Early Kidney Allograft Dysfunction (Threatened Allograft): Comparative Effectiveness of Continuing Versus Discontinuation of Tacrolimus and Use of Sirolimus to Prevent Graft Failure: A Retrospective Patient-Centered Outcome Study.

BACKGROUND: Due to lack of treatment options for early acute allograft dysfunction in the presence of tubular-interstitial injury without histological features of rejection, kidney transplant recipients are often treated with sirolimus-based therapy to prevent cumulative calcineurin inhibitor exposure and to prevent premature graft failure. METHODS: We analyzed transplant recipients treated with sirolimus-based (n = 220) compared with continued tacrolimus-based (n = 276) immunosuppression in recipients of early-onset graft dysfunction (threatened allograft) with the use of propensity score-based inverse probability treatment weighted models to balance for potential confounding by indication between 2 nonrandomized groups. RESULTS: Weighted odds for death-censored graft failure (odds ratio [OR], 1.20; 95% confidence interval [95% CI], 0.66-2.19, P = 0.555) was similar in the 2 groups, but a trend for increased risk of greater than 50% loss in estimated glomerular filtration rate from baseline in sirolimus group (OR, 1.90; 95% CI, 0.96-3.76; P = 0.067) compared with tacrolimus group. Sirloimus group compared with tacrolimus group had increased risk for death with functioning graft (OR, 2.01; 95% CI, 1.29-3.14; P = 0.002) as well as increased risk of late death (death after graft failure while on dialysis) (OR, 2.39; 95% CI, 1.59-3.59; P < 0.001). Analysis of subgroups based on the absence or presence of T cell-mediated rejection or tubulointerstitial inflammation in the index biopsy, or the use of different types of induction agents, and all subgroups had increased risk of death with functioning graft and late death if exposed to sirolimus-based therapy. CONCLUSIONS: Use of sirolimus compared with tacrolimus in recipients with early allograft dysfunction during the first year of transplant may not prevent worsening of allograft function and could potentially lead to poor survival along with increased risk of late death.

Current State of Immunosuppression: Past, Present, and Future.

The success of solid-organ transplantation was made possible by recognizing that destruction of the graft is caused by an alloimmune-mediated process. For the past decade, immunosuppressive protocols have used a combination of drugs that significantly decreased the rate of acute organ rejection. Despite advances in surgical and medical care of recipients of solid-organ transplants, long-term graft survival and patient survival have not improved during the past 2 decades. Current immunosuppression protocols include a combination of calcineurin inhibitors, such as tacrolimus, and antiproliferative agents (most commonly mycophenolate mofetil), with or without different dosing regimens of corticosteroids. Mammalian target of rapamycin inhibitors were introduced to be used in combination with cyclosporine-based therapy, but they did not gain much acceptance because of their adverse event profile. Belatacept, a costimulatory inhibitor, is currently being studied in different regimens in an effort to replace the use of calcineurin inhibitors to induce tolerance and to improve long-term outcomes. Induction therapy is now being used in more than 90% of kidney transplants and more than 50% cases of other solid-organ transplantation such as lung, heart, and intestinal transplants. As a result of these combination immunosuppressive (IS) therapy protocols, not only the incidence but also the intensity of episodes of acute rejection have decreased markedly, and at present 1-year graft and patient survival is almost 98% for kidney transplant recipients and approximately greater than 80% for heart and lung transplants. Evolving concepts include the use of donor-derived bone marrow mesenchymal cells to induce tolerance, to minimize the use of maintenance IS agents, and to prevent the development of adverse events associated with long-term use of maintenance IS therapy.

Efficacy and safety of carvedilol in treatment of heart failure with chronic kidney disease: a meta-analysis of randomized trials.

BACKGROUND: The safety and efficacy of different types of ß-blocker therapy in patients with non-dialysis-dependent chronic kidney disease (CKD) and systolic heart failure (HF) are not well described. We assessed whether treatment of systolic HF with carvedilol is efficacious and safe in adults with CKD. METHODS AND RESULTS: We performed a post hoc analysis of pooled individual patient data (n=4217) from 2 multinational, double-blinded, placebo-controlled, randomized trials, CAPRICORN (Carvedilol Postinfarct Survival Control in Left Ventricular Dysfunction Study) and COPERNICUS (Carvedilol Prospective Randomized, Cumulative Survival study). Primary outcome was all-cause mortality. Secondary outcomes included cardiovascular mortality, HF mortality, first HF hospitalization, the composite of cardiovascular mortality or first HF hospitalization, and sudden cardiac death. Non-dialysis-dependent CKD was defined by estimated glomerular filtration rate ≤60 mL/min/1.73 m(2), using the abbreviated Modification of Diet in Renal Disease equation. CKD was present in 2566 of 4217 (60.8%) of the cohort, 50.4% of whom were randomly assigned to carvedilol therapy. Within the CKD group, treatment with carvedilol decreased the risks of all-cause mortality (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.63 to 0.93; P=0.007), cardiovascular mortality (HR, 0.76; 95% CI, 0.62 to 0.94; P=0.011), HF mortality (HR, 0.68; 95% CI, 0.52 to 0.88; P=0.003), first hospitalization for HF (HR, 0.74; 95% CI, 0.61 to 0.88; P=0.0009), and the composite of cardiovascular mortality or HF hospitalization (HR, 0.75; 95% CI, 0.65 to 0.87; P<0.001) but was without significant effect on sudden cardiac death (HR, 0.76; 95% CI, 0.56 to 1.05; P=0.098). There was no significant interaction between treatment arm and study type. Carvedilol was generally well tolerated by both groups of patients, with an increased relative incidence in transient increase in serum creatinine without need for dialysis and other electrolyte changes in the CKD patients. However, in a sensitivity analysis among HF subjects with estimated glomerular filtration rate <45 mL/min/1.73 m(2) (CKD stage 3b), the efficacy of carvedilol was not significantly different from placebo. CONCLUSIONS: This analysis suggests that the benefits of carvedilol therapy in patients with systolic left ventricular dysfunction with or without symptoms of HF are consistent even in the presence of mild to moderate CKD. Whether carvedilol therapy is similarly efficacious in HF patients with more advanced kidney disease requires further study.

Minimizing the risk of chronic allograft nephropathy.

Chronic allograft nephropathy, now defined as interstital fibrosis and tubular atrophy not otherwise specified, is a near universal finding in transplant kidney biopsies by the end of the first decade posttransplantation. After excluding death with functioning graft, caused by cardiovascular disease or malignancy, chronic allograft nephropathy is the leading cause of graft failure. Original assumptions were that this was not a modifiable process but inexorable, likely due to past kidney injuries. However, newer understandings suggest that acute or subacute processes are involved, and with proper diagnosis, appropriate interventions can be instituted. Our method involved a review of the primary and secondary prevention trials in calcineurin inhibitor withdrawal. Some of the more important causes of progressive graft deterioration include subclinical cellular or humoral rejection, and chronic calcineurin inhibitor toxicity. Early graft biopsy, assessment of histology, and changes in immunosuppression may be some of the most important measures available to protect graft function. The avoidance of clinical inertia in pursuing subtle changes in graft function is critical. Modification in maintenance immunosuppression may benefit many patients with early evidence of graft deterioration.

Chronic allograft dysfunction: can we use mammalian target of rapamycin inhibitors to replace calcineurin inhibitors to preserve graft function?

PURPOSE OF REVIEW: Graft loss after first year of transplantation can be due to composite of factors that may include immunological and nonimmunological factors. Among the nonimmunological factors, toxicity of immunosuppression drugs, especially calcineurin inhibitor (CNI) toxicity is perhaps the leading cause of graft dysfunction. The most common phenotype associated with progressive graft dysfunction is the development of interstitial fibrosis and tubular atrophy not otherwise specified, a hallmark finding of chronic allograft nephropathy as well as CNI toxicity. Protocol biopsies have demonstrated that histological lesions of CNI toxicity can develop as early as 3 months posttransplantation. RECENT FINDINGS: Early detection of interstitial fibrosis and tubular atrophy offers the opportunity for replacement of the CNI with mammalian target of rapamycin inhibitors. Early detection of CNI-associated graft damage even before the onset of graft dysfunction is critical to prevent progressive nephron loss. Furthermore, the conversion to sirolimus in patients with advanced graft dysfunction may not be beneficial. SUMMARY: Until the day transcriptomic assays and high-density microarrays are available routinely to detect the incipient graft injury, early allograft biopsy, preferably during the first 3-6 months of transplantation can detect the presence of interstitial fibrosis and tubular atrophy not otherwise specified before the onset of graft dysfunction and replacement of CNI with sirolimus could prevent the progressive nephron loss.

Cholesterol embolization syndrome induced by thrombolytic therapy.

Cholesterol embolization syndrome (CES) induced by thrombolytic therapy is a rare syndrome with a high incidence of morbidity and mortality. The variability in clinical presentations may cause a delay in diagnosis of CES. This article presents a comprehensive review of the English literature from January 1980 to December 2007 identifying all published case reports of CES induced by thrombolytic therapy. Multiple electronic databases were searched and relevant reference lists were hand searched to identify all case reports. Thirty cases of thrombolytic-induced CES were identified. Indications for thrombolysis were acute myocardial infarction (28 patients) and deep venous thrombosis (two patients). Skin and renal involvement were the most common presentations. Skin manifestations included livedo reticularis, rash, and skin mottling. Other clinical symptoms included cyanotic toes, gastrointestinal bleeding, or perforation, myalgias, retinal emboli, and CNS involvement. Morbidity and mortality were high. Outcomes included chronic hemodialysis in eight patients, four patients underwent amputations, seven patients developed or had progression of their chronic kidney disease, and seven deaths occurred.CES presents as multiorgan dysfunction and should be considered in the differential diagnosis of the symptom complex that may develop after thrombolytic therapy. Diagnosis of CES can be difficult as a result of the variable clinical presentations. A thorough clinical history and physical examination are essential first steps in establishing a diagnosis. Confirmatory diagnosis requires biopsy of the target organs. Measures to reduce the likelihood of recurrence should be taken and include avoidance of anticoagulation therapy and vascular procedures. Unfortunately, therapy remains supportive and the outcome is invariably poor.

Spontaneous cutaneous ulcers in a patient with a moderate degree of chronic kidney disease: a different spectrum of calciphylaxis.

Calciphylaxis is characterized by the development of spontaneous skin ulcers that often progress to deep tissue necrosis. We present a case of calciphylaxis in a patient with chronic kidney disease (CKD) prior to the initiation of dialysis. We conclude that calciphylaxis should be considered in the differential diagnosis of skin ulcerations in patients with any degree of CKD.

Polyomavirus BK versus JC replication and nephropathy in renal transplant recipients: a prospective evaluation.

BACKGROUND: JC virus (JCV) viruria is more common than BK virus (BKV) viruria in healthy individuals but in kidney transplants (KT), polyomavirus nephropathy (PVAN) is primarily caused by BKV. Few cases of PVAN have been attributed to JCV. Systematic studies on JCV replication in KT are lacking. METHODS: Out of a cohort of KT patients screened with urine cytology, patients shedding decoy cells were studied (n=103). Molecular studies demonstrated BKV, JCV, or BKV+JCV shedding in 58 (56.3%), 28 (27.2%), and 17 (16.5%), respectively. Biopsy was performed when decoy cells persisted 2 months or serum creatinine increased >20%. RESULTS: BKV viruria was strongly associated with BKV viremia (93%), PVAN (48%, P=0.01) and graft loss (P=0.03). Higher BKV viremia correlated with graft dysfunction (P=0.01), more advanced histological pattern of PVAN (P<0.0001), and more infected cells in biopsy (P=0.0001). BKV viremia of > or =10,000 copies/mL was significantly associated with histologically confirmed PVAN (P=0.0001). Reduction of immunosuppression lead to disappearance of decoy cells in patients shedding BK (>93%). JCV viruria, was more often asymptomatic (P=0.002) and affected older patients (P=0.02). JCV PVAN was less common (21.4%) and was characterized by sparse cytopathic changes but significant inflammation and fibrosis. JCV viremia was rare (14.2%), transient, and low (mean 2.0E+03/mL). After reduction of immunosuppression decoy cells persisted in >50% of patients with JCV (P=0.0001), but no graft loss occurred. During the period of the current study, the incidence of BKV-PVAN was 5.5% and the incidence of JCV-PVAN was 0.9%. CONCLUSIONS: The data point to significant differences of BKV and JCV biology regarding replication and disease in KT patients, with important implications for screening and management.

Acute renal failure and nephrotic range proteinuria due to amyloidosis in an HIV-infected patient.

Amyloidosis is an uncommon cause of renal disease in HIV-positive patients. Diagnosis is challenging, treatment options are limited, and prognosis remains poor. We discuss an HIV-positive patient with acute renal failure and nephrotic range proteinuria. The differential diagnosis included nephropathy due to trimethoprim/sulfamethoxazole, tenofovir, HIV, hepatitis C, heroin, or multifactorial causes. Serum and urine study findings were inconclusive. Rapid clinical deterioration ensued and a renal biopsy was performed. Pathologic examination revealed eosinophilic, amorphous material in the glomerular tufts that stained red-orange with Congo red stain. Immunohistochemical analysis confirmed amyloid A (AA) amyloidosis. AA amyloidosis occurs as a complication of chronic infection or chronic inflammatory disease. It has been reported in intravenous or subcutaneous drug abusers, some of whom were HIV-positive. This case underscores the importance of tissue diagnosis to determine the cause of renal disease in HIV-positive patients. Clinical diagnosis, based on CD4 count, viral load, and degree of proteinuria, may not predict the pathological diagnosis in HIV-positive patients.

Chronic kidney disease: a risk factor for cardiovascular disease.

The goal of risk stratification of CVD inpatients with CKD is to lead to effective and early intervention and to prevent the adverse outcomes associated with this complex multisystem disease that is characteristic of growing number of patients with CKD in the general population and of patients receiving dialysis therapy or kidney transplantation. By 2030, there will be 2.24 million patients with ESRD in the United States, and approximately 1.3 million of these cases of ESRD will be caused by diabetes mellitus. Thus, CVD in this high-risk population presents a challenge for the nephrology and the cardiology community.

Effect of kidney transplantation on left ventricular systolic dysfunction and congestive heart failure in patients with end-stage renal disease.

OBJECTIVES: We examined the impact of kidney transplantation on left ventricular ejection fraction (LVEF) in end-stage renal disease (ESRD) patients with congestive heart failure (CHF). BACKGROUND: The ESRD patients with decreased LVEF and a poor New York Heart Association (NYHA) functional class are not usually referred for transplant evaluations, as they are considered to be at increased risk of cardiac and surgical complications. METHODS: Between June 1998 and November 2002, 103 recipients with LVEF < or =40% and CHF underwent kidney transplantation. The LVEF was re-assessed by radionuclide ventriculography gated-blood pool (MUGA) scan at six and 12 months and at the last follow-up during the post-transplant period. RESULTS: Mean pre-transplant LVEF% increased from 31.6 +/- 6.7 (95% confidence interval [CI] 30.3 to 32.9) to 52.2 +/- 12.0 (95% CI 49.9 to 54.6, p = 0.002) at 12 months after transplantation. There was no perioperative death. After transplantation, 69.9% of patients achieved LVEF > or =50% (normal LVEF). A longer duration of dialysis (in months) before transplantation decreased the likelihood of normalization of LVEF in the post-transplant period (odds ratio 0.82, 95% CI 0.74 to 0.91; p < 0.001). The NYHA functional class improved significantly in those with normalization of LVEF (p = 0.003). After transplantation, LVEF >50% was the only significant factor associated with a lower hazard for death or hospitalizations for CHF (relative risk 0.90, 95% CI 0.86 to 0.95; p < 0.0001). CONCLUSIONS: Kidney transplantation in ESRD patients with advanced systolic heart failure results in an increase in LVEF, improves functional status of CHF, and increases survival. To abrogate the adverse effects of prolonged dialysis on myocardial function, ESRD patients should be counseled for kidney transplantation as soon as the diagnosis of systolic heart failure is established.

BK virus-associated nephropathy in renal allograft recipients: rescue therapy by sirolimus-based immunosuppression.

BACKGROUND: BK virus nephritis (BKN) in recipients of renal allografts has reemerged during the past 5 years. Despite increased incidence, therapeutic options remain limited and progression of the disease often leads to allograft failure. METHODS: From May 2002 to July 2002, we performed protocol biopsies in 25 recipients of kidney allografts with progressive allograft dysfunction; three patients demonstrated unexpected histopathologic features of BKN. We tested the hypothesis that replacement of their lymphocytotoxic and nephrotoxic immunosuppression (combination of mycophenolate and tacrolimus) with sirolimus- and prednisone-based therapy can lead to disappearance of the virus without increasing the risk of acute rejection. RESULTS: During the median follow-up of 18 months after sirolimus and prednisone therapy, decoy cells disappeared first, followed by progressive decrease in the median plasma BK virus-DNA load, and undetectable levels at the last follow-up. Patients remained free of acute rejection, and follow-up median estimated creatinine clearance increased to 67 mL/min (range 62-75 mL/min) from 52 mL/min (range 51-54 mL/min) at the time of diagnosis. CONCLUSIONS: Further studies are needed, but at present these preliminary results offer a new direction for therapeutic intervention in recipients of renal allografts with BKN.

Retransplantation in patients with graft loss caused by polyoma virus nephropathy.

The characteristics and outcome in 10 patients who underwent retransplantation after losing their renal grafts to BK virus-associated nephropathy (BKAN) are described. The patients underwent retransplantation at a mean of 13.3 months after failure of the first graft. Nephroureterectomy of the first graft was performed in seven patients. Maintenance immunosuppression regimens after the first and second grafts were similar, consisting of a combination of a calcineurin inhibitor, mycophenolate mofetil, and prednisone. BKAN recurred in one patient 8 months after retransplantation, but stabilization of graft function was achieved with a decrease in immunosuppression and treatment with low-dose cidofovir. After a mean follow-up of 34.6 months, all patients were found to have good graft function with a mean creatinine of 1.5 mg/dL. From this collective experience from five transplant centers (although the follow-up after retransplantation was not extensive), it can be concluded that patients with graft loss caused by BKAN can safely undergo retransplantation. The risk of recurrence does not seem to be increased in comparison with the first graft.

Recent developments in toxic nephropathy.

Toxic nephropathy is an important cause of reversible renal injury if detected early. Renal damage can be due to several different mechanisms affecting different segments of the nephron, renal microvasculature or interstitium. Clinical signs may not be apparent in the early stages and assessment of renal function should include thorough evaluation of glomerular filtration rate, proximal and distal tubular function. A kidney biopsy may be indicated to establish the cause and effect relationship. The presence of comorbid conditions such as older age, diabetes mellitus, hypertension and congestive heart failure have a significant influence on the patient's ability to recover from the toxic effects. A significant degree of drug-induced renal toxicity is only acceptable if the causative agent is used for the curative treatment of an underlying disease but not if the aim is the palliative or supportive therapy. The decision to reduce the dose or to stop the toxic agent must be based on the ultimate goal of therapy and the patient's baseline health status.

Expression of NHERF-1, NHERF-2, PDGFR-alpha, and PDGFR-beta in normal human kidneys and in renal transplant rejection.

Sodium-hydrogen exchanger regulatory factor-1 and -2 (NHERF-1 and NHERF-2) are adaptor proteins that regulate renal electrolyte transport and interact with the platelet-derived growth factor receptors (PDGFR). The distribution of the NHERF proteins and PDGFR was studied in normal human kidneys and in renal transplant rejection using immunocytochemistry. In normal kidneys, NHERF-1 was detected in proximal tubules. NHERF-2 was detected in glomeruli, peritubular capillaries, and collecting duct principal cells. NHERF-2 was also weakly detected in the proximal tubule. PDGFR-beta was detected in glomeruli but not in tubules while PDGFR-alpha was detected in renal tubules and minimally in glomeruli. Acute and chronic transplant rejection was associated with increased expression of PDGFR-alpha in tubules and expression in the glomeruli. PDGFR-beta expression in the glomeruli was increased in transplant rejection and became detectable in tubules. Expression of NHERF-1 and NHERF-2 was not different in the patient groups. These results indicate that in contrast to the rat, both NHERF isoforms are detected in the human proximal tubule. In renal transplant rejection, there is increased expression of both PDGFR subtypes consistent with a role for PDGF in injury or repair.