Reversal of chronic cyclosporine nephrotoxicity after heart transplantation-potential role of mycophenolate mofetil.

BACKGROUND: Chronic cyclosporine nephrotoxicity (CCN) after heart transplantation is a progressive condition that may lead to end-stage renal failure. The extent to which CCN is reversible with reduction or withdrawal of cyclosporine therapy is unknown. The aim of this study was to assess the reversibility of CCN and to assess the safety and efficacy of a strategy of cyclosporine dosage reduction, combined with conversion from azathioprine to mycophenolate mofetil (AZA/MMF switch) to maintain immunosuppression. METHODS: An AZA/MMF switch followed by cyclosporine dose reduction was undertaken in 30 heart transplant recipients (23 men, 7 women; mean age, 54 +/- 2 years) with established CCN at a mean of 90 +/- 9 months after transplantation (range, 17-182 months). The mean maintenance MMF dosage was 2.3 +/- 0.1 g/day (n = 28). Mean cyclosporine dosage was decreased from 2.3 +/- 0.2 mg/kg/day before AZA/MMF switch to 1.6 +/- 0.2 mg/kg/day. RESULTS: Three patients (10%) were withdrawn from MMF, 2 because of diarrhea and the third because of severe pneumonia that developed within 2 weeks of AZA/MMF switch. All 3 were restabilized with AZA. One patient (4%) experienced acute rejection 7 months after AZA/MMF switch. This resolved after an oral pulse of prednisolone. Systemic infections occurred in 6 patients within 12 months of AZA/MMF switch. Actuarial survival 1 year after AZA/MMF switch was 86% +/- 6%. One patient died of infection and 3 of other causes. Serum creatinine concentration decreased from 248 +/- 15 micromol/liter before cyclosporine dosage reduction to 193 +/- 11 micromol/liter and 206 +/- 19 micromol/liter at 3 and 12 months after dosage reduction (both p < 0.01 versus baseline, n = 23). Of the 23 patients who remained on MMF at 12 months, a decrease in serum creatinine was documented in 19 (83%). Four patients showed no improvement or showed deterioration in renal function, and three of these progressed to end-stage renal failure. CONCLUSIONS: Chronic cyclosporine nephrotoxicity has a significant reversible component in most patients. A strategy of AZA/MMF switch combined with cyclosporine dosage reduction is generally well tolerated and results in short-term improvement in renal function in most patients. Close vigilance is required during the first 12 months after AZA/MMF switch because both acute rejection and infection may occur.     

Cyclosporine withdrawal in stable renal transplant recipients after azathioprine-mycophenolate mofetil conversion

BACKGROUND: Cyclosporine A (CsA) nephrotoxicity is a nonimmunologic factor of chronic allograft dysfunction (CAD) in kidney transplant recipients. Mycophenolate mofetil (MMF) may allow CsA dosage reduction or even complete withdrawal in selected populations with CsA nephrotoxicity or CAD. The aim of the present study was to evaluate the efficacy and safety of CsA withdrawal after azathioprine (AZA)-MMF conversion in a population of stable renal transplant recipients. METHODS: Twenty-eight first cadaver kidney recipients were included. AZA was then discontinued, MMF was introduced and after 4 months CsA was completely withdrawn. All patients underwent inuline clearance measurement and renal biopsy at inclusion and at the end of the follow-up (40 wk). RESULTS: CsA was completely discontinued in 20 patients. No patient lost his graft during the study period, but 1 patient experienced a reversible acute rejection episode. Inuline clearance improved significantly in the whole series. At the end of follow-up, histological worsening was observed in 50% of patients without any specific risk factor. In these patients, inuline clearance did not improve. Systolic blood pressure, the need for anti-hypertensive drugs and HDL cholesterol improved. CONCLUSION: In stable kidney transplant recipients, CsA withdrawal after AZA replacement by MMF switch was safe with regard to acute rejection. It improved blood pressure and the lipid profile, but, in 50% of patients was associated with histologic deterioration.     

Prospective, Pilot, Open-Label, Short-Term Study of Conversion to Leflunomide Reverses Chronic Renal Allograft Dysfunction

Leflunomide (LEF) is a synthetic isoxazole derivative with anti-inflammatory and antiviral properties, which has been reported to prevent acute rejection and delay progression of chronic allograft nephropathy (CAN) in animal models. We performed a pilot, crossover trial in 22 renal transplant recipients who were converted from azathioprine (AZA) or mycophenolate mofetil (MMF) to LEF in an effort to slow progression of renal dysfunction [deteriorating renal function (n = 5), cyclosporine (CyA) nephrotoxicity (n = 4) or biopsy-proven CAN (n = 13)]. Baseline maintenance immunosuppression consisted of CyA, AZA or MMF and prednisone. Six-month postconversion patient and graft survival was 100% and 91%, respectively. Mean serum creatinine 6months preconversion was 2.2 +/- 0.6mg/dL, at initiation was 3.0 +/- 1.1 mg/dL, and 6 months postconversion was 2.8 +/- 1.3 mg/dL. The rate of change in serum creatinine was 35 +/- 39%/6 months preconversion and -5 +/- 21%/6 months postconversion to LEF (p = 0.003). Two patients discontinued LEF for diarrhea and myalgia. No readmissions, increase in liver function tests, infections or acute rejection episodes occurred. Mean CyA levels did not change, 146 +/- 72 ng/ mL pre-LEF vs. 132 +/- 51 ng/mL post-LEF, p = NS. Conversion to LEF reversed progression of chronic renal allograft dysfunction with minimal toxicity.     

Improvement of impaired renal function in heart transplant recipients treated with mycophenolate mofetil and low-dose cyclosporine

BACKGROUND: Cyclosporine (CsA) nephrotoxicity is a common problem after cardiac transplantation. We have studied the impact of CsA dose reduction in association with mycophenolate mofetil (MMF) treatment on renal function in heart transplant recipients with suspected CsA nephrotoxicity (serum creatinine level >2 mg/dl). METHODS: Twelve heart transplant recipients (11 men, 1 woman; 111 to 1813 days after transplantation) with CsA-based immunosuppression (plus azathioprine and/or steroids) and a serum creatinine level >2.0 mg/dl were started on a daily dose of 2000 mg of MMF. Dilated cardiomyopathy was the underlying disease in nine patients, ischemic cardiomyopathy in three patients. Mean patient age was 57 years (range 44-69 years). Azathioprine was discontinued and CsA slowly tapered. Creatinine clearance, serum creatinine level, urea nitrogen, and uric acid were monitored. CsA levels were measured, and CsA dose was adjusted for whole blood levels of 70-120 microg/L. Ten patients still had endomyocardial biopsies, whereas one had echocardiographic controls only. RESULTS: One grade 1B rejection episode according to ISHLT (International Society for Heart and Lung Transplantation) was observed until 1 year after the switch to MMF. One patient was excluded due to gastrointestinal side effects. CONCLUSIONS: Conversion from azathioprine to MMF with consecutive reduction of CsA in heart transplant recipients with CsA-impaired renal function improves renal function as evidenced by lower serum creatinine, urea nitrogen, uric acid, and higher creatinine clearance.     

Does mycophenolate mofetil increase the incidence of cytomegalovirus disease compared with azathioprine after cadaveric kidney transplantation?

Although most of the published papers had not found increase in the incidence of CMV disease in kidney transplant recipients treated with mycophenolate mofetil (MMF), we had feeling from everyday practice that after its introduction number of patients with CMV disease has increased. To test this hypothesis, we performed retrospective analysis of our database, comparing the incidence of CMV disease in patients treated with azathioprine (AZA) and patients treated with MMF. CMV disease was defined as CMV antigenemia (positive CMV pp65 determined by ELISA test) plus any of the following: decrease leucocytes or platelets, increased transaminases, increase in serum creatinine. The azathioprine treated group (AZA group) included 280 patients (132 female) treated for 17,672 months with AZA + Cyclosporine A (CyA) + steroid, or AZA + steroid, while the MMF group included 219 patients (112 female) treated for 5079 months with MMF + CyA + steroid, or MMF + steroid. There was no difference in acute rejection episodes between the AZA and the MMF group. The AZA group had 51 CMV disease episodes (1 episode per 346.5 treatment months), and the MMF group experienced 43 episodes (1 per 118.1 months) (P < .01). Mean onset of CMV disease was 32.65 +/- 47.69 (SD) months after transplantation in the AZA group, and 3.72 +/- 4.43 in the MMF group. There was no difference between two treatment groups regarding the donor-recipient CMV status mismatch. Despite having the increased incidence of CMV disease, MMF group had less severe disease compared to AZA group with decrease in leukocyte count in 11.6% vs 15.7% of episodes, decrease in platelet count in 20.9% vs 21.6%, elevation of transaminases in 18.6% vs 29.4% respectively, and finally increase in serum creatinine greater than 20% in 51.2% in MMF vs 74.5% in AZA group. Five patients from the AZA group experienced CMV pneumonitis with the mortality rate of 80%. Only one patient from the MMF group had CMV pneumonitis, and he survived. According to our results, patients treated with MMF have increased risk for development of CMV disease. However, the disease course is less severe, and less frequently accompanied with deterioration of renal function in comparison to the AZA group.     

Mycophenolate mofetil may allow cyclosporine and steroid sparing in de novo heart transplant patients

BACKGROUND: Mycophenolate mofetil (MMF) provides superior prophylaxis against acute rejection when compared with azathioprine (AZA) in heart and renal transplantation. However, it remains unclear whether this results in improved survival or reduced morbidity after heart transplantation. METHOD: In a sequential study, 240 cardiac transplant patients were treated with either MMF (n=119) or AZA (n=121) both in combination with cyclosporine and corticosteroids after rabbit antithymocyte globulin induction. RESULTS: By protocol lower cyclosporine levels were targeted in the MMF group during the first year (e.g. 203+/-52 ng/mL MMF vs. 236+/-59 ng/mL AZA, P=0.0006 at 6 months). Patient survival at 1 year (82% MMF vs. 79% AZA, P=0.55) and at 3 years was similar in both groups. The cumulative probability of receiving antirejection treatment within 1 year was lower in the MMF group, as was biopsy-proven acute rejection with International Society of Heart and Lung Transplantation grade > or =3A (24% vs. 35%, P=0.03). The MMF group also had fewer episodes requiring cytolytic therapy (6% vs. 13%, P=0.04) and more patients had steroids withdrawn by 1 year (66% vs. 32%, P<0.001). Renal function was better in the MMF group with lower creatinine levels at 1 year (133+/-45 vs. 155+/-46 micromol/L, P=0.0004). Calculated creatinine clearance (Cockcroft and Gault formula) at 1 year was also better (MMF 74+/-32 mL/min vs. AZA 62+/-24 mL/min, P=0.004). CONCLUSION: Our results suggest that immunosuppression with MMF rather than AZA may allow lower cyclosporine levels, better renal function, and increased steroid weaning at 1 year while also achieving better control of acute rejection.     

Reduced kidney transplant rejection rate and pharmacoeconomic advantage of mycophenolate mofetil.

BACKGROUND: Several multinational controlled clinical trials have shown that triple therapy immunosuppressive regimens which include mycophenolate mofetil (MMF), cyclosporin A (CSA) and steroids (S) are superior compared with conventional regimens which include azathioprine (AZA), CSA and S, mainly because MMF reduces the rate of acute rejection episodes in the first 6 months after kidney transplantation. Post-marketing studies are useful to evaluate the general applicability and costs of MMF-based immunosuppressive regimens. METHODS: Based on the excellent results of the published controlled clinical trials, we have changed the standard triple therapy immunosuppressive protocol (AZA+CSA+S) to an MMF-based regimen (MMF+CSA+S) at our centre. To analyse the impact of this change in regimen, we have monitored 6-month patient and graft survival, rejection rate, serum creatinine and CSA levels, as well as the costs of the immunosuppressive and anti-rejection treatments, in 40 consecutive renal transplant recipients (MMF group) and have compared the data with 40 consecutive patients transplanted immediately prior to the change in regimen (AZA group). RESULTS: Recipient and donor characteristics were similar in the AZA and MMF groups. Patient survival (37/40; 92.5% in the AZA group vs 38/40; 95% in the MMF group), graft survival (36/40 vs 36/40; both 90%) and serum creatinine (137+/-56 vs 139+/-44 micromol/l) after 6 months were not significantly different. However, the rate of acute rejection episodes (defined as a rise in creatinine without other obvious cause and treated at least with pulse steroids) was significantly reduced with MMF from 60 to 20% (P=0.0005). The resulting cost for rejection treatment was lowered 8-fold (from sFr. 2113 to 259 averaged per patient) and the number of transplant biopsies was lowered > 3-fold in the MMF group. The cost for the immunosuppressive therapy was increased 1.5-fold with MMF (from sFr. 5906 to 9231 per patient for the first 6 months). CONCLUSIONS: The change from AZA to MMF resulted in a significant reduction in early rejection episodes, resulting in fewer diagnostic procedures and rehospitalizations. The optimal long-term regimen in terms of patient and pharmacoeconomic benefits remains to be defined.     

New immunosuppressive treatment in kidney transplantation

BACKGROUND: Mycophenolate mofetil (MMF) has been successfully introduced into clinical practice with evident benefits for renal transplant recipients. SUBJECTS AND METHODS: To evaluate some clinical results of MMF introduction, two groups of subjects underwent cadaveric renal transplants over the last 3 years and were retrospectively investigated. The first group (AZA group) contained 40 subjects (26 males and 14 females) on triple-drug therapy with steroids, cyclosporine and azathioprine (AZA). The second group (MMF group) contained 25 patients ( 19 males and 6 females) on the same regime with steroids and cyclosporine but MMF was administered as a third drug instead of AZA. The AZA group received renal transplant after a mean dialytic time of 32 +/- 19 months and the AZA group's dialytic time was 39.9 +/- 17 months. Clinical data, collected after a minimum 12 months observational period included a crude mortality rate and survival analysis recognized by Kaplan-Meyer curve, creatinine, creatinine clearance, rejection episodes and major clinical events such as infections and acute tubular necrosis. RESULTS: One subject died in each group. For kidney graft survival, Kaplan Meyer survival analysis showed a mean survival time of 1170.04 days in the AZA group vs 845 in the MMF group without statistical significance. Graft survival demonstrated 5:40 (12.5%) graft losses in the AZA group vs no kidney transplant loss in the MMF group (the only deceased patient had a well functioning kidney). The curve of graft cumulative proportion survival analysis demonstrated a more improved survival in the MMF group, but this difference did not reach a statistical significance (p = 0.07). Acute rejection episodes in the AZA group were 37.5% vs. 20% in the MMF group. In both groups, CMV infection was successfully treated with specific antiviral agents. CONCLUSIONS: MMF represents an important step towards induction and maintenance of immunosuppression. Our experience in a relatively small cohort investigated in a single center, demonstrates encouraging results regarding graft survival in comparison to those detected in conventional triple drug therapy. Surprisingly, in spite of stronger immunosuppressive treatment, the prevalence of CMV infections was not statistically different in the MMF versus the AZA group.     

The effect of cyclosporine on mortality and renal function in living related pediatric kidney transplant recipients

The outcome, incidence of acute rejection episodes, complications and cyclosporine (CyA) induced nephrotoxicity were studied in 10 pediatric kidney transplant recipients who were grafted from one-haplotype indentical parent with immunosuppression of CyA and prednisolone (Pred). Excellent patient and graft survival could be achieved in this population with low incidences of acute rejection or serious complications as when compared with the results of azathioprine (AZ) treated pediatric patients. With a mean follow-up of 12.9 months (range 1 to 50 months), the patient survival rate was 100 per cent and the graft survival rate was 100, 84, 84 and 84 per cent at 1, 2, 3 and 4 years post transplantation, respectively. Serum creatinine levels in the group were 0.97, 1.17, 1.14 and 1.2 mg/dl at 3, 6, 12 and 24 months post transplantation, respectively. The incidence of treated acute rejection episodes was 20 per cent (2 out of 10) in the CyA-treated children, whereas it was 53 per cent (9 of 17) in the Az-treated children. Five children who had undergone transplant surgery before they were 11 years old displayed linear growth in height after their transplantation. There have been no opportunistic infections, aseptic necrosis or peptic ulcers in this group and cyclosporine nephrotoxicity has not been a serious problem in the pediatric recipients. Only 10 per cent (1 out of 10) of the recipients displayed acute nephrotoxicity and only one recipient has converted from CyA+Pred to CyA+AZ+Pred (Three drug therapy) due to persistent nephrotoxicity. Cyclosporine and prednisolone have therefore constituted a relatively safe, effective immunosuppressive regimen for pediatric renal allograft recipients. This paper was presented at the 7th international congress of pediatric nephrology.     

A single center's clinical experience with quadruple immunosuppression including ATG or IL2 antibodies and mycophenolate mofetil in simultaneous pancreas–kidney transplants

Acute rejection remains a major problem in simultaneous pancreas–kidney (SPK) transplant and occurs in 60–100% of the cases.
With the introduction of mycophenolate mofetil (MMF) replacing azathioprine (AZA) as a basis immunosuppressant, reduced rates of rejection have been reported. This study investigates the frequency and clinical relevance of allograft rejection in SPK patients receiving anti‐thymocyte globulin (ATG) or Basiliximab® induction therapy and cyclosporine Neoral® (CyA), MMF, steroid basis immunosuppression.
Between December 1996 and October 1999, 21 consecutive patients (15 males, 6 females) received a SPK transplant at our institution with a mean±standard deviation (SD) age of 42±6 yr. Of these, 14 patients were treated with anti‐thymocyte globulin (ATG) Fresenius® (rabbit) 3–5 mg/kg for 6±2 d, cyclosporine Neoral (CyA) (trough levels 350–400 ng/mL), MMF 3 g/d and low dose steroid therapy. Seven SPK patients were treated with Basiliximab (Simulect®, Novartis 20 mg on d 0 and d 4 post‐transplant) instead of ATG. The patients had an average human leucocyte antigen (HLA) mismatch of 3.9/6 and a negative cross match. All patients remained on triple drug therapy. Three patients were switched to tacrolimus instead of Neoral for CyA intolerance. The mean±SD cold ischemia time (CIT) of the organs was 10.1±2.4 h for the pancreas and 10.5±2.6 h for the kidney.
Results: Biopsy‐proven rejection occurred in the kidney of 1 ATG patient (8%), which responded to steroid bolus therapy. One of the patients (14%) with Basiliximab induction developed renal allograft rejection, which was resolved after a 6‐d course of anti‐CD3 mAb (OKT3) treatment. All patients (100%) were free from rejection in the pancreas, as measured by urine amylase levels and glycemic control without the need for exogenous insulin with a mean glycosylated hemoglobin (HBA₁C) of 5.1±0.7% and serum creatinine with a mean of 1.24±0.24 mg/dL in a mean follow‐up period of 17±15 months (median 12, range 2–37).
Conclusion: Triple drug immunosuppression including cyclosporine, MMF and low dose steroids with ATG or interleukin 2 (IL2) receptor antibodies induction therapy appears to be a very suitable immunosuppressive regimen for combined pancreas–kidney transplant (PKT) with a marked reduction in the incidence of rejection.     

骁悉和环孢素-A预防肾移植术后早期急性排斥反应

目的 探讨骁悉和环孢素－Ａ预防肾移植术后早期急性排斥反应的效果。方法 回顾性分析１９９７年１２月￣１９９９年１月临床资料完整肾移植患者１４６例,随访时间６￣１６个月。根据应用免疫抑制剂方案的不同分为硫唑嘌呤（Ａｚａ）组（环孢素－Ａ、泼尼松龙、Ａｚａ）和骁悉（ＭＭＦ）组（环孢素－Ａ、泼尼松、ＭＭＦ）。其中Ａｚａ组７８例,ＭＭＦ组６８例。所有受者术前行人类白细胞抗原（ＨＬＡ）配型,ＨＬＡ错配≤３个位点     

Mycophenolate mofetil (MMF) in the treatment of chronic renal rejection

BACKGROUND: Experimental studies suggest the efficacy of MMF in the treatment of chronic renal rejection in rats. Studies on the efficacy of MMF in chronic renal rejection in man are scarce and controversial. AIM: The aim of this study was to verify in a prospective non-randomized study the efficacy of MMF given at the dose of 2 g/day in substitution of azathioprine (AZA) in the chronic rejection of cadaveric kidney transplantation. PATIENTS AND METHODS: Twelve patients with histologically proven chronic renal rejection were enrolled. The patients were 5 males and 7 females. Mean age 38.3 +/- 13.8 years, with a mean duration of transplant of 39 +/- 19 months. Mean serum creatinine values at -6, -3, 0, +3, +6, +12 months were respectively 1.72 +/- 0.33, 1.84 +/- 0.36, 2.15 +/- 0.50, 1.88 +/- 0.54, 1.81 +/- 0.71, 1.73 +/- 0.58 mg/dl. Mean creatinine clearance values were 58.85 +/- 10.06,48.8 +/- 13.3,45.8 +/- 10.2, 54.7 +/- 13.3, 51 +/- 12.7, 57.7 +/- 18.5 ml/min. Mean deltaGFR before MMF was -2.15 ml/month. RESULTS: After MMF introduction, the overall GFR decrease attenuated. In particular in seven patients after MMF administration, we obtained a significant reduction of mean serum creatinine value (1.84 +/- 0.55 vs. 1.38 +/- 0.41mg/dl; p = 0.004). In three patients, we obtained a stabilization in GFR. Two patients were slowly progressing even after MMF introduction. After a switch to MMF in almost all patients, we obtained an improvement of renal function. In three patients, we obtained a stabilization of renal function without regression. In particular, seven patients showed a remarkable improvement of renal function. CONCLUSIONS: In conclusion our data even if concerning a small number of patients, confirm the efficacy of MMF in the treatment of renal allograft chronic dysfunction.     

Short-term combination of mycophenolate mofetil with cyclosporine as a therapeutic option for renal transplant recipients: A prospective,multicenter, randomized study

BACKGROUND: Mycophenolate mofetil (MMF), compared to azathioprine (AZA), reduces acute rejection and treatment failure in cyclosporine (CsA) and steroid regimens, but its effect on graft survival is unproven from prospective studies and prolonged use is costly. This study evaluated the efficacy and tolerability of replacing MMF by AZA after 3 months. METHODS: This 28 center, prospective, 12-month, parallel group, open-label study, randomized patients to three groups with microemulsion formulation of CsA (ME-CsA) and steroids as baseline therapy. Group 1 (n=158) received MMF for 3 months, replaced by AZA for 9 months; group 2 (n=162) received MMF for 12 months; and group 3 (n=157) received AZA for 12 months. RESULTS: Treatment failure and the cumulative rate of acute rejection were significantly lower in the MMF groups compared with the AZA group (P=0.007 and P=0.03, respectively). Graft loss, death, and safety profiles of all three treatments were similar over 12 months, as were mean serum creatinine levels. Switching from MMF to AZA did not affect treatment failure. No patient in group 1 experienced a recurrent rejection after month 3, one patient died, and nine patients experienced first rejection episodes. Most rejections (6/9) were steroid-sensitive and histologically mild. CONCLUSIONS: Replacement of MMF by AZA after 3 months of therapy with ME-CsA and steroids provides comparable efficacy and safety profiles to continuous MMF over 12 months. Although apparently a cost-effective option, long-term studies are required to assess the benefit/risk ratio of this therapy switch in different patient subpopulations.     

Safe conversion of mycophenolate mofetil to azathioprine in kidney transplant recipients with sirolimus-based immunosuppression

Aim:   Mycophenolate mofetil (MMF) is a powerful immunosuppressive drug with established efficacy and safety. The long-term use of MMF may bring increased risk of for infection and malignancy and also increased cost of transplantation. The search for minimization of immunosuppressive protocol has led to an open randomized clinical trial of conversion from MMF to azathioprine (AZA).
Methods:   A total of 50 kidney allograft recipients treated with prednisone, sirolimus and MMF were randomized into two groups: converted (AZA group) and continuing (MMF group). The average duration of MMF therapy prior to conversion was 43 months in each group. Inclusion criteria included: patients with serum creatinine levels of less than 200 µmol/L; no past history of acute vascular rejection or recent acute rejection 6 months before randomization; and normal liver function tests.
Results:   Baseline demographics were similar in the two groups. During the 12 month observation period, there were no acute rejection episodes in either group. There were no significant differences in overall patient or graft survival or function. AZA-treated patients had a lower incidence of gastrointestinal complications ( P  = 0.03). Daily cost reduction in the AZA group was more than $US8.79/day per patient.
Conclusion:   In general, replacing MMF with AZA in stable renal transplant recipients is well tolerated and was cost effective with no increased risk of rejection. As the this study was on relatively small samples, larger and longer follow-up studies will be needed to confirm these expected advantages for the long-term outcome and to assess the long-term safety of this minimization of immunosuppressive therapy.     

Mycophenolate Mofetil Is Associated with Altered Expression of Chronic Renal Transplant Histology

Mycophenolate mofetil (MMF) reduces acute rejection in controlled trials of kidney transplantation and is associated with better registry graft survival. Recent experimental studies have demonstrated additional antifibrotic properties of MMF, however, human histological data are lacking. We evaluated sequential prospective protocol kidney biopsies from two historical cohorts treated with cyclosporine (CSA)-based triple therapy including prednisolone and either MMF (n = 25) or azathioprine (AZA, n = 25). Biopsies (n = 360) were taken from euglycemic kidney-pancreas transplant recipients. Histology was independently assessed by the Banff schema and electron microscopic morphometry. MMF reduced acute rejection and OKT3 use (p < 0.05) compared with AZA. MMF therapy was associated with limited chronic interstitial fibrosis, striped fibrosis and periglomerular fibrosis (p < 0.05-0.001), mesangial matrix accumulation (p < 0.01), chronic glomerulopathy scores (p < 0.05) and glomerulosclerosis (p < 0.05). MMF was associated with delayed expression of CSA nephrotoxicity, reduced arteriolar hyalinosis, striped fibrosis and tubular microcalcification (p < 0.05-0.001). The beneficial effects of MMF remained in recipients without acute rejection. Retrospective analysis shows that MMF therapy was associated with substantially reduced fibrosis in the glomerular, microvascular and interstitial compartments, and a delayed expression of CSA nephrotoxicity. These outcomes may be due to a limitation of immune-mediated injury and suggest a direct effect of reduced fibrogenesis.     

Increased incidence of allograft rejection in stable heart transplant recipients after late conversion from mycophenolate mofetil to azathioprine.

Mycophenolate mofetil (MMF) is a safe and effective immunosuppressive agent in kidney and liver transplantation. Preliminary studies also support its use in heart transplantation. However, the cost of MMF is substantially greater than azathioprine (AZA), the current alternative. Since the majority of rejection episodes occur within the first few months of transplantation, using MMF early after transplantation and subsequently converting to AZA, after the risk of rejection has diminished, might be cost-effective. In order to evaluate the safety of such a strategy in heart transplant recipients, we reviewed the rejection profiles of a group of patients who were converted from MMF to AZA late after transplantation. Forty-three stable patients on chronic MMF therapy as part of an open-label, long-term safety study were converted to either commercially available MMF (CellCept) or AZA, at the conclusion of the study. Demographic variables, rejection histories before and after conversion, and immunosuppressive regimens were examined. Twenty-three patients were continued on commercial MMF and 20 were converted to AZA therapy. The average duration of MMF therapy prior to conversion was 41 months in each group. Baseline demographics were similar in the two groups. Treated allograft rejection occurred in 10 of 20 patients converting to AZA, as compared to only 1 of 23 patients remaining on MMF; p = 0.002. Additionally, mean scores (1-5 scale) for the three biopsies before and after conversion favored continued MMF therapy (1.5+/-0.6 before and 1.2+/-0.4 after conversion in MMF group vs. 1.3+/-0.5 before and 1.7+/-0.9 after conversion to AZA; p = 0.02). No allograft loss occurred as a result of conversion. These data suggest that conversion from MMF to AZA, even late after transplantation, can be associated with allograft rejection. The costs associated with these rejection episodes (the additional immunosuppressive agents, endomyocardial biopsies, and physician visits) may exceed the potential cost savings of converting stable heart transplant recipients from MMF to AZA.     

CYCLOSPORIN A (CyA) MONITOrING BY CALCULATION OF AREA UNDER THE CURVE (AUC)

Background The introduction of CyA resulted in a significant prolongation in renal transplant survival but was complicated by the difficulty in distinguishing between transplant rejection and drug toxicity. More recently the conversion of stable transplant recipients to the microemulsion form of CyA resulted in significant nephrotoxicity at trough levels that were previously within the therapeutic range. We have studied AUC determinations as an alternative to trough monitoring for transplant recipients. Methods Fifty five renal transplant recipients underwent venesection prior to administration of their morning CyA dose (Pre) then 2 hours after the dose (post). The Pre (C0) and the post (C2) CyA levels were determined using the AXSYM system (Abbot) then the AUC determined from the equation where AUC = 1.84 X C0 + 4.39 X C2 + 312.66 (Keown et al 1996). Two or more AUC determinations were performed in 13 patients. The serum creatinine (Cr), age, sex, weight, CyA dose, calculated creatinine clearance (Cockcroft and Gault) and history of rejection were recorded at the time of CyA assay. Results 63 patient were studied (41 males & 22 females). The average age was 46 years (range 20‐72). The mean serum creatinine was 0.168 (range 0.07‐0.415). The C2 was the major determinant of the AUC with a correlation coefficient of 0.99 (R squared). The C0 had a weaker correlation with AUC (R squared 0.34). Serum Cr, total CyA dose, dose/kg did not correlate significantly with AUC. In individual patients who underwent multiple AUC determinations there was insufficient data to correlate with renal function. Conclusion The strong correlation between C2 and AUC suggests that a single 2 h CyA estimation is sufficient to determination the AUC using the equation AUC = 4.6 X C2 + 432. This will permit further studies of the role of CyA AUC to optimise immunosuppressive therapy without doubling the number and cost of CyA determinations.     

Cyclosporin withdrawal with concomitant conversion from azathioprine to mycophenolate mofetil in renal transplant recipients with chronic allograft nephropathy: a 2-year follow-up

Because recent large studies have demonstrated that mycophenolate mofetil (MMF) is superior to azathioprine (AZA) as a post-transplant immunosuppressant, it has been speculated that MMF could have a cyclosporin (CsA)-sparing effect in renal transplant recipients with chronic allograft dysfunction. Between April 1996 and October 1998, 31 patients with chronic allograft dysfunction were assigned to have conversion from AZA to MMF with concomitant CsA withdrawal. Patient and graft outcomes were analysed. Mean follow-up time after MMF conversion was 27+/-11 months. Serum creatinine concentration (sCt) significantly decreased after conversion and remained stable at the end of follow-up (227+/-31 micro mol/l vs. 185+/-50 micro mol/l; P<0.0005). Mean variation in sCt was -24% after conversion, whereas it was +20% in the year before conversion ( P<0.001). There was a significant inverse relationship between proteinuria at baseline and improvement in renal function (r=-0.35; P=0.01). Proteinuria increased during follow-up (0.79+/-0.6 vs. 1.79+/-1.08 g/day; P=0.04). Isolated CsA nephropathy was associated with the best outcome. Renal function significantly improved in patients with grade 1 chronic rejection and remained stable in patients with grade 2 chronic rejection. Two patients (6.5%) experienced late acute rejection, respectively 13 and 24 months after CsA withdrawal. Eight patients (29%) experienced systemic infections requiring hospitalization. Blood pressure control and lipid profile improved after conversion. CsA withdrawal with a concomitant switch from AZA to MMF allows a substantial and durable improvement in renal function. Both allograft histology and proteinuria at baseline are predictive of the evolution of renal function after conversion. Physicians should consider the risk of over-immunosuppression possibly associated with this therapeutic strategy.     

Reduction of immunosuppressive load in renal transplant recipients with a low donor-specific cytotoxic T-lymphocyte precursor frequency is safe

BACKGROUND: Tapering of immunosuppressive medication is indicated to prevent long-term side effects. Recently, we have shown that renal transplant recipients can safely be converted from calcineurin inhibitors to MMF or AZA when their donor-specific cytotoxic T-lymphocyte precursor frequencies (CTLpf) are below 10/10(6) PBMC. We wondered whether a low CTLpf also had predictive value when immunosuppressive medication was reduced in patients only on MMF or AZA and steroid medication. METHODS: Renal transplant recipients with stable renal function at least 2 years after transplantation and with low (<10/10(6) PBMC) CTLpf were included. Their MMF or AZA dose was reduced to 75% and to 50% of the original dose at 4 months and 8 months after inclusion. Endpoint of the study was 12 months after inclusion or developing acute rejection. RESULTS: Forty-five patients have reached the 1-year follow up endpoint. Their median time after transplantation was 4.2 years (range 2.0-15.5 years). Acute rejection was seen in one patient only (who had discontinued all his medication). CONCLUSION: In patients with low CTLpf long after kidney transplantation, a 50% reduction of immunosuppression is safe and further decreasing their immunosuppressive load is the obvious next step.     

Urine macrophage migration inhibitory factor concentrations as a diagnostic tool in human renal allograft rejection.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is a potent activator of macrophages and T cells. Previous studies have shown that local MIF production is increased in acute renal allograft rejection, suggesting that it may play an important role in the rejection process. AIMS: To determine if urine and serum MIF concentrations: (1) are increased in acute rejection, and (2) can be used as noninvasive tools to discriminate between acute rejection (AR) and cyclosporine nephrotoxicity (CyA toxicity). METHODS: In a prospective study of nine renal allograft patients (five acute rejection and four stable), serial urine MIF concentrations were measured by ELISA in the first 14 days after transplantation. In a retrospective study, MIF concentrations in urine and serum were measured in 24 patients who were biopsied for acute renal transplant dysfunction (11 AR, 13 CyA toxicity). Urine and serum MIF were also measured in 23 stable renal transplant patients and 10 normals. RESULTS: MIF was readily detected in the urine of normal healthy controls (106+/-61 pg/micromol creatinine). In the prospective study, the urinary MIF concentration was increased substantially on day 1 posttransplantation and subsequently fell in parallel with the serum creatinine. However, urine MIF increased before episodes of biopsy proven acute rejection. The retrospective study showed that urine MIF concentrations in patients with AR were increased 5-fold compared to normal controls (439+/-313 pg/micromol Cr; P<0.01). In contrast, urine MIF concentrations in CyA toxicity were not significantly different to normal controls (145+/-119 pg/micromol Cr; P=NS). A marked increase in MIF immunostaining was seen in biopsies of AR, but not in CyA toxicity. No significant differences were evident in serum MIF levels between normals and any transplant patient group. CONCLUSIONS: These results suggest that measurement of urine MIF concentration may be useful in monitoring renal transplant patients for acute rejection and as a discriminator from cyclosporine nephrotoxicity.