Chronic renal allograft nephropathy

Chronic rejection/chronic allograft nephropathy is the most prevalent cause of renal graft loss after the first year post-transplant. Chronic rejection/chronic allograft nephropathy is characterized by a slow progressive deterioration of graft function, often in combination with proteinuria and hypertension. Both immunologic and non-immunologic factors play key roles in the pathogenesis of chronic allograft nephropathy. Acute rejection episodes are the most prevalent risk factor for chronic rejection. Many risk factors for chronic allograft nephropathy have been identified, such as delayed graft function, nephron-dosing mismatch, repeated acute rejection episodes, and pathologically severe rejection. However, the precise pathogenesis of chronic allograft nephropathy remains elusive. The differential diagnosis of immunologically mediated chronic rejection and chronic rejection caused by non-immunologic factors is usually not possible using clinical parameters. The histopathologic findings of chronic allograft nephropathy are progressive interstitial fibrosis and remodelling of the vascular wall, and these findings are nonspecific. However, typical chronic transplant glomerulopathy, which affects glomerular tufts, as well as the multilayering of the peritubular capillary basement membrane, are characteristic of immunologic chronic rejection. Furthermore, in long-surviving patient with an allograft treated with a potent immunosuppressive agent, a calcineurin inhibitor, two or more concomitant independent lesions often develop. Therefore, the term "chronic allograft nephropathy" may be clinically preferable to "chronic rejection" to describe the gradual decline in graft function months or years after transplantation, in the absence of a well defined mechanism of graft dysfunction. The most effective way to prevent chronic allograft nephropathy is to avoid any kind of graft damage via either immunologic or non-immunologic mechanisms. Received: April 1, 2000 / Accepted: May 2, 2000     

Pathogenesis of chronic renal allograft dysfunction

The pathogenesis of chronic renal allograft dysfunction was reviewed. Chronic rejection/chronic renal allograft nephropathy is the most prevalent cause of renal graft loss after the first year post-transplant. Both immunologic and non-immunologic factors play key roles in the pathogenesis of chronic allograft nephropathy. Acute rejection episodes are the most prevalent risk factor for chronic rejection. Many risk factors for chronic allograft nephropathy have been identified, such as glomerular hyper-filtration, delayed graft function, repeated acute rejection, systemic hypertension and hyperlipidemia. However, the precise pathogenesis of chronic allograft nephropathy remains obscure. The differential diagnosis of immunologically mediated chronic rejection and chronic allograft dysfunction caused by non-immunologic factors is usually impossible using clinical parameters. The histopathologic findings of chronic allograft nephropathy are progressive interstitial fibrosis with tubular atrophy and thickening of vascular intima, and these findings are non-specific. Therefore, the term chronic allograft nephropathy may be clinically preferable to chronic rejection to describe the gradual decline in graft function. The most effective way to prevent chronic allograft dysfunction is to avoid any kind of graft damage via immunologic or non-immunologic pathway.     

Chronic allograft nephropathy: An update.

Chronic allograft nephropathy is the most prevalent cause of renal transplant failure in the first post-transplant decade, but its pathogenesis has remained elusive. Clinically, it is characterized by a slow but variable loss of function, often in combination with proteinuria and hypertension. The histopathology is also not specific, but transplant glomerulopathy and multilayering of the peritubular capillaries are highly characteristic. Several risk factors have been identified, such as advanced donor age, delayed graft function, repeated acute rejection episodes, vascular rejection episodes, and rejections that occur late after transplantation. A common feature of chronic allograft nephropathy is that it develops in grafts that have undergone previous damage, although the mechanism(s) responsible for the progressive fibrosis and tissue remodeling has not yet been defined. Hypotheses to explain chronic allograft nephropathy include the immunolymphatic theory, the cytokine excess theory, the loss of supporting architecture theory, and the premature senescence theory. The most effective option to prevent chronic allograft nephropathy is to avoid graft injury from both immune and nonimmune mechanisms.     

Chronic rejection in renal transplantation

With renal transplantation, chronic rejection is currently the most prevalent cause of late transplant failure. Clinically, chronic rejection presents as chronic transplant dysfunction, characterized by a slow loss of function, often in combination with hypertension and proteinuria. Transplant glomerulopathy and multilayering of the peritubular capillaries are highly characteristic for chronic rejection. Risk factors have been identified and include young recipient age, black race, presensitization, histoincompatibility, 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 immune responses resulting from indirect recognition of alloantigens. Progression factors such as advanced donor age, renal dysfunction, hypertension, proteinuria, hyperlipidemia, and smoking play an important role. At the tissue level, senescence conditioned by ischemia/reperfusion may contribute to the development of chronic rejection. 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.     

Early acute rejection does not affect chronic allograft nephropathy and death censored graft failure

BACKGROUND: Even with the development of modern immunosuppression, an acute rejection episode is a major complication after renal transplantation. Acute rejection episodes have been used as clinical indicators for chronic allograft nephropathy and graft loss. We investigated the timing and frequency of acute rejection episodes in relation to long-term graft survival and chronic allograft nephropathy. METHODS: The Long Term Efficacy and Safety Surveillance study of transplant patients receiving cyclosporin (Neoral) included 1706 adult renal transplants (1995 to 2003) with a functioning graft for at least 1 year. The impact on death-censored long-term graft survival was evaluated for acute rejection episodes (single or multiple) within 3 months, at 3 to 6 months, at 6 to 12 months, or at over 1 year posttransplant. A stepwise binary logistic regression was employed to identify independent risk factors for the time to occurrence of an acute rejection episode. RESULTS: An acute rejection episode occurring within 3 months posttransplantation had no effect on either death-censored long-term graft failure (P=.2157) or chronic allograft nephropathy (P=.9331). However, an acute rejection episode occurring at 1 year or later posttransplantation was significantly associated with death censored long-term graft failure (P <.0001) and chronic allograft nephropathy (P <.0001). The numbers of HLA-DR mismatches and younger recipient ages were independent risk factors for early acute rejection. CONCLUSION: Among patients whose graft survives at least 12 months, an early acute rejection episode within 3 months posttransplant was not associated with either death-censored long-term graft survival or chronic allograft nephropathy among adults treated with cyclosporin. However, an acute rejection episode occurring at 1 year or later posttransplantation showed a positive association with death-censored long-term graft survival or chronic allograft nephropathy. Lower numbers of HLA-DR mismatches sum to reduce the occurrence of acute rejection and the hospitalization time.     

The association of viral infection and chronic allograft nephropathy with graft dysfunction after renal transplantation

BACKGROUND: The long-term effect of viral infections on graft dysfunction and rejection after renal transplantation is uncertain. METHODS: A cohort of 37 renal transplant recipients was followed prospectively for 3 years. Creatinine clearance rate at 6 months and 3 years and chronic allograft nephropathy were correlated with the detection of cytomegalovirus (CMV), human herpesvirus 6 and human herpesvirus 7 and BK virus DNA, CMV disease, and acute rejection. RESULTS: CMV disease was significantly associated with poor graft function at 6 months, whereas chronic allograft nephropathy was associated with graft dysfunction at 3 years. Both CMV disease and detection of human herpesvirus 6 DNA were associated with chronic allograft nephropathy. CONCLUSIONS: CMV disease was a significant cause of early graft dysfunction, whereas the presence of chronic allograft nephropathy was the main determinant of poor long-term graft function. The role of viral infections in chronic allograft nephropathy deserves further investigation.     

Prevalence and association of post-renal transplant anemia

In some renal allograft recipients, anemia persists or develops following transplantation. Anemia is associated with pre-operative blood loss and allograft dysfunction, including delayed graft function, acute rejection and chronic allograft dysfunction. To study the prevalence and association of post-renal transplant anemia, we studied 200 renal transplant recipients; 131 (65.5%) patients were males and 69 (34.5%) patients were females, and age ranged from 17 to 67 years, with a mean of 37.7 ± 10.8 years. All patients were receiving cyclosporine, prednisolone and mycophenolate mofetil (MMF). Complete blood count was done at two times: three and six months post-renal transplant. There were 74% anemic patients three months after renal transplantation and 45% anemic patients six months after renal transplantation. High creatinine value, female gender, delayed graft function, episodes of acute rejection, perioperative blood loss and infections were the only significant independent risk factors for prevalence of anemia post-renal transplant. In our study, we did not find an association between MMF and cyclosporine nor angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptors blocker (ARBs) with anemia. This study demonstrates that anemia is a common complication during the first six months after kidney transplantation, with several risk factors precipitating this complication.     

Current thinking on chronic renal allograft rejection: issues, concerns, and recommendations from a 1997 roundtable discussion

Chronic rejection accounts for most renal allograft losses after the first year posttransplantation. On March 24 and 25, 1997, a roundtable of five transplant surgeons, two nephrologists, and one pathologist assembled in Dallas, Texas, to review critical issues surrounding chronic renal allograft rejection. This article summarizes the presentations and relevant discussions of this meeting regarding the cause of chronic rejection, clinical diagnoses, risk factors, future prospects for intervention strategies, and general recommendations for the transplant community. Growing evidence indicates that chronic rejection is the aggregate sum of irreversible immunologic and nonimmunologic injuries to the renal graft over time. A history of acute rejection episodes and inadequate immunosuppression, likely attributable to inconsistent cyclosporine exposure or poor patient compliance, are among the most recognizable immunologic risk factors for chronic rejection. Donor organ quality, delayed graft function, and other donor and recipient variables leading to reduced nephron mass are nonimmunologic factors that contribute to the progressive deterioration of renal graft function. Clinical management of renal transplant recipients should incorporate both immunologic- and nonimmunologic-based intervention strategies aimed at minimizing risk factors to thwart the progression of chronic rejection and improve long-term allograft and patient survival.     

Renal transplantation 2004: where do we stand today?

In spite of considerable progress in immunosuppressive and supportive treatment, numerous problems persist which interfere with the success of renal transplantation. Before transplantation has been performed, factors impacting on outcome include the donor (living vs cadaver, age and HLA system) as well as the recipient (age, immunological reactivity, potential sensitization and duration of dialysis). These are the main factors that affect the outcome of the transplant, particularly in the long-term. After transplantation a number of events may put graft function at risk: potential recurrence of the primary renal disease in the allograft; 'de novo' renal disease triggered by infections, drugs or autoimmunity; and non-specific progression promoters, such as diabetes, hypertension, proteinuria, nephrotoxic agents and/or viral infections. The two most frequent causes of chronic allograft dysfunction are (i) chronic rejection (often triggered by preceding acute rejection, delayed graft function or poor compliance) and (ii) calcineurin-inhibitor nephrotoxicity (more likely to develop in kidneys of older donors or in marginal kidneys). The differential diagnosis between these two entities is generally difficult, but some histological clues (reduplication of glomerular basement membrane, obliterating vasculopathy and C4d deposits) as well as the demonstration of humoral antibodies are pointers suggesting rejection. Treatment of chronic graft dysfunction is difficult, whatever the cause, particularly in cases with advanced renal lesions. Therefore, early diagnosis is of paramount importance. In this regard, graft biopsy can be of great help. In spite of many problems and complications, not only short-term but also long-term results of renal transplantation are improving progressively, as documented by CTS data showing that in Europe for transplants performed between 1982 and 1984 the mean graft half-life was 7 years, while for transplants performed between 1997 and 1999 it was 20 years.     

肾移植术后血脂的变化对移植肾功能的影响

目的:探讨肾移植患者血脂代谢情况及其对移植肾功能的影响。方法:检测89例肾移植患者肾移植前、后的血脂水平,并与移植后1年内发生急性排斥反应及移植后1年时发生慢性移植肾功能不全的患者进行血清肌酐水平相关性分析。结果:与正常对照组比较,肾移植前、后的血清总胆固醇、低密度脂蛋白胆固醇的水平显著升高(P<0.01),甘油三酯、高密度脂蛋白胆固醇、极低密度脂蛋白胆固醇水平无显著差异。血载脂蛋白A1水平显著低于正常对照组(P<0.01)。移植前、后上述血脂水平无显著差异。移植前高胆固醇血症与急性排斥反应的发生存在相关性,高胆固醇血症对慢性移植肾功能不全患者血清肌酐水平升高存在影响。结论:肾移植患者血脂代谢紊乱明显不同于正常人群,高脂血症对急性排斥反应及慢性移植肾功能不全的发生具有不良影响。     

The pathobiology of chronic allograft nephropathy: immune-mediated damage and accelerated aging

Chronic allograft nephropathy includes chronic calcineurin nephrotoxicity, recurrent and de novo glomerulonephritis and a group of disorders with graft dysfunction of unknown etiology designated chronic rejection. Review of risk factors of the latter category show that the chronic rejection lesions emerge in organs that have undergone injury. Despite the relevance of nonalloantigen-dependent progression factors in the tissue injury, alloantigen-dependent factors predominate in the pathogenesis. Lately, B cell responses have received increasing interest in transplant rejection and include responses against both major histocompatibility complex (MHC) and tissue-specific antigens, mainly on the endothelium and in the glomeruli. These humoral responses are thought to be involved in the development of vascular and glomerular lesions. Furthermore, at the tissue level, markers of senescence are found in the tubular epithelium contributing to the lesions of tubular atrophy and interstitial fibrosis.     

Immunologic risk factors and glomerular C4d deposits in chronic transplant glomerulopathy

BACKGROUND: Chronic transplant glomerulopathy is an uncommon cause of chronic transplant dysfunction of unknown pathogenesis. We evaluated the epidemiologic, clinical, and histologic features of chronic transplant glomerulopathy. To determine the possible contribution of humoral immune responses, we assessed glomerular deposition of C4d. METHODS: From a cohort of 1111 kidney transplants (1983 to 2001) with at least 6 months of graft function, we identified 18 cases with chronic transplant glomerulopathy (1.6%) showing double contours of the glomerular basement membrane (GBM) on light microscopy. To assess the risk factors, this group was compared with 739 patients with stable function using multivariate Cox regression analysis. Paraffin sections of 11/18 biopsies were stained with polyclonal C4d antibodies. Sera of 13/18 patients could be tested for antidonor human leukocyte antigen (HLA) antibodies by enzyme-linked immunosorbent assay (ELISA). Patients with chronic allograft nephropathy without chronic transplant glomerulopathy or predominant cyclosporine nephrotoxicity were used as controls. RESULTS: Chronic transplant glomerulopathy was diagnosed at a median of 8.3 (range 2.6-12.5) years posttransplantation. Panel reactive antibodies at time of transplantation, RR 1.23 (1.05-1.45) per 10% increase, and late acute rejection episodes, RR 7.6 (1.8-31.7), were independently associated with chronic transplant glomerulopathy. We found glomerular C4d deposits in 10/11 biopsies showing chronic transplant glomerulopathy and in only 2/13 controls. Peritubular capillary C4d deposits and donor-specific anti-HLA antibodies were demonstrated in 4 and 3 of the 10 patients with glomerular C4d deposits, respectively. CONCLUSION: Presensitization and late acute rejection episodes were the risk factors identified. Glomerular C4d deposits suggest that chronic transplant glomerulopathy emerges from in situ humoral rejection. Chronic transplant glomerulopathy should be considered as a manifestation of immune-mediated injury.     

Polyomavirus nephropathy after renal transplantation: a single centre experience

BACKGROUND: Polyomavirus associated nephropathy (PVN) in renal transplant recipients has been observed with increasing frequency recently and has emerged as a cause of allograft failure linked to highly potent new immunosuppressive regimens containing tacrolimus or mycophenolate mofetil (MMF). METHODS: Polyomavirus associated nephropathy was identified in nine out of 182 patients who received renal transplantation between October 1998 and July 2003. PVN was confirmed by allograft biopsy. The clinical records of these nine patients were reviewed, as were all of the allograft biopsies. Electron microscopy was performed in all nine cases. After the diagnosis of PVN, maintenance immunosuppression was reduced. The clinical course and outcome of the PVN patients were reviewed in relation to manipulation of immunosuppressive agents. RESULTS: There were nine cases of PVN in renal transplant recipients and the incidence of PVN was 4.9%. All patients with PVN were under triple immunosuppression comprising tacrolimus and MMF. The mean time to a diagnosis of PVN was 7.8 months after transplantation. Three of the nine patients received antirejection therapy prior to PVN. Seven out of nine PVN patients presenting acute allograft dysfunction were initially treated with high-dose intravenous steroid pulse or OKT3 before reduction of the immunosuppression. After reduction of the immunosuppression, seven patients stabilized their renal function. Two (22%) lost their grafts due to persistent PVN and chronic rejection. Two (22%) patients later developed acute rejection after reduction of the immunosuppression. CONCLUSION: PVN can cause allograft dysfunction and graft loss. Renal allograft recipients who are at risk of PVN should be routinely screened with urine cytology and quantitative measurements of viral load in the blood, particularly patients who had graft dysfunction. Early diagnosis and judicious alteration of immunosuppressive agents might permit a superior prognosis and reduce the graft loss from PVN in renal transplant recipients.     

Acute Humoral Rejection in an ABO Compatible Combined Liver–Kidney Transplant—The Kidney Is Not Always Protected

Combined liver–kidney transplantation has become a common practice for the treatment of patients with concurrent end-stage renal disease and end-stage liver disease. Liver transplantation in the setting of multiorgan transplantation is thought to have a protective effect against humoral rejection even when a positive crossmatch is obtained prior to surgery. In most centers, a pre liver–kidney transplant crossmatch is rarely performed because of the known immunoprotective effect of the liver allograft. In this report, a case of acute humoral rejection in the kidney allograft after a combined liver–kidney transplant is described. Although humoral rejection was treated using plasmapheresis, intravenous immunoglobulin and rituximab, the kidney required 3 months to recover function and finally progressed to chronic allograft nephropathy. A heightened index of suspicion for acute humoral rejection of the renal allograft is necessary when performing combined liver–kidney transplants to highly sensitized patients due to previous organ transplants.     

Weight gain after living-related renal transplantation affects long-term graft function

Weight gain is a common problem in renal transplant recipients. This study investigated whether weight gain after living-related renal transplantation affects long-term graft function. The cohort included 93 patients (28 females, 65 males of mean age, 33.78 +/- 9.78 years who were recipients of kidneys from living-related donors. The data set related risk factors to occurrence of chronic allograft nephropathy (CAN): namely, number of HLA mismatches, PRA levels, delayed graft function, acute rejection, suboptimal immunosuppression, hypertension, hyperlipidemia, and size mismatch. Patients with a 10% increase in body mass index sustained throughout at least 2 years posttransplantation were categorized as group 1 (abnormal weight gain; n = 65) and the others were categorized as group 2 (no or normal weight gain; n = 28). Chronic allograft nephropathy was more frequent among group 1 (P < .03). The mean times to CAN diagnosis in groups 1 and 2 were 1053.41 +/- 461.86 days and 1128.57 +/- 416.09 days, respectively (P > .05). Of all the risk factors for CAN, occurrence of acute rejection was the most important (OR = 5.39, 95% CI: 2.07 to 14.03, P < .001). When this factor was excluded, weight gain emerged as the most important risk factor (OR = 3.04, 95% CI: 1.01 to 9.69, P < .04). There were no significant differences between the groups with respect to the frequencies of immunologic and nonimmunologic risk factors (P > .05 for all). The results suggest that excessive weight gain after living-related renal transplantation may be an additional risk factor for development of CAN. Patients should pay attention to diet and control weight gain after transplantation.     

Mycophenolate mofetil reduces late renal allograft loss independent of acute rejection

BACKGROUND: Mycophenolate Mofetil (MMF) has been shown to significantly decrease the number of acute rejection episodes in renal transplant recipients during the 1st year. A beneficial effect of MMF on long-term graft survival has been more difficult to demonstrate. This beneficial effect has not been detected, despite the impact of acute rejection on the development of chronic allograft nephropathy and experimental evidence that MMF may have a salutary effect on chronic allograft nephropathy independent of that of rejection. METHODS: Data on 66,774 renal transplant recipients from the U.S. renal transplant scientific registry were analyzed. Patients who received a solitary renal transplant between October 1, 1988 and June 30, 1997 were studied. The Cox proportional hazard regression was used to estimate relevant risk factors. Kaplan-Meier analysis was performed for censored graft survival. RESULTS: MMF decreased the relative risk for development of chronic allograft failure (CAF) by 27% (risk ratio [RR] 0.73, P<0.001). This effect was independent of its outcome on acute rejection. Censored graft survival using MMF versus azathioprine was significantly improved by Kaplan-Meier analysis at 4 years (85.61% v. 81.9%). The effect of an acute rejection episode on the risk of developing CAF seems to be increasing over time (RR=1.9, 1988-91; RR=2.9, 1992-94; RR=3.7, 1995-97). CONCLUSION: MMF therapy decreases the risk of developing CAF. This improvement is only partly caused by the decrease in the incidence of acute rejection observed with MMF; but, is also caused by an effect independent of acute rejection.     

Predictive factors in chronic allograft nephropathy

Chronic allograft nephropathy (CAN) is characterized by progressive renal dysfunction leading in many cases to graft loss. The pathogenesis of CAN involves both immune and nonimmune factors. Concerning immune factors, one of the most remarkable predictors of CAN is acute rejection, which is associated with a worse prognosis if there are multiple episodes or when late onset occurs. Delayed graft function is also a major risk factor for CAN because of a correlation between late restoration of renal function after transplantation and long-term decreased graft survival. High creatinine levels at 6 months and 1 year after transplantation, proteinuria, viral infections, and cardiovascular risk factors are additional significant parameters for the development of CAN. Recent findings suggest that a high renal segmental arterial resistance index measured by Doppler ultrasonography in intrarenal vessels is associated with poor allograft function. Moreover, the study of patient genetic profile represents a new approach to identify predictive factors for CAN.     

Chronic allograft dysfunction: mechanisms and new approaches to therapy

Renal allograft failure is the most common cause of end-stage renal disease beyond the early posttransplantation period, accounting for 25% to 30% of patients awaiting renal transplantation. Despite recent advances in immunosuppressive therapy, improvements in long-term graft survival have not been commensurate with those observed in 1-year graft survival. The most common cause of chronic allograft loss is an incompletely understood clinicopathological entity sometimes called chronic rejection, chronic allograft dysfunction or in the case of kidneys, chronic allograft nephropathy. Although the precise mechanism(s) responsible for the characteristic pathological changes are still unclear, it is generally agreed that both alloantigen-dependent and alloantigen-independent factors influence the development of chronic allograft nephropathy. This article will address the potential mechanisms responsible for the pathogenesis of chronic dysfunction in solid organ grafts and the current approaches to management, including newer therapies designed to prevent the progression of the disease.     

Longitudinal analysis of chronic allograft nephropathy: clinicopathologic correlations

BACKGROUND: Loss of the allograft from chronic allograft nephropathy and death of the patient from vascular, malignant, or infective disease are the major problems in renal transplantation today. Protocol biopsy of the long-term kidney has provided new data with which to develop strategies for prevention and treatment of chronic allograft nephropathy. METHODS: Two series of long-term protocol biopsies are reviewed. In the first, renal biopsies were obtained at time 0, and at 3 months and 12 months, and the recipients of the renal allografts were followed up for up to 15 years. In the second, the kidneys of recipients of simultaneous pancreas kidney transplants were biopsied annually for 10 years, and the results correlated with clinical events. RESULTS: Chronic allograft nephropathy is caused by acute and chronic immune-mediated damage, as well as by chronic calcineurin inhibitor nephrotoxicity. Both immune and nonimmune mechanisms exacerbate pre-existing donor disease and ischemia-reperfusion injury. Established interstitial fibrosis and arteriolar hyalinosis lead to progressive glomerular sclerosis and eventual loss of the graft. CONCLUSION: Protocol biopsies have shown that clinical parameters of renal function underestimate the severity of chronic graft damage. Strategies for preventing or treating chronic renal allograft dysfunction and subsequent graft loss must better control rejection and simultaneously avoid nephrotoxicity.     

Chronic allograft nephropathy

Chronic allograft nephropathy (CAN) is the leading cause of renal allograft loss in paediatric renal transplant recipients. CAN is the result of immunological and nonimmunological injury, including acute rejection episodes, hypoperfusion, ischaemia reperfusion, calcineurin toxicity, infection and recurrent disease. The development of CAN is often insidious and may be preceded by subclinical rejection in a well-functioning allograft. Classification of CAN is histological using the Banff classification of renal allograft pathology with classic findings of interstitial fibrosis, tubular atrophy, glomerulosclerosis, fibrointimal hyperplasia and arteriolar hyalinosis. Although improvement in immunosuppression has led to greater 1-year graft survival rates, chronic graft loss remains relatively unchanged and opportunistic infectious complications remain a problem. Protocol biopsy monitoring is not current practice in paediatric transplantation for CAN monitoring but may have a place if new treatment options become available. Newer immunosuppression regimens, closer monitoring of the renal allograft and management of subclinical rejection may lead to reduced immune injury leading to CAN in the paediatric population but must be weighed against the risk of increased immunosuppression and calcineurin inhibitor nephrotoxicity.