Daniel Abramowicz

Urothelial carcinoma associated with the use of a Chinese herb (Aristolochia Fangchi)

BACKGROUND Chinese-herb nephropathy is a progressive form of renal fibrosis that develops in some patients who take weight-reducing pills containing Chinese herbs. Because of a manufacturing error, one of the herbs in these pills (Stephania tetrandra) was inadvertently replaced by Aristolochia fangchi, which is nephrotoxic and carcinogenic. METHODS The diagnosis of a neoplastic lesion in the native urinary tract of a renal-transplant recipient who had Chinese-herb nephropathy prompted us to propose regular cystoscopic examinations and the prophylactic removal of the native kidneys and ureters in all our patients with end-stage Chinese-herb nephropathy who were being treated with either transplantation or dialysis. Surgical specimens were examined histologically and analyzed for the presence of DNA adducts formed by aristolochic acid. All prescriptions written for Chinese-herb weight-reducing compounds during the period of exposure (1990 to 1992) in these patients were obtained, and the cumulative doses were calculated. RESULTS Among 39 patients who agreed to undergo prophylactic surgery, there were 18 cases of urothelial carcinoma (prevalence, 46 percent; 95 percent confidence interval, 29 to 62 percent): 17 cases of carcinoma of the ureter, renal pelvis, or both and 1 papillary bladder tumor. Nineteen of the remaining patients had mild-to-moderate urothelial dysplasia, and two had normal urothelium. All tissue samples analyzed contained aristolochic acid-related DNA adducts. The cumulative dose of aristolochia was a significant risk factor for urothelial carcinoma, with total doses of more than 200 g associated with a higher risk of urothelial carcinoma. CONCLUSIONS The prevalence of urothelial carcinoma among patients with end-stage Chinese-herb nephropathy (caused by aristolochia species) is a high.

Randomized Trial of Plasma Exchange or High-Dosage Methylprednisolone as Adjunctive Therapy for Severe Renal Vasculitis

Systemic vasculitis associated with autoantibodies to neutrophil cytoplasmic antigens (ANCA) is the most frequent cause of rapidly progressive glomerulonephritis. Renal failure at presentation carries an increased risk for ESRD and death despite immunosuppressive therapy. This study investigated whether the addition of plasma exchange was more effective than intravenous methylprednisolone in the achievement of renal recovery in those who presented with a serum creatinine >500 micromol/L (5.8 mg/dl). A total of 137 patients with a new diagnosis of ANCA-associated systemic vasculitis confirmed by renal biopsy and serum creatinine >500 micromol/L (5.8 mg/dl) were randomly assigned to receive seven plasma exchanges (n = 70) or 3000 mg of intravenous methylprednisolone (n = 67). Both groups received oral cyclophosphamide and oral prednisolone. The primary end point was dialysis independence at 3 mo. Secondary end points included renal and patient survival at 1 yr and severe adverse event rates. At 3 mo, 33 (49%) of 67 after intravenous methylprednisolone compared with 48 (69%) or 70 after plasma exchange were alive and independent of dialysis (95% confidence interval for the difference 18 to 35%; P = 0.02). As compared with intravenous methylprednisolone, plasma exchange was associated with a reduction in risk for progression to ESRD of 24% (95% confidence interval 6.1 to 41%), from 43 to 19%, at 12 mo. Patient survival and severe adverse event rates at 1 yr were 51 (76%) of 67 and 32 of 67 (48%) in the intravenous methylprednisolone group and 51 (73%) of 70 and 35 of (50%) 70 in the plasma exchange group, respectively. Plasma exchange increased the rate of renal recovery in ANCA-associated systemic vasculitis that presented with renal failure when compared with intravenous methylprednisolone. Patient survival and severe adverse event rates were similar in both groups.

Sirolimus in association with mycophenolate mofetil induction for the prevention of acute graft rejection in renal allograft recipients

INTRODUCTION A previous trial in renal transplantation comparing sirolimus (rapamycin) to cyclosporine (CsA) in a triple-drug therapy regimen with azathioprine and corticosteroids found that the incidence of acute rejection was similar (approximately 40%) with a trend for better renal function with sirolimus. METHODS In 14 European centers, first cadaveric renal allograft recipients were randomized to receive sirolimus (n = 40) or CsA (n = 38) in an open-label design. All patients received corticosteroids and mycophenolate mofetil 2 g/day. Sirolimus and CsA were concentration controlled; trough levels of mycophenolic acid and prednisolone were also measured. RESULTS At 12 months, graft survival (92.5% sirolimus vs. 89.5% CsA), patient survival (97.5% sirolimus vs. 94.7% CsA), and the incidence of biopsy-proven acute rejection (27.5% sirolimus vs. 18.4% CsA) were not statistically different. The use of antibodies to treat suspected rejection episodes was also similar (7.5% sirolimus vs. 5.3% CsA). More sirolimus patients received bolus steroid therapy (20 vs. 11, P = 0.068). From month 2 onward, the calculated glomerular filtration rate was consistently higher in sirolimus-treated patients. The adverse events reported more frequently with sirolimus were thrombocytopenia (45% vs. 8%) and diarrhea (38% vs. 11%). In the CsA group, increased creatinine (18% vs. 39%), hyperuricemia (3% vs. 18%), cytomegalovirus infection (5% vs. 21%), and tremor (5% vs. 21%) were observed significantly more often. DISCUSSION Patient and graft survival and the incidence of biopsy-proven acute rejection at 12 months were comparable between sirolimus and CsA, whereas safety profiles were different. These data suggest that sirolimus may be used as primary therapy for the prevention of acute rejection.

Release of tumor necrosis factor, interleukin-2, and gamma-interferon in serum after injection of OKT3 monoclonal antibody in kidney transplant recipients

High levels of tumor necrosis factor-alpha, interleukin-2, and gamma-interferon appeared in the circulation of kidney transplant recipients after the first injection of the monoclonal antibody OKT3. This initial injection was systematically followed by fever. The three cytokines were released in all patients (n = 9), with peak serum levels of tumor necrosis factor occurring 1 hr after OKT3 injection and those of interleukin-2 and gamma-interferon after 2 hr. Cytokines were not released after the second and third OKT3 injections, when CD3+ cells had disappeared from blood. These findings suggest that circulating cytokines are released by T cells after activation by OKT3. These cytokines are probably involved in the systematic reactions observed after injection of OKT3.

The Efficacy and Safety of 200 Days Valganciclovir Cytomegalovirus Prophylaxis in High-Risk Kidney Transplant Recipients

Late‐onset cytomegalovirus (CMV) disease is a significant problem with a standard 3‐month prophylaxis regimen. This multicentre, double‐blind, randomized controlled trial compared the efficacy and safety of 200 days’ versus 100 days’ valganciclovir prophylaxis (900 mg once daily) in 326 high‐risk (D+/R–) kidney allograft recipients. Significantly fewer patients in the 200‐day group versus the 100‐day group developed confirmed CMV disease up to month 12 posttransplant (16.1% vs. 36.8%; p < 0.0001). Confirmed CMV viremia was also significantly lower in the 200‐day group (37.4% vs. 50.9%; p = 0.015 at month 12). There was no significant difference in the rate of biopsy‐proven acute rejection between the groups (11% vs. 17%, respectively, p = 0.114). Adverse events occurred at similar rates between the groups and the majority were rated mild‐to‐moderate in intensity and not related to study medication. In conclusion, this study demonstrates that extending valganciclovir prophylaxis (900 mg once daily) to 200 days significantly reduces the incidence of CMV disease and viremia through to 12 months compared with 100 days’ prophylaxis, without significant additional safety concerns associated with longer treatment. The number needed to treat to avoid one additional patient with CMV disease up to 12 months posttransplant is approximately 5.

Prevalence and management of anemia in renal transplant recipients: a European survey

The TRansplant European Survey on Anemia Management (TRESAM) documented the prevalence and management of anemia in kidney transplant recipients. Data from 72 transplant centers in 16 countries were screened, involving 4263 patients who had received transplants 6 months, 1, 3 or 5 years earlier. The mean age of transplant recipients was 45.5 years at transplantation. The most common etiology was chronic glomerulonephritis. The most common comorbidities were coronary artery disease, hepatitis B/C, and type 2 diabetes. The mean hemoglobin levels before transplantation were significantly higher in the more recently transplanted recipients. At enrollment, 38.6% of patients were found to be anemic. Of the 8.5% of patients who were considered severely anemic, only 17.8% were treated with epoetin. There was a strong association between hemoglobin and graft function; of the 904 patients with serum creatinine >  2 mg/dL, 60.1% were anemic, vs. 29.0% of those with serum creatinine ≤ 2 mg/dL (p  <  0.01). Therapy with angiotensin‐converting enzyme (ACE) inhibitors, angiotensin II receptor antagonists, mycophenolate mofetil (MMF) or azathioprine was also associated with a higher likelihood of anemia. The prevalence of anemia in the transplant recipients was remarkably high and appeared to be associated with impaired renal function and with ACE inhibitors and angiotensin II receptor antagonist use. Further studies should be carried out to interpret whether appropriate management of anemia after kidney transplantation may improve long‐term outcome.

Multiple pathways to allograft rejection.

Allograft rejection results from a complex process involving both the innate and acquired immune systems. The innate immune system predominates in the early phase of the allogeneic response, during which chemokines and cell adhesion play essential roles, not only for leukocyte migration into the graft but also for facilitating dendritic and T-cell trafficking between lymph nodes and the transplant. This results in a specific and acquired alloimmune response mediated by T cells. Subsequently, T cells and cells from innate immune system function synergistically to reject the allograft through nonexclusive pathways, including contact-dependent T cell cytotoxicity, granulocyte activation by either Th1 or Th2 derived cytokines, NK cell activation, alloantibody production, and complement activation. Blockade of individual pathways generally does not prevent allograft rejection, and long-term allograft survival is achieved only after simultaneous blockade of several of them. In this review, we explore each of these pathways and discuss the experimental evidence highlighting their roles in allograft rejection.

Cyclosporine Withdrawal from a Mycophenolate Mofetil–Containing Immunosuppressive Regimen: Results of a Five-Year, Prospective, Randomized Study

Maintenance immunosuppression with cyclosporine (CsA) is associated with nephrotoxicity, hyperlipidemia, and hypertension. This long-term study (core study + 4 yr of follow-up) investigated the long-term efficacy and safety of CsA withdrawal from a mycophenolate mofetil (MMF)-based regimen. Seventy-seven patients were maintained on CsA, MMF, and steroids (CsA-MMF group), and 74 were given a CsA-free regimen of MMF and steroids (MMF group). Serum creatinine and creatinine clearance were measured at 6-month intervals. Patient and graft survival, acute rejection episodes, malignancies, BP, and lipid profile were also recorded. At 5 yr, patient and graft survival was 93 and 88%, respectively, for the MMF group and 95 and 92%, respectively, for the CsA-MMF group. During follow-up, seven MMF patients experienced acute rejection episodes compared with one CsA-MMF patient (P = 0.0283). Nine grafts were lost to chronic rejection in the MMF group versus three in the CsA-MMF group. No demographic or immunologic characteristics were associated with acute or chronic rejection in the MMF group, but the doses of both MMF and steroids decreased significantly between 1 and 5 yr. The MMF group showed a trend toward improved creatinine clearance (67.4 versus 61.7 ml/min; P = 0.0500). Withdrawal of CsA from an MMF-containing immunosuppressive regimen resulted in an increased risk for acute rejection episodes and graft loss as a result of rejection throughout the 5-yr study period. The creatinine clearance-confirmed improvement in renal function observed at year 1 was maintained at 5 yr BP and cholesterol levels were well controlled in both groups.

Twelve-month evaluation of the clinical pharmacokinetics of total and free mycophenolic acid and its glucuronide metabolites in renal allograft recipients on low dose tacrolimus in combination with mycophenolate mofetil

Background: The establishment of a rationale for therapeutic drug monitoring for mycophenolic acid (MPA) and outlining a therapeutic window remains a challenging task in renal transplantation. Furthermore, the pharmacokinetic characteristics of free and total MPA and its glucuronides depend directly or indirectly on graft function and the type of co‐administered calcineurin‐inhibitor. Methods: The authors conducted a prospective 12‐month multicenter pharmacokinetic study on MPA (MPA, free MPA, free fraction MPA) and its metabolites (MPAG, Acyl‐MPAG). The aim of this study was to examine the long‐term pharmacokinetic characteristics of MMF when combined with tacrolimus in renal allograft recipients and to identify a possible relationship between these pharmacokinetic parameters and clinical outcome parameters. Results: They have demonstrated that in renal transplant recipients MPA, free MPA, Acyl‐MPAG and MPAG have a particular pharmacokinetic profile when combined with tacrolimus which differs from the combination with CsA. They could not establish a relationship between pre‐dose trough concentration of MPA and its metabolites and clinical efficacy endpoints and drug‐related adverse events, except for anemia. Conclusions: These findings suggest that trough plasma concentration monitoring of MPA and its metabolites might not provide a useful clinical tool for guiding MMF dose adjustments to avoid drug‐related toxicity. More extensive pharmacokinetic measurements like area under the concentration curves might be necessary for routine therapeutic drug monitoring of MMF.

Daclizumab versus Antithymocyte Globulin in High-Immunological-Risk Renal Transplant Recipients

Nondepleting anti-CD25 monoclonal antibodies (daclizumab) and depleting polyclonal antithymocyte globulin (Thymoglobulin) both prevent acute rejection, but these therapies have not been directly compared in a high-risk, HLA-sensitized renal transplant population. We randomly assigned 227 patients, who were about to receive a kidney graft from a deceased donor, to either Thymoglobulin or daclizumab if they met one of the following risk factors: current panel reactive antibodies (PRA) >30%; peak PRA >50%; loss of a first kidney graft from rejection within 2 yr of transplantation; or two or three previous grafts. Maintenance immunosuppression comprised tacrolimus, mycophenolate mofetil, and steroids. Compared with the daclizumab group, patients treated with Thymoglobulin had a lower incidence of both biopsy-proven acute rejection (15.0% versus 27.2%; P = 0.016) and steroid-resistant rejection (2.7% versus 14.9%; P = 0.002) at one year. One-year graft and patient survival rates were similar between the two groups. In a comparison of rejectors and nonrejectors, overall graft survival was significantly higher in the rejection-free group (87.2% versus 75.0%; P = 0.037). In conclusion, among high-immunological-risk renal transplant recipients, Thymoglobulin is superior to daclizumab for the prevention of biopsy-proven acute rejection, but there is no significant benefit to one-year graft or patient survival.