Cardiovascular events following renal transplantation: role of traditional and transplant-specific risk factors.

Cardiovascular mortality is increased in transplant recipients. However, studies including non-fatal events are critical to assess the burden of disease and to identify novel risk factors. We described the incidence of fatal and non-fatal events, and explored associations and interactions among traditional and transplant-specific risk factors and cardiovascular events (CVE) in a cohort of 922 patients transplanted between 1993 and 1998. One hundred and seventy-six patients experienced 201 CVE (111 cardiac, 48 cerebrovascular, 42 peripheral-vascular). Most CVE were non-fatal. Factors associated with cardiac events were (adjusted hazard ratios) tobacco (3.53; P<0.001), obesity (2.92; P<0.001), diabetes (2.63; P<0.001), multiple rejections (2.19; P=0.008), prior CVE (2.0; P=0.004), dialysis >1 year (1.91; P=0.007), and overweight status (1.68; P=0.04); with cerebrovascular events: diabetes and peritoneal dialysis (11.95; P<0.001), age >45 (6.77; P<0.001), diabetes (4.87; P<0.001), prior CVE (3.73; P<0.001), creatinine >141 micromol/l (3.16; P=0.001), peritoneal dialysis (3.06; P=0.027), and obesity (0.32; P=0.046); with peripheral-vascular events: diabetes (8.48; P<0.001), tobacco and cytomegalovirus (3.88; P<0.001), age >45 (2.31; P=0.019), and prior CVE (2.25; P=0.016); with mortality: tobacco and deceased-donor (3.52; P<0.001), age >45 (1.81; P=0.002), diabetes (1.76; P=0.002), pulse pressure (1.64; P=0.029), prior CVE (1.52; P=0.04), and dialysis >1 year (1.47; P=0.04). The majority of CVE post-transplant were non-fatal. Previous CVE was strongly associated with CVE post-transplant. Interactions among transplant-specific and traditional risks impacted significantly the incidence of CVE. Modifiable factors such as duration of dialysis, deceased-donor transplantation, and acute rejection should be viewed as cardiovascular risks.

Late mortality after orthotopic liver transplantation.

BACKGROUND: Mortality within the first year after orthotopic liver transplantation (OLTx) is usually due to infection or allograft failure. Late complications leading to death after OLTx have not been extensively evaluated. The aim of this study was to determine the incidence of late mortality and to identify the most common causes and risk factors associated with late mortality after OLTx. METHODS: A total of 479 OLTx were performed in 459 patients (320 males, 139 females; mean age 47 years, range 13 to 69) between September 1991 and April 2000. All patient deaths among liver transplant recipients who survived more than 1 year after transplantation (follow-up mean 3.4 years, median 3, range 1 to 8.6) were reviewed. RESULTS: In all, 122 allografts (24%) were lost in 109 patients during the study period (24%). Seventy-five allografts were lost in 69 patients by 1 year (15%). Forty-seven allografts were lost in 40 patients who survived at least 1 year (9.6%). Actuarial survivals at 2 years, 5 years, and 9 years were 95%, 85%, and 80%, respectively (based on 100% survival at 1 year). The causes of the late mortality were malignancy (9 patients), disease recurrence (8), late infection (6), renal failure complications (5), cardiovascular complications (4), chronic rejection (3), gastrointestinal hemorrhage (2), medication noncompliance (1), and unknown (2). CONCLUSIONS: Malignancy and disease recurrence are the major causes of late mortality among adult OLTx recipients. Pharmacologic immunosuppression is associated with many of the causes of late mortality. Advances in immunosuppression with less toxicity may improve long-term survival after OLTx.

Use of basiliximab and daclizumab in kidney transplantation.

Kidney transplantation represents a major medical victory in patients with whom dialysis and medical therapy have failed. To increase survival rates and optimize the use of limited organs, both patient care and immunosuppression therapy must be improved. Reduction in rejection episodes or severity of rejection may ultimately improve long-term allograft survival. Traditional engineered monoclonal antibodies have been associated with severe cytokine release reactions and an increased risk of opportunistic infections. Basiliximab and daclizumab are chimeric and humanized monoclonal antibodies which inhibit thymus-dependent lymphocyte proliferation. Interleukin-2 also affects the proliferation of natural killer cells, macrophages and monocytes, bursa-equivalent lymphocytes, epidermal dendritic cells, and lymphokine-activated killer cells. Interleukin-2 receptor antagonists have been shown to reduce the incidence of acute rejection without increasing the incidence of opportunistic infections or malignancy. Further studies are needed to evaluate the overall effect of these agents on long-term patient and allograft survival.

Nephrotoxicity of immunosuppressive drugs: new insight and preventive strategies.

Cyclosporine and tacrolimus reduce allograft rejection, improve allograft half-life and patient survival. Ironically, the nephrotoxicity of these agents may adversely affect allograft survival in renal transplant recipients or cause end-stage renal diseases in other solid organ and bone marrow transplant recipients. Acute dose-dependent and chronic non-dose-dependent nephrotoxicity has been reported in both transplant recipients and patients with autoimmune disorders. Preliminary evidence suggests that drug therapeutic monitoring has little value in the diagnosis or management of nephrotoxicity associated with calcineurin inhibitors. Although the exact mechanism of nephrotoxicity is not fully understood, several factors have been implicated in the pathogenesis of immunosuppressive-induced nephrotoxicity. Renal and systemic vasoconstriction, increased release of endothelin-1, decreased production of nitric acid and increased expression of TGF-beta are the major adverse pathophysiologic abnormalities of these agents. Reducing the dose of a calcineurin inhibitor, or using protocols without calcineurin inhibition may ultimately minimize the risk of drug toxicity and improve allograft and patient survival. New experiences with non-nephrotoxic agents and protocols including mycophenolate and sirolimus allow for early calcineurin inhibitor reduction or elimination without increasing the risk of allograft rejection.

Effect of grapefruit juice on cyclosporin A pharmacokinetics in pediatric renal transplant patients.

Cyclosporin A (CsA) is an important immunosuppressant that is prone to numerous drug interactions. Grapefruit juice has been investigated, as a possible adjunct to CsA dosing in adult renal transplant recipients, to decrease CsA metabolism and reduce dosages. This study investigated this combination in pediatric renal transplant patients. Six stable pediatric renal transplant patients were entered into an open-label, four-period cross-over study in which patients were given their current CsA dose as either an oral solution (CsA-Sol) or a microemulsion (CsA-ME). In addition, drugs were administered concurrently with water or grapefruit juice. Steady-state pharmacokinetic profiles were taken during each of the four periods. Following the concurrent administration of grapefruit juice, CsA whole-blood 12-h trough levels were significantly increased during CsA-Sol dosing. Furthermore, the CsA elimination rate constant was significantly reduced during the same period. After CsA-ME dosing, no differences in CsA pharmacokinetics were found between concurrent water or grapefruit ingestion. Grapefruit juice co-administration reduced the production of CsA metabolites, AM1 and AM9, during CsA-Sol dosing. No changes in CsA metabolite production were found when patients were given CsA-ME with grapefruit juice as compared with water. Hence, alterations in CsA absorption and elimination occur with concurrent grapefruit juice ingestion when stable pediatric renal transplant patients are taking the oral CsA solution, but not the microemulsion formulation. These changes may be mediated by alterations in intestinal or hepatic metabolism, or drug absorption. The effect of grapefruit juice on CsA absorption is not readily predictable in these patients.

Renal toxicity of protease inhibitors.

Introduction of several classes of antiviral agents for the treatment of immunodeficiency virus has led to increased survival and improved quality of life for patients with HIV infection. Protease inhibitors have become the mainstays of current therapy in patient with AIDS. Renal intolerance of indinavir is a rare but important complication in HIV positive patients. The renal function of patients receiving indinavir should be closely monitored. Benign and asymptomatic crystalluria occurs in 4-13% of HIV positive patients. Several cases of acute renal failure, renal atrophy and interstitial nephritis have also been reported. A hydration protocol consisting of one to two liters of fluid should be initiated three hours after each indinavir dose. If significant renal insufficiency persists, temporary indinavir withdrawal or switching to another protease inhibitor should be considered.

Association of fungal infection and increased mortality in liver transplant recipients.

BACKGROUND: Invasive fungal infection is associated with increased morbidity and mortality following orthotopic liver transplantation (OLTx). Understanding the risk factors associated with fungal infection may facilitate identification of high-risk patients and guide appropriate initiation of antifungal therapy. OBJECTIVES: The aim of this study was to determine the incidence of fungal infections, identify the most common fungal pathogens, and determine the risk factors associated with fungal infections and mortality in OLTx recipients. METHODS: Medical records from 96 consecutive OLTx in 90 American veterans (88 males, 2 females; mean age 48 years, range 32 to 67) performed from January 1994 to December 1997 were retrospectively reviewed for fungal infection in the first 120 days after transplantation. Infection was defined by positive cultures from either blood, urine (<105 CFU/mL), cerebrospinal or peritoneal fluid, and/or deep tissue specimens. Superficial fungal infection and asymptomatic colonization were excluded from study. All patients received cyclosporine, azathioprine, and prednisone as maintenance immunosuppressive therapy. Fungal prophylaxis consisted of oral clotrimazole (10 mg) troches, five times per day during the study period. RESULTS: Thirty-five patients (38%) had documented infection with one or more fungal pathogens, including Candida albicans (25 of 35; 71%), C torulopsis (7 of 35; 20%), C tropicalis (2 of 35; 6%), non-C albicans (2 of 35; 6%), Aspergillus fumigatus (4 of 35; 11%), and Cryptococcus neoformans (1 of 35; 3%). The crude survival for cases with or without fungal infection was 68% and 87%, respectively (P <0.0001). The median intensive care unit stay and overall duration of hospitalization were significantly longer for patients with fungal infection (P <0.01). The mean time interval from transplantation to the development of fungal infection was 15 days (range 4 to 77) with a mean survival time from fungal infection to death of 21 days (range 3 to 64). Fungal infections occurred significantly more often in patients with renal insufficiency (serum creatinine >2.5 mg/dL), biliary/vascular complications, and retransplantation. CONCLUSIONS: Fungal infections were associated with increased morbidity and mortality following OLTx, with Candida albicans being the most common pathogen. Treatment strategies involving antifungal prophylaxis for high-risk patients and earlier initiation of antifungal therapy in cases of presumed infection are warranted.

Nephrotoxicity of immunosuppressive drugs: long-term consequences and challenges for the future.

The calcineurin inhibitors cyclosporin A (CsA) and tacrolimus (FK506) are associated with dose- and efficacy-limiting adverse events, including nephrotoxicity, which may diminish their overall benefits for long-term graft survival. Nephrotoxicity is difficult to distinguish from chronic allograft rejection and is a particular problem in the setting of renal transplantation. Minimizing immunosuppressant-induced nephrotoxicity could improve long-term renal allograft survival. However, to obtain significant long-term improvement in renal allograft outcomes, it may be necessary to adopt new immunosuppressive regimens that rely less on calcineurin inhibitors. Recipients of other transplanted organs, as well as patients with autoimmune diseases who require immunosuppressant therapy, could also benefit from this change in immunosuppressive drug strategy because their healthy, native kidneys are particularly susceptible to the nephrotoxic effects of CsA and FK506. CsA- and FK506-sparing regimens, which use reduced doses of CsA and FK506 in combination with other nonnephrotoxic immunosuppressants, may be the best current option for reducing nephrotoxicity. The chemical immunosuppressant mycophenolate mofetil (MMF) has been used as part of CsA- and FK506-sparing regimens that provide improved renal function while maintaining adequate immunosuppression. Such regimens should reduce patient morbidity and mortality. Also, because immunosuppressant-induced nephrotoxicity has been associated with significant financial costs, CsA- and FK506-sparing regimens should result in substantial savings in health care costs.

Immunosuppressant-induced nephropathy: pathophysiology, incidence and management.

Immunosuppressant-induced nephrotoxicity, in particular chronic progressive tubulointerstitial fibrosis/arteriopathy induced by the calcineurin inhibitors cyclosporin and tacrolimus, has become the 'Achilles heel' of immunosuppressive agents. The use of calcineurin inhibitors as primary immunosuppressants in hepatic and cardiac transplantation has led to end-stage renal disease and dialysis. Calcineurin inhibitor-induced acute renal failure may occur as early as a few weeks or months after initiation of cyclosporin therapy. The clinical manifestations of acute renal dysfunction are caused by vasoconstriction of renal arterioles, and include reduction in glomerular filtration rate, hypertension, hyperkalaemia, tubular acidosis, increased reabsorption of sodium and oliguria. The acute adverse effects of calcineurin inhibitors on renal haemodynamics are thought to be directly related to the cyclosporin or tacrolimus dosage and blood concentration. However, new clinical data indicate that calcineurin inhibitor-induced chronic nephropathy can occur independently of acute renal dysfunction, cyclosporin dosage or blood concentration. Several strategies have been evaluated to attenuate cyclosporin-induced nephropathy, but their efficacy remains unknown. Cytokine release syndrome associated with the use of muronomab-CD3 (OKT-3) can also contribute to the pathogenesis of transient acute tubular necrosis and renal dysfunction following renal transplantation. Continued research and clinical experience should provide information regarding the aetiology of cyclosporin-induced chronic progressive tubulointerstitial fibrosis/arteriopathy and its potential treatment.

Fatal fulminant hepatitis associated with bromfenac use.

OBJECTIVE: To report a case of fulminant hepatic failure associated with the use of bromfenac, a new analog of the phenyl acetate class of nonsteroidal antiinflammatory drugs. CASE SUMMARY: A 60-year-old white woman with liver failure who had no known history of chronic liver disease was transferred to the liver transplant unit for evaluation. For three months preceding her illness, the patient was treated with bromfenac 25 mg po qid for arthritic pain. Prior to the initiation of bromfenac, her liver function test results were normal. Etiologic evaluation at presentation was unremarkable. The patient's condition continued to deteriorate, with the development of hepatic encephalopathy and worsening liver function test results while awaiting liver transplantation. Progressive hepatic and renal dysfunction along with respiratory decompensation ensued, and the patient died 48 days after initial presentation. CONCLUSIONS: Fulminant hepatic failure associated with the prolonged use of bromfenac appears to be an idiosyncratic response consistent with experience with other agents of its class. This case along with other cases of serious hepatotoxicity associated with the use of this agent ultimately resulted in bromfenac's removal from the market.

Vancomycin-resistant Enterococcus in liver transplant patients.

BACKGROUND: Vancomycin-resistant Enterococcus (VRE) infection is emerging in the transplant population, and there is no effective antibiotic therapy available. The aims of this retrospective review were to (1) investigate the outcome of and (2) identify common characteristics associated with VRE infection and colonization in orthotopic liver transplant (OLTx) candidates. METHODS: From October 1994 through September 1998, 126 isolates of VRE were identified in 42 of 234 OLTx recipients and 5 OLTx candidates who did not proceed to transplantation. Data were collected by patient chart review or from a computerized hospital database. RESULTS: The 1-year mortality rate with VRE infection was 82%, and with VRE colonization, 7%. This mortality rate contrasts with a 14% 1-year mortality for non-VRE transplant patients (P <0.01, infected patients and colonized patients). Characteristics of VRE colonized and infected patients included recent prior vancomycin (87%), coinfection by other microbial pathogens (74%), recent prior susceptible enterococcal infection (72%), concurrent fungal infection (62%), additional post-OLTx laparotomies (47%), and renal failure (Cr >2.5 mg/dL or need for dialysis; 43%). Biliary complications were seen in 52% of post-OLTx VRE-infected or VRE-colonized patients (versus 22% in non-VRE transplant patients, P <0.05). CONCLUSION: VRE infection is associated with a very high mortality rate after liver transplantation. The incidence of biliary complications prior to VRE isolation is very high in VRE-infected and VRE-colonized patients. The most common characteristics of VRE patients were recent prior vancomycin use, recent prior susceptible enterococcal infection, coinfection with other microbial pathogens, and concurrent fungal infection. With no proven effective antimicrobial therapy for VRE, stringent infection control measures, including strict and limited use of vancomycin, must be practiced.

Distant processing of pancreas islets for autotransplantation following total pancreatectomy.

BACKGROUND: Small duct chronic pancreatitis is associated with intractable pain and failure to thrive, usually unresponsive to conventional management approaches. Total pancreatectomy is considered after failure of medical intervention. The major morbidity following total pancreatectomy is diabetes mellitus with its associated complications. This adverse outcome can be mitigated through autotransplantation of islets recovered from the pancreatectomy specimen. This approach has been limited historically owing to the absence of an on-site islet processing facility. We present the results from 5 pancreatectomized patients whose islets were prepared 1,500 miles away. METHODS: Five patients (4 women, 1 man, average age 42 years) who failed medical therapy and were not candidates for longitudinal pancreaticojejunostomy underwent total/completion pancreatectomy (4 total, 1 completion) for intractable symptoms from idiopathic small duct chronic pancreatitis. The resected pancreata were preserved in ViaSpan solution and were transferred to an islet processing laboratory by commercial airliner and returned. The dispersed pancreatic islet tissue was infused into a portal vein tributary through an operatively placed catheter after systemic heparinization. RESULTS: All 5 patients experienced complete relief from pancreatic pain; 2 had significant residual discomfort from underlying Crohn's disease. Three of the 5 patients had minimal or no insulin requirement after autotransplantation (median follow-up of 23 months); 1 patient continued with glycemic control difficulties related to Crohn's disease. One patient died 17 months following autotransplantation from an unrelated pneumonia. CONCLUSION: Total pancreatectomy with autologous islet transplantation can offer patients with idiopathic small duct chronic pancreatitis pain relief without the sequelae of diabetes mellitus and can be performed without an on-site islet processing facility. All patients undergoing total/ completion pancreatectomy should be considered candidates for this procedure.

A practical guide to the management of hypertension in renal transplant recipients.

Hypertension as well as hypotension can be harmful to a newly transplanted renal allograft. Elevated blood pressure is also a major risk factor for cardiovascular death, which is a frequent occurrence despite successful renal transplantation. Renal artery stenosis, immunosuppressive drugs, chronic rejection, retained native kidneys, and excessive extracellular fluid volume may all contribute to post-transplant hypertension. Antihypertensive agents are widely used in the management of post-transplant hypertension. Careful clinical judgement and knowledge of the pharmacology, pharmacodynamics, pharmacokinetics, adverse drug reaction profiles, potential contraindications, and drug-drug interactions of antihypertensive agents are important when therapy with antihypertensive drugs is initiated in renal transplant recipients. Since blood pressure elevation in any individual is determined by a large number of hormonal and neuronal systems, the effect of antihypertensive agents on the allograft should be considered a critical factor in the management of hypertension in renal transplant recipients. Most renal transplant recipients have other risk factors for premature cardiovascular death such as diabetes mellitus, hypercholesterolemia, insulin resistance, obesity, left ventricular hypertrophy and ischaemic heart disease. Initial antihypertensive therapy should be tailored individually according to the patient's risk factors. A realistic therapeutic goal for blood pressure management in the initial post-operative state is a systolic blood pressure <160 mm Hg and a diastolic blood pressure <90 mm Hg with lower pressure targets becoming applicable late post-transplantation.

Interaction between tacrolimus and nefazodone in a stable renal transplant recipient.

Tacrolimus (FK-506) is an important immunosuppressive agent most often given for maintenance immunosuppression to prevent acute cellular organ rejection. A 57-year-old woman with end-stage renal disease presumed secondary to chronic glomerulonephritis underwent a living related renal allograft transplantation. She tolerated the surgery well and was discharged on postoperative day 5. She was stabilized with prednisone, azathioprine, and tacrolimus. Two years after transplantation, nefazodone 50 mg twice/day orally was prescribed due to depression. After 1 week of nefazodone therapy the patient experienced headache, confusion, and "gray areas" in her vision, without abnormal ophthalmologic findings. Her serum creatinine was elevated to 2.2 mg/dl (baseline 1.5 mg/dl), and trough tacrolimus level was markedly elevated (> 30 ng/ml). Both tacrolimus and nefazodone are metabolized by the cytochrome P450 (CYP) 3A4 system. We suspect that nefazodone inhibits metabolism of tacrolimus. Coadministration of antidepressant agents such as nefazodone, or any other drug that inhibits the CYP3A4 isoenzyme subfamily, should be anticipated to interfere with tacrolimus metabolism. Monitoring blood concentrations of tacrolimus is vital, and appropriate dosage adjustments are required when the two drugs are administered concurrently to avoid serious interactions such as nephrotoxicity and neurotoxicity.

Efficacy and safety of low molecular weight heparin in renal transplantation.

BACKGROUND: Deep venous thrombosis (DVT) is a common problem with potentially devastating results in patients undergoing major surgical procedures. Certain renal transplant recipients are particularly at risk for allograft loss as a consequence of renal vein and artery thrombosis. Over the past few years, low molecular weight heparin has been well established as an accepted modality of treatment and prophylaxis of DVT. The efficacy and safety of low molecular weight heparin in the prophylaxis of DVT following renal transplantation in adults has not previously been reported. METHODS: Dalteparin was administered to 120 adult renal transplant recipients postoperatively at the Oregon Health Sciences University. RESULTS: No patient developed allograft arterial or venous thrombosis. One patient developed subclavian vein thrombosis. No bleeding complications were encountered, and side effects were very minimal. CONCLUSION: Prophylaxis with dalteparin is an effective and safe modality for the prevention of thrombosis in adult patients undergoing renal transplantation.