Rapamycin in patients with chronic renal allograft dysfunction

PURPOSE: Nephrotoxicity of calcineurin inhibitors (CNI) complicates the management of chronic renal allograft dysfunction. Rapamycin is a promising immunosuppressive agent free of nephrotoxicity. The effect of conversion from CNI to rapamycin in recipients with chronic allograft dysfunction is still unclear. We investigated the effect of rapamycin in patients with chronic allograft dysfunction. METHODS: We conducted a prospective study on kidney transplant recipients with chronic allograft dysfunction. The patients were under classic CNI, mycophenolate mofetil, and prednisolone triple therapy. They had progressive deterioration of the allograft function. They were converted from CNI to rapamycin directly and observed for 6 months. The CNI serum levels before the conversion were within recommended range. Allograft function, clinical features and adverse effects were evaluated before and after the rapamycin conversion. RESULTS: A total of 16 patients were enrolled. Six of them (37.5%) failed to have a smooth conversion because of deterioration of allograft function and intractable adverse effects. Ten patients (62.5%) went through the 6-month observation period with improved graft function. The average reduction of serum creatinine was 27.7% (p < 0.001) in successful conversion. There were no significant differences on age, gender, lipid profile, sugar control, and rapamycin levels between successful and failed conversion. Anemia and diastolic blood pressure were significantly improved after successful conversion. The failed patients had a longer transplantation period (6.1 +/- 4.1 vs. 11.2 +/- 3.4 yr, p < 0.05). Two of them (12.5%) developed bacteria pneumonia. Self-limited diarrhea developed in three patients (18.8%). CONCLUSION: We suggested that conversion from CNI to rapamycin was beneficial in some kidney transplant recipients with chronic allograft dysfunction.     

Current views on chronic rejection after lung transplantation

Chronic lung allograft dysfunction (CLAD) was recently introduced as an overarching term mainly to classify patients with chronic rejection after lung transplantation, although other conditions may also qualify for CLAD. Initially, only the development of a persistent and obstructive pulmonary function defect, clinically identified as bronchiolitis obliterans syndrome (BOS), was considered as chronic rejection, if no other cause could be identified. It became clear in recent years that some patients do not qualify for this definition, although they developed a chronic and persistent decrease in FEV₁, without another identifiable cause. As the pulmonary function decline in these patients was rather restrictive, this was called restrictive allograft syndrome (RAS). In the present review, we will further elaborate on these two CLAD phenotypes, with specific attention to the diagnostic criteria, the role of pathology and imaging, the risk factors, outcome, and the possible treatment options.     

Protocol biopsies after kidney transplantation

Numerous studies have investigated features of allograft injury in renal biopsies obtained in stable kidney transplants. Evaluation of protocol biopsies has revealed a considerably high prevalence of subclinical acute rejection (SAR) and chronic allograft nephropathy (CAN) already in early phases after transplantation. The meanwhile well-established association of SAR and CAN in protocol biopsy with long-term allograft failure and the finding of superior allograft outcome after treatment of SAR in a randomized prospective study may point to clinical relevance of this procedure. In this review, potential benefits and risks associated with kidney allograft biopsy in stable renal transplant recipients are discussed.     

霉酚酸酯治疗慢性移植物功能减退的多中心研究

目的　探讨霉酚酸酯 (MMF)治疗慢性移植物功能减退 (CAD)的疗效和安全性。方法　应用霉酚酸酯 (MMF)替换硫唑嘌呤 (Aza)或环磷酰胺 (CTX) ,并联合小剂量环孢素A(CsA)和泼尼松 (Pred )治疗 78例CAD患者的方案。平均随访 9.84个月 ,研究并分析该方案的效果和并发症。结果　应用MMF联合小剂量CsA和Pred治疗后 ,有 74例患者的血清肌酐 (SCr)下降 ,随访时与应用前比较 ,差异有显著性 (P <0 .0 5 ) ;治疗有效率达 94 .9% ;4例治疗无效。用MMF转换治疗后 ,尿蛋白减轻或消失 ,血压下降。贫血、腹泻等不良反应发生率为 33.3%。结论　MMF联合小剂量CsA和Pred治疗CAD是有效和安全的。贫血、腹泻是转换治疗的主要副作用。     

Rescue therapy with tacrolimus in simultaneous pancreas/kidney transplantation

Abstract Tacrolimus has been effective both in primary and rescue therapy following steroid and OKT3-resistant acute rejection in liver and kidney transplantation. Due to the effects of tacrolimus on glucose metabolism, there has been concern about its use in simultaneous pancreas/kidney transplantation. We report on the results of six patients (three female, three male, age 35.2 ± 7.3 years) converted from cyclosporin A to tacrolimus following simultaneous pancreas/kidney transplantation in steroid-resistant acute rejection. Tacrolimus was induced 2.8 ± 1.7 months (range 1–4.8 months) after transplantation; follow-up was 3–18 months. Following conversion, creatinine levels declined in all patients [3.5 ± 1.2 mg/dl before conversion, 3.0 ± 1.9 mg/dl ( n = 6) at three months, 1.4 ± 0.1 mg/dl at 1 year (n = 3)]. Before conversion, fasting blood glucose levels averaged 154 ± 33 mg/dl, with three patients receiving insulin. Three months later no patient required insulin, the mean glucose level being 107 ± 23 mg/dl ( n = 6); at 1 year it was 92 ± 9 mg/dl ( n - 3). One patient lost his pancreatic graft after 4 months due to a mycotic aneurysm. We conclude that conversion to tacrolimus is a safe and effective treatment in cases of steroid-resistant rejections following pancreas/kidney transplantation.     

Long‐term results after conversion from calcineurin inhibitors to sirolimus in renal transplant patients

Martinez‐Mier G, Avila‐Pardo SF, Mendez‐Lopez MT, Budar‐Fernandez LF. Long‐term results after conversion from calcineurin inhibitors to sirolimus in renal transplant patients.
Clin Transplant 2010: 24: 467–473.
© 2009 John Wiley & Sons A/S. Abstract: Background: Calcineurin inhibitors (CNI) toxicity is one of the contributing factors for the development and progression of chronic allograft dysfunction (CAD). Conversion to sirolimus (SRL) from CNI improves renal function kidney in transplant recipients. Methods: A retrospective review from patients abruptly converted from CNI to SRL over a three yr period is reported. Results: Thirty‐nine patients were converted 55.2 ± 58 months after renal transplantation. 24 month patient and graft survival was 100% and 92%. Acute rejection incidence was 7.6%. Overall, serum creatinine (SCr) and Cockcroft–Gault creatinine clearance (CGCrCl) improved. In responders, SCr improved from 2.48 ± 0.8 to 1.94 ± 0.8 mg/dL (p < 0.05) CGCrCl improved from 37.8 ± 17.4 to 51.9 ± 23.8 mL/min at two years. An increase in proteinuria was observed from conversion to month 12 in responders (189.4 ± 512.8 to 488.3 ± 890.6 mg/day, p < 0.05) and from conversion to month six in non‐responders (1179.4 ± 2001.1 to 2357 ± 4172.9 mg/day, p < 0.05). Low proteinuria had positive predictive value for renal response after conversion. Conclusion: Conversion from CNI to SRL with CAD is associated with improved renal function with an increase in proteinuria. Low proteinuria is a possible positive predictive factor for successful conversion.     

Rescue therapy with tacrolimus in simultaneous pancreas/kidney transplantation

Tacrolimus has been effective both in primary and rescue therapy following steroid and OKT3-resistant acute rejection in liver and kidney transplantation. Due to the effects of tacrolimus on glucose metabolism, there has been concern about its use in simultaneous pancreas/kidney transplantation. We report on the results of six patients (three female, three male, age 35.2 ± 7.3 years) converted from cyclosporin A to tacrolimus following simultaneous pancreas/kidney transplantation in steroid-resistant acute rejection. Tacrolimus was induced 2.8 ± 1.7 months (range 1–4.8 months) after transplantation; follow-up was 3–18 months. Following conversion, creatinine levels declined in all patients [3.5 ± 1.2 mg/dl before conversion, 3.0 ± 1.9 mg/dl (n = 6) at three months, 1.4 ± 0.1 mg/dl at 1 year (n = 3)]. Before conversion, fasting blood glucose levels averaged 154 ± 33 mg/dl, with three patients receiving insulin. Three months later no patient required insulin, the mean glucose level being 107 ± 23 mg/dl (n = 6); at 1 year it was 92 ± 9 mg/dl (n = 3). One patient lost his pancreatic graft after 4 months due to a mycotic aneurysm. We conclude that conversion to tacrolimus is a safe and effective treatment in cases of steroid-resistant rejections following pancreas/kidney transplantation.     

Impact of chronic allograft nephropathy and subsequent modifications of immunosuppressive therapy on late graft outcomes in renal transplantation.

BACKGROUND: Chronic allograft nephropathy (CAN) is the leading cause of organ failure in renal transplant recipients. We retrospectively evaluated the impact of varying immunosuppression in CAN patients on long-term graft survival. METHODS: We retrospectively analysed 158 cyclosporin (CsA)-treated renal transplant recipients with biopsy-proven CAN with follow-up of >1 year. Immunosuppression remained unchanged in 75 (NOVAR) and was modified in 83 patients (VAR). In 36.1% of VAR patients, it was increased; in 63.8%, the addition of other immunosuppressants was associated with a 20% reduction in or withdrawal of CsA. A regression model, for creatinine clearance (CrCl) slope analysis after therapy variation, and Cox's analysis were applied. RESULTS: In VAR patients, two-phase regression did not show a correlation between the inflection point in the CrCl slope and treatment variation. Changing immunosuppression gave a borderline advantage in long-term graft survival compared with NOVAR (P = 0.088). In univariate analysis, severe histological lesions, proteinuria >0.5 g/day and CrCl <25 ml/min at biopsy correlated with poor graft outcome (P = 0.0009). In multivariate analysis, only proteinuria and low CrCl remained significative. Stratifying histological lesions in relation to therapy variation showed that severe lesions significantly decreased survival in both VAR and NOVAR groups; however, the highly negative impact of severe lesions in NOVAR patients on graft survival [relative risk (RR) 3.602] was reduced in VAR patients (RR 1.951), with a 10 year graft survival since biopsy of 0.16 vs 0.34 (P = 0.0001). CONCLUSIONS: In transplant patients with CAN, variation of immunosuppression can reduce the negative impact of severe chronic lesions.     

Late graft failure after kidney transplantation as the consequence of late versus early events

Beyond the first posttransplant year, 3% of kidney transplants fail annually. In a prospective, multicenter cohort study, we tested the relative impact of early versus late events on risk of long‐term death‐censored graft failure (DCGF). In grafts surviving at least 90 days, early events (acute rejection [AR] and delayed graft function [DGF] before day 90) were recorded; serum creatinine (Cr) at day 90 was defined as baseline. Thereafter, a 25% rise in serum Cr or new‐onset proteinuria triggered graft biopsy (index biopsy, IBx), allowing comparison of risk of DCGF associated with early events (AR, DGF, baseline serum Cr >2.0 mg/dL) to that associated with later events (IBx). Among 3678 patients followed for 4.7 ± 1.9 years, 753 (20%) had IBx at a median of 15.3 months posttransplant. Early AR (HR = 1.77, P < .001) and elevated Cr at Day 90 (HR = 2.56, P < .0001) were associated with increased risk of DCGF; however, later‐onset dysfunction requiring IBx had far greater impact (HR = 13.8, P < .0001). At 90 days, neither clinical characteristics nor early events distinguished those who subsequently did or did not undergo IBx or suffer DCGF. To improve long‐term kidney allograft survival, management paradigms should promote prompt diagnosis and treatment of both early and later events.     

Increase of proteinuria after conversion from calcineurin inhibitor to sirolimus-based treatment in kidney transplant patients with chronic allograft dysfunction.

BACKGROUND: Conversion from calcineurin inhibitor to sirolimus, rapamycin has become an option in patients with chronic allograft dysfunction (CAD). However, in many cases an increase of proteinuria has been observed. The aim was to characterize the course of this so far unexplained proteinuria after conversion. METHODS: In 149 renal transplant patients from various Spanish centres, proteinuria and renal function were analysed 6 months before until 6 months after conversion. Patients were divided into three groups according to mean proteinuria before conversion (1:300-3500 mg/day; 3:>3.5 g/day). RESULTS: Generally patients showed an increase of proteinuria from 864+/-1441 (0-12125) to 1541+/-1878 (0-10976) mg/day after conversion; P<0.001. Group 1: 145+/-92 vs 669+/-868 mg/day, P<0.001; group 2: 1041+/-799 vs 1995+/-2021 mg/day, P<0.001; group 3: 6205+/-3184 vs 4859+/-2122 mg/day, P=NS. Patients with an increase of proteinuria of >500 mg/day (n=60; 40%) had a higher serum creatinine before conversion compared with patients with no or moderate increase (2.5+/-0.8 vs 2.15+/-0.72 mg/dl; P=0.002). The group that experienced an increase>500 mg/day had a higher serum creatinine after conversion compared with the patients with no or moderate increase (2.8+/-1.0 vs 2.1+/-1.2; P<0.001). Of 64 patients, 19 in group 1 showed an increase>500 mg/day. CONCLUSION: Conversion for CAD can be associated with an increase of proteinuria in patients with pre-existing renal damage; however, it preserves renal function in patients with better creatinine and proteinuria before conversion, and might not be of benefit if advanced loss of renal function and high proteinuria are already present before conversion.     

Effects of mycophenolate mofetil on donor-specific antibody formation in renal transplantation

BACKGROUND: Mycophenolate mofetil (MMF) is a routinely used immunosuppressive agent that selectively blocks T- and B-lymphocyte proliferation. The present study was designed to investigate the effects of this drug on human leukocyte(HLA) antibody production in general and donor-specific antibody (DSA) formation in particular in 154 recipients of renal allografts. PATIENTS AND METHODS: Renal allograft recipients were subdivided into three groups. Group 1 patients (n = 60) had received MMF since transplantation in combination with either cyclosporin A or tacrolimus and steroids. Group 2 patients (n = 29) had received an MMF-free immunosuppressive regimen initially followed by addition of MMF some time later. Group 3 patients (n = 65) had received no MMF. Cyclosporin A or tacrolimus in combination with azathioprine and/or steroids were used for immunosuppression. DSA were demonstrated by enzyme-linked immunosorbent assay (ELISA) for detection of panel-reactive antibodies of HLA class I and II specificity. RESULTS: The HLA antibodies were found in 16.7%, 27.6% and 30.8% of transplant recipients in groups 1, 2 and 3, respectively. DSA were found in 8.3%, 17.2% and 20.0%, and non-DSA in 10.0%, 20.7% and 24.6%, of patients in groups 1, 2 and 3, respectively. CONCLUSION: The MMF reduces anti-HLA class I and II antibody production and consequently DSA production in renal allograft recipients. Our data indicate this effect to be more pronounced in patients given MMF immediately after transplantation than in those in whom MMF is introduced some time later. The presence of DSA in the serum of renal allograft recipients is associated with poorer graft function (higher serum creatinine and more rejection episodes).