Contrasting effect of new HCMV pUL54 mutations on antiviral drug susceptibility: Benefits and limits of 3D analysis.

Human cytomegalovirus (HCMV) resistance to antiviral drugs is a major drawback of repeated or long-duration treatment in immunocompromised patients. Resistance testing is usually performed by genotypic assays. For accurate interpretation of these assays, the role of new mutations in HCMV resistance has to be assessed. Two previously unknown UL54 single point mutations (D515Y and V787A) were characterized for phenotypic drug-resistance by marker transfer analysis using bacterial artificial chromosome (BAC) mutagenesis. Increases in 50% inhibitory concentrations of ganciclovir and foscarnet were found for both mutated recombinant strains showing that mutations D515Y and V787A induce resistance to both antivirals. Importantly, none of those impacted the viral growth kinetics. For a better understanding of their molecular resistance mechanisms, a 3D homology model was used to localize the mutated amino-acids in functional domains of UL54 and predict their impact on UL54 function and resistance. However, 3D homology model analysis has limits and phenotypic characterization using BAC-HCMV is still essential to measure the role of unknown mutations.

[Clinical efficacy of eculizumab as treatment of gemcitabine-induced thrombotic microangiopathy: A case report]. / Efficacité de l'éculizumab comme traitement de la microangiopathie thrombotique induite par la gemcitabine : à propos d'un cas.

INTRODUCTION: Gemcitabine-induced thrombotic microangiopathy is a rare event whose management is not yet consensual. The use of eculizumab could be of interest. CASE REPORT: A 68-year-old woman was treated by gemcitabine as adjuvant chemotherapy of a pancreatic adenocarcinoma. Two months later, the patient presented with mechanical hemolytic anemia, thrombocytopenia and high blood pressure that led to the diagnosis of thrombotic microangiopathy. Gemcitabine was stopped. Plasma exchange therapy was introduced since hematological and renal parameters had worsened. As clinical efficacy was insufficient, eculizumab was introduced at a dose of 900 mg per week 4 times, then 1200 mg every 2 weeks. Symptoms along with hematological and nephrological analysis were back to physiological standards after 7 intravenous injections. CONCLUSION: Eculizumab seems to be an effective treatment against gemcitabine-induced thrombotic microangiopathy in case of severe hematological and renal injuries associated with a lack of response to plasma exchange therapy.

Impact of pretransplant human leukocyte antigen-C and -DP antibodies on kidney graft outcome.

The aim of our study was to determine whether the presence of specific human leukocyte antigen (HLA)-C and -DP antibodies before transplantation influenced graft outcomes in immunized recipients. Two groups of pretransplant immunized recipients were studied: patients with only classical HLA-A, -B, -DR, -DQ antibodies (n = 176) and those with classical plus HLA-C and/or -DP antibodies (n = 27). Acute antibody-mediated rejection was preferentially associated with the presence of pretransplant anti-HLA-C and -DP antibodies (5/6 cases). In four cases, acute rejection episodes were followed by graft loss within 15 months after transplantation. There was a significant increase in the number of acute rejection episodes especially antibody-mediated acute rejections (P = .036) and in the number of graft losses for immunologic reasons (P < .001) among the group with pretransplant anti-C and -DP antibodies. Pretransplant anti-DP antibodies seemed to be involved more frequently in poor graft outcomes as shown in several recent published cases. We need to investigate their specific role among a larger cohort, taking into account an epitope analysis.

Renal transplantation in patients with AA amyloidosis nephropathy: results from a French multicenter study.

Although end-stage renal disease related to AA amyloidosis nephropathy is well characterized, there are limited data concerning patient and graft outcome after renal transplantation. We performed a multicentric retrospective survey to assess the graft and patient survival in 59 renal recipients with AA amyloidosis. The recurrence rate of AA amyloidosis nephropathy was estimated at 14%. The overall, 5- and 10-year patient survival was significantly lower for the AA amyloidosis patients than for a control group of 177 renal transplant recipients (p = 0.0001, 0.028 and 0.013, respectively). In contrast, we did not observe any statistical differences in the 5- and 10- year graft survival censored for death between two groups. AA amyloidosis-transplanted patients exhibited a high proportion of infectious complications after transplantation (73.2%). Causes of death included both acute cardiovascular events and fatal septic complications. Multivariate analysis demonstrated that the recurrence of AA amyloidosis on the graft (adjusted OR = 14.4, p = 0.01) and older recipient age (adjusted OR for a 1-year increase = 1.06, p = 0.03) were significantly associated with risk of death. Finally, patients with AA amyloidosis nephropathy are eligible for renal transplantation but require careful management of both cardiovascular and infectious complications to reduce the high risk of mortality.

Long-Term Impact of Cyclosporin Reduction with MMF Treatment in Chronic Allograft Dysfunction: REFERENECE Study 3-Year Follow Up.

Calcineurin inhibitor (CNI) toxicity contributes to chronic allograft nephropathy (CAN). In the 2-year, randomized, study, we showed that 50% cyclosporin (CsA) reduction in combination with mycophenolate mofetil (MMF) treatment improves kidney function without increasing the risk for graft rejection/loss. To investigate the long-term effect of this regimen, we conducted a follow up study in 70 kidney transplant patients until 5 years after REFERENCE initiation. The improvement of kidney function was confirmed in the MMF group but not in the control group (CsA group). Four graft losses occurred, 2 in each group (graft survival in the MMF group 95.8% and 90.9% in control group). One death occurred in the control group. There was no statistically significant difference in the occurrence of serious adverse events or acute graft rejections. A limitation is the weak proportion of patient still remaining within the control group. On the other hand, REFERENCE focuses on the CsA regimen while opinions about the tacrolimus ones are still debated. In conclusion, CsA reduction in the presence of MMF treatment seems to maintain kidney function and is well tolerated in the long term.

The Impact of type 2 diabetes on mortality in end-stage renal disease patients differs between genders.

BACKGROUND/AIMS: In diabetics with end-stage renal disease (ESRD), risk of death has been reported to be non-constant after the first dialysis, and different outcomes have been observed between genders. We assessed the impact of type 2 diabetes (T2DM) on mortality in dialysis regarding its differential effect by gender using time-dependent analyses. METHODS: All T2DM and non-diabetic (no-DM) patients who started dialysis in two renal units in Lyon, France, between January 1, 1995, and December 31, 2007, were included. In multivariate analyses, the Cox model and Shoenfeld residual approach were used to assess the effect of T2DM on dialysis mortality by gender. RESULTS: We included 235 T2DM (males: 57.9%) and 480 no-DM (males: 65.6%) patients. In males, the adjusted hazard ratio (aHR) for death in T2DM versus no-DM was 0.83 (p = 0.20) and was constant over time after the first renal replacement therapy (RRT) (p = 0.88). In females, aHR for death in T2DM versus no-DM patients was not constant over time (p = 0.002). It was 0.64 (p = 0.13) within the first year after the first RRT and 2.10 (p = 0.002) after the first year. Evolutions with time of these aHR by gender were significantly different (p = 0.009). CONCLUSIONS: T2DM was associated with death only in females. This association was not constant over time after the first dialysis.

A Simple Modeling-free Method Provides Accurate Estimates of Sensitivity and Specificity of Longitudinal Disease Biomarkers.

OBJECTIVE: To assess the time-dependent accuracy of a continuous longitudinal biomarker used as a test for early diagnosis or prognosis. METHODS: A method for accuracy assessment is proposed taking into account the marker measurement time and the delay between marker measurement and outcome. It dealt with markers having interval-censored measurements and a detection threshold. The threshold crossing times were assessed by a Bayesian method. A numerical study was conducted to test the procedures that were later applied to PCR measurements for prediction of cytomegalovirus disease after renal transplantation. RESULTS: The Bayesian method corrected the bias induced by interval-censored measurements on sensitivity estimates, with corrections from 0.07 to 0.3. In the application to cytomegalovirus disease, the Bayesian method estimated the area under the ROC curve to be over 75% during the first 20 days after graft and within five days between marker measurement and disease onset. However, the accuracy decreased quickly as that delay increased and late after graft. CONCLUSIONS: The proposed Bayesian method is easy to implement for assessing the time-dependent accuracy of a longitudinal biomarker and gives unbiased results under some conditions.

High pretransplantation soluble CD30 levels: impact in renal transplantation.

In a retrospective study, the impact of the level of pretransplantation soluble CD30 molecule (sCD30) was evaluated on 3 year transplant survival, as well as the number and grade of acute rejection episodes among kidney recipients engrafted between 2000 and 2002. One hundred and ninety sera of 190 patients sampled on the cross-match day were tested for sCD30 concentrations using an enzyme-linked immunosorbent assay (ELISA) kit (Biotest). For the analysis, a sCD30 cutoff level of 100 U/mL was chosen: 87 (46%) recipients had a level >100, and 103 (54%) <100. All cases (5) of immunological graft loss showed a high sCD30 level. The rate of biopsy-proven acute rejection was 26% in the sCD30 >100 group versus 22% in the sCD30 <100 groups. Among the first graft population (n = 157), the rate was 27% for sCD30 >100 versus 20% for the lower level. The difference was more important for grade II acute rejection (Banff criteria): 6/87 (7%) showed high sCD30 versus 2/103 (2%) with sCD30 <100. This analysis became significant for anti-HLA immunization: 11 (13%) recipients developed anti-HLA class II antibodies in the first group (sCD30 >100) versus 1 (1%) in the second group (sCD30 <100; P < .01). A high pretransplantation sCD30 was not a significant risk factor for an acute rejection episode, but it seemed to be more predictive for antibody-mediated acute rejection and immunological graft loss. However, many recipients showed an increased pretransplantation concentration without any rejection episode or graft loss. Consequently, sCD30 pregraft measurements cannot be used as a predictor for acute kidney rejection among our transplant center, nor as an aid to adapt the immunosuppressive regimen.

Tolerability of enteric-coated mycophenolate sodium to 1 year in combination with cyclosporine and corticosteroids in renal transplant recipients.

Enteric-coated mycophenolate sodium (EC-MPS) is therapeutically equivalent to mycophenolate mofetil, but delays release of mycophenolic acid until it reaches the small intestine. De novo renal transplant patients taking part in a 12-month, multicenter, randomized study received cyclosporine microemulsion (CsA-ME, early or delayed to day 6), EC-MPS, steroids, and interleukin-2 antagonist induction. Tolerability data relating to EC-MPS are reported. Ninety-seven patients were randomized to early CsA-ME and 100 patients to delayed CsA-ME. Median daily dose of EC-MPS was 1440 mg at all time points throughout the 12-month period. The most frequently reported adverse events were constipation, anemia, urinary tract infection, abdominal pain, leukopenia, and cytomegalovirus infection; there were four malignancies. Fifty patients (24.6%) discontinued EC-MPS prematurely by 12 months, including 42 patients (84%) who discontinued owing to adverse events. No patient discontinued treatment because of gastrointestinal adverse events. Two-thirds of patients (137 [67.5%]) maintained full EC-MPS dose throughout the 12-month study and did not require any dose reduction or dose interruption. EC-MPS is well tolerated in de novo renal transplant recipients when administered in combination with CsA-ME and steroids, with low rates of dose reductions or interruptions. Gastrointestinal adverse events were responsible for dose reduction or interruption in only 5% of patients.

Impact of cyclosporine reduction with MMF: a randomized trial in chronic allograft dysfunction. The 'reference' study.

Long-term use of calcineurine inhibitors (CNIs) may contribute to the development of chronic allograft dysfunction (CAD). We investigate the impact of the introduction of MMF combined with cyclosporine (CsA) 50% dose reduction. An open, randomized, controlled, multicenter, prospective study was conducted in 103 patients, receiving a CsA-based therapy with a serum creatinine between 1.7-3.4 mg/dL, more than 1 year after transplantation. They were randomized to receive MMF with half dose of CsA (MMF group) or to continue their maintenance CsA dose (control group). A total of 96 weeks after randomization, the evolution of renal function assessed by regression line analysis of 1/SeCr improved in the MMF group (positive slope) vs. the control group (negative slope), 4.2 x 10(-4) vs. -3.0 x 10(-4), respectively (p < 0.001). Concurrently, the absolute renal function improved significantly in the MMF group. No episode of biopsy-proven acute rejection occurred. One patient in each group lost his graft because of biopsy-proven chronic allograft nephropathy. There was a significant decrease of triglycerides level in the MMF group. Anemia and diarrhea were statistically more frequent in the MMF group. In CAD, the reduction of CsA in the presence of MMF results in significant improvement in renal function during a 2-year follow-up.

Sirolimus conversion for patients with posttransplant Kaposi's sarcoma.

This retrospective study aimed to evaluate the benefit of switching from calcineurin inhibitors (CnI) to sirolimus in posttransplant Kaposi's sarcoma (KS). Fourteen patients monitored in five French departments who had developed posttransplant KS were switched from CnI to sirolimus either abruptly (n=9) or progressively (n=5) with trough levels 5-12 ng/mL. Two patients had a complete remission, eight a partial response, and five no significant improvement of KS. The mean time to response was 3.9 months. After a mean follow-up of 16 months, 3 partial responders, with previous severe and refractory KS, suffered again from KS progression despite the lack of concomitant infectious or neoplastic event. These relapses occurred 5-9 months after switching. The tolerance of sirolimus has been excellent except for in one patient who developed severe interstitial pneumonitis. Sirolimus is usually useful in the management of posttransplant KS. It may be, however, ineffective or transiently effective in some patients with severe KS. Prospective studies with pharmacodynamic evaluation are important in order to better assess the duration of responses and the mechanisms of primary and acquired drug resistance.

[Kaposi's sarcoma and organ transplantation: 22 cases]. / Maladie de Kaposi et transplantation d'organes: 22 cas.

BACKGROUND: The discovery of the Human Herpes virus 8 (HHV8) improved our knowledge of the pathogenesis of Kaposi's sarcoma. After organ transplantation, Kaposi's sarcoma exhibits distinctive features compared with other forms of the disease. PATIENTS AND METHODS: We report 22 cases of post-transplant Kaposi's sarcoma (12 kidneys, 2 kidney-pancreas, 6 livers and 2 hearts). The aim of this retrospective study was to analyze clinical and virological characteristics in these transplant patients and to specify the frequency of HHV8 seroconversions in this population. RESULTS: Twenty-one patients showed cutaneous lesions and 9 had visceral involvement. HHV8 serology was positive in 16/20 patients at transplantation and in 21/22 cases at the time of Kaposi's sarcoma diagnosis. Most cases corresponded to viral reactivations whereas seroconversions occurred in 2 cases and may have been linked to viral transmission by the graft. Treatment led to recovery in 68p. 100 of the cases. Two heart-transplant patients died from their disease. We included in our series two cases of re-transplanted patients without recurrence of Kaposi's sarcoma and one case of familial Kaposi's sarcoma. DISCUSSION: Seroconversions after transplantation emphasize the interest of systematic screening of HHV8 serology in transplant recipients and their donors.

Chronic renal failure and end-stage renal disease are associated with a high rate of mortality after heart transplantation.

The aim of the study was to analyze the etiology, the factors for progression of chronic renal failure to end-stage-renal disease (ESRD), and the influence of ESRD on the survival rate among a cohort of 59 heart transplant patients (HTP) referred for the management of chronic renal failure (CRF). At the time of the first nephrology consultation (6 +/- 4.25 years after cardiac transplantation) the mean creatininemia was 261.5 +/- 99 micromol/L and mean creatinine clearance (Cockcroft formula) was 32 +/- 15 mL/min. The cause of CRF were calcineurin inhibitor toxicity in 38.9% of patients, vascular events in 15.2%, hemolytic uremic syndrome in 5%, membranous glomerulopathy in 3.3%, diabetes in two patients, focal/segmental glomerulosclerosis in 3.3%, renal hypoplasia in 1.7%, and unknown in 27%. Evolution to ESRD occurred in 38.9% of patients: 17 patients started hemodialysis, three peritoneal dialysis, and two received a preemptive kidney transplantation. Creatininemia (micromol/L) at the time of nephrology referral was 229.2 +/- 72.6 versus 315.8 +/- 113.4 (P < .001) and creatinine clearance (mL/min) was 34.9 +/- 15.1 versus 27.3 +/- 13.7 (P = .049) for patients with CRF versus ESRD, respectively. Both proteinuria (g/24 hours) of 1 +/- 2.2 versus 2.3 +/- 1.8 (P = .02) and tobacco use in 35.1% versus 54.4% (P = .045) were significantly associated with progression of CRF, while age at the time of heart transplantation, cause of cardiac failure and renal failure, high blood pressure, type 2 diabetes, dyslipidemia, alcoholism, cirrhosis, and cerebral vascular accident were not. Death occurred in 18 HTP: 50% of patients with ESRD and 18.5% of patients with CRF-a 2.6 relative risk of of death in HTP patients with ESRD compared with HTP with CRF only (P < .01).

[Improving the interlaboratory variation for creatinine serum assay]. / Dosage de la créatininémie en 20003: état des lieux analytique et essai de standardisation de l'étalonnage.

PURPOSE: To assess inter-assay variation and accuracy of blood creatinine measurements as well as the effect of the standardization of the calibration procedures on inter-assay variation. METHODS: Inter-assay variation and accuracy were assessed using 30 frozen human sera and 3 certified reference materials, which were analysed by 17 creatinine assays (colorimetric: 12, enzymatic: 4, HPLC: 1). Usual calibration procedure was compared with two common calibration procedures using either a reference material (404.1 micromol/L), or secondary sera calibrators (69, 115 et 180 micromol/L). RESULTS: Most of the commercially available methods display inaccuracy, > 10% for creatininemia < 150 micromol/L in most cases. For this concentration range, the mean creatininemia was statistically significantly different as a function of the assay used (p < 0.001). Enzymatic assays produced lower results than colorimetric ones for low creatinine levels but higher results for high creatinine levels. Assays being calibrated according to the manufacturer's recommendations, the median dispersion factor was 14% for the 20 samples between 45 and 150 micromol/L, and 8% for the 10 samples between 250 and 350 micromol/L. The calibration procedure modified inter-assay variation significantly (p < 0.001) but we gained little advantage from both common calibration procedures. A significant decrease of inter-assay variation occurred within each technical group (colorimetric or enzymatic) when a common calibration was performed using calibrators which concentration(s) was(were) close to the concentrations to be measured. CONCLUSIONS: Inter-assay variation is too high to allow prediction of glomerular filtration rate (GFR) or creatinine clearance from serum creatinine level. Our results highlight the interest of a calibration procedure using several concentrations with at least one between 90 and 150 micromol/L. The marketing of such a calibrator should be considered in order to decrease inter-assay variation in the range of creatinine levels which defines a mild chronic renal failure. Such an approach will certainly reduce inter-assay variation only within each technical group but could allow to include technical group as a co-variable in the algorithms developed for predicting GFR or creatinine clearance. A global transferability will certainly need the correlation of all types of creatinine assays versus a definitive method, whom definition remains uncertain.

Induction versus noninduction in renal transplant recipients with tacrolimus-based immunosuppression.

BACKGROUND: The aim of this study was to compare the efficacy and safety of induction treatment with antithymocyte globulins (ATG) followed by tacrolimus therapy with immediate tacrolimus therapy in renal transplant recipients. METHODS: This 12-month, open, prospective study was conducted in 15 centers in France and 1 center in Belgium; 309 patients were randomized to receive either induction therapy with ATG (n=151) followed by initiation of tacrolimus on day 9 or immediate tacrolimus-based triple therapy (n=158). In both study arms, the initial daily tacrolimus dose was 0.2 mg/kg. Steroid boluses were given in the first 2 days and tapered thereafter from 20 mg/day to 5 mg/day. Azathioprine was administered at 1-2 mg/kg per day. RESULTS: At month 12, biopsy-confirmed acute rejections were reported for 15.2% (induction) and 30.4% (noninduction) of patients (P=0.001). The incidence of steroid-sensitive acute rejections was 7.9% (induction) and 22.2% (noninduction)(P=0.001). Steroid-resistant acute rejections were reported for 8.6% (induction) and 8.9% (noninduction) of patients. A total of nine patients died. Patient survival and graft survival at month 12 was similar in both treatment groups (97.4% vs. 96.8% and 92.1% vs. 91.1%, respectively). Statistically significant differences in the incidence of adverse events were found for cytomegalovirus (CMV) infection (induction, 32.5% vs. noninduction, 19.0%, P=0.009), leukopenia (37.3% vs. 9.5%, P<0.001), fever (25.2% vs. 10.1%, P=0.001), herpes simplex (17.9% vs. 5.7%, P=0.001), and thrombocytopenia (11.3% vs. 3.2%, P=0.007). In the induction group, serum sickness was observed in 10.6% of patients. The incidence of new onset diabetes mellitus was 3.4% (induction) and 4.5% (noninduction). CONCLUSION: Low incidences of acute rejection were found in both treatment arms. Induction treatment with ATG has the advantage of a lower incidence of acute rejection, but it significantly increases adverse events, particularly CMV infection.

[Epidemiology and etiology chronic renal insufficiency]. / Epidémiologie et étiologie de l'insuffisance rénale chronique.

End-stage renal failure (ESRF) is a medical and a public health problem in France and in developed countries due to the increased incidence (100 per million of persons (pmp) in France, in 1998 /year) and prevalence rates (600 pmp in 1998; +8%/year) and due to the high cost of the renal replacement therapy (RRT). This increase is mainly due to the increased incidence and prevalence of type 2 diabetic and vascular nephropathies that represent more than 50% of the ESRF causes. This progression is the consequence of an access to RRT for patients older than 60, of the population ageing, and of a better prevention and management of cardio-vascular complications in elderly ans diabetic patients. More than 30% of the patients are referred too late, leading to an increased morbi-mortality. Clear recommendations are required to make an early diagnosis of renal failure (plasma creatinine > or = 137 mumol/L in man and > or = 104 mumol/L in woman), mainly in the group of at risk patients and in order to improve the management of these patients before the end-stage renal disease.

[Which method of dialysis for the type 2 diabetic?]. / Quelle méthode de dialyse chez le diabétique de type 2?

Type 2 diabetes is becoming a major cause of chronic renal failure leading to health care problem. Literature data do not allow to choose between hemodialysis or peritoneal dialysis as the treatment of choice of end stage renal failure in type II diabetic patients according to their co-morbidities. A retrospective study was performed in 28 type II diabetic patients, either 11% of the total population, who started dialysis in our center between 1994 and 1997. Fourteen patients had chosen peritoneal dialysis and 14 hemodialysis. The 2 groups were not different for their initial neurological, cardiovascular, ophthalmological complications and for their metabolic control. After a mean follow-up of 14 months on dialysis a significant higher number of infections (9 versus 4), of hospitalisation days (34 +/- 19 versus 6.5 +/- 5.5), of technical transfers (6 versus 0) and of deaths (5 versus 0) were recorded in patients on peritoneal dialysis, without any difference in the metabolic control. A prospective, multicenter study is required to identify the best dialysis technique in type 2 diabetic patients, according to their co-morbidities and the dialysis dose.