Charles F. Shield

Randomized Trial Of Tacrolimus (prograf) In Combination With Azathioprine Or Mychophenolate Mofetil Versus Cyclosporine (neoral) With Mycophenolate Mofetil After Cadaveric Kidney Transplantation1, 2

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.

Isoform switching of type IV collagen is developmentally arrested in X-linked Alport syndrome leading to increased susceptibility of renal basement membranes to endoproteolysis.

Normal glomerular capillaries filter plasma through a basement membrane (GBM) rich in alpha3(IV), alpha4(IV), and alpha5(IV) chains of type IV collagen. We now show that these latter isoforms are absent biochemically from the glomeruli in patients with X-linked Alport syndrome (XAS). Their GBM instead retain a fetal distribution of alpha1(IV) and alpha2(IV) isoforms because they fail to developmentally switch their alpha-chain use. The anomalous persistence of these fetal isoforms of type IV collagen in the GBM in XAS also confers an unexpected increase in susceptibility to proteolytic attack by collagenases and cathepsins. The incorporation of cysteine-rich alpha3(IV), alpha4(IV), and alpha5(IV) chains into specialized basement membranes like the GBM may have normally evolved to protectively enhance their resistance to proteolytic degradation at the site of glomerular filtration. The relative absence of these potentially protective collagen IV isoforms in GBM from XAS may explain the progressive basement membrane splitting and increased damage as these kidneys deteriorate.

Randomized trial of tacrolimus plus mycophenolate mofetil or azathioprine versus cyclosporine oral solution (modified) plus mycophenolate mofetil after cadaveric kidney transplantation: results at 2 years.

Background. A previous report described the 1-year results of a prospective, randomized trial designed to investigate the optimal combination of immunosuppressants in kidney transplantation. Recipients of first cadaveric kidney allografts were treated with tacrolimus+mycophenolate mofetil (MMF), cyclosporine oral solution (modified) (CsA)+MMF, or tacrolimus+azathioprine (AZA). Results at 1 year revealed that optimal efficacy and safety were achieved with a regimen containing tacrolimus+MMF. The present report describes results at 2 years. Methods. Two hundred twenty-three recipients of first cadaveric kidney allografts were randomized to receive tacrolimus+MMF, CsA+MMF, or tacrolimus+AZA. All regimens contained corticosteroids, and antibody induction was used only in patients who experienced delayed graft function. Patients were followed up for 2 years. Results. The results at 2 years corroborate and extend the findings of the previous report. Patients randomized to either treatment arm containing tacrolimus experienced improved kidney function. New-onset insulin dependence remained in four, three, and four patients in the tacrolimus+MMF, CsA+MMF, and tacrolimus+AZA treatment arms, respectively. Furthermore, patients with delayed graft function/acute tubular necrosis who were treated with tacrolimus+MMF experienced a 23% increase in allograft survival compared with patients receiving CsA+MMF (P =0.06). Patients randomized to tacrolimus+MMF received significantly lower doses of MMF compared with those administered CsA+MMF. Conclusions. All three immunosuppressive regi-mens provided excellent safety and efficacy. How-ever, the best results overall were achieved with tacrolimus+MMF. The combination may provide particular benefit to kidney allograft recipients who develop delayed graft function/acute tubular necrosis. Renal function at 2 years was better in the tacrolimus treatment groups compared with the CsA group.

A Randomized Clinical Trial Of Induction Therapy With Okt3 In Kidney Transplantation

A randomized, prospective multicenter trial was conducted to compare the safety and efficacy of OKT3 as an induction therapy with that of conventional immunosuppressive therapy administered to cadaveric renal allograft recipients. Two hundred fifteen patients were treated either with OKT3 plus azathioprine and steroids for 14 days with the delayed addition of cyclosporine on day 11, or with conventional immunosuppression (steroids, azathioprine, and cyclosporine). OKT3 patients had significantly fewer rejection episodes (51% vs. 66%, P=0.032), a longer time to initial rejection (46 days vs. 8 days, P=0.001), and fewer rejection episodes per patient (0.82 vs. 1.14, P=0.014) than conventionally treated patients. Kaplan-Meier estimates of two-year graft and patient survival rates were 84% and 95%, respectively, for the OKT3-treated group, and 75% and 94%, respectively, for the conventionally treated group. Following a subsequent first rejection episode, OKT3 reversed 93% of the rejections in patients receiving OKT3 induction therapy and 94% in patients receiving conventional therapy. Adverse experiences reported during OKT3 induction therapy were similar to those seen when the drug was used for rejection. Following initial exposure, 40.3% of the patients tested were positive for anti-OKT3 antibody, only 6.7% of which were of high titer (1:1000). In the presence of low titer (1:100 or less) antibody, OKT3 was successful in reversing rejection in five of six retreated patients tested. In conclusion, treatment with OKT3 (in combination with azathioprine, steroids, and the delayed addition of cyclosporine) is an effective approach for renal allograft maintenance.

Randomized trial of tacrolimus + mycophenolate mofetil or azathioprine versus cyclosporine + mycophenolate mofetil after cadaveric kidney transplantation : Results at three years

Methods. Two hundred twenty-three recipients of first cadaveric kidney allografts were randomized to receive tacrolimus (TAC) + mycophenolate mofetil (MMF), TAC + azathioprine (AZA), or cyclosporine (Neoral; CsA) + MMF. All regimens contained corticosteroids, and antibody induction was used only in patients who experienced delayed graft function (DGF). Patients were followed-up for 3 years. Results. The results at 3 years corroborate and extend the findings of the 2-year results. Patients with DGF treated with TAC+MMF experienced an increase in 3-year allograft survival compared with patients receiving CsA+MMF (84.1% vs. 49.9%, P =0.02). Patients randomized to either treatment arm containing TAC exhibited numerically superior kidney function when compared with CsA. During the 3 years, new-onset insulin dependence occurred in 6, 3, and 11 patients in the TAC+MMF, CsA+MMF, and TAC+AZA treatment arms, respectively. Furthermore, patients randomized to TAC+MMF received significantly lower doses of MMF as compared with those who received CsA+MMF. Conclusion. All three immunosuppressive regimens provided excellent safety and efficacy. However, the best results overall were achieved with TAC+MMF. The combination may provide particular benefit to kidney allograft recipients with DGF. In patients who experienced DGF, graft survival was better at 3 years in those patients receiving TAC in combination with either MMF or AZA as compared with the patients receiving CsA with MMF.

Stage-Specific Action of Matrix Metalloproteinases Influences Progressive Hereditary Kidney Disease

Background Glomerular basement membrane (GBM), a key component of the blood-filtration apparatus in the in the kidney, is formed through assembly of type IV collagen with laminins, nidogen, and sulfated proteoglycans. Mutations or deletions involving α3(IV), α4(IV), or α5(IV) chains of type IV collagen in the GBM have been identified as the cause for Alport syndrome in humans, a progressive hereditary kidney disease associated with deafness. The pathological mechanisms by which such mutations lead to eventual kidney failure are not completely understood. Methods and Findings We showed that increased susceptibility of defective human Alport GBM to proteolytic degradation is mediated by three different matrix metalloproteinases (MMPs)—MMP-2, MMP-3, and MMP-9—which influence the progression of renal dysfunction in α3(IV) −/− mice, a model for human Alport syndrome. Genetic ablation of either MMP-2 or MMP-9, or both MMP-2 and MMP-9, led to compensatory up-regulation of other MMPs in the kidney glomerulus. Pharmacological ablation of enzymatic activity associated with multiple GBM-degrading MMPs, before the onset of proteinuria or GBM structural defects in the α3(IV) −/− mice, led to significant attenuation in disease progression associated with delayed proteinuria and marked extension in survival. In contrast, inhibition of MMPs after induction of proteinuria led to acceleration of disease associated with extensive interstitial fibrosis and early death of α3(IV) −/− mice. Conclusions These results suggest that preserving GBM/extracellular matrix integrity before the onset of proteinuria leads to significant disease protection, but if this window of opportunity is lost, MMP-inhibition at the later stages of Alport disease leads to accelerated glomerular and interstitial fibrosis. Our findings identify a crucial dual role for MMPs in the progression of Alport disease in α3(IV) −/− mice, with an early pathogenic function and a later protective action. Hence, we propose possible use of MMP-inhibitors as disease-preventive drugs for patients with Alport syndrome with identified genetic defects, before the onset of proteinuria.

Assessment Of Health-related Quality Of Life In Kidney Transplant Patients Receiving Tacrolimus (fk506)-based Versus Cyclosporine-based Immunosuppression1,2

BACKGROUND We evaluated health-related quality of life (HQL) in kidney transplant patients participating in a multicenter, prospective, randomized, phase III trial comparing tacrolimus to cyclosporine. HQL data were available for 303 of 412 patients and assessed with the SF-36 Health Survey and six multi-item scales: Current Health, Health Outlook, Health Distress, Fleming Self-Esteem, Bergner Physical Appearance, and Sexual Functioning. METHODS Patients completed surveys at baseline, week 6, and months 3, 6, and 12. The mean change in HQL was evaluated by rejection occurrence and number of hospitalizations. Analysis of covariance was used to model endpoint HQL scores as a function of treatment group and baseline HQL. RESULTS All scales but two met psychometric standards for group-level comparisons. Baseline demographics and HQL scores were not different by treatment. The mean HQL change was lower for patients with rejection compared with no rejection in seven of eight SF-36 scales and three of four remaining supplemental scales. One year after transplantation, study patients were functioning at least as well as half of the general population in Vitality and Role-Emotional Functioning, moving from the 18th percentile of the U.S. population scores to the 50th percentile for Vitality and 54th percentile for Role-Emotional Functioning. Patients improved their percentile ranking by at least 20 points in five of eight SF-36 scales. CONCLUSIONS Patients with kidney disease demonstrate substantial HQL burden before transplantation, and transplantation is associated with substantial HQL improvements. Rejection is associated with less HQL improvement. Endpoint HQL values were significantly different (P<0.05) by treatment, favoring tacrolimus, in the Bergner Physical Appearance scale, which was designed to measure the HQL impact of side effects such as gingival hyperplasia and facial hirsutism on physical appearance.

Ten-year experience in transplantation of A2 kidneys into B and O recipients

BACKGROUND This article summarizes our 10-year multicenter experience with transplantation of 50 blood group A2 and A2B kidneys into B and O patients. METHODS Since 1986, we have transplanted kidneys from 46 cadaver donors and 4 living donors who were blood group A2 (47 donors) or A2B (3 donors) into 19 B and 31 O patients. In 1991, we began allocating these kidneys preferentially to B and O recipients who were selected based on a history of low (< or =4) anti-A IgG isoagglutinin titers. Immunosuppression was no different from that used in ABO-compatible grafts. RESULTS The 1-month function rate before thus selecting the patients was 68% (19/28), but is now 94% (17/18). Two-year cadaver-donor graft survival with this selection method is 94%, compared with 88% for 640 concurrent and consecutive ABO-compatible transplants (log-rank, 0.15). All four living-related transplants are still functioning, with a mean follow-up of 71 months. Since we began allocating A2 kidneys preferentially to B and O recipients, the percentage of the B patients who received A2 or A2B kidneys has increased from 29% (8/28) to 55% (10/18). CONCLUSIONS Transplantation of A2 or A2B kidneys into B and O patients is clinically equivalent to that of ABO-compatible transplantation when recipients are selected by low pretransplant anti-A titer histories. This approach increases access of blood group B recipients to kidneys.

Long-term graft survival is improved in cadaveric renal retransplantation by flow cytometric crossmatching.

BACKGROUND Cadaveric renal retransplantation is associated with a higher risk of early graft failure than primary grafts. A large proportion of those graft losses is likely attributable to donor-directed HLA class I antibodies, detectable by flow cytometry cross-matching but not by conventional crossmatching techniques. METHODS Long-term graft survival in a group of 106 recipients of consecutive cadaveric renal regrafts between 1990 and 1997, in whom a negative flow T-cell IgG crossmatch was required for transplantation, was compared with two other groups of cadaveric transplant recipients. The first group consisted of 174 cadaveric regrafts transplanted between 1985 and 1995 using only a negative anti-human globulin (AHG) T-cell IgG crossmatch. The second group was primary cadaveric transplants done concurrently with the flow group (1990 to 1997) using only the AHG T-cell IgG crossmatch. RESULTS The long-term (7 year) graft survival rate of flow crossmatch-selected regraft recipients (68%; n= 106) was significantly improved over that of regraft recipients who were selected for transplantation by only the AHG crossmatch technique (45%; n=174; log-rank=0.001; censored for patients dying with a functioning graft). Graft outcome for the flow cross-matched regraft recipients was not significantly different from that of primary cadaveric patients (72%; n=889; log-rank=0.2; censored for patients dying with a functioning graft). Finally, a positive B-cell IgG flow cytometric crossmatch had no influence on long-term regraft outcome. CONCLUSIONS The use of the flow T-cell IgG cross-match as the exclusion criterion for cadaveric renal retransplantation yields an improved long-term graft outcome over that obtained when only the AHG cross-match is used and has improved survival of regraft recipients to the level of our primary cadaveric renal transplant population.

USE OF ANTITHYMOCYTE GLOBULIN FOR REVERSAL OF ACUTE ALLOGRAFT REJECTION

A prospective randomized study evaluating the effectiveness of antithymocyte globulin (ATG) for reversal of established rejection was undertaken in 20 recipients of related donor renal allografts. The patients were initially treated with azathioprine and prednisone. With the onset of acute rejection they were randomly assigned to additional treatment with either ATG or high-dose steroids. Eight of 10 patients treated with ATG had prompt reversal of acute rejection and have had no further evidence of rejection. Two of the patients had continuing evidence of rejection after several days of ATG treatment and therefore received high-dose steroids as well. One patient regained normal function but the second suffered repeated rejection episodes which eventually resulted in allograft failure. All 10 patients treated with high-dose steroids had initial reversal of rejection, although four required irradiation of the graft and actinomycin therapy as well and five patients subsequently required treatment for second and third rejection episodes. One patient in this group died with perforated divertic-ulitis following reversal of rejection. With a mean followup of 14 months, 9 of 10 patients treated with ATG have functional allografts, renal function being normal in 8 patients. Nine of 10 patients treated with steroids have functional grafts but renal function remains impaired in three. The effectiveness of ATG when added at the time of acute allograft rejection has been demonstrated. The major advantage of ATG for rejection reversal has been a marked decrease in the cumulative steroid dose administered to these patients. This may avoid many long-term adverse effects of steroids such as the fatal diverticulitis complication observed in this study. An additional suggested benefit is a decreased incidence of second rejection episodes in the ATG-treated patients.