Timothy H. Mathew

BACKGROUND: The search for more effective and less toxic immunosuppressive agents to control transplant rejection has led to the extensive testing of mycophenolate mofetil (MMF) in clinical renal transplantation. METHODS: A pooled analysis of three phase III, randomized, double-blind, multicenter clinical trials conducted in the United States, Canada, Europe, and Australia was performed to further characterize the efficacy of MMF in renal allograft recipients. The three studies enrolled a total of 1493 patients. Triple- and quadruple-therapy regimens of cyclosporine, corticosteroids, and standardized MMF dosages with and without antilymphocyte induction were used: MMF in twice-daily doses of 1.0 g or 1.5 g (MMF 2 g or 3 g) was compared with placebo (PLA) or azathioprine (AZA). The primary efficacy endpoint in the individual trials was biopsy-proven rejection or treatment failure at 6 months. This pooled analysis focused on graft loss, patient death, incidence and treatment of rejection episodes, and graft function (serum creatinine) at 1 year. RESULTS: At 1 year, the graft survival rate was 90.4% and 89.2% in the MMF 2 g and 3 g groups, respectively, compared with 87.6% in the PLA/AZA group. This difference was not statistically significant. MMF significantly reduced the incidence of rejection episodes: 40.8% for PLA/AZA patients versus 19.8% and 16.5% for the MMF 2 g and MMF 3 g groups, respectively. Renal function was consistently better for both MMF treatment groups at 3, 6, and 12 months. CONCLUSIONS: MMF proved superior to AZA as a posttransplant immunosuppressant in conjunction with cyclosporine and corticosteroids. MMF-treated groups showed reduced incidence and severity of rejection episodes, similar graft survival, and better graft function over 12 months.

BACKGROUND: Three large-scale clinical trials conducted in North America, Europe, and Australia showed that mycophenolate mofetil (MMF) decreases the incidence of acute renal allograft rejection in the first 6 months after transplant compared with placebo or azathioprine. This study extends the randomized, prospective, double-blind trial of MMF conducted by the Tricontinental Mycophenolate Mofetil Renal Transplantation Study Group. METHODS: Patients (n=503) were randomized to receive 100-150 mg of azathioprine (AZA) (n=166), 2 g of MMF (n=173), or 3 g of MMF (n=164) per day, in conjunction with cyclosporine and prednisone from the time of transplantation. RESULTS: During the first 6 months, the incidence of biopsy-proven acute graft rejection (BPR) was reduced by approximately 50% in the MMF 2 g (19.7%) and MMF 3 g (15.9%) groups compared with the AZA group (35.5%). The incidence of treatment failure during the first 6 months, including BPR, death, graft loss, and early withdrawal without prior BPR, was significantly decreased: AZA, 50%, compared with MMF 2 g, 38.2% (P=0.0287), and MMF 3 g, 34.8% (P=0.0045). At 3 years after transplant, both intent-to-treat and on-study (censoring at 90 days after treatment) analyses of graft and patient survival showed a trend toward advantage for MMF 2 g and 3 g vs. AZA (intent-to-treat: 81.9% and 84.8% vs. 80.2%; on-study: 84.0% and 86.4% vs. 82.7%), although this trend did not reach statistical significance. Rejection was the principal cause of graft loss in all groups: AZA, 9.9%; MMF 2 g, 5.8%; and MMF 3 g, 3.0%. Graft function (intent-to-treat and on-study) was comparable in all three groups at 3 years. Gastrointestinal toxicity, leukopenia, and tissue-invasive cytomegalovirus disease were more common in the MMF 3 g group both during and after the first posttransplant year. Lymphoproliferative disorders were diagnosed in one AZA (0.6%), two MMF 2 g (1.2%), and three MMF 3 g (1.8%) patients. Other (non-lymphoproliferative disorders, noncutaneous) malignancies occurred in six AZA (3.7%), four MMF 2 g (2.3%), and nine MMF 3 g (5.5%) patients. Mortality was comparable in all three groups (AZA, 8.6%; MMF 2 g, 4.7%; MMF 3 g, 9.1%) by 3 years of follow-up. CONCLUSION: MMF significantly reduced the incidence of rejection in the first 6 months, but there was not a significant improvement in graft survival throughout the 3 years after cadaver kidney transplantation.

We examined the rates of malignancy at 2 yr after transplantation in renal allograft patients receiving sirolimus (SRL) in continuous combination with cyclosporine (CsA), SRL as base therapy or SRL maintenance therapy after early withdrawal of CsA. A total of 1295 patients were enrolled in two double-blind studies comparing SRL with azathioprine (AZA) or placebo administered in continuous regimens with CsA. In two other trials (n = 161), SRL given as base therapy was compared with CsA. In the fifth trial, patients were randomly assigned at 3 months to either remain on CsA + SRL therapy (n = 215) or to have CsA eliminated with SRL being continued in concentration-controlled doses (n = 215). At 2 yr after transplantation, patients receiving SRL in continuous combination with CsA had a significantly lower incidence of skin cancer compared with patients receiving placebo. Patients receiving SRL as base therapy had no malignancies compared with a 5% incidence in those receiving CsA. The incidence of malignancy was significantly lower in patients receiving concentration-controlled SRL with elimination of CsA compared with those who remained on CsA + SRL. Based on the currently available data, patients receiving SRL-based therapy without CsA or SRL maintenance therapy after early CsA withdrawal have lower rates of malignancy in the first 2 yr after renal transplantation. SRL immunotherapy may be beneficial in protecting renal transplant patients from skin cancer even when given in combination with CsA.

Optimal detection and subsequent risk stratification of people with chronic kidney disease (CKD) requires simultaneous consideration of both kidney function (glomerular filtration rate [GFR]) and kidney damage (as indicated by albuminuria or proteinuria). Measurement of urinary albuminuria and proteinuria is hindered by a lack of standardisation regarding requesting, sample collection, reporting and interpretation of tests. A multidisciplinary working group was convened with the goal of developing and promoting recommendations that achieve consensus on these issues. The working group recommended that the preferred method for assessment of albuminuria in both diabetic and non-diabetic patients is urinary albumin-to-creatinine ratio (UACR) measurement in a first-void spot urine specimen. Where a first-void specimen is not possible or practical, a random spot urine specimen for UACR is acceptable. The working group recommended that adults with one or more risk factors for CKD should be assessed using UACR and estimated GFR every 1-2 years, depending on their risk-factor profile. Recommended testing algorithms and sex-specific cut-points for microalbuminuria and macroalbuminuria are provided. The working group recommended that all pathology laboratories in Australia should implement the relevant recommendations as a vital component of an integrated national approach to detection of CKD.

Graft function at 6 or 12 mo is positively correlated with renal transplant survival. The 36-mo results of a study that tested whether withdrawing cyclosporine (CsA) from a sirolimus (SRL)-CsA-steroid (ST) regimen would affect renal graft survival are reported. Eligible patients (n = 430) who were receiving SRL-CsA-ST were randomly assigned at 3 mo to remain on SRL-CsA-ST or to have CsA withdrawn (SRL-ST group). At 36 mo, the calculated GFR was significantly better with SRL-ST (47.3 versus 59.4 ml/min; P < 0.001) as was the slope of the GFR (-3.6 versus 0.8 ml/min; P < 0.001). This was accompanied by growing trend for improved graft survival in the SRL-ST group (85.1% versus 91.2%, P = 0.052 at 36 mo; 81.4% versus 91.2%, P = 0.015 in a cumulative data analysis up to 54 mo), despite numerically more biopsy-proven acute rejections after randomization (5.6% versus 10.2%; P = 0.107). Lipid parameters were similar between groups, whereas both systolic and diastolic BP were significantly lower in the SRL-ST group. Investigator-reported hypertension, abnormal kidney function, edema, hyperuricemia, hyperkalemia, gingival hyperplasia, and Herpes zoster occurred significantly more often in SRL-CsA-ST patients. Abnormal liver function test results, hypokalemia, thrombocytopenia, and abnormal healing were reported significantly more often with SRL-ST. The discontinuation rate was significantly higher for SRL-CsA-ST (48% versus 38%; P = 0.041). In conclusion, withdrawing CsA from a SRL-CsA-ST regimen at 3 mo after transplantation resulted in long-term benefits for renal transplant recipients.