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PubMed1998

Transplantation of pediatric en bloc cadaver kidneys into adult recipients.

BACKGROUND: To maximize the renal donor pool, cadaveric pediatric en bloc kidneys have been transplanted as a dual unit by some transplant centers. We compared the short- and long-term outcomes of adult recipients of cadaveric pediatric en bloc renal transplants versus those of matched recipients of cadaveric adult kidneys. METHODS: Thirty-three adults who received pediatric en bloc kidney transplants between April 1990 and September 1997 were retrospectively identified and were compared with 33 matched adults who received adult cadaveric kidney transplants. The groups were identical for transplantation era, immunosuppression, recipient sex, race, cause of renal failure, mean weight, and follow-up duration (37.8 vs. 37.5 months). The mean recipient age study versus control was lower (36.3 vs. 48.9 years, P=0.0003). Results. There was no difference between the en bloc and adult donor groups in the 3-year patient survival rates (95% vs. 87%, P=0.16) or the 3-year graft survival rates (87.3% vs. 84.2%, P=0.35). Further, there was no difference in en bloc patient or en bloc graft survival time stratified by recipient age (14-44 vs. >45 years, P=0.11), en bloc donor age (<24 vs. >24 months, P=0.39), or recipient weight (<60, 61-75, >75 kg; P=0.60). Differences in serum creatinine (mg/dl) for the en bloc versus the control group at the time of discharge (3.0 vs. 7.8 mg/dl, P=0.06), at 1 year (1.4 vs. 2.0 mg/dl, P=0.06), and at 2 years (1.1 vs. 1.6 mg/dl, P=0.14) had dissipated by the time of the 5-year follow-up examination (1.1 vs. 1.6 mg/dl, P=0.14). Vascular complications were more prevalent in the en bloc group: renal vein thrombosis (one case), thrombosis of donor aorta (two cases), arterial thrombosis of one renal moiety (two cases), and renal artery stenosis (two cases). There were no differences between groups in delayed graft function, acute or chronic rejection, posttransplant hypertension, posttransplant protein-uria, or long-term graft function. CONCLUSIONS: Collectively, these data indicate that transplanting pediatric en bloc kidneys into adult recipients results in equivalent patient and graft survival compared with adult cadaveric kidneys. Further, the data also suggest that pediatric en bloc kidneys need not be strictly allocated based on recipient weight or age criteria.

Adolescent↗
PubMed1998

Can an immunologically, nonreactive potential allograft recipient undergo transplantation without a donor-specific crossmatch?

Performance of the pretransplant crossmatch requires 4 or more hours . Delays in the crossmatch might alter operating room availability and thereby increase donor organ cold ischemia time that might then result in increased risk of delayed graft function. To avoid these problems, recipients could be identified who would be expected to display negative donor crossmatches and who could be transplanted with a concurrent or retrospective rather than a pretransplant crossmatch. We, therefore, evaluated the percent reactive antibodies and donor IgG-antihuman globulin (AHG) crossmatch results of 1165 sera from 220 potential allograft recipients. Twenty-five (11%) of 220 recipients consistently displayed a 0% PRA and, with only one exception, their sera (n= 156) tested IgG-AHG crossmatch-negative against potential cadaveric donors (a 0.6% IgG-AHG positive crossmatch risk). These data suggest that the timing of the pretransplant serum crossmatch could be altered for a highly selected group of immunologically nonreactive recipients.

Female↗
PubMed1999

Renal transplantation in end-stage sickle cell nephropathy.

BACKGROUND: The role of renal transplantation as treatment for end-stage sickle cell nephropathy (SCN) has not been well established. METHODS: We performed a comparative investigation of patient and allograft outcomes among age-matched African-American kidney transplant recipients with ESRD as a result of SCN (n=82) and all other causes (Other-ESRD, n=22,565). RESULTS: The incidence of delayed graft function and predischarge acute rejection in SCN group (24% and 26%) was similar to that observed in the Other-ESRD group (29% and 27%). The mean discharge serum creatinine (SCr) was 2.7 (+/-2.5) mg/dl in the SCN recipients compared to 3.0 (+/-2.5) mg/dl in the Other-ESRD recipients (P=0.42). There was no difference in the 1-year cadaveric graft survival (SCN: 78% vs. Other-ESRD: 77%), and the multivariable adjusted 1-year risk of graft loss indicated no significant effect of SCN (relative risk [RR]=1.39, P=0.149). However, the 3-year cadaveric graft survival tended to be lower in the SCN group (48% vs. 60%, P=0.055) and their adjusted 3-year risk of graft loss was significantly greater (RR= 1.60, P=0.003). There was a trend toward improved survival in the SCN transplant recipients compared to their dialysis-treated, wait-listed counterparts (RR=0.14, P=0.056). In comparison to the Other-ESRD (RR=1.00), the adjusted mortality risk in the SCN group was higher both at 1 year (RR=2.95, P=0.001) and at 3 years (RR=2.82, P=0.0001) after renal transplantation. CONCLUSIONS: The short-term renal allograft result in recipients with end-stage SCN was similar to that obtained in other causes of ESRD, but the long-term outcome was comparatively diminished. There was a trend toward better patient survival with renal transplantation relative to dialysis in end-stage SCN.

Adolescent↗
PubMed1999

Pediatric renal transplantation under tacrolimus-based immunosuppression.

BACKGROUND: Tacrolimus has been used as a primary immunosuppressive agent in adult and pediatric renal transplant recipients, with reasonable outcomes. Methods. Between December 14, 1989 and December 31, 1996, 82 pediatric renal transplantations alone were performed under tacrolimus-based immunosuppression without induction anti-lymphocyte antibody therapy. Patients undergoing concomitant or prior liver and/or intestinal transplantation were not included in the analysis. The mean recipient age was 10.6+/-5.2 years (range: 0.7-17.9). Eighteen (22%) cases were repeat transplantations, and 6 (7%) were in patients with panel-reactive antibody levels over 40%. Thirty-four (41%) cases were with living donors, and 48 (59%) were with cadaveric donors. The mean donor age was 27.3+/-14.6 years (range: 0.7-50), and the mean cold ischemia time in the cadaveric cases was 26.5+/-8.8 hr. The mean number of HLA matches and mismatches was 2.8+/-1.2 and 2.9+/-1.3; there were five (6%) O-Ag mismatches. The mean follow-up was 4.0+/-0.2 years. RESULTS: The 1- and 4-year actuarial patient survival was 99% and 94%. The 1- and 4-year actuarial graft survival was 98% and 84%. The mean serum creatinine was 1.1+/-0.5 mg/dl, and the corresponding calculated creatinine clearance was 88+/-25 ml/min/1.73 m2. A total of 66% of successfully transplanted patients were withdrawn from prednisone. In children who were withdrawn from steroids, the mean standard deviation height scores (Z-score) at the time of transplantation and at 1 and 4 years were -2.3+/-2.0, -1.7+/-1.0, and +0.36+/-1.5. Eighty-six percent of successfully transplanted patients were not taking anti-hypertensive medications. The incidence of acute rejection was 44%; between December 1989 and December 1993, it was 63%, and between January 1994 and December 1996, it was 23% (P=0.0003). The incidence of steroid-resistant rejection was 5%. The incidence of delayed graft function was 5%, and 2% of patients required dialysis within 1 week of transplantation. The incidence of cytomegalovirus was 13%; between December 1989 and December 1992, it was 17%, and between January 1993 and December 1996, it was 12%. The incidence of early Epstein-Barr virus-related posttransplant lymphoproliferative disorder (PTLD) was 9%; between December 1989 and December 1992, it was 17%, and between January 1993 and December 1996, it was 4%. All of the early PTLD cases were treated successfully with temporary cessation of immunosuppression and institution of antiviral therapy, without patient or graft loss. CONCLUSIONS: These data demonstrate the short- and medium-term efficacy of tacrolimus-based immunosuppression in pediatric renal transplant recipients, with reasonable patient and graft survival, routine achievement of steroid and anti-hypertensive medication withdrawal, gratifying increases in growth, and, with further experience, a decreasing incidence of both rejection and PTLD.

Actuarial Analysis↗
PubMed1999

The clinical usefulness of the renal allograft biopsy in the cyclosporine era: a prospective study.

BACKGROUND: The renal allograft biopsy is generally accepted as the gold standard for clarifying the cause of renal dysfunction. However, the clinical usefulness of this procedure has rarely been studied prospectively, nor have most studies included follow-up of patients to delineate the influence of the biopsy on clinical outcome. In this study, we evaluated prospectively the clinical usefulness of the allograft biopsy in renal transplant recipients receiving cyclosporine (CyA). METHODS: During a 21-month period, 82 biopsies were performed. In 54 instances (47 patients), we outlined a presumed diagnosis and tentative treatment plan before the procedure. After the biopsy, a definitive diagnosis was made and an appropriate patient management approach was instituted. We analyzed the incidence of change in patient management that resulted from histological findings. All patients were followed to monitor their response to treatment and allograft survival. In cases of biopsy-proven acute cellular rejection (ACR) or cyclosporine (CyA) toxicity, clinical and laboratory data from the day of the biopsy were reviewed to determine their diagnostic value. RESULTS: One biopsy specimen was inadequate for definitive interpretation. The biopsy findings resulted in a change in patient management in 22 (41.5%) of the remaining 53 cases (change group). The incidence of altered patient management was 38.7% in biopsy specimens taken in the first month, 55.6% between 1 and 12 months, and 38.5% after 1 year posttransplantation. A change in management was required in 2 of 2 patients with chronic allograft dysfunction, in 44.4% of the 45 patients with acute allograft dysfunction, and in none of the patients with delayed graft function (n=6). Within the first week of treatment 19 of 22 (86.4%) in the change group and 25 of 31 (80.6%) in the no change group had a positive response to therapy. The 1-year allograft survival rate was also similar between the two groups. None of the clinical and laboratory data was useful in distinguishing ACR from CyA toxicity. CONCLUSIONS: Renal allograft biopsy findings alter patient management recommendations in approximately 40% of patients in whom a presumptive diagnosis had been made on the basis of clinical and laboratory findings. Patients who had a change in patient management because of biopsy findings demonstrated a response to therapy and allograft survival similar to those of patients who had no alteration in management plan after the biopsy.

Adult↗
PubMed1999

Predictors of renal transplant histology at three months.

BACKGROUND: The quality of a damaged kidney, the complexity of the surgery, and the events in the first weeks after transplantation, such as delayed graft function (DGF) and acute rejection, may influence its histological appearance and long-term survival. The aim of this study was to evaluate the importance of these factors in predicting renal allograft histology at 3 months. METHODS: Prospective, protocol kidney biopsy specimens (n=112), obtained 3 months after transplantation, were scored for chronic damage by the Banff schema and evaluated by multivariate analysis against donor factors, implantation histology, prior recipient sensitization, ischemia, perioperative factors, and subsequent clinical events, such as DGF and acute rejection. RESULTS: Adequate samples were obtained in 102 of 112 biopsies and classified as chronic Banff grade 0 (n=22), grade I (n=56), grade II (n=23), or grade III (n=1). Acute Banff scores were minimal. DGF occurred in 49% and was the strongest predictor of tubulointerstitial damage at 3 months. DGF correlated with acute tubular necrosis on the implantation biopsy specimen and with the number of acute rejection episodes; DGF also correlated with the Banff grades of chronic glomerulitis, chronic interstitial fibrosis, and tubular atrophy scores (P<0.05-0.001) in the 3-month biopsy specimen. By multivariate analysis, chronic tubular atrophy was independently predicted by the presence of vascular disease in the donor biopsy specimen, DGF, and vascular rejection occurring within the first 3 months (P<0.05-0.001). Chronic interstitial fibrosis was unrelated to fibrosis in the donor biopsy specimen but was independently predicted by DGF, donor age, and vascular rejection (P<0.05-0.001). Vascular disease in the donor biopsy specimen correlated with chronic intimal thickening (r=0.36, P<0.01) and arteriolar hyalinosis score (r=0.54, P<0.001) on the 3-month biopsy specimen. Banff chronic intimal vascular thickening was independently predicted by donor biopsy specimen vascular grade, prior vascular rejection episodes, and renal cold ischemia time (P<0.05-0.01). There were no correlates with the mean cyclosporine (CsA) dose, blood levels, diagnosis of CsA toxicity, or cellular rejection within the first 3 months. CONCLUSIONS: This study has demonstrated that the quality of the donor organ at implantation was strongly predictive of subsequent renal histology in grafts functioning at 3 months. Vascular rejection and DGF had a significant long-term effect on graft damage, but cellular rejection and simple measures of CsA exposure did not.

Acute Disease↗
PubMed1999

Neoral monitoring by simplified sparse sampling area under the concentration-time curve: its relationship to acute rejection and cyclosporine nephrotoxicity early after kidney transplantation.

BACKGROUND: Cyclosporine (CsA) dosing is traditionally based on trough blood levels (C0) rather than area under the concentration-time curve (AUC), although AUC correlates better with posttransplantation clinical events. For Neoral, AUC based on limited sampling correlates closely with full 12-hr AUC. The purpose of our study was to correlate C0 with AUC based on CsA levels at 0, 1, 2, 3, and 4 hr after dose (PK0-4) and to compare this AUC with C0 in predicting acute rejection (AR) and acute cyclosporine nephrotoxicity (CsANT) in de novo first kidney transplant patients. METHODS: PK0-4 was done 2-4 days after starting Neoral for 156 patients. All received CsA-based triple-drug immunosuppression without antibody induction. AUC was calculated as projected 12-hr (AUC0-12) and actual 4-hr (AUC0-4) from the PK0-4 using the parallel trapezoid rule. Neoral dosing was based on C0 not AUC. AUC was retrospectively compared with C0 as a predictor of AR and CsANT during the first 90 days. RESULTS: C0 correlated poorly with AUC0-12 and AUC0-4 (r=0.61 and r=0.42). C0 (mean+/-SEM) levels were not significantly different in 34 patients with and 109 without AR (293+/-21 vs. 294+/-11 microg/L, P=0.95). AUC0-12 and AUC0-4 were significantly lower in patients with than without AR (AUC0-12 9090+/-598 vs. 10608+/-336 microg x h/L, P=0.01; AUC0-4 3934+/-306 vs. 4802+/-166 microg.h/L, P=0.006). In stepwise regression analysis only AUC0-12 or AUC0-4 (P=0.03/P=0.02) and delayed graft function (P=0.007) predicted AR. AUC0-12, AUC0-4, and C0 were all significantly higher in patients with CsANT than without CsANT (AUC0-12 11746+/-650 vs. 10023+/-301 microg x h/L, P=0.01; AUC0-4 5270+/-358 vs. 4474+/-150 microg x h/L, P=0.01; C0 343+/-18 vs. 287+/-10 microg/L, P=0.01), but in stepwise regression analysis C0 was not an independent predictor of CsANT. Patients with AUC0-12 in the range of 9500 to 11500 microg x h/L or AUC0-4 between 4400 and 5500 microg x h/L had the lowest incidence of AR (13% and 7%, respectively) without significantly higher risk for CsANT. CONCLUSION: C0 correlates poorly with AUC based on PK0-4. Early AUC based on PK0-4 is more closely associated with AR and CsANT than is C0. Our data suggest that a target AUC0-12 of 9500-11500 or AUC0-4 of 4400-5500 microg x h/L may provide optimal Neoral immunosuppression.

Acute Disease↗
PubMed1999

Laparoscopic versus open donor nephrectomy: comparing ureteral complications in the recipients and improving the laparoscopic technique.

BACKGROUND: Laparoscopic live donor nephrectomy (LDN) is a recently developed procedure, the performance of which needs to be studied. Given the reported advantages in the donors, this study looks at graft outcome and ureteral complications in recipients of kidneys procured by open donor nephrectomy (ODN) versus LDN. METHODS: The LDN recipients consisted of 193 patients since 3/27/96. A total of 168 ODN recipients from 1991 to 1998 served as controls. Immunosuppression protocols were similar for both groups. RESULTS: Two-year graft survival for LDN and ODN was 98% and 96%, respectively. Two-year patient survival for LDN and ODN was 98% and 97%, respectively. The incidence of delayed graft function and mean serum creatinine at 3 and 12 months was similar in both groups. However, the number of ureteral complications that required operative repair was significantly higher for LDN recipients compared to ODN recipients, 7.7% (n=15) vs. 0.6% (n=1) respectively (P=0.03). Ureteral stenting was required in an additional 3.1% (n=6) of LDN and 2.4% (n=4) of ODN (P=NS). There was, however, a learning curve with time. For the first 130 LDN patients, a total of 20 ureteral complications were recorded, whereas only one occurred in the more recent 63 patients (P=0.03). CONCLUSIONS: The higher ureteral complication rate in LDN recipients has improved over time as technical causes have been identified. We have noted significant improvement in ureteral viability by using the endogastrointestinal anastomosis instrument on the ureter and peri-ureteral tissue. LDN is therefore an excellent alternative to ODN. Identification of hazards unique to this technique is critical before its broader application.

Adult↗
PubMed1999

Increased incidence of postoperative infections associated with peritoneal dialysis in renal transplant recipients.

BACKGROUND: Infection is a frequent postoperative complication in renal transplant recipients. However, little information is available concerning the effect of pretransplantation dialysis modality on posttransplantation complications including infection. We therefore evaluated the effect of hemodialysis (HD) versus peritoneal dialysis (PD) on the incidence of postoperative infection as well as several other posttransplantation outcomes. METHODS: A retrospective analysis was performed using medical records covering the period 30 days after transplantation of 156 dialysis patients who underwent renal transplantation at a single center during a 22-month period. Of these patients, 103 received only HD, 32 received only PD, 13 received PD in the past and HD immediately before transplantation (PH/HD), and 8 received HD in the past and PD immediately before transplantation (HD/PD). The presence of culture-proven infection, types of infecting organisms, length of initial hospital stay, and incidence of rejection during the first 30 days after transplantation were determined for each patient. RESULTS: All groups were similar with regard to age, race, gender, underlying disease, donor type, incidence of delayed graft function, and perioperative antibiotic prophylaxis. There were more infectious complications within 30 days after transplantation in patients on PD just prior to transplantation (PD and HD/PD) than in HD patients (67.5% vs. 25.9%, P<0.00001). When types of infectious organisms were assessed, PD patients were found to have a greater incidence of infections with microorganisms that colonize human skin (P<0.0001). The median length of hospital stay was 3 days longer for PD patients and 6.5 days longer for HD/PD patients than for patients receiving HD (P=0.01 and 0.04), and PD and HD/PD patients were more likely to have an episode of rejection than HD patients (P=0.02). CONCLUSIONS: Renal replacement therapy with PD immediately before transplantation negatively affects outcome as compared with HD, predisposing patients to a greater incidence of postoperative infections and rejection and a longer hospital stay. Further study in a randomized controlled trial may help determine how adjustment of the dialysis method can optimize transplantation outcome.

Adult↗
PubMed2000

Immunologic and nonimmunologic factors: different risks for cadaver and living donor transplantation.

BACKGROUND: There is a debate about the relative contribution of immunologic (rejection) and nonimmunologic (limited nephron mass) factors in long-term graft survival. METHODS: Using multivariate analysis, we studied the association of the following variables with outcome: delayed graft function (DGF), acute rejection, recipient race (black vs. nonblack), donor age (<50 vs. > or =50), donor race, and donor and recipient gender. Because of the association between DGF and rejection, recipients were grouped as follows: DGF, rejection; DGF, no rejection; no DGF, rejection; no DGF, no rejection. Data were analyzed on 1199 first kidney transplants in adults (752 living donor, 447 cadaver donor) done between January 1, 1985 and December 31, 1996. Two analyses were done: first, all transplants; second, only those with > or =1 year survival. For both, there was no difference in risk factors if death with function was or was not censored. RESULTS: For all cadaver transplant recipients, risk factors were acute rejection, DGF plus rejection, black recipient race, and donor age > or =50. For living donor recipients, only acute rejection was a risk factor. When only 1-year graft survivors were considered, risk factors were the same: for cadaver recipients, risk factors were acute rejection, DGF plus rejection, black recipient race, and donor age > or =50; for living donor recipients the risk factor was rejection. CONCLUSION: We found immunologic factors (rejection with or without DGF) to be significant in both living donor and cadaver donor transplants. Nonim. munologic factors (donor age, recipient race) were significant only in cadaver donor transplants.

Acute Disease↗
PubMed2000

Outcome in recipients of dual kidney transplants: an analysis of the dual registry patients.

BACKGROUND: A novel but controversial method to increase the utilization of aged donor kidneys is the transplantation of both kidneys as a dual transplant. Initial single-center reports demonstrated outcomes similar to single kidneys from younger donors. In this report, we compare outcome in recipients of kidneys from donors > or =54 years of age who received a single kidney transplant reported to the United Network for Organ Sharing Scientific Registry versus a dual kidney transplant reported to the Dual Kidney Registry. METHODS: A retrospective analysis was performed, comparing four donor and nine recipient and outcome variables between recipients of a single versus a dual transplant between March 1993 and March 1999. RESULTS: Dual versus single transplants from donors > or =54 years of age have a significantly decreased incidence of delayed graft function, and lower serum creatinines up to 2 years after transplant despite having kidneys from significantly older donors with poorer HLA matching. CONCLUSIONS: Dual kidney transplants improve graft performance and outcome in recipients of kidneys from donors > or =54 years of age.

Aged↗
PubMed2000

A model of gradual onset brain death for transplant-associated studies in rats.

BACKGROUND: The relatively few studies that have examined the systemic events after brain death have primarily involved large animals. For more precise definition of the physiology of this central catastrophe and its influence on peripheral organs, we have established a reproduceable model of gradual onset brain death in rats. METHODS: The central injury is induced by graded inflation of a Fogarty catheter placed intracranially under EEG and blood pressure monitoring. The rats were mechanically ventilated for 6 hr before removal of their kidneys. Complications and mortality are discussed. RESULTS: The majority (83%) of the 100 experimental animals could be used as organ donors. After a transient period of autonomic storm, the mean arterial blood pressure remained consistently between 80-100 mmHg, not appreciably different from controls. Despite normotension, the transplanted kidneys from brain dead donors showed a significantly longer interval to regain uniform cortical color and turgor than kidneys from control animals. CONCLUSIONS: We describe a controlled model of gradual onset brain death in the rat in which normotension can be sustained for several hours before the kidneys are removed for transplantation. Despite stable donor blood pressure, ischemia of peripheral organs may explain in part the increased incidence of delayed graft function of cadaver kidneys compared with those from living donors. This model is suitable for transplant-related studies involving organs from donors with irreversible central injury.

Animals↗
PubMed2000

Selective omission of the donor cross-match before renal transplantation: efficacy, safety and effects on cold storage time.

BACKGROUND: A donor lymphocyte cross-match (XM) test performed before renal transplantation is considered mandatory but may delay the transplant and increase the cold storage time. With careful documentation of sensitizing events and with knowledge of previous antibody screening results, it is often possible to predict the XM result for a given donor HLA mismatch. In this study, a policy was adopted of omitting the pretransplant XM in patients in whom a negative result was predicted with absolute confidence. METHODS: Recipients were selected for cadaveric donor kidney transplantation using a computer algorithm based on HLA match, sensitization status, time on the waiting list and donor and recipient age. The immediate pretransplant cross-match test was omitted in non-sensitized recipients and in sensitized recipients where antibody specificities were precisely defined and not against donor HLA. RESULTS: From October 1997 to May 1999, 53 of 96 (55%) consecutive cadaveric kidney donor transplants were performed without a pretransplant XM. In all cases, a negative donor HLA-specific antibody XM was confirmed after transplantation. Omission of the pre-transplant XM was associated with a significant reduction in cold ischemic time (15.0 hr vs. 18.2 hr, P=0.01) and a reduced incidence of delayed graft function (13% vs. 33%, P=0.03). However, there was no difference in transplant outcome at 1 year. CONCLUSION: Rigorous attention to priming events together with careful antibody screening allows the pre-transplant XM test to be safely omitted in approximately half the patients awaiting renal transplantation. This policy allows a modest reduction in cold ischemia time, but it remains to be seen whether this is of clinical benefit.

Adult↗
PubMed2000

Randomized trial of tacrolimus (Prograf) in combination with azathioprine or mycophenolate mofetil versus cyclosporine (Neoral) with mycophenolate mofetil after cadaveric kidney transplantation.

BACKGROUND: Our clinical trial was designed to investigate the optimal combination of immunosuppressants for renal transplantation. METHODS: A randomized three-arm, parallel group, open label, prospective study was performed at 15 North American centers to compare three immunosuppressive regimens: tacrolimus + azathioprine (AZA) versus cyclosporine (Neoral) + mycophenolate mofetil (MMF) versus tacrolimus + MMF. All patients were first cadaveric kidney transplants receiving the same maintenance corticosteroid regimen. Only patients with delayed graft function (32%) received antilymphocyte induction. A total of 223 patients were randomized, transplanted, and followed for 1 year. RESULTS: There were no significant differences in baseline demography between the three treatment groups. At 1 year the results are as follows: acute rejection 17% (95% confidence interval 9%, 26%) in tacrolimus + AZA; 20% (confidence interval 11%, 29%) in cyclosporine + MMF; and 15% (confidence interval 7%, 24%) in tacrolimus + MMF. The incidence of steroid resistant rejection requiring antilymphocyte therapy was 12% in the tacrolimus + AZA group, 11% in the cyclosporine + MMF group, and 4% in the tacrolimus + MMF group. There were no significant differences in overall patient or graft survival. Tacrolimus-treated patients had a lower incidence of hyperlipidemia through 6 months posttransplant. The incidence of posttransplant diabetes mellitus requiring insulin was 14% in the tacrolimus + AZA group, 7% in the cyclosporine + MMF and 7% in the tacrolimus + MMF groups. CONCLUSIONS: All regimens yielded similar acute rejection rates and graft survival, but the tacrolimus + MMF regimen was associated with the lowest rate of steroid resistant rejection requiring antilymphocyte therapy.

Adult↗
PubMed2000

Sensitization and sensitivity: defining the unsensitized patient.

BACKGROUND: Since the landmark studies of Patel and Terasaki in the late 1960s, pretransplant cross-matching has been performed by HLA laboratories on a 24-hr/7-day basis. In fact, regulating agencies such as the American Society for Histocompatibility and Immunogenetics and the United Network for Organ Sharing have mandated prospective crossmatching for selected solid organ transplants. However, two recent publications (Transplantation 1998; 66: 1833; and Transplantation 1998; 66: 1835) have suggested a change to this approach. Specifically, those authors advocate the transplantation of non-sensitized individuals without a final prospective cross-match as a means to reduce cold ischemia time and the incidence of delayed graft function. Such considerations were predicated upon results generated by cytotoxicity-based antibody screening. We and others, however, have reported that a flow cytometric-based assay is a more sensitive method to detect alloantibodies than cytotoxicity. Furthermore, an increasing number of reports document that graft survival is improved among patients whose final flow cytometric crossmatches were negative compared to patients with positive flow cytometric crossmatches. Although we agree that it is reasonable to transplant truly non-sensitized patients without a prospective final crossmatch, our data demonstrate that a large number of patients deemed non-sensitized by cytotoxicity-based antibody assessment are, in fact, sensitized. METHODS: Panel-reactive antibody (PRA) testing was performed with 703 sera from 527 patients. The patient population consisted of individuals awaiting either renal or cardiac transplantation. PRA evaluations were performed using lymphocyte cytotoxicity (antiglobulin-enhanced, complement-dependent cytotoxicity [AHG-CDC]) or assays (enzyme-linked immunosorbent assay [ELISA]; flow cytometry) in which solubilized HLA molecules were affixed to solid phase matrices. RESULTS: PRA activity in 264 sera from 88 patients was evaluated by AHG-CDC, ELISA, and flow cytometry. Results among the three methods were concordant for 83% of these sera. Discordant results occurred with 32 samples and demonstrated a distinct hierarchy in the sensitivity of the three techniques to detect alloantibodies. None of the 32 sera were positive by AHG-CDC, 20/32 were positive by ELISA, and 32/32 were positive by flow cytometry. Subsequent studies revealed that, among 527 patients, 302 (57%) exhibited 0% PRA by AHG-CDC. Of these 302 AHG-CDC-negative patients, 76 (25%) had class I or class II antibodies detectable using a flow cytometric approach. Within the AHG-CDC-negative/flow cytometric-positive patients, PRA values exhibited a wide range (6-99%) for both class I and class II antibodies. The average PRA was 27% and 38% for class I and II, respectively. Retrospective flow cytometric crossmatches performed for 30 recipients of cardiac allografts whose AHG-CDC PRA were 0% revealed that 11/30 crossmatches were positive. CONCLUSIONS: The concept of transplanting non-sensitized patients without a prospective final crossmatch is appealing and, if bona fide, clearly makes sense. However, our data demonstrate that how a patient is deemed non-sensitized is critical. The difference between AHG- and flow cytometric-based PRA testing is significant and can result in transplantation of alloimmunized patients considered to be non-sensitized. Therefore, we recommend that, if a transplant center chooses to forego a prospective final crossmatch, the decision to do so should be based on methods more sensitive than AHG-CDC.

Antibodies, Anti-Idiotypic↗
PubMed2000

Evaluation of the older cadaveric kidney donor: the impact of donor hypertension and creatinine clearance on graft performance and survival.

BACKGROUND: The use of older donors for cadaveric renal transplantation (CRT) remains controversial because older donors are associated with decreased graft survival, yet offer the opportunity for donor pool expansion. We investigated the impact of two age-related donor factors, hypertension and calculated creatinine clearance (C(Cr)), as predictors of graft outcome in recipients of CRTs from donors > or =55 years of age. METHODS: We reviewed 33,595 recipients of CRTs reported to UNOS since 4/1/94, of which 4,732 were from donors aged > or =55 years. Outcome measures were graft survival, serum creatinine, and incidence of delayed graft function with 3 years of follow-up. We first analyzed the effect of hypertension on outcome from donors > or =55 years: 2679 donors had no hypertension, 1058 had hypertension < or =10 years, and 557 had hypertension > 10 years. Next, the effect of donor C(Cr) as a risk predictor was investigated. Based on this analysis, recipients of older donors were grouped into two cohorts for comparison: 2570 donors with C(Cr)<80 ml/min and 2162 donors with C(Cr) > or =80 ml/min. RESULTS: Actuarial graft survival from donors aged <55 years was 88.0, 83.4, and 78.5% at 1, 2, and 3 years, vs. 80.6, 73.5, and 65.3% from donors > or =55 years (P<0.0001). When stratified by hypertension, older donors hypertensive > 10 years had survivals of 77, 66, and 57% vs. 81, 73, and 65% from donors without hypertension (P<0.017) and 80, 74, and 66% from donors hypertensive <10 years (P<0.017). When stratified by C(Cr), older donors with C(Cr) <80 ml/min had survivals of 77, 69, and 62% vs. 83, 76, and 66% from donors with C(Cr) > or =80 (P<0.0001). Finally, older donors with both hypertension > 10 years and C(Cr) <80 ml/min had survivals of 77, 61, and 53%. CONCLUSIONS: Long-standing hypertension and low calculated creatinine clearance are risk factors for decreased graft survival of CRTs from older donors. When both factors are present, graft survival is significantly decreased.

Aged↗
PubMed2000

Protection of autotransplanted pig kidneys from ischemia-reperfusion injury by polyethylene glycol.

BACKGROUND: Ischemia-reperfusion injury (IRI) is often responsible for graft rejection and leads to delayed graft function of cadaveric kidneys. We have shown that adding polyethylene glycol (PEG 20M) to the preservation solutions helps protect isolated perfused pig kidneys against cold ischemia and reperfusion injury. METHODS: We compared the effects of adding PEG to a simplified high-K+ perfusion solution of cold-stored kidneys to Euro-Collins or University of Wisconsin solutions on the function of reperfused autotransplanted pig kidneys. The left kidney was cold-flushed with the preservation solutions and stored for 48 hr at 4 degrees C before reimplantation. Creatinine clearance and fractional excretion of sodium were analyzed 2 days before surgery and over 7 days after transplantation. Histological sections were obtained 40 min after reperfusion and on day 7 after surgery. RESULTS: Adding PEG to the perfusate significantly reduced IRI from autotransplanted pig kidneys. Creatinine clearance was significantly higher and fractional excretion of sodium was significantly lower in pigs transplanted with kidneys cold-flushed with PEG-supplemented perfusate than in those flushed with Euro-Collins or University of Wisconsin solutions. PEG supplementation also better preserved the integrity of kidney cells and markedly reduced interstitial cell infiltrates. CONCLUSION: PEG protects against IRI and reduces early cellular inflammation. PEG may impair the recruitment and migration of leukocytes into retransplanted pig kidneys. Cold preservation of donor organs with PEG-supplemented solutions may therefore help limit IRI in human renal transplantation.

Animals↗
PubMed2001

Effect of histological damage on long-term kidney transplant outcome.

BACKGROUND: Chronic renal allograft failure remains a major challenge to overcome. Factors such as donor quality, delayed graft function (DGF), acute rejection, and immunosuppression are known to affect long-term outcome, but their relationship to histological damage to graft outcome is unclear. METHODS: Protocol kidney biopsies (n=112) obtained at 3 months after transplantation yielded 102 with adequate tissue. Histology was scored by the Banff schema, and compared with implantation biopsies (n=91), repeat 12-month histology (n=39), decline in serum creatinine and serial isotopic glomerular filtration rate, onset of chronic allograft nephropathy (CAN), and actuarial graft survival censored for death with a functioning graft. RESULTS: At a median follow-up of 9.3 years, 20 patients had graft failure and 26 died with a functioning graft. Banff chronic nephropathy was present in 24% of 3-month biopsies, and was predicted by microvascular disease in the donor, cold ischemia, DGF, and acute vascular rejection (P<0.001). Acute glomerulitis at 3 months correlated with segmental glomerulosclerosis at 12 months, subsequent recurrent glomerulonephritis, and graft failure (P<0.01). Subclinical rejection at 3 months occurred in 29% of biopsies, correlated with prior acute rejection and HLA mismatch, and led to chronic histological damage by 12 months (r=0.25-0.67, P<0.05-0.001). Subclinical rejection, arteriolar hyalinosis, and tubulitis present at 3 months had resolved by 12 months. The 10-year survival rates for Banff chronic nephropathy were 90.4% for grade 0, 81.0% grade 1, and 57.9% for grades 2 or greater (P<0.01). Early tubulointerstitial damage at 3 months profoundly influenced graft survival beyond 10 years. CAN was predicted by kidney ischemia, 3-month chronic intimal vascular thickening, tubular injury, proteinuria, and late rejection. Chronic fibrointimal thickening of the small arteries and chronic interstitial fibrosis at 3 months independently predicted graft loss and decline in renal function (P<0.05-0.001). CONCLUSIONS: Early transplant damage occurs in the tubulointerstitial compartment from preexisting donor kidney injury and discrete events such as vascular rejection and DGF. Subsequent chronic damage and graft failure reflect accumulated previous injury and chronic interstitial fibrosis, vascular impairment, subclinical rejection, and injury from late rejection. CAN may be conceptualized as the sequelae of incremental and cumulative damage to the transplanted kidney. The duration of graft survival is dependent and predicted by the quality of the transplanted donor kidney combined with the intensity, frequency, and irreversibility of these damaging insults.

Adult↗