William D. Payne

Risk factors for chronic rejection in renal allograft recipients.

Chronic rejection is a major barrier to long-term renal allograft survival. Cyclosporine, though effective at reducing graft loss to acute rejection, has had little impact on the incidence of chronic rejection. Between June 2, 1986 and January 22, 1991, 587 kidney-alone transplants (566 patients) were performed, and had been entered into our renal transplant database and had at least 1 year of follow-up: 103 with biopsy-proven chronic rejection (37 living-related donor, 66 cadaver) and 484 without chronic rejection (236 LRD 248 CAD). The 5-year patient survival was 84% for recipients with biopsy-proven chronic rejection vs. 89% without (P = .08). The 5-year graft survival was 31% for recipients with biopsy-proven chronic rejection vs. 81% without (P < .0001). Using multivariate analysis, we determined the impact on the incidence of chronic rejection of these variables: transplant number, age at transplant (< 18 years, 18 to 50 years, > 50 years), gender, human leukocyte antigen matching, peak and transplant panel-reactive antibody, acute rejection episodes, infections (including cytomegalovirus, viral, and bacterial), donor age, and CsA dosage at 1 year (< 5 mg/kg vs. > or = 5 mg/kg). Logistic regression models were fit to the data using a forward stepwise selection procedure. In this analysis, risk factors included an acute rejection episode (P < .001), CsA dosage < 5 mg/kg/day at 1 year (P = .007), infection (P = .023), female gender (P = .042), and retransplant (P = .103). Individual analyses were done for CAD and LRD recipients. For both groups, important variables were acute rejection, infection, CsA dosage at 1 year, and age at transplant. In conclusion, acute rejection, CsA dosage < 5 mg/kg/day at 1 year, and infection are the major risk factors for the development of chronic rejection, suggesting that chronic rejection may be the result of inadequate immunosuppression (acute rejection episodes and low CsA dosage) or the production of inflammatory cytokines (infections).

The impact of an acute rejection episode on long-term renal allograft survival (t1/2)

An acute renal transplant rejection episode has been shown to be associated with decreased 1-year graft survival. The impact on long-term outcome is undefined. We studied the impact of an acute rejection episode on t1/2, the time it takes for 1/2 of the grafts functioning at 1 year to fail. Use of t1/2 avoids inclusion of early graft loss to acute rejection or complications of treatment. Since 1/1/86, a total of 653 patients have received a primary kidney transplant and had at least 1 year of function. Recipients were divided by the incidence and timing of rejection: no rejection; 1 rejection within the first year; >1 rejection, the first episode in the first year; and ≥ rejection, the first episode after the first year. A single rejection episode in the first year reduced t1/2 (45±11 years in those with no rejection vs. 25±8 years in those with 1 in the first year). Multiple rejections (t1/2=5±11 years) and a first rejection after the first year (t1/2=3±1 years) have a significant effect (P<.05). Both living and cadaver donor recipients with rejection had shortened t1/2. For those with >1 rejection, the first episode in the first year, and those with ≥1 rejection, the first episode after the first year, chronic rejection was the predominant cause of graft loss; noncompliance also played a role. We conclude that a single rejection episode shortens t1/2. Those with >1 rejection, the first episode within the first year, and those with ≥1 rejection, the first episode after the first year, are at high risk for late graft loss.

Early versus late acute renal allograft rejection : impact on chronic rejection

We studied the effect of acute renal allograft rejection and its timing on the development of chronic rejection and subsequent graft loss. Between January 1, 1987 and April 30, 1991, 424 patients at the University of Minnesota received a primary kidney transplant (minimum follow-up, 1 year). Patients were subdivided by donor source, presence or absence of acute rejection, and the timing of acute rejection onset (early, ≤ 60 days vs. late, > 60 days post-transplant). For living donor (LD) transplant recipients (n=219), the incidence of chronic rejection is 0.8% in those who had no acute rejection (n=130), 20% in those with acute rejection ≤60 days (n=59) (P<0.001 vs. no acute rejection), and 43% in those with acute rejection > 60 days (n=30) (P<0.001 vs. no acute rejection, P=0.04 vs. early acute rejection). For cadaver (CAD) transplant recipients (n=205), the incidence of chronic rejection is 0% in those who had no acute rejection (n=109), 36% in those with acute rejection ≤ 60 days (n=69) (P<0.001 vs. no acute rejection), and 63% in those with acute rejection > 60 days (n=27) (P<0.001 vs. no acute rejection, P=0.03 vs. early acute rejection). For both LD and CAD recipients, no grafts have been lost to chronic rejection among those who did not first have at least 1 acute rejection episode. In contrast, 23 patients with acute rejection have had graft loss to chronic rejection. For both LD and CAD recipients, those with > 1 acute rejection episode had significantly more chronic rejection than those with only 1 rejection (P<0.05). There was no significant difference in the incidence of chronic rejection based on whether the first acute rejection episode was steroid resistant or steroid responsive. We conclude that acute rejection is strongly related to the development of biopsy-proven chronic rejection and subsequent graft loss. Patients undergoing their first acute rejection episode > 60 days (vs. ≤ 60 days) have an increased incidence of chronic rejection.

The impact of cyclosporine and combination immunosuppression on the incidence of posttransplant diabetes in renal allograft recipients

The incidence of posttransplant diabetes mellitus (PTDM) was compared in three groups of renal transplant recipients: nondiabetic patients who had been randomized between 1980 and 1983 to receive antilymphoblast globulin (ALG), azathioprine (AZA), and prednisone (P) (group 1) or cyclosporine (CsA) plus prednisone (group 2). Group 3 consisted of a more recent (1984-85) cohort who were given a combination of azathioprine, cyclosporine, and prednisone (+/- ALG). PTDM developed in 20 of 173 previously nondiabetic 18-55-year-old patients. Three of 47 patients (6.4%) in group 1, 4 of 58 patients (6.9%) in group 2, and 13 of 68 patients in group 3 (19.1%) developed PTDM. Thus in the two groups composing the concurrent prospective randomized trial (groups 1 and 2) the incidence of PTDM did not differ. The subsequent patients who were given a combination of ALG, azathioprine, cyclosporine, and prednisone developed a significantly greater incidence of PTDM even though the total dose of cyclosporine and prednisone were lower than in groups 1 and 2. PTDM usually occurred within two months of transplantation, and 11 of 17 patients who initially required insulin are still dependent upon exogenous insulin. The incidence of PTDM was not significantly affected by sex of the recipient, HLA-type, primary renal disease, rejection episodes, primary vs. secondary transplant, or prior splenectomy. The incidence of PTDM is greater in patients older than 45 (34.2% vs. 5.2%), and heavier than 70 kg (21.1% vs. 5.1%); in recipients of cadaveric allografts (15.7% vs. 4.6%); and in patients who were hospitalized for infections (22.4% vs. 4.7%). CsA levels tended to be higher in the group 2 and 3 patients who developed PTDM than in those who remained nondiabetic. One-year actuarial patient survival in those with PTDM was 83.3% vs. 98% (P less than .01) in the nondiabetic and graft survival was 77.1% vs. 87.1% (NS). The combination of Minnesota ALG, azathioprine, cyclosporine, and prednisone appears to predispose older, heavier recipients of cadaver allografts to the development of PTDM. The risk of PTDM must be weighed against the more usual results of improved patient and graft survival using this combination of immunosuppression.

2,500 living donor kidney transplants: A single-center experience

ObjectiveTo review a single center’s experience and outcome with living donor transplants. Summary Background DataOutcome after living donor transplants is better than after cadaver donor transplants. Since the inception of the authors’ program, they have performed 2,540 living donor transplants. For the most recent cohort of recipients, improvements in patient care and immunosuppressive protocols have improved outcome. In this review, the authors analyzed outcome in relation to protocol. MethodsThe authors studied patient and graft survival by decade. For those transplanted in the 1990s, the impact of immunosuppressive protocol, donor source, diabetes, and preemptive transplantation was analyzed. The incidence of rejection, posttransplant steroid-related complications, and return to work was determined. Finally, multivariate analysis was used to study risk factors for worse 1-year graft survival and, for those with graft function at 1 year, to study risk factors for worse long-term survival. ResultsFor each decade since 1960, outcome has improved after living donor transplants. Compared with patients transplanted in the 1960s, those transplanted in the 1990s have better 8-year actuarial patient and graft survival rates. Death with function and chronic rejection have continued to be a major cause of graft loss, whereas acute rejection has become a rare cause of graft loss. Cardiovascular deaths have become a more predominant cause of patient death; infection has decreased. Donor source (e.g., ideally HLA-identical sibling) continues to be important. For living donor transplants, rejection and graft survival rates are related to donor source. The authors show that patients who had preemptive transplants or less than 1 year of dialysis have better 5-year graft survival and more frequently return to full-time employment. Readmission and complications remain problems; of patients transplanted in the 1990s, only 36% never required readmission. Similarly, steroid-related complications remain common. The authors’ multivariate analysis shows that the major risk factor for worse 1-year graft survival was delayed graft function. For recipients with 1-year graft survival, risk factors for worse long-term outcome were pretransplant smoking, pretransplant peripheral vascular disease, pretransplant dialysis for more than 1 year, one or more acute rejection episodes, and donor age older than 55. ConclusionsThese data show that the outcome of living donor transplants has continued to improve. However, for living donors, donor source affects outcome. The authors also identify other major risk factors affecting both short- and long-term outcome.

Are wound complications after a kidney transplant more common with modern immunosuppression

Background. The most common surgical complication after a kidney transplant is likely related to the wound. The purpose of this analysis was to determine the incidence of, and risk factors for, wound complications (e.g., infections, hernias) in kidney recipients and to assess whether newer immunosuppressive drugs increase the risk for such complications. Methods. Between January 1, 1984 and September 30, 1998, we performed 2013 adult kidney transplants. Of these 2013 recipients, 97 (4.8%) developed either a superficial or a deep wound infection. Additionally, 73 (3.6%) recipients developed either a fascial dehiscence or a hernia of the wound. We used univariate and multivariate techniques to determine significant risk factors and outcomes. Results. Mean time to development of a superficial infection (defined as located above the fascia) was 11.9 days posttransplant; to development of a deep infection (defined as located below the fascia), 39.2 days; and to development of a hernia or fascial dehiscence, 12.8 months. By multivariate analysis, the most significant risk factor for a superficial or deep wound infection was obesity (defined as body mass index>30 kg/m2) (RR=4.4, P =0.0001). Other significant risk factors were a urine leak posttransplant, any reoperation through the transplant incision, diabetes, and the use of mycophenolate mofetil (MMF) (vs. azathioprine) for maintenance immunosuppression (RR=2.43, P =0.0001). Significant risk factors for a hernia or fascial dehiscence were any reoperation through the transplant incision, increased recipient age, obesity, and the use of MMF (vs. azathioprine) for maintenance immunosuppression (RR=3.54, P =0.0004). Use of antibody induction and treatment for acute rejection were not significant risk factors for either infections or hernias. Death-censored graft survival was lower in recipients who developed a wound infection (vs. those who did not); it was not lower in recipients who developed an incisional hernia or facial dehiscence (vs. those who did not). Conclusions. Despite immunosuppression including chronic steroids, the incidence of wound infections, incisional hernias, and fascial dehiscence is low in kidney recipients. As with other types of surgery, the main risk factors for postoperative complications are obesity, reoperation, and increased age. However, in kidney recipients, use of MMF (vs. azathioprine) is an additional risk factor –one that potentially could be altered, especially in high-risk recipients.

Causes of renal allograft loss. Progress in the 1980s, challenges for the 1990s.

A variety of refinements in the care of kidney transplant recipients have been instituted over the past decade. The authors studied the overall impact of these refinements on kidney allograft losses at a single institution. To do this they compared the causes and rates of graft loss for primary kidney transplants in the 1970s (January 1,1970 to December 31,1979; n = 1012; 657 nondi-abetics, 355 diabetics; 617 living donors, 395 cadaver donors) versus the 1980s (January 1, 1980 to December 31, 1989; n = 1,384; 756 nondiabetics, 628 diabetics; 740 living donors, 644 cadaver donors). Overall patient survival improved significantly, with rates at 1, 5, and 10 years of 94%, 84%, and 68% for the 1980s, compared with 86%, 69%, and 57% for the 1970s (p < 0.001). Actuarial graft survival also improved significantly, with rates at 1, 5, and 10 years of 86%, 71%, and 52% for the 1980s, compared with 73%, 58%, and 43% for the 1970s (p < 0.001). This improvement occurred even though there were proportionately more cadaver donors and diabetic recipients in the 1980s. For both decades combined, 24% of the lost grafts were due to chronic rejection, 18% to cardiovascular causes of death with function, 13% to infectious causes of death with function, and 11% to acute rejection. The overall gain in graft survival rates in the 1980s was principally due to fewer cases of acute rejection and fewer infectious deaths. Improvement in graft survival due to the two leading causes–chronic rejection and cardiovascular causes of death–was relatively small, if any. These data indicate that future kidney transplantation research should emphasize prevention of chronic rejection and cardiovascular death.

Delayed graft function in the absence of rejection has no long-term impact. A study of cadaver kidney recipients with good function at 1 year after transplantation

We previously reported that delayed graft function (DGF) in the absence of biopsy-proven acute rejection (Rej) had no effect on outcome of primary cadaver kidney transplantation (TX). By contrast, DGF in combination with Rej strongly predicted poor long-term graft survival. We asked whether this poor long-term outcome was due to early graft loss associated with DGF, or to an ongoing process leading to late graft loss. To answer this question, we studied a subset of 298 cadaver kidney transplant recipients who had not suffered early graft loss and had a serum creatinine level < or = 2.0 mg/dl at 1 year after TX. The incidence of DGF (defined by dialysis during the first week after TX) in this subset was 19%. DGF was associated with cold ischemia time >24 hr (P = 0.0003) and Rej (P = 0.06). For grafts with versus without DGF, the incidence of late acute Rej (>1 year after TX) was similar. Actuarial graft survival was similar for Rej-free recipients with versus without DGF (P = 0.9) and was worse for those with Rej and no DGF (P < 0.02). Importantly, however, in our recipients who all had a serum creatinine level < or = 2.0 mg/dl at 1 year after TX, the worst long-term outcome was noted in the subgroup with both DGF and Rej (P < 0.0001). By multivariate analysis, DGF was also only a risk factor in combination with Rej (P = 0.002, relative risk = 3.7), while a 0-antigen HLA mismatch had no impact. Patient survival decreased for recipients with both DGF and Rej by univariate (P = 0.009) and multivariate (P = 0.02, relative risk = 2.9) analyses. We conclude that DGF without Rej has no impact on long-term survival. However, our data for recipients with both DGF and Rej suggest that a chronic ongoing process leads to late graft failure. Further research is necessary to identify the exact pathophysiology of this process, which appears to be, at least in part, HLA antigen independent.

A single institution, randomized, prospective trial of cyclosporin versus azathioprine-antilymphocyte globulin for immunosuppression in renal allograft recipients.

Between September 26, 1980 and December 31, 1983, 230 splenectomized, transfused renal allograft recipients were randomized to treatment with either cyclosporin-prednisone (N = 121, 68 diabetic and 53 nondiabetic recipients; 73 cadaver and 48 related donor grafts) or azathioprine-prednisone-antilymphocyte globulin (N = 109, 61 diabetic and 48 nondiabetic recipients; 69 cadaver and 40 related donor grafts). The results were analyzed on March 31, 1984. Actuarial patient survival rates at 2 years were 88% in the cyclosporin and 91% in the azathioprine groups (p = 0.649). Graft survival rates at 2 years were 82% in all cyclosporin and 77% in all azathioprine-treated recipients (p = 0.150); the corresponding figures in the recipients of related donor grafts were 87% vs. 83% (p = 0.656), and in the recipients of cadaver donor grafts were 78% vs. 73% (p = 0.178). The 2-year graft survival rates were 81% in cyclosporin and 74% in azathioprine-treated diabetic recipients (p = 0.150) and 83% in cyclosporin and 81% in azathioprine-treated nondiabetic recipients (p = 0.604). Within the cyclosporin and azathioprine treatment groups, the differences in graft survival rates between diabetic and nondiabetic recipients were not significant (p = 0.822 and 0.423, respectively). Although there were no significant differences in graft survival rates, the cumulative incidence of rejection episodes within the first post-transplant year was significantly lower in the cyclosporin (34%) than in the azathioprine (60%) treated recipients (p = 0.001). In recipients of technically successful cadaver kidney grafts, the incidence of acute tubular necrosis (ATN) was 31% in cyclosporin and 30% in azathioprine-treated recipients (p = 0.822). Graft survival rates in azathioprine- and cyclosporin-treated recipients who did or did not undergo ATN were 72% vs. 89% (p = 0.011). The mean (+/- S.D.) serum creatinine levels (mg/dl) at 1 year were higher in cyclosporin (2.0 +/- 0.6) than in azathioprine (1.5 +/- 0.5) treated recipients (p = less than 0.001). A reduction in cyclosporin dose because of nephrotoxicity was required in 96 of the cyclosporin-treated patients (70%), and 25 were switched to treatment with azathioprine (21%). The incidence of all infections in cyclosporin-treated patients was approximately half of that in azathioprine-treated patients, and only nine per cent of the cyclosporin-treated patients were diagnosed to have cytomegalovirus infections during the first post-transplant year vs. 28% in azathioprine-treated patients (p = 0.002).(ABSTRACT TRUNCATED AT 400 WORDS)

Short- and long-term outcomes of kidney transplants with multiple renal arteries

ObjectiveThe authors determined whether the use of kidney allografts with multiple renal arteries adversely affects post-transplant graft and patient outcome or increases the incidence of vascular and urologic complications. BackgroundKidney grafts with multiple renal arteries have been associated with an increased incidence of early vascular and urologic complications. Kidney transplants with single versus multiple renal arteries have not been compared in regard to long-term graft and patient outcome or post-transplant incidence of hypertension, acute tubular necrosis, rejection, and late vascular and urologic complications. MethodsWe analyzed 998 adult kidney transplants done from December 1, 1985 through June 30, 1993, in which only the recipients external or internal iliac artery was used for anastomosis. We divided the study population into 3 groups: Group A—1 renal artery, 1 arterial anastomosis (n = 835), Group B—>1 renal artery, 1 arterial anastomosis (n = 112), Group C—>1 renal artery, >1 arterial anastomosis (n = 51). We compared the incidence of post-transplant hypertension, acute tubular necrosis, acute rejection, and vascular and urologic complications; mean creatinine levels at 1, 3, and 5 years post-transplant; and patient and graft survival. Univariate and multivariate analyses were done to identify risk factors for vascular complications. ResultsWe found no significant differences among the three groups for the following variables: post-transplant hypertension, acute tubular necrosis, acute rejection, creatinine levels, early vascular and urologic complications, and graft and patient survival. In kidneys with single arteries, the presence (vs. absence) of an aortic patch and the type of the arterial anastomosis (end-to-end to the hypogastric vs. end-to-side to the external iliac artery) did not have an impact on the incidence of early or late vascular complications. In kidneys with multiple arteries, only the rate of late renal artery stenosis was higher, the rate of early vascular and urologic complications was not different. Our multivariate analysis identified acute tubular necrosis as a risk factor for renal artery and vein thrombosis; graft placement on the left side for arterial thrombosis; and preservation time ≥ 24 hours and multiple renal arteries for renal artery stenosis.