Kathy Savas

Bio: Kathy Savas is an academic researcher from Cleveland Clinic. The author has contributed to research in topics: Kidney transplantation & Mycophenolic acid. The author has an hindex of 9, co-authored 12 publications receiving 972 citations.

Kidney transplantation without calcineurin inhibitor drugs: a prospective, randomized trial of sirolimus versus cyclosporine.

Abstract: Background Progressive nephrotoxicity caused by calcineurin inhibitor drugs contributes to the long-term decline in renal function in kidney transplant patients. Methods We conducted a randomized, prospective trial of calcineurin inhibitor drug avoidance in 61 adult primary kidney transplant recipients. Each patient received induction therapy with 20 mg basiliximab on days 0 and 4, and maintenance therapy with mycophenolate mofetil 1 g two times per day and steroids. Thirty-one patients received sirolimus, 5 mg daily after a 15-mg loading dose. Doses were then concentration-controlled to keep 24-hr trough levels at 10 to 12 ng/mL for 6 months and 5 to 10 ng/mL thereafter. Thirty patients began cyclosporine therapy at 6 to 8 mg/kg per day in divided doses and were then concentration-controlled to keep 12-hr troughs of 200 to 250 ng/mL. Results Mean follow-up is 18.1 months (range, 12-26 months). The percentages of 1-year patient survival, graft survival, and biopsy-confirmed acute rejection rates were not significantly different between the sirolimus-treated patients (96.7%, 96.7%, and 6.4%, respectively) and the cyclosporine-treated patients (100%, 95.4%, and 16.6%, respectively). At 6 and 12 months, respectively, the sirolimus-treated patients enjoyed significantly better (P=0.008 and P=0.004) mean serum creatinine levels (1.29 and 1.32 mg/dL) and calculated creatinine clearances (77.8 and 81.1 mL/min) than cyclosporine-treated patients (1.74 and 1.78 mg/dL, and 64.1 and 61.1 mL/min, respectively). Sirolimus-treated recipients have significantly (P=0.001) higher 1-year trough levels of mycophenolic acid (4.16 ng/mL) than cyclosporine-treated patients (1.93 ng/mL). Sirolimus also delays the repopulation of basiliximab-depleted CD25 T cells compared with cyclosporine. Conclusions Calcineurin inhibitor drug avoidance with basiliximab induction and sirolimus provides comparable 1-year transplant outcomes, with significantly better renal function in primary renal allograft recipients.

The impact of sirolimus, mycophenolate mofetil, cyclosporine, azathioprine, and steroids on wound healing in 513 kidney-transplant recipients.

Abstract: Background. The aim of this study was to determine whether there has been an increase in the incidence or severity of wound-healing complications that can be attributed to the introduction of newer immunosuppressive drugs. Methods. Consecutive series of adult kidney-only transplant recipients were selected from our Unified Transplant Database backward from September 2002. There were 513 patients divided into groups on the basis of their maintenance immunosuppression given for at least the first 30 days posttransplant. Group I (152) was given sirolimus, mycophenolate mofetil, and prednisone (SRL/MMF/P) between March 2000 and September 2002; group II (168) was given cyclosporine A (CsA)/MMF/P between January 1999 and July 2002; and group III (193) was given azathioprine (AzA)/CsA/P between January 1993 and December 1997. A classification system for wound-healing problems was developed, and each of the three groups was analyzed by univariate and multivariate analysis. Results. From groups III to II to I, there was a significant increase in mean age (42.4 vs. 49 years), percent of patients diabetic (17% vs. 29%), mean body mass index (BMI) (24.2 vs. 27.1 kg/m2), and percent BMI greater than 30 (13.5% vs. 27%). The cumulative percentage of all wound-healing problems between group I (19.7%) vs. group II (16.1%) and group III (15.6%) was not significantly different. The most significant risk factor was a recipient BMI greater than 30 (P =0.0012) and delayed graft function (P =0.0041). Conclusions. During a 10-year period marked by changing recipient demographics, the introduction of MMF and SRL did not result in a significant increase in transplant wound-healing complications. The most significant risk factor associated with transplant wound-healing complications remains body weight, which was the major influence for each of the immunosuppressive drug combinations described.

Kidney transplantation with sirolimus and mycophenolate mofetil-based immunosuppression: 5-year results of a randomized prospective trial compared to calcineurin inhibitor drugs.

Abstract: Background We report the 5-year outcomes from a randomized prospective trial in primary adult renal allograft recipients, designed to evaluate calcineurin inhibitor (CNI)-free immunosuppression on kidney transplant function. Methods Sixty-one patients were randomized to either sirolimus (n=31) or cyclosporine (n=30) after basiliximab induction and mycophenolate mofetil (MMF) with steroids. Sirolimus was concentration controlled at 10-12 ng/mL for at least 6 months. Results After 5 years, sirolimus-MMF-steroids compared to cyclosporine-MMF-steroids provides similar patient survival (87.1 vs. 90%, P=0.681), acute rejection rates (12.9 vs. 23.3%, P=0.22), total cholesterol (209.1 vs. 204.3 mg/dL, P=0.973), urine protein/creatinine ratios (0.398 vs. 0.478 mg/dL, P=0.72), and overall medical and surgical morbidity (P=NS). Although unadjusted patient survival was similar, sirolimus based CNI-free patients had longer death censored graft survival (96.4 vs. 76.7%, P=0.0265), higher glomerular filtration rate (GFR) by the abbreviated Modified Diet in Renal Disease (66.7 vs. 50.7 cc/min, P=0.0075), and fewer graft losses from chronic allograft nephropathy. The Banff chronic scores at two years were strong predictors of 5-year GFR. At 5 years, there were six de novo (three solid organ, three skin) cancers in the CNI group and only two de novo (one skin, one leukemia, no solid organ) cancers in the sirolimus group (P=NS). Conclusions This study of low to moderate risk patients demonstrates that excellent 5-year kidney transplant outcomes can be achieved without CNI drugs, when therapeutic drug monitoring of sirolimus is employed. The application of CNI drug avoidance protocols to high-risk recipients (retransplants, highly sensitized, etc.), extrarenal allograft recipients, or alternative drug regimens such as steroid or MMF elimination should be subjected to controlled trials.

Immunosuppressive Drugs for Kidney Transplantation

Abstract: Suppression of allograft rejection is central to successful organ transplantation; thus, immunosuppressive agents are crucial for successful allograft function. Immunosuppressive drugs are used for induction (intense immunosuppression in the initial days after transplantation), maintenance, and reversal of established rejection. This review considers the use of immunosuppressive drugs in organ transplantation, focusing on renal transplantation.

The mTOR pathway is regulated by polycystin-1, and its inhibition reverses renal cystogenesis in polycystic kidney disease.

Abstract: Autosomal-dominant polycystic kidney disease (ADPKD) is a common genetic disorder that frequently leads to renal failure. Mutations in polycystin-1 (PC1) underlie most cases of ADPKD, but the function of PC1 has remained poorly understood. No preventive treatment for this disease is available. Here, we show that the cytoplasmic tail of PC1 interacts with tuberin, and the mTOR pathway is inappropriately activated in cyst-lining epithelial cells in human ADPKD patients and mouse models. Rapamycin, an inhibitor of mTOR, is highly effective in reducing renal cystogenesis in two independent mouse models of PKD. Treatment of human ADPKD transplant-recipient patients with rapamycin results in a significant reduction in native polycystic kidney size. These results indicate that PC1 has an important function in the regulation of the mTOR pathway and that this pathway provides a target for medical therapy of ADPKD.

Immunosuppressive drugs in kidney transplantation: impact on patient survival, and incidence of cardiovascular disease, malignancy and infection.

Abstract: Renal transplant recipients have increased mortality rates when compared with the general population. The new immunosuppressive drugs have improved short-term patient survival up to 95% at 1–2 years, but these data have to be confirmed in long-term follow-up. Furthermore, no particular regimen has proved to be superior over others with regard to patient survival.

Chronic Renal Allograft Dysfunction

Abstract: The major causes of renal transplant loss are death from vascular, malignant or infectious disease, and loss of the allograft from chronic renal dysfunction associated with the development of graft fibrosis and glomerulosclerosis. Chronic allograft nephropathy (CAN) is the histologic description of the fibrosis, vascular and glomerular damage occurring in renal allografts. Clinical programs rely on monitoring change in serum creatinine for identification of patients at risk of CAN, but this change occurs late in the course of the disease, and underestimates the severity of pathologic change. CAN has several causes: ischemia-reperfusion injury, ineffectively or untreated clinical and subclinical rejection, and superimposed calcineurin inhibitor nephrotoxicity, exacerbating pre-existing donor disease. Once established, interstitial fibrosis and arteriolar hyalinosis lead to progressive glomerulosclerosis over the subsequent years. There have been a number of approaches to treatment aimed at reducing the impact of CAN, mostly centered around avoidance of calcineurin inhibitors through their elimination in all, or just selected, patients. These immunosuppression strategies combine corticosteroids with azathioprine or mycophenolate mofetil, and/or sirolimus and everolimus. Late identification of CAN in individual patients has meant that strategies for intervening to prevent chronic renal allograft dysfunction and subsequent graft loss tend to be "too little and far too late."

Sirolimus in De Novo Heart Transplant Recipients Reduces Acute Rejection and Prevents Coronary Artery Disease at 2 Years A Randomized Clinical Trial

Abstract: Background— Sirolimus reduces acute rejection in renal transplant recipients and prevents vasculopathy in nonhuman primates and in-stent restenosis in humans. Its effects on rejection and transplant vasculopathy in human heart transplant recipients are unknown. Methods and Results— In a randomized, open-label study, sirolimus was compared with azathioprine in combination with cyclosporine and steroids administered from the time of cardiac transplantation. We report 6-month rejection rates (primary end point), 12-month safety and efficacy data, and 6- and 24-month graft vasculopathy data in 136 cardiac allograft recipients randomly assigned (2:1) to sirolimus (n=92) or azathioprine (n=44). At 6 months, the proportion of patients with grade 3a or greater acute rejection was 32.4% for sirolimus 3 mg/d ( P =0.027), 32.8% for sirolimus 5 mg/d ( P =0.013), and 56.8% for azathioprine. Patient survival at 12 months was comparable among groups. Intracoronary ultrasound at 6 weeks, 6 months, and 2 years demonstrated highly significant progression of transplant vasculopathy in azathioprine-treated patients. At 6 months, a highly significant absence of progression in intimal plus medial proliferation and significant protection against luminal encroachment was evident in sirolimus-treated patients, and these effects were sustained at 2 years. Conclusions— Sirolimus use from the time of transplantation approximately halved the number of patients experiencing acute rejection. The measurable development of transplant vasculopathy at 6 months and 2 years in patients receiving azathioprine was not observed in patients receiving sirolimus. Received March 7, 2004; revision received June 3, 2004; accepted June 3, 2004.