Fuad S. Shihab

A Prospective, Randomized, Double-Blind, Placebo-Controlled Multicenter Trial Comparing Early (7 Day) Corticosteroid Cessation Versus Long-Term, Low-Dose Corticosteroid Therapy

Objective:To compare outcomes with early corticosteroid withdrawal (CSWD) and chronic low dose corticosteroid therapy (CCS). Summary Background Data:Final, 5-year results from the first randomized, double-blind, placebo-controlled trial of early CSWD (at 7 days posttransplant) are presented. Methods:Adult recipients of deceased and living donor kidney transplants without delayed graft function were randomized to receive prednisone (5 mg/d after 6 months posttransplant) or CSWD. Blinding was maintained for 5 years. This clinical trial is registered at www.clinicaltrials.gov (NCT00650468). Results:Results in 386 patients CSWD (n = 191), CCS (n = 195) are presented (CSWD; CCS). No differences were observed at 5 years in the proportion of patients experiencing: primary end point (composite of death, graft loss, or moderate/severe acute rejection) (30/191 (15.7%); 28/195 (14.4%)), patient death (11/191(5.8%);13/195 (6.7%)), death-censored graft loss (11/191 (5.8%); 7/195(3.6%)), biopsy confirmed acute rejection (BCAR) (34/191 (17.8%); 21/195 (10.8%), P = 0.058), moderate/severe acute rejection (15/191 (7.9%); 12/195 (6.2%)). Kaplan Meier analyses of the primary end point and its components also showed no differences; but BCAR was higher with CSWD (P = 0.04). Increased BCAR episodes were primarily corticosteroid-sensitive Banff 1A rejections: the incidence of antibody-treated BCAR was similar between groups (11/191 (5.8%); 13/195 (6.7%)). No differences in renal function were observed at 5 years: mean serum creatinine (1.5 ± 0.6; 1.5 ± 0.7 mg/dL), or Cockroft Gault calculated creatinine clearance (58.6 ± 19.7; 59.8 ± 20.5 mL/min). CSWD was associated with improved serum triglycerides (evaluated by mean and median change from baseline) at all time points (except at 5 years measured by mean change). Weight change also demonstrated changes favoring CSWD (median change from baseline at 5 years: 5.1 vs. 7.7 kg, P = 0.05). New onset diabetes after transplant (NODAT) was similar with respect to proportions who required treatment (23/107 (21.5%)); 18/86 (20.9%); however, fewer CSWD patients required insulin for NODAT at 5 years (4/107 (3.7%)); 10/86 (11.6%), P = 0.049). Changes in HgA1c values (from baseline) were lower in CSWD patients at all time points except 4 years. Conclusions:Early CSWD, compared with CCS, is associated with an increase in BCAR primarily because of mild, Banff 1A, steroid-sensitive rejection, yet provides similar long-term renal allograft survival and function. CSWD provides improvements in cardiovascular risk factors (triglycerides, NODAT requiring insulin, weight gain). Tacrolimus/MMF/antibody induction therapy allows early CSWD with results comparable to long-term low dose (5 mg/d) prednisone therapy.

Results of the double-blind, randomized, multicenter, phase III clinical trial of thymoglobulin versus Atgam in the treatment of acute graft rejection episodes after renal transplantation

BACKGROUND Thymoglobulin, a rabbit anti-human thymocyte globulin, was compared with Atgam, a horse anti-human thymocyte globulin for the treatment of acute rejection after renal transplantation. METHODS A multicenter, double-blind, randomized trial with enrollment stratification based on standardized histology (Banff grading) was conducted. Subjects received 7-14 days of Thymoglobulin (1.5 mg/kg/ day) or Atgam (15 mg/kg/day). The primary end point was rejection reversal (return of serum creatinine level to or below the day 0 baseline value). RESULTS A total of 163 patients were enrolled at 25 transplant centers in the United States. No differences in demographics or transplant characteristics were noted. Intent-to-treat analysis demonstrated that Thymoglobulin had a higher rejection reversal rate than Atgam (88% versus 76%, P=0.027, primary end point). Day 30 graft survival rates (Thymoglobulin 94% and Atgam 90%, P=0.17), day 30 serum creatinine levels as a percentage of baseline (Thymoglobulin 72% and Atgam 80%; P=0.43), and improvement in posttreatment biopsy results (Thymoglobulin 65% and Atgam 50%; P=0.15) were not statistically different. T-cell depletion was maintained more effectively with Thymoglobulin than Atgam both at the end of therapy (P=0.001) and at day 30 (P=0.016). Recurrent rejection, at 90 days after therapy, occurred less frequently with Thymoglobulin (17%) versus Atgam (36%) (P=0.011). A similar incidence of adverse events, post-therapy infections, and 1-year patient and graft survival rates were observed with both treatments. CONCLUSIONS Thymoglobulin was found to be superior to Atgam in reversing acute rejection and preventing recurrent rejection after therapy in renal transplant recipients.

Mechanism of fibrosis in experimental tacrolimus nephrotoxicity

The clinical use of tacrolimus (FK506) is limited by nephrotoxicity. The pathogenesis of fibrosis in chronic FK506 nephrotoxicity remains unknown. Because transforming growth factor (TGF)-beta plays a key role in the fibrogenesis of many diseases, including cyclosporine nephrotoxicity, we studied a salt-depleted rat model of chronic FK506 nephropathy in which clinically relevant FK506 blood levels are obtained and which shows similarities to the lesions described in patients receiving FK506. Pair-fed rats were treated with either FK506 (1 mg/kg/day s.c.) or an equivalent dose of vehicle and were killed at 7 or 28 days. Characteristic histologic changes of tubular injury, interstitial fibrosis, and arteriolopathy developed in FK506-treated rats at 28 days and were accompanied by worsening kidney function, decreased concentrating ability, and enzymuria. FK506-treated kidneys had a progressive increase in the expression of TGF-beta1 and matrix proteins (biglycan, tenascin, fibronectin, and type I collagen). This effect seems to be specific because the expression of type IV collagen, a basement membrane collagen, was not affected. Matrix deposition was present mostly in the tubulointerstitium and vessels in accordance with the FK506 chronic lesion. The expression of plasminogen activator inhibitor-1, a protease inhibitor influenced by TGF-beta, followed TGF-beta1 and matrix proteins, suggesting that the fibrosis of chronic FK506 nephropathy likely involves the dual action of TGF-beta1 on matrix deposition and degradation. Since both peripheral and tissue renin expression were elevated with FK506, the renin-angiotensin system may play a role in the pathogenesis of this condition.

Cytomegalovirus Incidence Between Everolimus Versus Mycophenolate in De Novo Renal Transplants: Pooled Analysis of Three Clinical Trials

Everolimus (EVR) in heart and renal transplant (RTx) recipients may be associated with a decreased incidence of cytomegalovirus (CMV). A detailed analysis of the association between EVR versus mycophenolic acid (MPA) and CMV events has not been reported. CMV data from 2004 de novo RTx recipients from three‐randomized, prospective, EVR studies A2309 (N = 833), B201 (N = 588) and B251 (N = 583) were retrospectively analyzed to identify differences between two EVR dosing groups and MPA. EVR groups received 1.5 mg/day, or 3 mg/day with either standard (SD‐CsA) or reduced dose cyclosporine (RD‐CsA). Controls received MPA with SD‐CsA. CMV prophylaxis was as per center practice. CMV incidence (infection/syndrome, disease, viremia) was captured per local center evaluations. Kaplan–Meier analyses demonstrated that freedom from CMV viremia and infection/syndrome was significantly greater for EVR versus MPA for recipients without CMV prophylaxis. Among recipients who received prophylaxis, freedom from viremia was greater for EVR 3.0 mg; freedom from infection/syndrome was greater for EVR 3.0 and 1.5 mg. Although freedom from organ involvement was numerically greater for EVR, it was not statistically significant. This analysis documents significant reductions in the incidence of CMV infection/syndrome and viremia in EVR‐treated de novo RTx recipients, especially those who did not receive CMV prophylaxis versus MPA.

Role of Socioeconomic Status in Kidney Transplant Outcome

There is controversy regarding the influence of genetic versus environmental factors on kidney transplant outcome in minority groups. The goal of this project was to evaluate the role of certain socioeconomic factors in allograft and recipient survival. Graft and recipient survival data from the United States Renal Data System were analyzed using Cox modeling with primary variables of interest, including recipient education level, citizenship, and primary source of pay for medical service. College (hazard ratio [HR] 0.93, P < 0.005) and postcollege education (HR 0.85, P < 0.005) improved graft outcome in the whole group and in patients of white race. Similar trends were observed for recipient survival (HR 0.9, P < 0.005 for college; HR 0.88, P = 0.09 for postcollege education) in the whole population and in white patients. Resident aliens had a significantly better graft outcome in the entire patient population (HR 0.81, P < 0.001) and in white patients in subgroup analysis (HR 0.823, P < 0.001) compared with US citizens. A similar effect was observed for recipient survival. Using Medicare as a reference group, there is a statistically significant benefit to graft survival from having private insurance in the whole group (HR 0.87, P < 0.001) and in the black (HR 0.8, P < 0.001) and the white (HR 0.89, P < 0.001) subgroups; a similar effect of private insurance is observed on recipient survival in the entire group of patients and across racial groups. Recipients with higher education level, resident aliens, and patients with private insurance have an advantage in the graft and recipient outcomes independent of racial differences.

Pirfenidone Treatment Decreases Transforming Growth Factor‐β1 and Matrix Proteins and Ameliorates Fibrosis in Chronic Cyclosporine Nephrotoxicity

Chronic cyclosporine (CsA) nephrotoxicity is characterized by tubulointerstitial fibrosis. Pirfenidone (PFD) is a novel antifibrotic compound that was shown to prevent and even reverse fibrosis. The mechanism of action of PFD is unclear but involves inhibition of transforming growth factor‐β (TGF‐β). Salt‐depleted rats were administered CsA, CsA + PFD, vehicle (VH) or VH + PFD and sacrificed at 28 days. Physiologic and histologic changes were studied in addition to TGF‐β1, plasminogen activator inhibitor‐1 (PAI‐1) and biglycan mRNA expressions by Northern blot. TGF‐β1 immunohistochemistry was also performed. Treatment with PFD ameliorated CsA‐induced fibrosis by about 50% (p < 0.05). CsA‐induced decrease in creatinine clearance improved with PFD but the difference was not significant. TGF‐β1, PAI‐1 and biglycan mRNA expressions increased with CsA (p < 0.05 vs. VH) but strikingly improved with PFD treatment (p < 0.05 vs. CsA), which brought the levels down to VH levels. PFD treatment also decreased TGF‐β1 protein expression by 80%. These results demonstrate that PFD can attenuate renal fibrosis in this model. PFD was associated with a decrease in TGF‐β1 expression, which, in turn, was associated with a decrease in matrix deposition. These experiments suggest that PFD can be clinically useful for preventing chronic CsA nephrotoxicity and may prove to be helpful in other progressive renal diseases.

Randomized trial of everolimus-facilitated calcineurin inhibitor minimization over 24 months in renal transplantation.

Background Strategies allowing calcineurin inhibitor minimization while maintaining efficacy may improve renal transplant outcomes. Methods A2309 was a 24-month, phase IIIb, open-label trial of 833 de novo renal transplant recipients randomized to everolimus, targeting trough concentrations of 3–8 or 6–12 ng/mL plus reduced-exposure cyclosporine A (CsA) or to mycophenolic acid (MPA) 1.44 g per day plus standard-exposure CsA. All patients received basiliximab±corticosteroids. The incidence of the primary composite efficacy endpoint and its components (treated biopsy-proven acute rejection, graft loss, death, or loss to follow-up), renal function (serum creatinine and estimated glomerular filtration rate), and adverse events (AEs) were compared at 24 months; as per the protocol, these analyses were not noninferiority. Results Composite efficacy failure rates (95% confidence interval for difference vs. MPA) were 32.9% (−2.2%, 13.0%), 26.9% (−7.9%, 6.8%), and 27.4% at month 24 in the everolimus 3–8 and 6–12 ng/mL and MPA groups, respectively. Mean estimated glomerular filtration rate (Modification of Diet in Renal Disease) at month 24 was 52.2 (−2.1, 5.5 mL/min/1.73 m2), 49.4 (−4.8, 2.7 mL/min/1.73 m2), and 50.5 mL/min/1.73 m2, respectively. AEs were generally mild to moderate in severity and comparable between the groups. AEs leading to discontinuation were reported in 28.5% (P=0.03 vs. MPA), 30.6% (P=0.007 vs. MPA), and 20.5% of patients receiving everolimus 3–8 and 6–12 ng/mL and MPA, respectively. Conclusions Everolimus trough concentrations targeted to 3–8 ng/mL, along with a greater than 60% reduction in CsA exposure, was associated with comparable efficacy and renal function versus MPA plus standard-exposure CsA over the 2-year period. A significantly higher incidence of AEs led to discontinuation in the everolimus groups compared with the MPA group.

Sodium depletion enhances fibrosis and the expression of TGF-β1 and matrix proteins in experimental chronic cyclosporine nephropathy

The major limitation to the clinical use of cyclosporine (CsA) is renal toxicity. In the past, the lack of an animal model of chronic CsA nephropathy has hampered the study of its pathogenesis. Rats given CsA and placed on a low sodium diet (LSD) develop a histology similar to human lesions of chronic CsA nephropathy, a phenomenon not observed in animals on a normal sodium diet (NSD). We have previously shown that transforming growth factor-beta1 (TGF-beta1) is involved in the CsA-induced renal fibrosis in rats on a LSD. We hypothesized that sodium depletion is critical to the increase in TGF-beta1 expression, which, in turn, results in excessive matrix accumulation. Pair-fed rats were placed on a NSD or LSD, treated with CsA or vehicle, and killed at 7 or 28 days (N = 4 to 6 in each group). All rats achieved similar blood pressure control, and all CsA-treated rats achieved similar CsA blood levels. However, while CsA did not affect creatinine clearance in rats on a NSD, it lowered creatinine clearance in rats on a LSD (P < 0.01). Cyclosporine-induced tubulointerstitial fibrosis and arteriolopathy was observed at 28 days only in the rats on a LSD (P < 0.05). In addition, peripheral renin activity was increased only in the rats on a LSD (P < 0.01), while it remained normal in the rats on a NSD. In addition, CsA-treated rats on a LSD developed a progressive increase in the mRNA expression of TGF-beta1 and the matrix proteins biglycan and type I collagen at 7 and 28 days. Most of the changes were seen at 28 days (P < 0.001 for TGF-beta1, P < 0.01 for biglycan and type I collagen). On the other hand, CsA treatment in rats on a NSD did not affect the mRNA expression of TGF-beta1 and matrix proteins. Most of the changes in the immunofluorescence deposition of the glycoproteins tenascin and fibronectin EDA+ were in the tubulointerstitium and vessels of the kidneys of rats on a LSD and were mostly significant at 28 days, in accordance with the characteristic histology of chronic CsA nephropathy. The mRNA expression of plasminogen activator inhibitor-1, a protease inhibitor involved in matrix degradation and stimulated by TGF-beta1, was observed only in kidneys of rats on a LSD (P < 0.01). Since sodium depletion elevates peripheral renin activity, our experiments suggest a role for the renin-angiotensin system in the expression of TGF-beta1 and matrix proteins in CsA-induced renal fibrosis of rats on a LSD.

A Retrospective Analysis of Ezetimibe Treatment in Renal Transplant Recipients

A retrospective review was conducted to determine the safety and efficacy of ezetimibe as a treatment option for renal transplant recipients. We evaluated the medical records of 34 adult renal transplant recipients receiving ezetimibe as monotherapy or combination therapy. Fasting lipid profiles were obtained at baseline and at 1–6 months post‐ezetimibe initiation. Twenty patients received cyclosporine, 12 patients received tacrolimus, 1 patient received either sirolimus or no calcineurin therapy at the time of ezetimibe initiation. Monotherapy was started in 8 patients, who had all previously failed statins, and combination therapy was utilized in 26 patients. Monotherapy or combination therapy resulted in a mean reduction in total cholesterol of 23.3%, triglycerides 40.2%, low‐density lipoproteins 16.8% and high‐density lipoproteins 4.8% after 3.1 months of therapy. Ezetimibe as combination or monotherapy is a safe and effective treatment option for dyslipidemia in renal transplant recipients without changes in calcineurin inhibitor levels or renal function.

Mycophenolate Mofetil Ameliorates Arteriolopathy and Decreases Transforming Growth Factor-β1 in Chronic Cyclosporine Nephrotoxicity

Afferent arteriolopathy is the most characteristic lesion of chronic cyclosporine (CsA) nephrotoxicity. We investigated the effect of therapeutic doses of mycophenolate mofetil (MMF) in a model of chronic CsA nephrotoxicity where transforming growth factor‐β (TGF‐β) was shown to play a central role.