunosuppressive therapy in high-risk transplant patients: dose-dependent efficacy of mycophenolate mofetil in African-American renal allograft recipients. U.S. Renal Transplant Mycophenolate Mofetil Study Group

BACKGROUND

Numerous studies have demonstrated that renal allograft survival is reduced in African-Americans (AAs). This posthoc racial subgroup analysis (AAs vs. non-AAs) tested whether mycophenolate mofetil (MMF) might have favorable implications for the treatment of AA renal allograft recipients.

METHODS

Patients received a triple therapy regimen of corticosteroids, cyclosporine, and azathioprine (AZA) 1-2 mg/kg/day, MMF 2 g/day (MMF 2 g), or MMF 3 g/day (MMF 3 g).

RESULTS

AAs in the AZA group had the highest biopsy-proven rejection/treatment failure (BPR/TF) rate (57.5% vs. 43.5% for non-AAs). AAs in the MMF 3 g group showed a significant reduction in BPR/TF (57.5% vs. 24.2%, P=0.0008). BPRs were more frequent for AAs in either the AZA (47.5%) or MMF 2 g group (31.8%) than in the MMF 3 g group (12.1%), whereas rejections were reduced for non-AAs receiving either MMF dosage (AZA, 35.5%; MMF 2 g, 15.7%; MMF 3 g, 18.8%). AAs in the AZA group experienced BPR/TF earlier than AAs in the MMF 3 g group (median onset at 64 days vs. > 183 days, P=0.0012). But AAs in the MMF 3 g experienced BPR/TF the latest among the six subgroups of treatment and race. AAs had more severe rejection episodes and higher serum creatinine levels at 6 months after transplant, regardless of treatment group.

CONCLUSIONS

Dose-dependent prevention of acute rejection in AAs is best afforded by a dosage of MMF at 3 g/day, whereas 2 g/day provides a superior benefit/risk ratio for non-AAs. MMF at 3 g/day thus provides an improvement over conventional immunosuppressive strategies in reducing the frequency of acute rejections in this immunologically high-risk group.

Long-term renal allograft survival: prognostic implication of the timing of acute rejection episodes

BACKGROUND

The timing of an acute rejection may have a variable impact on renal allograft survival. To determine whether the time of first acute transplant rejection (ATR) is an independent predictor of long-term allograft survival, we studied 31,600 first cadaveric renal transplants that were functional on the first transplant anniversary, from 217 U.S. centers.

METHODS

Transplant patients were divided into four groups according to the time to the first ATR: no rejection in year 1 (group I); predischarge ATR (group II); first ATR between discharge and month 6 (group III); and first ATR in months 7-12 (group IV).

RESULTS

Four-year allograft survival after year 1, estimated by a Cox proportional hazard model adjusting for 19 cofactors, was 78%, 72%, 69%, and 54% for groups I-IV, respectively (P<0.0001 for each comparison to group I). In those patients who had ATR episodes in more than one time period, later episodes were associated with worse long-term allograft survival, an observation that was independent of previous ATR episodes.

CONCLUSIONS

We conclude that late occurrence of a first acute rejection portends a worse prognosis for allograft survival after the first year. Later rejections, in combination with previous rejections, also lead to worse long-term allograft survival. Unlike early ATRs occurring in the setting of supervised immunosuppression, late occurring ATR may reflect inadequate immunosuppression from noncompliant behavior or may reflect disruption or lack of immune tolerance to the allograft. Efforts to minimize late transplant loss require a combination of strategies directed at both immunologic and behavioral factors.

Benefits of continued cyclosporine through an indigent drug program

Financial circumstances force some stable renal transplant recipients to discontinue cyclosporine (CsA). Previous results from our center document a subgroup of these patients at increased risk for acute rejection and allograft loss, namely, those of African ancestry. After 1988, such disadvantaged recipients have been able to receive CsA at no charge through the National Organization for Rare Disorders (NORD). At the University of Alabama at Birmingham, 54 patients were enrolled in the NORD program between 1988 and 1994. Acute rejection, allograft survival, and patient survival in these patients were compared with those in 42 patients who, prior to 1988, were withdrawn from CsA for financial reasons. Both groups were similar socioeconomically. The mean follow-up was 69 +/- 33 months (+/-SD) in the withdrawal group and 45 +/- 14 months in those entering the NORD program. Acute rejections occurred with similar frequency in both groups before CsA withdrawal (45%) or NORD enrollment (48%). In contrast, acute rejections were more common in patients after the onset of CsA withdrawal (38%) than after NORD enrollment (11%) (P < 0.01). Black patients withdrawn from CsA experienced more acute rejections than their counterparts in the NORD program (57% v 15%) (P < 0.01). White NORD recipients also experienced fewer acute rejections, although the difference was not statistically significant (withdrawal group 16% v NORD group 4%; P = 0.29). Rejection episodes were accompanied by reduced graft survival in black patients withdrawn from CsA, while significant improvement was seen in those remaining on CsA-based therapy (P < 0.05). No difference in allograft survival was seen among white patients in either group (withdrawal group 74% v NORD group 82%; P = 0.33). Thus, long-term access to CsA through the NORD program reduced acute rejections and improved allograft survival in an economically disadvantaged subgroup of renal transplant recipients. These findings emphasize the importance of continued access to CsA in black renal transplant recipients and its influence on long-term allograft survival.