The impact of acute rejection episodes on long-term graft function and outcome in 1347 primary renal transplants treated by 3 cyclosporine regimens

Effects of CYP3A4*22 and POR*28 variations on the pharmacokinetics of tacrolimus in renal transplant recipients: a meta-analysis of 18 observational studies

PURPOSE

This study aimed to investigate the association between cytochrome P450 (CYP) 3A4*22 and cytochrome P450 oxidoreductase (POR)*28 variations and the pharmacokinetics of tacrolimus.

METHODS

Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science (SCI), MEDLINE, and Embase were systematically searched from inception to August 2022. The outcomes were weight-adjusted daily dose and dose-adjusted trough concentration (C0/Dose).

RESULTS

The study included 2931 renal transplant recipients from 18 publications. Weight-adjusted daily dose of CYP3A4*1/*1 carriers was 0.04 (WMD = 0.04, 95% CI: 0.02 to 0.06), 0.03 (WMD = 0.03, 95% CI: 0.02 to 0.05), 0.02 (WMD = 0.02, 95% CI: 0.01 to 0.03), or 0.02 mg/kg/day (WMD = 0.02, 95% CI: 0.00 to 0.04) higher than CYP3A4*22 carriers in Caucasians at 1 month, 3 months, 6 months, or 12 months post-transplantation. Conversely, C0/Dose was lower for CYP3A4*1/*1 carriers at 3 days (SMD = -0.35, 95% CI: -0.65 to -0.06), 1 month (SMD = -0.67, 95% CI: -1.16 to -0.18), 3 months (SMD = -0.60, 95% CI: -0.89 to -0.31), 6 months (SMD = -0.76, 95% CI: -1.49 to -0.04), or 12 months post-transplantation (SMD = -0.69, 95% CI: -1.37 to 0.00). Furthermore, C0/Dose of POR*1/*1 carriers was 22.64 (WMD = 22.64, 95% CI: 2.54 to 42.74) or 19.41 (ng/ml)/(mg/kg/day) (WMD = 19.41, 95% CI: 9.58 to 29.24) higher than POR*28 carriers in CYP3A5 expressers at 3 days or 7 days post-transplantation, and higher in Asians at 6 months post-transplantation (SMD = 0.96, 95% CI: 0.50 to 1.43).

CONCLUSIONS

CYP3A4*22 variant in Caucasians restrains the metabolism of tacrolimus, while POR*28 variant in CYP3A5 expressers enhances the metabolism of tacrolimus for renal transplant recipients. However, further well-designed prospective studies are necessary to substantiate these conclusions given some limitations.

The Association Between Kidney Donor Profile Index and 1-y Graft Function

The association between Kidney Donor Profile Index (KDPI) and 1-y estimated glomerular filtration rate (eGFR) with long-term kidney graft survival is well known. Yet, the association between KDPI and 1-y eGFR remains uncertain considering the several concurrent competing risk factors.

Methods

This single-center, retrospective cohort study analyzed data from 3059 consecutive deceased donor kidney transplant recipients with a 1-y follow-up from January 2013 to December 2017. The aim was to determine the association between the KDPI strata (0%-35%, 36%-50%, 51%-85%, 86%-100%) and 1-y eGFR estimated by the CKD-EPI equation.

Results

The incidence of delayed graft function (50.6% versus 59.3% versus 62.7% versus 62.0%; P < 0.001) and cytomegalovirus infection (36.7% versus 36.6% versus 43.3% versus 57.8%; P < 0.001) increased with increasing KDPI strata but not biopsy-proven acute rejection (9.1% versus 9.8% versus 8.4% versus 9.1%; P = 0.736). The median 1-y eGFR decreased with increasing KDPI strata (64.8 versus 53.5 versus 46.9 versus 39.1 mL/min/1.73 m²; P < 0.001). In the Cox regression, the higher the KDPI was, the lower the probability of a lower 1-y eGFR was. Assuming the 0%-35% strata as the reference, the likelihood of eGFR <50 mL/min/1.73 m² was increased by 76.6% (hazard ratio [HR] = 1.767, 95% confidence interval [CI] = 1.406-2.220), 2.24- and 2.87-fold higher for KDPI higher >35%-50% (HR = 2.239, 95% CI = 1.862-2.691), and >51%-85% (HR = 2.871, 95% CI = 2.361-3.491), respectively. Other variables associated with a lower graft function were donor sex (HR male versus female = 0.896, 95% CI = 0.813-0.989) and cold ischemia time (HR for each hour = 1.011, 95% CI = 1.004-1.019). This association was sustained after the Poisson mediation analysis, including delayed graft function, cytomegalovirus, and acute rejection as mediators.

Conclusions

In this cohort of deceased donor kidney recipients, KDPI, and cold ischemia time were the major independent risk factors associated with lower 1-y kidney function.

Donor-specific ELISPOT assay for predicting acute rejection and allograft function after kidney transplantation: A systematic review and meta-analysis

Acute rejection remains an important problem after kidney transplantation. Enzyme-linked immunosorbent spot (ELISPOT) assay has been investigated extensively and has shown promising results as a predictor of allograft rejection. The objective of this study was to systematically review and analyze the predictive value of the donor-specific ELISPOT assay to identify recipients at risk for acute rejection. Electronic databases were searched for studies reporting donor-specific ELISPOT and kidney transplantation outcomes. Odds ratio (OR) for acute rejection was calculated, along with standardized mean difference (SMD) of cytokine producing-cells between recipients with and without acute rejection. Pooled estimates were calculated using random-effect models. The positive ELISPOT cutoff frequencies were extracted from each study. From 665 articles found, 32 studies were included in the meta-analysis. IFN-γ was the most investigated cytokine (30 out of 32 studies). Patients with positive pre-transplantation donor-reactive IFN-γ ELISPOT had an OR of 3.3 for acute rejection (95%-CI 2.1 to 5.1), and OR of 6.8 (95%-CI 2.5 to 18.9) for post-transplantation ELISPOT. Recipients with rejection had significantly higher frequencies of pre- and post-transplantation cytokine producing-cells (SMD 0.47, 95%-CI 0.07 to 0.87 and SMD 3.68, 95%-CI 1.04 to 6.32, respectively). Pre-transplantation ELISPOT had a positive predictive value of 43% and a negative predictive value of 81% for acute rejection. A positive ELISPOT result was associated with a lower estimated glomerular filtration rate (SMD -0.59, 95%-CI -0.83 to -0.34). In conclusion, patients with a high frequency of donor-reactive IFN-γ ELISPOT are at higher risk for acute rejection. The donor-specific IFN-γ ELISPOT assay can serve as an immune-monitoring tool in kidney transplantation.

Once-Daily versus Twice-Daily Tacrolimus in Kidney Transplantation: A Systematic Review and Meta-analysis of Observational Studies

BACKGROUND

Tacrolimus is the most commonly prescribed medication in initial immunosuppressive regimens to prevent acute rejection in kidney transplant recipients (KTRs). Tacrolimus was originally available as an immediate-release formulation (IR-Tac) given twice daily. Extended-release tacrolimus (ER-Tac) given once daily was later developed with the expectation of improved medication adherence. Data from observational studies, which compared outcomes between ER-Tac and IR-Tac in different populations of KTRs including those who are unlikely to be enrolled in randomized clinical trials, have been reported.

PURPOSE

To evaluate the incidence of biopsy-proven acute rejection (BPAR) at 12 months together with other outcomes reported in observational studies among adult KTRs who received ER-Tac compared to IR-Tac.

METHODS

In accordance with the recommendations of the Cochrane Collaboration and the Meta-analysis of Observational Studies in Epidemiology, we systematically reviewed all observational studies that compared clinical outcomes between ER-Tac and IR-Tac in KTRs. The systematic searches were conducted on PubMed, EMBASE, Scopus, and Web of Science without language restriction. Reference lists were also searched and reviewed. Data were extracted for BPAR, graft survival, patient survival, estimated glomerular filtration rate (eGFR), serum creatinine (Scr), creatinine clearance (CrCl), at different times after kidney transplantation (KT). A meta-analysis was performed to integrate the results from the eligible studies. This study is registered with PROSPERO, number CRD42019135705.

RESULTS

From the 1401 articles screened, 10 observational studies in KTRs who received tacrolimus were included. The pooled results showed significantly lower BPAR with ER-Tac than with IR-Tac at 12 months post-KT (5 studies, n = 659; RR, 0.69; 95% CI 0.51-0.95; p = 0.02; I² = 0%). No significant differences in BPAR at other time points after KT were found. Graft survival, patient survival, Scr, and eGFR were comparable between groups at different times over approximately 1 year after transplantation.

CONCLUSIONS

Based upon currently available evidence in observational studies, 30% lower risk of BPAR was observed in ER-Tac group compared with IR-Tac group at 12 months post-KT, while there was no significant difference in BPAR risk at any other studied time points. No differences in graft- and patient-survival rates and kidney function were found. Given the limitations of observational studies to make causal inference, as well as quality limitations among the included studies, caution should be exercised in interpreting these findings.

A Half-Century 3000 Cases of Kidney Transplant Experiences in a Single Hospital: the Longest Registry in Korea

BACKGROUND

This study aims to analyze the entire registry of kidney transplant over the past 50 years and understand the clinical significance.

METHODS

From the data on 3012 kidney transplants performed at our center between March 1969 and September 2018, we analyzed retrospectively clinical variables.

RESULTS

Until September 2018, there have been 3012 kidney transplants performed. The number of primary transplant cases was 2755 (91.8%), which included 16 cases of simultaneous liver-kidney transplant, and the number of repeated transplants was 245 (225 second transplants [7.5%] and 20 third transplants [0.7%]). There were 3 simultaneous pancreas kidney transplants, and 3 small bowel-kidney transplants, one of them being transplanted at the same time. There was a single simultaneous heart-kidney transplant. The viability rates of a transplanted kidney for 1, 5, 10, 20, and 30 years were 97%, 92%, 90%, 51%, and 36%, respectively, and the patient survival rates were 96%, 89%, 82%, 64%, and 52%, respectively. Five-year graft survival rate of the first 1000 cases was 64.6%; those of the 1001st to 2000th cases and 2001^st to 3012th cases were 87.6% and 88.8%, respectively. There are statistically significant differences among the groups.

CONCLUSION

This study has identified the appropriate selection or control of immunotherapy, based on the risk level of kidney transplant recipient, is needed to minimize chronic rejection, which is the key cause of transplanted kidney failure.

Composite tissue allotransplantation: opportunities and challenges

Vascularized composite allotransplants (VCAs) have unique properties because of diverse tissue components transplanted en mass as a single unit. In addition to surgery, this type of transplant also faces enormous immunological challenges that demand a detailed analysis of all aspects of alloimmune responses, organ preservation, and injury, as well as the immunogenicity of various tissues within the VCA grafts to further improve graft and patient outcomes. Moreover, the side effects of long-term immunosuppression for VCA patients need to be carefully balanced with the potential benefit of a non-life-saving procedure. In this review article, we provide a comprehensive update on limb and face transplantation, with a specific emphasis on the alloimmune responses to VCA, established and novel immunosuppressive treatments, and patient outcomes.

[Decellularization of organs and tissues]

The use of allogenic materials in reconstructive surgery is of great scientific interest due to high availability of donor tissues. The positive aspects of allogenous tissue transplantation are complicated by the histological incompatibility of donor tissue and recipient organism. This incompatibility results hypersensitivity reaction towards the allogenous transplant followed by rejection of allogenic tissue and even death in some cases. Cellular biological incompatibility may be managed by decellularization of allogenous organs and tissues prior to transplantation. The improvement of decellularization techniques will facilitate application of allogenous tissues in complex reconstructive procedures and significantly increase the capabilities of reconstructive surgery.

Effect of Cold Preservation on Chronic Rejection in a Rat Hindlimb Transplantation Model

BACKGROUND

Previous studies on solid organ transplantation have shown that cold ischemia contributes to the development of chronic allograft vasculopathy. The authors evaluated the effect of cold ischemia on the development of chronic rejection in vascularized composite allotransplantation.

METHODS

Thirty rat hindlimbs were transplanted and divided into two experimental groups: immediate transplantation and transplantation after 7 hours of cold ischemia. The animals received daily low-dose immunosuppression with cyclosporine A for 2 months. Intimal proliferation, arterial permeability rate, leukocyte infiltration, and tissue fibrosis were assessed. The CD3, CD4, CD8, CD20, and CD68 cells per microscopic field (200×) were counted, and C4d deposition was investigated. Cytokine RNA analysis was performed to measure tumor necrosis factor-α, interleukin-6, and interleukin-10 levels.

RESULTS

Significant differences were found in the intimal proliferation and arterial permeability rate between the two groups (p = 0.004). The arterial permeability rate worsened in the most distal and small vessels (p = 0.047). The numbers of CD3, CD8, CD20, and CD68 were also statistically higher in the cold ischemia group (p < 0.05, all levels). A trend toward significance was observed with C4d deposition (p = 0.059). No differences were found in the RNA of cytokines.

CONCLUSIONS

An association between cold ischemia and chronic rejection was observed in experimental vascularized composite allotransplantation. Chronic rejection intensity and distal progression were significantly related with cold ischemia. The leukocyte infiltrates in vascularized composite allotransplantation components were a rejection marker; however, their exact implication in monitoring and their relation with cold ischemia are yet to be clarified.

Use of Basiliximab and Daclizumab in Kidney Transplantation

Kidney transplantation represents a major medical victory in patients with whom dialysis and medical therapy have failed. To increase survival rates and optimize the use of limited organs, both patient care and immunosuppression therapy must be improved. Reduction in rejection episodes or severity of rejection may ultimately improve long-term allograft survival. Traditional engineered monoclonal antibodies have been associated with severe cytokine release reactions and an increased risk of opportunistic infections. Basiliximab and daclizumab are chimeric and humanized monoclonal antibodies that inhibit thymus-dependent lymphocyte proliferation. Interleukin 2 also affects the proliferation of natural killer cells, macrophages and monocytes, bursa-equivalent lymphocytes, epidermal dendritic cells, and lymphokine-activated killer cells. Interleukin-2 receptor antagonists have been shown to reduce the incidence of acute rejection without increasing the incidence of opportunistic infections or malignancy. Further studies are needed to evaluate the overall effect of these agents on long-term patient and allograft survival.

Chronic Renal Transplant Rejection and Possible Anti-Proliferative Drug Targets

The global prevalence of renal transplants is increasing with time, and renal transplantation is the only definite treatment for end-stage renal disease. We have limited the acute and late acute rejection of kidney allografts, but the long-term survival of renal tissues still remains a difficult and unanswered question as most of the renal transplants undergo failure within a decade of their transplantation. Among various histopathological changes that signify chronic allograft nephropathy (CAN), tubular atrophy, fibrous thickening of the arteries, fibrosis of the kidney interstitium, and glomerulosclerosis are the most important. Moreover, these structural changes are followed by a decline in the kidney function as well. The underlying mechanism that triggers the long-term rejection of renal transplants involves both humoral and cell-mediated immunity. T cells, with their related cytokines, cause tissue damage. In addition, CD 20+ B cells and their antibodies play an important role in the long-term graft rejection. Other risk factors that predispose a recipient to long-term graft rejection include HLA-mismatching, acute episodes of graft rejection, mismatch in donor-recipient age, and smoking. The purpose of this review article is the analyze current literature and find different anti-proliferative agents that can suppress the immune system and can thus contribute to the long-term survival of renal transplants. The findings of this review paper can be helpful in understanding the long-term survival of renal transplants and various ways to improve it.

Outcomes of steroid-avoidance protocols in pediatric kidney transplant recipients

Advances in immunosuppression have facilitated increased use of steroid-avoidance protocols in pediatric kidney transplantation. To evaluate such steroid avoidance, a retrospective cohort analysis of pediatric kidney transplant recipients between 2002 and 2009 in the United Network for Organ Sharing database was performed. Outcomes (acute rejection and graft loss) in steroid-based and steroid-avoidance protocols were assessed in 4627 children who received tacrolimus and mycophenolate immunosuppression and did not have multiorgan transplants. Compared to steroid-based protocols, steroid avoidance was associated with decreased risk of acute rejection at 6 months posttransplant (8.3% vs. 10.9%, p = 0.02) and improved 5-year graft survival (84% vs. 78%, p < 0.001). However, patients not receiving steroids experienced less delayed graft function (p = 0.01) and pretransplant dialysis, were less likely to be African-American and more frequently received a first transplant from a living donor (all p < 0.001). In multivariate analysis, steroid avoidance trended toward decreased acute rejection at 6 months, but this no longer reached statistical significance, and there was no association of steroid avoidance with graft loss. We conclude that, in clinical practice, steroid avoidance appears safe with regard to graft rejection and loss in pediatric kidney transplant recipients at lower immunologic risk.

Enhanced de novo alloantibody and antibody-mediated injury in rhesus macaques

Chronic allograft rejection is a major impediment to long-term transplant success. Humoral immune responses to alloantigens are a growing clinical problem in transplantation, with mounting evidence associating alloantibodies with the development of chronic rejection. Nearly a third of transplant recipients develop de novo antibodies, for which no established therapies are effective at preventing or eliminating, highlighting the need for a nonhuman primate model of antibody-mediated rejection. In this report, we demonstrate that depletion using anti-CD3 immunotoxin (IT) combined with maintenance immunosuppression that included tacrolimus with or without alefacept reliably prolonged renal allograft survival in rhesus monkeys. In these animals, a preferential skewing toward CD4 repopulation and proliferation was observed, particularly with the addition of alefacept. Furthermore, alefacept-treated animals demonstrated increased alloantibody production (100%) and morphologic features of antibody-mediated injury. In vitro, alefacept was found to enhance CD4 effector memory T cell proliferation. In conclusion, alefacept administration after depletion and with tacrolimus promotes a CD4+memory T cell and alloantibody response, with morphologic changes reflecting antibody-mediated allograft injury. Early and consistent de novo alloantibody production with associated histological changes makes this nonhuman primate model an attractive candidate for evaluating targeted therapeutics.

Efficacy of anti-interleukin-2 receptor antibody (daclizumab) in reducing the incidence of acute rejection after renal transplantation

Background

Acute rejection remains a major problem in renal transplantation and represents one of the most important causes of chronic allograft dysfunction and late graft loss. Daclizumab is a genetically engineered human IgG1 monoclonal antibody that binds specifically to the α chain of the interleukin-2 receptor, and may thus reduce the risk of rejection after renal transplantation.

Objectives

The aim of this study was to examine the effect of daclizumab induction therapy combined with a triple immunosuppressive protocol including prednisolone,cyclosporine microemulsion (CsA), and mycophenolate mofetil (MMF), in reducing the incidence of acute rejection in recipients of living unrelated donor kidneys.

Patients and Methods

In this historical cohort study, 43 adult recipients of their first kidney allograft received daclizumab (three 1 mg/kg doses administered every 2 weeks) with triple immunosuppressive therapy (steroids, CsA, and MMF). This group was compared to 43 first-time graft recipients who received maintenance triple immunosuppressive therapy comprising steroids, CsA, and MMF. The end point was the incidence of biopsy confirmed acute rejection within 6 months after transplantation.

Results

At 6 months, 5 (11.6%) of the patients in the daclizumab group had biopsy-proven rejections, as compared to 14 (32.5%) in the control group (P = 0.017). The sex and the age of recipients had no impact on the incidence of acute rejection episodes in the two groups.

Conclusions

Adding interleukin-2 receptor antibody (daclizumab) to maintenance triple immunosuppressive therapy (prednisolone, CsA, and MMF) reduces the incidence of acute rejection episodes at 6 months in first-time transplant recipients of living unrelated donor.

Influence of Donor's Renal Function on the Outcome of Living Kidney Transplantation: 10-Year Follow-up

Purpose

With the improved surgical techniques and immunosuppression available today, conventional prognostic factors have taken on less significance. Accordingly, the native renal function of the donor is thought to be more important. Thus, we analyzed the prognostic significance of the donor's renal function as assessed by 24-hour urine creatinine clearance on kidney graft survival for 10 years after living kidney transplantation.

Materials and Methods

From January 1998 to July 2000, 71 living kidney transplantations were performed at a single institution. From among these, 68 recipients were followed for more than 6 months and were included in the present analysis. We analyzed kidney graft survival according to clinical parameters of the donor and the recipient.

Results

Mean follow-up duration of recipients after living kidney transplantation was 115.0±39.4 months (range, 10 to 157 months), and 31 recipients (45.6%) experienced kidney graft loss during this time period. Estimated mean kidney graft survival time was 131.8±6.2 months, and 5-year and 10-year kidney graft survival rates were estimated as 88.2% and 61.0%, respectively. Donor's mean 24-hour urine creatinine clearance (Ccr) before kidney transplantation was 122.8±21.2 ml/min/1.73 m² (range, 70.1 to 186.6 ml/min/1.73 m²). The 10-year kidney graft survival rates for cases stratified by a donor's Ccr lower and higher than 120 ml/min/1.73 m² were 39.0% and 67.2%, respectively (p=0.005). In univariate and multivariate analysis, donor's Ccr was retained as an independent prognostic factor of kidney graft survival (p=0.001 and 0.005, respectively).

Conclusions

Donor's 24-hour urine Ccr before living kidney transplantation was an independent prognostic factor of kidney graft survival. Therefore, it should be considered before living kidney transplantation.

Associations of pretransplant diabetes mellitus, new-onset diabetes after transplant, and acute rejection with transplant outcomes: an analysis of the Organ Procurement and Transplant Network/United Network for Organ Sharing (OPTN/UNOS) database

BACKGROUND

Diabetes and acute rejection are major contributors to morbidity and mortality in kidney transplant recipients. Immunosuppressive medications decrease acute rejection, but increase the frequency of new-onset diabetes after transplant. Our objective was to investigate the joint associations of diabetes (pretransplant diabetes and new-onset diabetes after transplant) and acute rejection with transplant outcomes in a recent transplant cohort.

STUDY DESIGN

Historical cohort study.

SETTING & PARTICIPANTS

37,448 recipients (age ≥ 18 years; 2004-2007) surviving with a functioning transplant for longer than 1 year were identified in the Organ Procurement and Transplant Network/United Network for Organ Sharing (OPTN/UNOS) database as of May 22, 2009.

PREDICTORS

Recipients were stratified into 6 mutually exclusive groups according to status of diabetes and acute rejection at 1 year: group 1, neither (reference; n = 20,964); group 2, new-onset diabetes alone (n = 2,140); group 3, pretransplant diabetes alone (n = 10,730); group 4, acute rejection alone (n = 2,282); group 5, new-onset diabetes and acute rejection (n = 361); and group 6, pretransplant diabetes and acute rejection (n = 1,061). Analyses were adjusted for other recipient, donor, and transplant characteristics. OUTCOMES MEASUREMENTS: Multivariate Cox regression analysis of time to transplant failure (overall and death censored) and mortality (all-cause and cardiovascular).

RESULTS

Median follow-up after 1 year was 548 days (25th-75th percentiles, 334-752 days). During this time, there were 3,047 outcomes of overall transplant failure. New-onset diabetes alone (group 2) was not associated significantly with any study outcomes. Groups 3-6 were associated with higher overall transplant failure risk. However, only groups 4-6 were associated with higher death-censored transplant failure risk. Group 3, 4, and 6 were associated with higher all-cause mortality risk, whereas only groups 3 and 6 were associated with higher cardiovascular mortality risk.

LIMITATIONS

Potential information bias with exposure, covariable, or outcome misclassification; relatively short follow-up.

CONCLUSIONS

Pretransplant diabetes is the major predictor of all-cause and cardiovascular mortality, and acute rejection during the first year is the major predictor of death-censored transplant failure in kidney recipients surviving with a functioning transplant for at least 1 year. The influence of new-onset diabetes on long-term outcomes needs further observation.

Dimethylarginine metabolism during acute and chronic rejection of rat renal allografts

Background. Dimethylarginines are inhibitors of NO synthesis and are involved in the pathogenesis of vascular diseases. In this study, we ask the question if asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) levels change during fatal and reversible acute rejection, and contribute to the pathogenesis of chronic vasculopathy.

Methods. The Dark Agouti to Lewis rat strain combination was used to investigate fatal acute rejection. Fischer 344 kidneys were transplanted to Lewis rats to study reversible acute rejection episode and the process of chronic rejection. Isograft recipients and untreated Lewis rats were used as controls. l-arginine derivatives were determined by HPLC, and ADMA-metabolizing enzymes were studied by quantitative RT–PCR and western blotting.

Results. Renal transplantation transiently increased dimethylarginine levels independent of acute rejection. ADMA plasma levels did not importantly differ between recipients undergoing fatal or reversible acute rejection, whereas SDMA was even lower in recipients of Fisher 344 grafts. In comparison to isograft recipients, ADMA and SDMA levels were slightly elevated during reversible, but not during the process of chronic rejection. Increased dimethylarginine levels, however, did not block NO synthesis. Interestingly, protein methylation, but not ADMA degradation, was increased in allografts.

Conclusions. Our data do not support the concept that renal allografts are protected from fatal rejection by dimethylarginines. Dimethylarginines may play a role in triggering chronic rejection, but a contribution to vascular remodelling itself is improbable. In contrast, differential arginine methylation of yet unknown proteins by PRMT1 may be involved in the pathogenesis of acute and chronic rejection.

Donor P-gp polymorphisms strongly influence renal function and graft loss in a cohort of renal transplant recipients on cyclosporine therapy in a long-term follow-up

Cyclosporin A (CsA) is a substrate for cytochrome P450 3A and the efflux transporter P-glycoprotein (P-gp; ABCB1), both abundantly expressed in the kidney. In a long-term follow-up of a cohort of patients who had received kidney transplants between the years 1990 and 2005, we retrospectively investigated the effect of CYP3A4, CYP3A5, and ABCB1 polymorphisms in kidney graft donors on recipients' renal function and risk of subsequent graft loss. DNA samples from 227 donors and clinical data from the 259 respective recipients were analyzed. Graft loss was significantly associated with the presence of the ABCB1 variant haplotype 1236T/2677T/3435T in the donor (1236T/2677T/3435T vs. other haplotypes: hazard ratio = 9.346; 95% confidence interval (CI) (2.278-38.461); P = 0.0019) and with previous episodes of acute organ rejection (hazard ratio = 3.077; 95% CI (1.213-7.812); P = 0.0178). The variant haplotype was also associated with a greater decrease in renal function (homozygotes for TTT -3.047 mlxmin(-1)/year; heterozygotes for TTT -4.435 mlxmin(-1)/year; others -2.186 mlxmin(-1)/year; P = 0.0240). The study showed that the presence of ABCB1 polymorphisms in donors influences long-term graft outcome adversely with decrease in renal function and graft loss in transplant recipients receiving CsA.

Composite tissue vasculopathy and degeneration following multiple episodes of acute rejection in reconstructive transplantation

Transplant vasculopathy has not been systematically investigated in composite tissue allotransplantation (CTA). The impact of multiple acute rejections (ARs) on long-term graft outcomes in reconstructive transplantation remains unknown. This study in a rat hind-limb allotransplantation model systematically analyzes vasculopathy and tissue-specific pathological changes secondary to multiple AR episodes. LEW rats were transplanted with BN rat hind limbs and treated as follows: Group 1 (Iso): isografts. Group 2 (CsA): Cyclosporine (CsA) qd; Group 3 (mult AR): CsA and dexamethasone only when AR was observed. No AR was observed in Groups 1 and 2. Multiple AR were observed in Group 3, and each episode was completely reversed (clinically) with pulsed CsA + dexamethasone treatment. Group 3 animals demonstrated significant vascular lesions along with skin and muscle atrophy, upregulation of profibrotic gene expression and fibrosis when compared to Groups 1 and 2. In addition, allograft bone was sclerotic, weak and prone to malunion and nonunion. Interestingly, vasculopathy was a late finding, whereas muscle atrophy with macrophage infiltration was seen early, after only a few AR episodes. Taken together, multiple AR episodes lead to vasculopathy and tissue-specific pathology in CTA. This is the first evidence of 'composite tissue vasculopathy and degeneration (CTVD)' in CTA.

Interstitial fibrosis quantification in renal transplant recipients randomized to continue cyclosporine or convert to sirolimus

Conversion from cyclosporine (CsA) to sirolimus at week 12 after kidney transplantation is associated with a significant improvement in renal function. The aim of this analysis was to investigate the effect of this conversion on interstitial fibrosis (IF), a hallmark of chronic allograft injury, in patients taking part in the CONCEPT trial. This multicenter, prospective, trial included 193 renal recipients randomized at week 12 to switch from CsA to sirolimus or to continue CsA, with mycophenolate mofetil. Routine biopsy with automated, quantified assessment of IF by a program of color segmentation was performed at 1 year in 121 patients. At 1 year, renal function was significantly improved in the conversion group as assessed by estimated GFR (MDRD) and measured GFR. Biopsy results, however, showed no between-group difference in percentage of IF. Calculated GFR at 1 year was significantly associated with the percentage of IF (p = 0.004, R(2)= 0.07). By multivariate analysis diabetic patients had more fibrosis than non-diabetic patients. In conclusion, although kidney transplant patients converted from CsA to sirolimus showed significant improvement in renal function, we found no difference of IF on 1-year biopsies.

Estimated one-yr glomerular filtration rate is an excellent predictor of long-term graft survival in pediatric first kidney transplants

Acute rejection episodes following pediatric renal transplantation have been progressively reduced by recent immunosuppressive regimens. Nevertheless, grafts continue to fail over time and surrogate parameters for long-term RGS are lacking. We investigated post-transplant renal function within the first yr as an independent predictor of long-term RGS in 104 pediatric first kidney transplant recipients (mean age 11.1 +/- 3.9 yr; mean follow-up 8.3 +/- 3.5 yr) transplanted between January 1989 and December 2000. GFR was assessed by use of the Schwartz formula at 30 days and six and 12 months after transplantation, respectively. Patients were further stratified at all times according to GFR: (i) GFR<45 mL/min/1.73 m(2), (ii) GFR 45-80 mL/min/1.73 m(2), and (iii) GFR>80 mL/min/1.73 m(2). Cox regression analysis including factors potentially influencing long-term RGS, e.g., age, gender, transplant yr, HLA-mismatch, underlying renal disease, clinical acute rejection, absolute GFR as well as the change in GFR within the first yr was performed. Graft failure occurred in 24 out of 104 patients (23%) 6.2 yr (mean) after transplantation corresponding to a cumulative five-yr graft survival of 87.5%. GFRs at 30 days and six and 12 months were significantly associated with long-term RGS in the univariate cox regression analysis (GFR at 30 days, p = 0.045; GFR at six months, p = 0.004; GFR at 12 months, p < 0.001). None of the other variables were significant parameters of correlation. Multivariate cox analysis revealed a GFR below 45 mL/min/1.73 m(2) at 12 months after transplantation as the only independent predictor of long-term RGS (hazard ratio 55.9, 95% CI 5.29-591, p = 0.001). GFR at 12 months post-transplant is an excellent surrogate parameter for long-term RGS in children. This parameter might be useful as a primary end-point in short-term pediatric clinical trials.

Response to ciclosporin treatment in Ethiopian and Nepali patients with severe leprosy Type 1 reactions

Leprosy type 1 reactions (T1R) are immune-mediated events with inflammation of peripheral nerves and skin. We report the clinical outcomes of a closely monitored open prospective trial in which eight Nepali and 33 Ethiopian patients with T1Rs were treated with an Indian generic formulation of ciclosporin (Cn; 5-7.5 mg/kg/day) for 12 weeks and followed up for 24 weeks after starting treatment. Outcomes were measured using a clinical severity score. Among the Nepalis, 75-100% improved in all acute clinical parameters; 67-100% patients maintained improvement, except for those with acute sensory nerve impairment among whom 67% relapsed after stopping treatment. The skin lesions of all Ethiopians on 5 mg/kg/day of Cn improved and 50-60% had peripheral nerve function improvement. Most Ethiopians needed a higher dose of Cn to improve nerve impairment and neuritis, and 50-78% of them developed worse clinical severity scores when Cn was stopped. Four Ethiopians and two Nepalis developed elevated serum creatinine levels on 7.5 mg/kg/day Cn, and three (9%) Ethiopians developed treatable hypertension. This suggests that Cn monotherapy is an effective treatment for severe T1R with few adverse effects. A dose of 5 mg/kg/day seems efficacious in Nepalis, but a higher dose may be required in Ethiopian patients.

Analysis of CC chemokine receptor 5 and 2 polymorphisms and renal transplant survival

Chronic rejection is an immune process leading to graft failure. By regulating the trafficking of leukocytes, chemokines and chemokine receptors are thought to be one of the reasons causing acute renal rejection (ARE), which increases the possibility of chronic rejection and organ destruction. This study was designed to investigate, in the Turkish population, an association of chemokine receptor genetic variants, CCR2V641, CCR5-59029-A/G, CCR5-Delta32 and acute renal rejection after renal transplant surgery. We carried out our study in 85 Turkish renal transplant patients (45 men, 40 women; mean age 39 +/- 2 years) by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. We found no significant difference in the incidence of rejection among patients possessing or lacking CCR5-Delta32. For the groups with and without acute renal rejection, we found a significant difference between the groups in A and G allele distribution in both CCR2V641and CCR559029 gene variants (p = 0.003 and p = 0.003, respectively). According to our findings, the risk of acute rejection in renal transplantation may be associated with genetic variation in the chemokine receptor genes CCR5-59029 and CCR2V641 in Turkey, and studies on these gene polymorphisms could be an ideal target for future interventions intended to prevent renal transplant loss.

Rabbit antithymocyte globulin versus basiliximab in renal transplantation

BACKGROUND

Induction therapy reduces the frequency of acute rejection and delayed graft function after transplantation. A rabbit antithymocyte polyclonal antibody or basiliximab, an interleukin-2 receptor monoclonal antibody, is most commonly used for induction.

METHODS

In this prospective, randomized, international study, we compared short courses of antithymocyte globulin and basiliximab in patients at high risk for acute rejection or delayed graft function who received a renal transplant from a deceased donor. Patients taking cyclosporine, mycophenolate mofetil, and prednisone were randomly assigned to receive either rabbit antithymocyte globulin (1.5 mg per kilogram of body weight daily, 141 patients) during transplantation (day 0) and on days 1 through 4 or basiliximab (20 mg, 137 patients) on days 0 and 4. The primary end point was a composite of acute rejection, delayed graft function, graft loss, and death.

RESULTS

At 12 months, the incidence of the composite end point was similar in the two groups (P=0.34). The antithymocyte globulin group, as compared with the basiliximab group, had lower incidences of acute rejection (15.6% vs. 25.5%, P=0.02) and of acute rejection that required treatment with antibody (1.4% vs. 8.0%, P=0.005). The antithymocyte globulin group and the basiliximab group had similar incidences of graft loss (9.2% and 10.2%, respectively), delayed graft function (40.4% and 44.5%), and death (4.3% and 4.4%). Though the incidences of all adverse events, serious adverse events, and cancers were also similar between the two groups, patients receiving antithymocyte globulin had a greater incidence of infection (85.8% vs. 75.2%, P=0.03) but a lower incidence of cytomegalovirus disease (7.8% vs. 17.5%, P=0.02).

CONCLUSIONS

Among patients at high risk for acute rejection or delayed graft function who received a renal transplant from a deceased donor, induction therapy consisting of a 5-day course of antithymocyte globulin, as compared with basiliximab, reduced the incidence and severity of acute rejection but not the incidence of delayed graft function. Patient and graft survival were similar in the two groups. (ClinicalTrials.gov number, NCT00235300 [ClinicalTrials.gov].).

Renal ischemia-reperfusion injury: new implications of dendritic cell-endothelial cell interactions

In renal ischemia/reperfusion (I/R) injury endothelial cells are a main target. The disturbance of endothelial cell physiology leads to endothelial swelling and narrowing of the blood vessel lumen. We attribute this effect to impairment of endothelial cell nitric oxide synthase (NOS). NO is significantly reduced in the course of hypoxia causing dysfunction of the vascular smooth muscle tone. Subsequently to an I/R injury, the inflammatory response results in endothelial activation with enhanced dendritic cell (DC) adhesion and migration. Thus, alloreactive leukocytes are recruited to the inflammatory site. Finally, dendritic cell-endothelial cell interactions may play a crucial role in antigen-specific allograft rejection in I/R renal injury. DCs, which activate naïve alloreactive T cells, play a central role in the establishment of alloantigen-specific immunity. In the course of hypoxia rejection is initiated at the activated layer of foreign endothelial cells (EC), which forms an immunogenic barrier for migrating DCs and T cells. Host DCs that bind to postischemic activated ECs invade the allografted tissues, or remain stationary in the subendothelial layer, or transmigrate into lymphoid vessels and secondary lymphoid organs, where they present alloantigens to naïve host T cells. Organ rejection is mediated by host alloreactive T cells, which are activated by donor DCs (direct activation) or host DCs (indirect activation). We hypothesized that DC-EC binding and migration is the first step in the renal I/R injury that mediates allotransplant rejection. We sought to better understand the downstream events of a renal I/R injury by understanding DC binding and migration, thereby seeking new strategies for more specific immunomodulatory interventions. Herein we developed a new allotransplant-rejection model after renal I/R injury.

Proteomic research in renal transplantation

Expression proteomics is a valuable tool for biomarker discovery. Currently there is a great deal of interest in the development of urine biomarkers for detection of renal allograft rejection as an alternative to percutaneous needle biopsy, which is the "gold standard." Needle biopsy is costly and associated with significant patient morbidity and mortality. This review will discuss the author's current work in proteomics-based urine biomarker discovery, as well as alternative approaches used by other groups that use SELDI mass spectrometry. The current state of urine transplant biomarkers will be discussed, and in conclusion there will be a brief discussion of how urine biomarkers will be used for transplant patient management once they are validated and analyte-specific assays are developed.

Glutathione depletion of stimulator cells inhibits responder T-cell immunogenicity in vitro and prolongs allograft survival in vivo

BACKGROUND

Pretransplant donor-organ immunomodulation may attenuate allograft rejection by changing the redox state of donor cells. This study explored impact of donor-cell redox-state alteration by glutathione (GSH) depletion on graft immunogenicity.

METHODS

Splenic and heart endothelial cells from Balb/c mice were treated with diethylmaleate (a GSH-depleting agent) and/or lipopolysaccharide to assess the impact of GSH depletion on alloreactivity by mixed lymphocyte reaction, endothelial cell adhesion by T-cell adhesion assay, intracellular adhesion molecule-1 expression by reverse transcriptionase-polymerase chain reaction, and nuclear factor-kappa B upregulation by electrophoretic mobility shift assay. Heterotopic heart transplants were performed as in vivo correlate.

RESULTS

GSH depletion decreased endothelial cell and splenic cell alloreactivity, decreased endothelial cell intracellular adhesion molecule-1 expression through attenuation of nuclear factor-kappa B activity, decreased endothelial cell adhesion, and prolonged heterotopic heart transplant graft survival.

CONCLUSIONS

GSH depletion may represent a significant immunomodulator of donor antigenicity to prevent transplant rejection.

Chronic allograft nephropathy

With the advent of calcineurin inhibitors, the success of kidney and other solid-organ transplants has improved significantly from the standpoint of reducing the incidence of acute rejection. Over the past 2 decades, both short-term allograft survival and acute rejection rates have dramatically improved with improved diagnostic and therapeutic techniques such as standardized pathology scoring; potent antirejection drugs such as anti-thymocyte globulin, interleukin-2 receptor antibodies, cyclosporine, tacrolimus, sirolimus, and mycophenolate mofetil; and improved infection control such as valganciclovir and antifungal therapy. However, long-term graft loss has remained at nearly constant levels over the same period of time, with the average half-life of a deceased-donor kidney transplant in the United States remaining approximately 1 decade. In addition to death with a functioning allograft and calcineurin toxicity, a chronic fibrotic process-known at various times as chronic rejection, chronic allograft dysfunction, and chronic allograft nephropathy (CAN)-account for the leading causes of transplant failure.

Increased urinary excretion of transforming growth factor-beta(1) in renal transplant recipients during cytomegalovirus infection

AIMS

Cytomegalovirus (CMV) is a suggested risk factor for chronic allograft nephropathy, and transforming growth factor-beta (TGF-beta) is a key fibrogenic molecule in this process. CMV has been shown to induce the expression of TGF-beta and several cytokines. We analyzed the impact of CMV on urinary excretion of TGF-beta, ICAM-1, TNF-alpha and correlated findings with biopsy histology.

MATERIAL

Urine samples from 46 renal transplant recipients were available for the study. Urine samples were taken when CMV infection was suspected, or for controlling of proteinuria or bacteriuria.

METHOD

CMV was diagnosed by antigenemia and viral cultures. Patients with previous CMV infection were excluded from the analysis. Urine samples were analyzed by ELISA-method to detect the levels of TNF-alpha, ICAM-1 and TGF-beta(1). Banff '97 criteria were used for scoring of protocol biopsies taken 6 months after transplantation.

RESULTS

At the time of the urine collection, 13/46 patients had CMV infection. Eight patients with no CMV infection were used as controls. TGF-beta(1) was significantly increased in the CMV group (samples taken mean 137+/-79 days post-transplantation) compared to controls (samples 139+/-64 days post-transplantation) (51.1+/-28.0 vs. 13.3+/-6.7 ng/mmol crea, p<0.001). No differences in the levels of other molecules were recorded. In the biopsies, interstitial fibrosis was significantly increased in the CMV group compared to controls.

CONCLUSIONS

Urinary excretion of TGF-beta(1) was increased in patients during CMV infection. This was associated with increased fibrosis in the biopsies.

Outcome of nonheart-beating donor kidneys with prolonged delayed graft function after transplantation

Nonheart-beating donor (NHBD) kidneys are frequently associated with delayed graft function (DGF), with a deleterious effect on kidney function and allograft survival. The influence and the duration of DGF on the outcome of NHBD kidneys are assessed. All recipients of an NHBD kidney in the period 1993-2003 were reviewed. Excluded from analysis were patients with primary nonfunction (PNF). One hundred and five patients with a functioning NHBD graft were reviewed: 23 (22%) had immediate function (group 1), 40 (38%) had DGF < or = 2 weeks (group 2), 31 (30%) had DGF 15 days to 4 weeks (group 3) and 11 (10%) had DGF for > 4 weeks (group 4). Creatinine clearance at 3 months was higher in groups 1 and 2 versus group 4 (p = 0.015 and p = 0.006, respectively) and was higher in group 2 versus group 4, at 1 year (p = 0.01). Graft survival was 95%, 98%, 97% and 89%, respectively, at 1 year and 95%, 85%, 77% and 89%, respectively, at 5 years, which was not significantly different. The duration of DGF in NHB kidneys has a negative effect on creatinine clearance, but no effect on graft survival.

Early Acute Rejection Episodes in Renal Transplantation in Relation to Immunosuppression Protocls: An Audit of 100 Cases

INTRODUCTION

Early acute rejection episodes (ARE) have deleterious effects on graft outcomes. The incidence of ARE in the first 3 months has been reported to be <20%. In a recent audit of ARE among 100 renal transplants, we observed the rates to be high (30%). We retrospectively collected details of donor type, induction therapy, immunosuppression medications, drug levels, HLA mismatches, acute tubular necrosis (ATN), and delayed graft function (DGF) to correlate with ARE and response to therapy.

RESULTS

Thirty rejection episodes occurred after a mean period of 14.3 days after transplantation. Ninety-one patients had induction treatment with either antithymocyte globulin (ATG) or interleukin 2 receptor antibodies (IL2 Rab). The drugs included cyclosporine, mycophenolate, sirolimus, azathioprine, and prednisolone in these patients. There was no significant difference in ARE among the different drug protocols (30.7%-35.2%). Subjects with 4 or more HLA mismatches displayed more ARE (40.3%) compared with those with 3 or less (23%). Subjects with ATN or DGF immediately posttransplantation had a higher incidence of ARE (39.2%) than those without them (26.3%). Deceased donor recipients had a higher episode of ARE (45.1%) compared with live related donor recipients (25%). On stratifying the known risk factors for ARE, subjects with no risk factors had the least (22.2%) ARE compared with those with one (32.5%) or two (47.6%) risk factors. Subjects who failed to achieve adequate cyclosporine (C2) levels showed significantly higher rates of ARE (86.9%) than those with adequate or higher levels (8.6%).

CONCLUSION

Higher HLA mismatches, DGF, deceased donor, and failure to achieve adequate cyclosporine levels were observed to be major risk factors for the development of ARE.

Basiliximab lowers the cyclosporine therapeutic threshold in the early post-kidney transplant period

Early adequate cyclosporine exposure has been shown to predict low acute rejection rate in kidney transplantation. The aim of this study is to determine the importance of exceeding the early cyclosporine therapeutic exposure threshold with basiliximab induction. A retrospective analysis of 166 first cadaveric and non-identical live donor transplant recipients treated with or without basiliximab induction, Neoral, mycophenolate mofetil and prednisone, was performed. Adequate exposure was defined as a 2-h post-Neoral dose cyclosporine level (C2) >1700 ng/mL at day 3. The primary outcome was acute rejection within the first 6 months. In the no basiliximab (control) group (n = 74), rejection occurred in 23% (17 of 74) of recipients and was strongly associated with low cyclosporine exposure on day 3. Acute rejection occurred in 38% (11 of 29) with C2 <1700 ng/mL compared with 13% (six of 45) with C2 >/=1700 ng/mL (p = 0.014). In the basiliximab group (n = 92), rejection occurred in only 11% (10 of 92) of recipients and did not correlate with cyclosporine exposure. Acute rejection occurred in 10% (four of 40) with C2 <1700 ng/mL compared with 12% (six of 52) with C2 >/=1700 ng/mL (p = 0.81). Therefore achieving cyclosporine therapeutic targets by day 3 may not be required when anti-IL2 receptor antibody induction is used.

Chronic renal allograft rejection: Pathophysiologic considerations

Chronic rejection is currently the most prevalent cause of renal transplant failure. Clinically, chronic rejection presents by chronic transplant dysfunction, characterized by a slow loss of function, often in combination with proteinuria and hypertension. The histopathology is not specific in most cases but transplant glomerulopathy and multilayering of the peritubular capillaries are highly characteristic. Several risk factors have been identified such as young recipient age, black race, presensitization, histoincompatability, and acute rejection episodes, especially vascular rejection episodes and rejections that occur late after transplantation. Chronic rejection develops in grafts that undergo intermittent or persistent damage from cellular and humoral responses resulting from indirect recognition of alloantigens. Progression factors such as advanced donor age, renal dysfunction, hypertension, proteinuria, hyperlipidemia, and smoking accelerate deterioration of renal function. At the tissue level, senescence conditioned by ischemia/reperfusion (I/R) may contribute to the development of chronic allograft nephropathy (CAN). The most effective option to prevent renal failure from chronic rejection is to avoid graft injury from both immune and nonimmune mechanism together with nonnephrotoxic maintenance immunosuppression.

IL-2 and TNF-α Promoter Polymorphisms in Patients With Acute Kidney Graft Rejection

INTRODUCTION

Proinflammatory cytokines have been implicated in the pathogenesis of acute kidney allograft rejection. The aim of the study was to examine the association between interleukin (IL)-2 -330 and tumor necrosis factor (TNF)-alpha -308 promoter polymorphisms and acute kidney allograft rejection.

METHODS

The study included 72 patients with long-term stable graft function, and 57 diagnosed with acute kidney allograft rejection.

RESULTS

Patients with acute kidney allograft rejection showed a prevalence of subjects with TNF-alpha T2 allele (P < .05). The risk of acute kidney allograft rejection diagnosis was 2.5-fold greater among carriers of the T2 allele than those homozygous for T1T1 (OR 2.53, 95% CI 1.19 to 5.37, P < .05) There was no statistically significant difference in the distribution of IL-2 genotypes between patients with stable graft function and acute kidney allograft rejection.

CONCLUSION

The results suggest that TNF-alpha-308 promoter polymorphism is a risk factor for acute kidney allograft rejection.

Efficacy and safety of basiliximab in kidney transplantation

The efficacy and safety of basiliximab, in combination with different maintenance regimens, are extensively addressed in the available literature. Basiliximab reduces the incidence of acute rejection, allows a safe reduction of steroid dosage, and is associated with economic savings, although there is substantially no proof that basiliximab prolongs either patient or graft survival. Initial basiliximab administration entails a low-risk and is associated with fewer adverse events than T cell depleting agents. However, life-threatening reactions were reported following re-exposure to basiliximab in recipients who lost graft function early after transplantation and, therefore, discontinued all immunosuppressive agents.

Noninvasive detection of renal allograft inflammation by measurements of mRNA for IP-10 and CXCR3 in urine

BACKGROUND

We explored the hypothesis that measurements of mRNA encoding interferon-inducible protein-10 (IP-10) or the chemokine receptor CXCR3 in urinary cells offer a noninvasive means of elucidating cellular traffic causing acute rejection of human renal allografts.

METHODS

We obtained 63 urine specimens from 58 renal allograft recipients who underwent 63 allograft biopsies to resolve the basis for graft dysfunction, and 27 additional urine samples from 24 other patients with stable allograft function. Twenty-seven of the 63 biopsies were classified as acute rejection, 20 as other, and 16 as chronic allograft nephropathy. We measured the levels of transcripts for IP-10 and CXCR3, and a constitutively expressed gene 18S rRNA in the urine specimens and correlated transcript levels with renal allograft diagnosis.

RESULTS

mRNA levels of IP-10 (P < 0.0001) or CXCR3 (P < 0.0001) but not the levels of 18S rRNA (P= 0.56) predicted intragraft cellular traffic causing acute rejection. Receiver-operating characteristic curve analysis demonstrated that acute rejection can be predicted with a sensitivity of 100% and a specificity of 78% using the (log-transformed) cutoff value of 9.11 copies of IP-10, and with a sensitivity of 63% and a specificity of 83% using the cutoff value of 11.59 copies of CXCR3. Immunohistologic analysis of allograft biopsies showed exuberant expression of IP-10 and CXCR3 during acute rejection whereas both were absent in grafts with stable function.

CONCLUSION

Our investigation demonstrates that intragraft cellular events associated with acute rejection of human renal allografts can be noninvasively identified by measurements of mRNA for IP-10 and CXCR3 in urinary cells.

Mycophenolates in transplantation

The discovery of mycophenolic acid (MPA) as a potent immunosuppressant, able to inhibit B- and T-cell proliferation by blocking production of guanosine nucleotides required for DNA synthesis, allowed its potential in the field of transplantation to be realized. Mycophenolate mofetil (MMF), an MPA prodrug, has been shown to be an effective immunosuppressant in transplant therapy. Clinical trials in renal, heart, and liver transplant recipients have demonstrated that, in combination with cyclosporine and steroids, MMF therapy can reduce the incidence and severity of acute rejection episodes and improve graft and patient survival as well as graft function. Although MMF is generally well tolerated, optimal therapy may be limited by associated side effects, in particular gastrointestinal (GI) toxicity, which may occur in over 40% of patients. Dose changes resulting from GI side effects may potentially lead to sub-therapeutic dosing and impaired clinical outcomes. An enteric-coated formulation delivering MPA - enteric-coated mycophenolate sodium (EC-MPS) has been developed to improve MPA-related upper GI adverse events. EC-MPS delays the release of MPA, consistent with a functional enteric-coating. Recent clinical trials have demonstrated that EC-MPS is as effective and safe as MMF in both de novo and maintenance renal transplant patients.

Improved Clinical Outcomes in Chinese Renal Allograft Recipients Receiving Lower Dose Immunosuppressants

BACKGROUND

The application of potent immunosuppressants has decreased the incidence of acute rejection and increased short- and long-term graft survival; however, these drugs cause a variety of complications. In China, many transplant centers have adopted the immunosuppressive protocols based on the white population, neglecting the differences between the races. The purpose of this study was to explore a suitable immunosuppressive regimen for Chinese renal allograft recipients.

METHODS

Two hundred cadaveric renal allograft recipients who underwent transplantation between July 1999 and October 2001 were observed. Before October 2000, 104 recipients received the conventional dose of immunosuppressants; thereafter, 96 recipients received lower dose treatment. Doses of immunosuppressive agents, the incidence of acute rejection and pulmonary infection, and patient and graft survival rates were compared between the two groups.

RESULTS

Doses of mycophenolate mofetil (MMF) and cyclosporine A (CsA) administered in the conventional dose group were significantly higher than in the lower dose group at 3 months posttransplant, as was prednisone at 6 months posttransplant. The incidence of acute rejection and subclinical rejection that was biopsy-proven or diagnosed by clinical manifestations was 17.3% and 19.8%, respectively, in the conventional dose group and the lower dose group within the first 6 months, and no significant difference was noted (P=0.55). The incidence of pulmonary infection, especially severe infection, was much higher in the conventional treatment group (40.1% and 26.9%, respectively) than that in the lower dose group (11.5% and 5.2%, respectively), and the differences were statistically significant (P<0.001). The corresponding 1-year survival rate of patients was 87.4% and 97.9% (P<0.01), and that of renal grafts was 85.5% and 96.9% (P<0.01), for patients receiving conventional dose and lower dose immunosuppressive drugs, respectively. The rate of death with a functioning allograft caused by infection in the conventional dose group was significantly higher than that in the lower dose group (12.5% vs. 0%, P<0.01).

CONCLUSIONS

The regimen of lower dose MMF, CsA, and prednisone in combination can significantly reduce the incidence of pulmonary infection, especially severe pulmonary infection, without increasing the incidence and severity of allograft rejection.

The role of anti-IL-2 receptor in high-risk kidney transplant patients

Anti-IL-2 receptor has been proved to be effective in reducing the rate of acute rejection in kidney transplantation and also improving both the rate of graft and patient survival. In this study, we retrospectively review the role of anti-IL-2 receptor as induction immunosuppression in immunologically high-risk kidney transplant patient compared with normally low-risk patients.

METHODS

From January 1999 to December 2002, we performed 246 kidney transplantations in two transplant centers in Bangkok. These were divided into two groups: group 1, high-risk group containing 50 patients who had one of the following criteria: (1) high panel reactive antibody (>50%); (2) retransplantation; (3) marginal donor (with expectancy of delayed graft function); (4) spouse donor; (5) >4 HLA mismatch. All group 1 patients receive anti-IL-2 receptor as induction immunosuppression (either Basiliximab (n = 27) or Daclizumab (n = 23).) Group 2 consisted of the control group of 196 patients with normal immunological risk. The following data of both groups were collected and analyzed: patient demography, type of donor, acute rejection incidence, severity, and time.

RESULTS

In this study, the anti-IL-2 receptors are 27 cases of Basiliximab and 23 cases of Daclizumab. The rates of acute rejection are not significantly different in both groups, namely, 46 of 194 (23.7%) in group 2 compared with 10 of 50 (20%) episodes in group 1 (P = .602). All rejections in both groups responded to pulse steroid treatment. The mortality rate and rate of graft failure were also not significantly different, i.e., 6 of 196 (3.1%) vs 2 of 50 (4.0%) (P = .666) and 7 of 196 (3.6%) vs 3 of 50 (6.0%) (P = .429) in low risk group versus high risk group, respectively. Kaplan-Meier estimates of the probabilities of acute rejection free, patient survival rate, and graft survival rate also showed no difference between groups.

CONCLUSIONS

The use of anti-IL-2 receptor antibodies as induction immunosuppression in immunologically high-risk patients results in the same rate of acute rejection, severity of acute rejection, graft survival, and patient survival as recipients with normal immunological risk.

Impaired Kidney Graft Survival is Associated with the TNF-α Genotype

BACKGROUND

The TNF2 allele at position -308 of the tumor necrosis factor (TNF)-alpha gene is associated with high TNF production. The purpose was to study the association of this gene polymorphism with rejection episodes and graft survival after kidney transplantation.

METHODS

A retrospective analysis of transplant outcomes of patients who only had been treated with one single form of immunosuppression consisting of cyclosporine, azathioprine, and prednisolon was performed.

RESULTS

We found that 115 (73%) patients had the TNF1/TNF1 genotype, whereas 42 (27%) were TNF2 positive. There was no difference in the overall acute rejection frequency between these two groups (50% in each), but our data showed a non-significant tendency towards a higher frequency of steroid resistant rejections in the TNF2 positive group (57% vs. 40%). There was no significant difference in graft survival between the two genotype groups, although an early tendency towards worse survival was seen in TNF2 recipients. However, the TNF2 positive recipients with rejection episodes had far worse graft survival compared with the TNF1/TNF1 recipients with rejection episodes (P<0.02). No difference was seen between the two genotype groups in patients without rejection episodes.

CONCLUSION

Our data propose that potentially high TNF producers with the TNF2 allele do not have an increased risk for rejection episodes, but if rejection episodes occur, they have a significantly increased risk for early graft loss. TNF production may intensify rejection, but is not a primary factor for the induction of such acute immune activation.

Role of integrin CD103 in promoting destruction of renal allografts by CD8 T cells

Infiltration of CD8(+)TCRalphabeta(+) T-effector populations (CD8 effectors) into graft epithelial compartments has long been recognized as a key lesion in progression of clinical renal allograft rejection. While the afferent phase of allograft immunity is increasingly well-defined, the efferent pathways by which donor-reactive CD8-effector populations access and ultimately destroy the graft renal tubules (rejection per se) have received remarkably little attention. This is an important gap in our knowledge of transplantation immunology, because epithelial compartments comprise the functional elements of most commonly transplanted organs including not only kidney, but also liver, lung, pancreas, and intestine. Furthermore, there is increasing evidence that attack of graft epithelial elements by CD8-effector populations not only causes short-term graft dysfunction but is also a major contributor to development of chronic allograft nephropathy and late graft loss, which now represent the salient clinical problems. Recent studies of the T-cell integrin, alpha(E)beta(7) (CD103), have provided insight into the mechanisms that promote interaction of CD8 effectors with graft epithelial compartments. The purpose of this communication is to review the known properties of the CD103 molecule and its postulated role in the efferent phase of renal allograft rejection.

Efficacy and safety of tacrolimus compared with cyclosporine microemulsion in primary simultaneous pancreas-kidney transplantation: 1-year results of a large multicenter trial

BACKGROUND

Simultaneous pancreas-kidney transplantation (SPK) transplantation has become an accepted therapy for type 1 diabetic patients with end-stage renal disease. This open-label, multicenter study compared the efficacy and safety of tacrolimus with the microemulsion (ME) formulation of cyclosporine in a clinical setting. The 1-year results are reported here.

METHODS

The study was conducted in 10 European centers and one center in Israel. One hundred three patients were randomly assigned to tacrolimus and 102 to cyclosporine-ME. All patients received concomitant rabbit anti-T-cell globulin induction therapy, mycophenolate mofetil (MMF), and short-term cortico-steroids. The initial daily oral doses were 0.2 mg/kg for tacrolimus, 7 mg/kg for cyclosporine-ME, and 2 to 3 g for MMF.

RESULTS

The 1-year incidence of biopsy-proven kidney or pancreas acute rejection was lower with tacrolimus (27.2%) than with cyclosporine-ME (38.2%; P = 0.09). Pancreas graft survival at 1 year was 91.3% with tacrolimus and 74.5% with cyclosporine-ME (P <0.0005). Renal graft survival was similar in the two study groups. There were no significant treatment-related differences in pancreatic or renal graft function. In total, 34 patients switched treatment from cyclosporine-ME to tacrolimus, but only 6 patients receiving tacrolimus required alternative therapy. Mean doses of MMF at 1 year were also lower in the tacrolimus group (1.36 vs. 1.67 g/day; P = 0.007).

CONCLUSION

These findings support the use of tacrolimus therapy for uremic patients with type 1 diabetes who are undergoing SPK transplantation.