Renal transplantation in black Americans

Renal transplantation for Indigenous Australians: identifying the barriers to equitable access

OBJECTIVE

To assess Indigenous Australians' access to renal transplantation, compared with non-Indigenous Australians. To examine whether disparities are due to a lower rate of acceptance onto the waiting list and/or a lower rate of moving from the list to transplantation.

DESIGN

National cohort study using data from the Australian and New Zealand Dialysis and Transplant Registry. We included all end-stage renal disease (ESRD) patients under 65 years of age who started treatment in Australia between January 1993 and December 1998. We used survival analysis to examine the time from commencement of renal replacement therapy (RRT) to transplantation. We measured time from commencement of RRT to acceptance onto the waiting list (stage 1), and time from acceptance onto the waiting list to transplantation (stage 2). The main outcome measures were (1) acceptance onto the waiting list and (2) receipt of a transplant, before 31 March 2000.

RESULTS

Indigenous patients had a lower transplantation rate (adjusted Indigenous: non-Indigenous rate ratio 0.32, 95% CI 0.25-0.40). They had both a lower rate of acceptance onto the waiting list (adjusted rate ratio 0.50, 95% CI 0.44-0.57) and a lower rate of moving from the list to transplantation (adjusted rate ratio 0.50, 95% CI 0.38-0.65). The disparities were not explained by differences in age, sex, co-morbidities or cause of renal disease.

CONCLUSIONS

Indigenous Australians face barriers to acceptance onto the waiting list and to moving from the list to transplantation. Further research to identify the causes could facilitate strategies to improve equity in transplantation.

HLA points assigned in cadaveric kidney allocation should be revisited: an analysis of HLA class II molecularly typed patients and donors

The points now assigned for the quality of HLA match have received significant scrutiny to be modified in an effort to help reduce disparity in access to kidneys of minority groups, and since differences in graft survival between groups of patients in each of the HLA matched groups is less now than in the past. We analyzed long-term (5-year) graft survival in 746 DR DNA typed recipients of cadaveric kidneys transplanted from 1994-2001 whose donors were also DR DNA typed, with allocation based on those DNA-based typings. Five-year graft survival was not significantly different for recipient groups irrespective of if they had zero (84%), one (92%), two (89%), or three to four B, DR mismatches (79%) (log-rank = 0.15; died with a functioning graft [DWFG] censored). Mismatching of three and four DR and DQ antigens in black but not white patients was associated with significantly worse survival (Relative Risk = 2.9) (p = 0.002). The incidence of minority transplants in the well-matched group (zero and one B, DR mismatch), 12.8% (20/156) was over half that of the less well-matched group, 27.1% (160/590) (p < 0.001). Our data indicate that the current HLA-B, DR-based point system used to allocate kidneys warrants re-evaluation. Our data, taken in the context of the UNOS data, which has recently been re-evaluated, suggest that the only HLA-DR remain as a component of the national kidney allocation algorithm so as to increase access of kidneys to minorities and minimize graft loss.

Recorded delirium in a national sample of elderly inpatients: potential implications for recognition

This retrospective study examined delirium and related confusional diagnoses recorded in patients older than age 60 discharged from Veterans Affairs (VA) acute inpatient units nationally in 1996 (n = 267,947). Only 4% of patients had delirium or related confusional diagnoses recorded. Patients with recorded delirium had significantly higher mortality than did those without recorded delirium or those with other confusional diagnoses ("organic psychoses"); the most common delirium types were dementia with delirium and alcohol intoxication/withdrawal delirium. Organic psychoses patients had the longest lengths of stay and significantly more admissions to nonmedical/surgical units and discharges to nursing homes; almost 20% were African American. The recorded rate of delirium in the VA health system likely underestimates true prevalence and possibly reflects nonrecognition of delirium in many older veterans. Certain motoric and etiologic types of delirium may be more commonly diagnosed and recorded. Future research should prospectively examine recognition of motoric and etiologic delirium subtypes and racial differences in delirium diagnoses.

Treatment of hypertension in African Americans and Latinos: the effect of JNC VI on urban prescribing practices

In 1997, national recommendations for the treatment of hypertension were made in the form of the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI). African American hypertensives are considered a special population with a higher prevalence of hypertension, and therefore, unique treatment needs. The study objective was to review medication use among an African American and Latino urban population in relation to the JNC recommendations. The study population was drawn from a preexisting cohort of African Americans and Latinos. Records were reviewed for self-description of hypertension and the use of any antihypertensive medication in individuals less than 60 years of age. A small subgroup of individuals was separately reviewed for specific medications used to treat hypertension. There were 34,118 individuals in the cohort greater than 45 years of age and less than 60 years of age that qualified for review; 40% were African American and 60% were Latino. Of the 13,593 African Americans, 6387 (47%) were hypertensive. Of the 20,525 Latinos, 29% were hypertensive. Only 56% of all hypertensives were on some blood pressure medication (61% of the African Americans and 48% of the Latinos). Within the subgroup of 550 individuals with detailed medication information (223 African Americans and 327 Latinos), calcium channel blockers and diuretics were the most frequently used medication among the African Americans and angiotensin-converting enzyme inhibitors were the most frequently used medication among the Latinos. Beta blockers were used only 13% of the time. The authors concluded that in this cohort of hypertensive urban Latinos and African Americans, more than 40% of individuals were not being treated for hypertension and, despite the guidelines suggested in JNC VI, few individuals were being treated for their hypertension with diuretic monotherapy or beta blockers as first-choice drugs. Instead there was extensive use of calcium channel blockers and angiotensin-converting enzyme inhibitors.

Rates and outcomes of primary and revision total hip replacement in the United States medicare population

BACKGROUND

Information on the epidemiology of primary total hip replacement is limited, and we are not aware of any reports on the epidemiology of revision total hip replacement. The objective of this study was to characterize the rates and immediate postoperative outcomes of primary and revision total hip replacement in persons sixty-five years of age and older residing in the United States.

METHODS

We used Medicare claims submitted by hospitals, physicians, and outpatient facilities between July 1, 1995, and June 30, 1996, to identify individuals who had undergone elective primary total hip replacement for a reason other than a fracture (61,568 patients) or had had revision total hip replacement (13,483 patients). Annual incidence rates of primary and revision total hip replacement were calculated, and multivariate modeling was used to evaluate the association between patient characteristics and surgical rates. The rates of occurrence of five complications within ninety days postoperatively were also evaluated, and relationships between those outcomes and patient characteristics were assessed with use of multivariate models adjusted for hospital and surgeon volume.

RESULTS

The rates of primary total hip replacement were three to six times higher than the rates of revision total hip replacement. Women had higher rates than men, and whites had higher rates than blacks. The rates of primary and revision total hip replacement increased with age until the age of seventy-five to seventy-nine years and then declined. The rates of complications occurring within ninety days after primary total hip replacement were 1.0% for mortality, 0.9% for pulmonary embolus, 0.2% for wound infection, 4.6% for hospital readmission, and 3.1% for hip dislocation. The rates after revision total hip replacement were 2.6%, 0.8%, 0.95%, 10.0%, and 8.4%, respectively. Factors associated with an increased risk of an adverse outcome included increased age, gender (men were at higher risk than women), race (blacks were at higher risk than whites), a medical comorbidity, and a low income.

CONCLUSIONS

Analysis of United States Medicare population data showed that the rates of total hip replacement increased with age up to the age of seventy-five to seventy-nine years and that blacks had a significantly lower rate of total hip replacement than whites. The overall rates of adverse outcomes were relatively low, but they were significantly higher after revision than after primary total hip replacement.

LEVEL OF EVIDENCE

Prognostic study, Level II-1 (retrospective study). See p. 2 for complete description of levels of evidence.

HLA matching and the United Network for Organ Sharing Allocation System: impact of HLA matching on African-American recipients of cadaveric kidney transplants

BACKGROUND

A recent proposal supports the elimination of allocation points for human leukocyte antigen (HLA) mismatches (MM) in cadaveric kidney transplantation. The intent is to increase access for some racial groups that might be disadvantaged by the representation of race-specific HLA in a largely white donor pool. We report our experience from two transplant centers that serve a large African American (AA) patient population.

METHODS

All cadaveric transplants into AA recipients from 1994 to 2000 (n=162) were included in a retrospective review.

RESULTS

Superior graft survival was observed in AA recipients of 0 MM transplants. When induction therapy was used, the graft survival at 3 years for the human leukocyte antigen (HLA)-BDR MM grades given allocation points (0,1,2 MM) was 82% versus only 49% for BDR MM grades not given points (3,4 MM: =0.0022).

CONCLUSIONS

Our collective experience demonstrates that AA patients having HLA-BDR MM grades given allocation points had better graft survival. Removing points for HLA from the national allocation system may result in significantly poorer outcome in AA kidney recipients.

Racial and ethnic composition of volunteer cord blood donors: comparison with volunteer unrelated marrow donors

BACKGROUND

Umbilical cord blood is an alternative peripheral blood progenitor cell source for patients who need transplantation. A presumed advantage of cord blood is the ability to increase minority recruitment.

STUDY DESIGN AND METHODS

The racial composition of five member cord blood banks of the National Marrow Donor Program (NMDP) was compared, representing 9020 cord blood donors with NMDP marrow donors from comparable geographic areas, representing 417,676 donors. Cord blood and marrow donors self-reported racial designations on questionnaires. Donor statistics were compared with baseline racial data of deliveries from participating hospitals for cord blood donors and with geographic census data for marrow donors.

RESULTS

The California, Florida, and Massachusetts cord blood banks recruited a lower percentage of minorities than the corresponding marrow donor centers. In New York and Colorado, minority recruitment was equivalent. In California, Florida, Massachusetts, and New York, the cord blood banks recruited a lower percentage of minorities than those delivering at the respective hospitals. The cord blood banks in California, Colorado, Florida, and Massachusetts recruited a lower percentage of minorities compared with delivery data than the corresponding marrow donor centers compared with census population (p < 0.001). In New York, the percentages were similar.

CONCLUSION

The problem of insufficient minority recruitment of cord blood has not yet been solved. Better strategies are needed to recruit minority donors.

Comparison of two drug regimens upon clinical outcome among renal transplant recipients with positive flow cytometric crossmatches

Renal transplant recipients with positive flow cytometric crossmatches (FCXM) face greater risk of early rejection and graft failure. It is clear that the pharmacologic needs of this high risk group have not been identified. We retrospectively compared the impact of two drug regimens upon early rejection and 5 yr actuarial survival among 324 primary cadaveric transplant recipients with positive and negative FCXM. Patients received either Regimen I (OKT3 induction, cyclosporine and steroids) or Regimen II (mycophenolate mofetil with cyclosporine or Prograf). Recipient gender, age, disease etiology, ethnic distribution and cytotoxic panel reactive antibody (PRA) were equivalent between regimens (p=ns). With Regimen I, the incidence of rejection was greater for FCXM positive vs. FCXM negative patients (51 vs. 21%, p=0.001). In contrast, with Regimen II the incidence of rejection for FCXM positive and FCXM negative patients was equivalent (18 vs. 12%, p=ns) and lower than patients treated with Regimen I (p < 0.01). Ethnic variation was only observed with Regimen I in which African Americans with positive FCXM had more rejections than Caucasians (60 vs. 45%, p < 0.05). Five-year actuarial survival was lower for FCXM positive vs. FCXM negative patients treated with Regimen I (40 vs. 75%, p=0.0006) or Regimen 2 (60 vs. 90%, p=0.001). Allograft survival was equivalent (p=ns) among FCXM positive individuals receiving Regimen I or II. However, allograft survival among FCXM negative individuals improved with Regimen II (p < 0.05). Ethnic variation in survival was not observed with either regimen (p=ns).

Ethnicity greatly influences cytokine gene polymorphism distribution

Polymorphisms in the regulatory regions of cytokine genes are associated with high and low cytokine production and may modulate the magnitude of alloimmune responses following transplantation. Ethnicity influences allograft half-life and the incidence of acute and chronic rejection. We have questioned whether ethnic-based differences in renal allograft survival could be due in part to inheritance of cytokine polymorphisms. To address that question, we studied the inheritance patterns for polymorphisms in several cytokine genes (IL-2, IL-6, IL-10, TNF-alpha, TGF-beta, and IFN-gamma) within an ethnically diverse study population comprised of 216 Whites, 58 Blacks, 25 Hispanics, and 31 Asians. Polymorphisms were determined by allele-specific polymerase chain reaction and restriction fragment length analysis. We found striking differences in the distribution of cytokine polymorphisms among ethnic populations. Specifically, significant differences existed between Blacks and both Whites and Asians in the distribution of the polymorphic alleles for IL-2. Blacks, Hispanics and Asians demonstrated marked differences in the inheritance of IL-6 alleles and IL-10 genotypes that result in high expression when compared with Whites. Those of Asian descent exhibited an increase in IFN-gamma genotypes that result in low expression as compared to Whites. In contrast, we did not find significant ethnic-based differences in the inheritance of polymorphic alleles for TNF-alpha. Our results show that the inheritance of certain cytokine gene polymorphisms is strongly associated with ethnicity. These differences may contribute to the apparent influence of ethnicity on allograft outcome.

Sensitized patients require sharing of highly matched kidneys

BACKGROUND

Improved HLA matching can allow for renal transplantation in sensitized patients. United Network for Organ Sharing (UNOS) is currently considering removing the points awarded for HLA matching.

METHOD

Twenty-six transplant centers shared kidneys, according to the algorithm: A, UNOS mandatory 0-mismatch (MM) share; B, UNOS mandatory 0-mm payback; C, 0 - B,Dr-MM; PRA> or = 40%; ROP tray negative; D, 0-B,Dr-MM; panel reactive antibodies (PRA) <40%; E, 0-B,Dr payback; F, local use.

RESULTS

A total of 354 patients received transplants through the program and were compared with 6492 control patients. There was a significantly greater primary nonfunction rate in sensitized patients in spite of similar length cold ischemia time. Blacks were not significantly disadvantaged by the HLA matching requirements of the program. White recipients were favored by the matching program to the detriment of race group "other." Women were more frequently found in the sensitized groups but were not favored by sharing. Retransplant patients and patients with current PRA > or = 40% were favored by the sharing program. Sharing for HLA match does not improve graft survival at 1, 2, 3 years.

CONCLUSIONS

(1). Elimination of suboptimal HLA matching by UNOS will probably not adversely affect 1-, 2-, and 3-year graft survival; (2). Removing the consideration for HLA matching will result in fewer transplant opportunities for highly sensitized patients such as retransplants and currently sensitized patients.

Relationship between patients' perceptions of disadvantage and discrimination and listing for kidney transplantation

OBJECTIVES

This study explored wait-listing decisions among African American and White men and women eligible for kidney transplants, focusing on lifetime experiences of race and sex discrimination as a possible influence.

METHODS

Patient records from 3 Baltimore-area hemodialysis units were reviewed, and semistructured face-to-face interviews were conducted with transplant-eligible patients and with unit staff members.

RESULTS

African American patients reported more racial discrimination, and women reported more sex discrimination. Women and older patients were less likely to be placed on the waiting list, as were patients with previous experiences of racial discrimination. Discrimination measures predicted list access more strongly than patient race.

CONCLUSIONS

Lifetime experience of and response to discrimination may contribute to race and sex differences in access to care and should be included in research on health care disparities.

A comparison between recipients receiving matched kidney and those receiving mismatched kidney from the same cadaver donor

The optimal allocation of cadaveric kidneys for transplantation with reference to human leukocyte antigen (HLA) match and sharing these organs to a distant center remains controversial. The current analysis was performed using the United Network for Organ Sharing (UNOS) database for cadaveric kidney transplants (Tx) between 1988 and 1997. The graft survivals of zero-mismatch (matched) kidneys with the mate (mismatched) kidneys were compared. There were 2385 donors and 4770 Tx. Significant differences in recipient demographics between matched and mismatched Tx were: fewer African-American race (AA) in the matched group (9.0% vs. 21.9%), higher number of previous Tx (25.5% vs. 14.8%) and elevated mean cold ischemia time (24.0 vs. 22.2 h). Post-Tx dialysis requirements were similar (22.8% vs. 24.1%, p = 0.62) and matched kidneys had to travel more distance (920 vs. 232 miles). Using a Cox model, the matched group had a decreased relative hazard of graft failure of 23.0% (p = 0.0002) or 35% (p < 0.0001) with and without censoring for death. There was significantly better graft survival in the matched recipients in all pairs except AA (matched) and non-AA (mismatched). For older donors (> or = 50 years, n = 1508), the matched grafts survival was marginally significant (p =0.05). Matched kidneys have improved survival compared with the mismatched kidneys despite the longer distance traveled. The benefit of mismatched transplants was predominantly seen in non-AA.

Factors associated with long-term renal allograft survival

Major advances in immunosuppression and reductions in the rates of acute rejection have led to increasing graft and patient survival rates during the past two decades. Chronic dysfunction of the renal allograft, however, remains a major clinical problem and probably represents the end result of the complex interplay between donor and recipient factors, immunologic injury, nonimmunologic insults, and drug-induced nephrotoxicity. Optimal function of the renal allograft is obtained by maintaining a balance between underimmunosuppression and acute rejection and overimmunosuppression and drug-induced toxicities. To minimize side effects while maintaining efficacy, immunosuppressive drugs are commonly used as combination therapy. Pharmacokinetic and pharmacodynamic interactions between these agents can affect graft survival and function. The evidence supporting the role of therapeutic drug monitoring as applied to commonly used immunosuppressants in modern transplantation is presented here, and the increasing role of therapeutic drug monitoring in the optimization of graft and patient survival rates in the modern era of renal transplantation is discussed.

Increased access to transplantation for blood group B cadaveric waiting list candidates by using A2 kidneys: time for a new national system?

Since blood group B end-stage renal disease (ESRD) patients have less access to donor kidneys and a higher minority composition than any other blood group, the United Network for Organ Sharing (UNOS) approved a voluntary national kidney allocation variance to allow organ procurement organizations (OPOs) to preferentially allocate A2 and A2B kidneys to B candidates. The Midwest Transplant Network OPO has preferentially allocated and transplanted kidneys from blood group A2 and A2B donors to our blood group B waiting list candidates for more than 7 years to increase access to kidneys for the B candidates on our OPO-wide waiting list. Between 1994 and 2000, a total of 121 blood group B ESRD patients from our OPO-wide cadaveric kidney waiting list were transplanted. Thirty-four per cent (41/121) of those B candidates received either an A2 or an A2B kidney. One- and 5-year graft survival rates for the group of B recipients of A2 or A2B kidneys were 91 and 85% (died with functioning graft [DWFG] censored), respectively, which were not significantly different from those of 91 and 80% for the 80 B recipients of B or O kidneys (Wilcoxon = 0.48; log-rank = 0.55). These data support the national trial for additional OPOs to voluntarily allocate A2 and A2B kidneys preferentially to B waiting list candidates, thus increasing access of blood group B patients to renal transplantation.

Renal allograft outcomes in African American versus Caucasian transplant recipients in the tacrolimus era

METHODS

Between January 1995 and December 1999, 185 kidney transplants were performed with tacrolimus (TAC)-based immunosuppression including 120 African American (AA, 65%) and 65 Caucasian recipients (C, 35%). Mean follow-up was 34 months. The AA group was characterized by a higher incidence of renal disease due to hypertension (72% AA vs 37% C, P <.001), pretransplant dialysis (95% AA vs 82% C, P =.003), waiting time (1.9 years AA vs 1.1 years C, P =.02), cadaveric donation (88% AA vs 68% C, P =.01), HLA mismatching (mean 3.5 AA vs 2.4 C, P <.001), and delayed graft function (DGF; 50% AA vs 22% C, P =.001).

RESULTS

The 5-year actuarial patient and graft survival rates were 96% AA versus 83% C (P = NS) and 83% AA versus 75% C, (P = NS), respectively. The incidence of acute rejection (21% AA vs 12% C, P = NS) and mean time to acute rejection (12 months AA vs 11 months C) were similar. Although the incidence of chronic allograft nephropathy (CAN) was comparable (7% AA vs 5% C), the mean time to CAN was shorter in AA recipients (18 months AA vs 37 months C, P =.03).

CONCLUSIONS

These results suggest marked improvement in post-transplant outcomes in the TAC era in patients with multiple immunologic risk factors including AA ethnicity, cadaveric donor source, DGF, and HLA mismatching.