Chk1 and the Host Cell DNA Damage Response as a Potential Antiviral Target in BK Polyomavirus Infection.

The human BK polyomavirus (BKPyV) is latent in the kidneys of most adults, but can be reactivated in immunosuppressed states, such as following renal transplantation. If left unchecked, BK polyomavirus nephropathy (PyVAN) and possible graft loss may result from viral destruction of tubular epithelial cells and interstitial fibrosis. When coupled with regular post-transplant screening, immunosuppression reduction has been effective in limiting BKPyV viremia and the development of PyVAN. Antiviral drugs that are safe and effective in combating BKPyV have not been identified but would be a benefit in complementing or replacing immunosuppression reduction. The present study explores inhibition of the host DNA damage response (DDR) as an antiviral strategy. Immunohistochemical and immunofluorescent analyses of PyVAN biopsies provide evidence for stimulation of a DDR in vivo. DDR pathways were also stimulated in vitro following BKPyV infection of low-passage human renal proximal tubule epithelial cells. The role of Chk1, a protein kinase known to be involved in the replication stress-induced DDR, was examined by inhibition with the small molecule LY2603618 and by siRNA-mediated knockdown. Inhibition of Chk1 resulted in decreased replication of BKPyV DNA and viral spread. Activation of mitotic pathways was associated with the reduction in BKPyV replication. Chk1 inhibitors that are found to be safe and effective in clinical trials for cancer should also be evaluated for antiviral activity against BKPyV.

The Genomic Response to TGF-ß1 Dictates Failed Repair and Progression of Fibrotic Disease in the Obstructed Kidney.

Tubulointerstitial fibrosis is a common and diagnostic hallmark of a spectrum of chronic renal disorders. While the etiology varies as to the causative nature of the underlying pathology, persistent TGF-ß1 signaling drives the relentless progression of renal fibrotic disease. TGF-ß1 orchestrates the multifaceted program of kidney fibrogenesis involving proximal tubular dysfunction, failed epithelial recovery or re-differentiation, capillary collapse and subsequent interstitial fibrosis eventually leading to chronic and ultimately end-stage disease. An increasing complement of non-canonical elements function as co-factors in TGF-ß1 signaling. p53 is a particularly prominent transcriptional co-regulator of several TGF-ß1 fibrotic-response genes by complexing with TGF-ß1 receptor-activated SMADs. This cooperative p53/TGF-ß1 genomic cluster includes genes involved in cellular proliferative control, survival, apoptosis, senescence, and ECM remodeling. While the molecular basis for this co-dependency remains to be determined, a subset of TGF-ß1-regulated genes possess both p53- and SMAD-binding motifs. Increases in p53 expression and phosphorylation, moreover, are evident in various forms of renal injury as well as kidney allograft rejection. Targeted reduction of p53 levels by pharmacologic and genetic approaches attenuates expression of the involved genes and mitigates the fibrotic response confirming a key role for p53 in renal disorders. This review focuses on mechanisms underlying TGF-ß1-induced renal fibrosis largely in the context of ureteral obstruction, which mimics the pathophysiology of pediatric unilateral ureteropelvic junction obstruction, and the role of p53 as a transcriptional regulator within the TGF-ß1 repertoire of fibrosis-promoting genes.

TGF-ß1-p53 cooperativity regulates a profibrotic genomic program in the kidney: molecular mechanisms and clinical implications.

Chronic kidney disease affects >15% of the U.S. population and >850 million individuals worldwide. Fibrosis is the common outcome of many chronic renal disorders and, although the etiology varies (i.e., diabetes, hypertension, ischemia, acute injury, and urologic obstructive disorders), persistently elevated renal TGF-ß1 levels result in the relentless progression of fibrotic disease. TGF-ß1 orchestrates the multifaceted program of renal fibrogenesis involving proximal tubular dysfunction, failed epithelial recovery and redifferentiation, and subsequent tubulointerstitial fibrosis, eventually leading to chronic renal disease. Recent findings implicate p53 as a cofactor in the TGF-ß1-induced signaling pathway and a transcriptional coregulator of several TGF-ß1 profibrotic response genes by complexing with receptor-activated SMADs, which are homologous to the small worms (SMA) and Drosophilia mothers against decapentaplegic (MAD) gene families. The cooperative p53-TGF-ß1 genomic cluster includes genes involved in cell growth control and extracellular matrix remodeling [e.g., plasminogen activator inhibitor-1 (PAI-1; serine protease inhibitor, clade E, member 1), connective tissue growth factor, and collagen I]. Although the molecular basis for this codependency is unclear, many TGF-ß1-responsive genes possess p53 binding motifs. p53 up-regulation and increased p53 phosphorylation; moreover, they are evident in nephrotoxin- and ischemia/reperfusion-induced injury, diabetic nephropathy, ureteral obstructive disease, and kidney allograft rejection. Pharmacologic and genetic approaches that target p53 attenuate expression of the involved genes and mitigate the fibrotic response, confirming a key role for p53 in renal disorders. This review focuses on mechanisms whereby p53 functions as a transcriptional regulator within the TGF-ß1 cluster with an emphasis on the potent fibrosis-promoting PAI-1 gene.-Higgins, C. E., Tang, J., Mian, B. M., Higgins, S. P., Gifford, C. C., Conti, D. J., Meldrum, K. K., Samarakoon, R., Higgins, P. J. TGF-ß1-p53 cooperativity regulates a profibrotic genomic program in the kidney: molecular mechanisms and clinical implications.

TGF-ß1/p53 signaling in renal fibrogenesis.

Fibrotic disorders of the renal, pulmonary, cardiac, and hepatic systems are associated with significant morbidity and mortality. Effective therapies to prevent or curtail the advancement to organ failure, however, remain a major clinical challenge. Chronic kidney disease, in particular, constitutes an increasing medical burden affecting >15% of the US population. Regardless of etiology (diabetes, hypertension, ischemia, acute injury, urologic obstruction), persistently elevated TGF-ß1 levels are causatively linked to the activation of profibrotic signaling networks and disease progression. TGF-ß1 is the principal driver of renal fibrogenesis, a dynamic pathophysiologic process that involves tubular cell injury/apoptosis, infiltration of inflammatory cells, interstitial fibroblast activation and excess extracellular matrix synthesis/deposition leading to impaired kidney function and, eventually, to chronic and end-stage disease. TGF-ß1 activates the ALK5 type I receptor (which phosphorylates SMAD2/3) as well as non-canonical (e.g., src kinase, EGFR, JAK/STAT, p53) pathways that collectively drive the fibrotic genomic program. Such multiplexed signal integration has pathophysiological consequences. Indeed, TGF-ß1 stimulates the activation and assembly of p53-SMAD3 complexes required for transcription of the renal fibrotic genes plasminogen activator inhibitor-1, connective tissue growth factor and TGF-ß1. Tubular-specific ablation of p53 in mice or pifithrin-α-mediated inactivation of p53 prevents epithelial G2/M arrest, reduces the secretion of fibrotic effectors and attenuates the transition from acute to chronic renal injury, further supporting the involvement of p53 in disease progression. This review focuses on the pathophysiology of TGF-ß1-initiated renal fibrogenesis and the role of p53 as a regulator of profibrotic gene expression.

The new kidney allocation system does not equally advantage all very high cPRA candidates - A single center analysis.

The new UNOS kidney allocation system awards very high points to candidates with cPRA 99% and 100%, and allows for national sharing for cPRA 100% candidates. We sought to determine the effect of this new kidney allocation system on candidates who are very highly sensitized (90-98% cPRA) but not eligible for very high points or national sharing by examining offers to these candidates for 5months pre-implementation and two consecutive 5month periods post-implementation and comparing them to cPRA⩾99% candidates. We found that the cPRA⩾99% candidates received significantly more offers and transplants after implementation, while offers and transplants to the 90-98% candidates decreased. A slight adjustment to the allocation system may be needed to provide more equitable distribution of kidneys to all high cPRA candidates.

Early steroid withdrawal results in improved patient and graft survival and lower risk of post-transplant cardiovascular risk profiles: A single-center 10-year experience.

Long-term use of steroids results in predictable secondary effects that can lead to increased morbidity and mortality. In this study, we present 10 years worth of data of early steroid withdrawal (ESW) immunosuppression consisting of mycophenolate, sirolimus, and tacrolimus. From 2003 to 2013, 563 kidney transplant recipients were weaned off steroids prior to discharge. We compared outcomes with that of our 65 historical controls maintained on steroids. We analyzed graft and patient survival and determined the incidence of steroid-related comorbidities such as hypertension, hypercholesterolemia, diabetes, coronary artery disease, and weight gain. Patients on ESW maintenance immunosuppression had improved patient and graft survival compared to controls. (HR: 0.23; P≤.011, 0.57; P=.026). Rates of biopsy-proven acute rejection were not different among both groups (HR: 1.24; P=.610). Incidence of post-transplant diabetes were reduced but not statistically significant (OR: 0.67; P=.138). Additionally, the development of hypertension (OR: 0.86, P≤.01), hypercholesterolemia (RR: 0.82; P=.027), CAD (RR: 0.43; P=.002), and >20 lbs. weight gain (RR: 0.29; P≤.01) was significantly improved over 10 years following initiation of ESW protocols. Early steroid withdrawal in renal transplant recipients results in improved patient and graft survival as well as better rates of post-transplant comorbid conditions.

History of the Department of Surgery at Albany Medical Center.

Surgeons have always played an integral role in the history of the Albany Medical Center and Albany Medical College. In addition to supporting vital patient care and teaching programs, the Department of Surgery has played an important administrative role providing the college with five deans. The origins of the Department of Surgery reach back to 1910 when the American Medical Association-sponsored Flexner report proposed dramatic changes in the structure and format of medical education in the United States. In response to the recommendations of the report, the medical center restructured its faculty and curriculum to meet the demands of a rapidly advancing profession. One result of this reorganization was the formation of the Department of Surgery in 1912. Dr. Arthur Elting was named the first Chair of the Department in 1915. This report will review the history of the Department, focusing on the eight surgeons who have served as Chair.

Monthly screening for polyoma virus eliminates BK nephropathy and preserves renal function.

BACKGROUND: Polyoma BK virus nephropathy is a serious complication after renal transplantation and is associated with a high rate of allograft failure. Progressive infection with BK virus in immunocompromised renal transplant recipients occurs in detectable stages: Viruria, viremia, then nephropathy. METHODS: In January, 2006, we initiated a plasma screening policy for all new transplant recipients, with monthly blood testing for BK virus by polymerase chain reaction (PCR). Between January 1, 2006, and February 28, 2007, 66 renal transplants were performed at our center. The 11 patients with a positive plasma BK PCR test underwent prompt reduction in baseline immunotherapy consisting of a 50% daily dose reduction (n = 6) or complete discontinuation of therapy with mycophenolate mofetil (n = 5). RESULTS: After reduction or discontinuation of mycophenolate mofetil, 10 patients became negative for BK virus in the plasma within 6 months. Progression to BK nephropathy has not occurred, and renal transplant dysfunction secondary to acute cellular rejection developed in only 1 patient (9%). One year post-transplant, the mean serum creatinine values for these 11 patients remained stable at 1.5 mg/dL. CONCLUSION: Monthly plasma screening for BK virus by PCR together with immunosuppressive regimen reduction prevents BK nephropathy. In addition, this intensive screening protocol is associated with a low rate of acute rejection and excellent preservation of renal function.

Sirolimus-based, calcineurin-inhibitor sparing immunotherapy, long-term (6-year) results.

At the Albany Medical Center, we have a long-term experience, mean follow-up of 75 months, in 50 renal transplant recipients treated with maintenance sirolimus, prednisone and a calcineurin-inhibitor sparing immunosuppressive regimen. One-year patient and graft survival was 98% and six-year patient and graft survival was 82% and 72% respectively. The rate of early acute rejection (<3 months) was only 10%. Furthermore, no late (>3 months) acute rejection episodes developed despite calcineurin-inhibitor dose minimization. In addition, recipient mean serum creatinine remained stable at 1.6 mg/dl throughout the 6-year follow-up period. Sirolimus is an effective maintenance immunosuppressive agent that safely allows for a reduction in calcineurin-inhibitor dosing.

Conversion from cyclosporine to tacrolimus in patients at risk for chronic renal allograft failure: 60-month results of the CRAF Study.

BACKGROUND: This study compared the long-term effects of switching from cyclosporine to tacrolimus on the incidence, progression, and severity of chronic renal allograft failure in patients with elevated serum creatinine levels. METHODS: Patients were assigned randomly (2:1) to switch to tacrolimus or remain on cyclosporine. Tacrolimus was initiated at 1/50th of the cyclosporine dose or 0.15 mg/kg/day, whichever dose was lower, to maintain trough concentrations between 5 and 15 ng/mL. Cyclosporine doses were adjusted to achieve trough concentrations between 100 and 300 ng/mL. RESULTS: At 60 months, the median change from baseline in serum creatinine was -0.2 mg/dL in the tacrolimus group and 0.3 mg/dL in the cyclosporine group (P=0.003). Median change in estimated creatinine clearance was 1.2 mL/min in the tacrolimus group and -4.1 mL/min in the cyclosporine group (P=0.019). The incidence of new-onset diabetes, hyperglycemia, hypertension, lymphoma, and malignancies was generally low and comparable between groups. Fewer patients in the tacrolimus group than in the cyclosporine group developed new cardiac conditions (11% vs. 28%, P=0.004), had low-density lipoprotein (LDL) cholesterol values more than 130 mg/dL (29% vs. 57%, P=0.002), or developed hyperlipidemia (24% vs. 67%, P=0.046) during the 60-month follow-up period. Despite these changes, patient and graft survival were similar for both groups. CONCLUSION: Switching from cyclosporine to tacrolimus resulted in improved renal function and a reduction in the occurrence of new-onset cardiac conditions and hyperlipidemia, with no increase in the incidence of new-onset diabetes or new-onset hyperglycemia. However, after 5 years there was no impact on patient or graft survival.

Early steroid withdrawal therapy in renal transplant recipients: a steroid-free sirolimus and CellCept-based calcineurin inhibitor-minimization protocol.

BACKGROUND: Maintenance steroid therapy is associated with significant morbidity and mortality in renal transplant recipients. Elimination of the many long-term side effects of corticosteroids, including those that impinge on cardiovascular risk, remains a laudable goal in designing immunosuppressive protocols. However, concern persists that prednisone-free maintenance immunotherapy in kidney transplant recipients will result in an increase incidence of acute rejections, renal dysfunction and ultimate graft loss. METHODS: From 24 March 2003 to 1 December 2004, 84 kidney transplant recipients (61 deceased donor, 23 living donors) discontinued prednisone on post-operative day 6. Immunotherapy consisted of polyclonal antibody induction (thymoglobulin) for five d and prednisone intraoperatively with a rapid taper over the next six d. Maintenance therapy consisted of a sirolimus and CellCept-based calcineurin inhibitor-minimization protocol. Tacrolimus and mycophenolate mofetil (CellCept) were initiated on day 0. Sirolimus immunotherpay was started on post-operative day 6 concomitant with the cessation of steroids. We compared outcomes with that of our historical controls, treated with sirolimus and tacrolimus, who did not discontinue steroids. In addition, we analyzed outcomes independently for recipients of living and deceased donors in the steroid-free protocol. RESULTS: The recipients on prednisone-free maintenance immunosuppression had excellent 2.5-yr actuarial patient survival (97%), graft survival (93%), and acceptable acute rejection-free graft survival (89%). The mean serum creatinine level (+/-SD) at one yr was 1.5 +/- 0.6 mg/dL and at two yr was 1.5 +/- 0.6 mg/dL. We noted that 5% of recipients developed cytomegalovirus (CMV) syndrome; 1%, polyoma nephropathy; 1%, post-transplant lymphoproliferative disorder (PTLD), and 5% developed post-transplant diabetes mellitus (PTDM). In all, 91% of kidney recipients with functioning grafts remain steroid-free as of 31 December 2005. When compared with historical controls, the recipients on the early steroid-withdrawal (ESW) protocol had comparable graft survival, acute rejection-free survival, graft function, but significantly better patient actuarial survival (p = 0.048). In addition, recipients on the steroid-free protocol had decreased prevalence of four risk factors for cardiovascular disease when compared with historical controls: hypertension (p = 0.008), hyperlipidemia (p = 0.003), weight gain (p = 0.024), and incidence of PTDM (p = 0.015). CONCLUSION: Early steroid-withdrawal in renal transplant recipients with a sirolimus and CellCept-based calcineurin inhibitor-minimimization protocol can effectively reduce many of the steroid-related side effects, decrease risk factors for cardiovascular disease, and is associated with improved recipient survival without compromising graft function.

The impact of obesity in renal transplantation: an analysis of paired cadaver kidneys.

BACKGROUND: Previous studies indicate that obesity is a risk factor in renal transplantation. However, these analyses did not control for variable donor factors that may strongly influence outcome. To control for donor variables such as age, cause of death, procurement techniques, preservation methods, cold ischaemia time and implantation technique, we analysed patient and graft survival in recipients of paired kidneys, derived from the same procurement procedure, preserved in the same manner, subjected to similar cold ischaemia time and implanted by the same surgical team. Between June 1992 and August 1999, 28 procurement procedures provided kidneys which were transplanted into one obese and one non-obese recipient. Body mass index (BMI) was calculated as kg/m2. Recipients were classified as obese (BMI > 30) or non-obese (BMI < 30). Immunotherapy for all recipients consisted of a triple therapy regimen of cyclosporine or prograf, azathioprine or cellcept, and prednisone. Patients with delayed graft function (DGF), defined as the need for dialysis within 72 h of the transplant procedure, were treated with anti-thymocyte globulin (ATG) or thymoglobulin (TMG) induction for 5-7 d. The rate of DGF (7.1 versus 10.7%) and acute rejection (39.3 versus 35.7%) were similar in the obese and non-obese recipient groups. Patient survival was similar at 1, 3 and 5 yr in both groups. In addition, graft survival was similar at 1 yr. However, a trend toward decreased medium-term graft survival, which reached significance at 5 yr, was observed in the obese group. Furthermore, mean serum creatinine at 1 yr was higher in the obese group (2.0) compared with the non-obese group (1, 4) (p=0.12). This analysis of paired cadaver kidneys indicated that obesity is not a risk factor for DGF, acute rejection, and 1-yr graft survival. However, a decreased medium- and long-term graft survival trend, which reached statistical significance at 5 yr, was observed in obese recipients.