Immunogenicity and Safety of the Adjuvanted Recombinant Zoster Vaccine in Chronically Immunosuppressed Adults Following Renal Transplant: A Phase 3, Randomized Clinical Trial.

BACKGROUND: The incidence of herpes zoster is up to 9 times higher in immunosuppressed solid organ transplant recipients than in the general population. We investigated the immunogenicity and safety of an adjuvanted recombinant zoster vaccine (RZV) in renal transplant (RT) recipients ≥18 years of age receiving daily immunosuppressive therapy. METHODS: In this phase 3, randomized (1:1), observer-blind, multicenter trial, RT recipients were enrolled and received 2 doses of RZV or placebo 1-2 months (M) apart 4-18M posttransplant. Anti-glycoprotein E (gE) antibody concentrations, gE-specific CD4 T-cell frequencies, and vaccine response rates were assessed at 1M post-dose 1, and 1M and 12M post-dose 2. Solicited and unsolicited adverse events (AEs) were recorded for 7 and 30 days after each dose, respectively. Solicited general symptoms and unsolicited AEs were also collected 7 days before first vaccination. Serious AEs (including biopsy-proven allograft rejections) and potential immune-mediated diseases (pIMDs) were recorded up to 12M post-dose 2. RESULTS: Two hundred sixty-four participants (RZV: 132; placebo: 132) were enrolled between March 2014 and April 2017. gE-specific humoral and cell-mediated immune responses were higher in RZV than placebo recipients across postvaccination time points and persisted above prevaccination baseline 12M post-dose 2. Local AEs were reported more frequently by RZV than placebo recipients. Overall occurrences of renal function changes, rejections, unsolicited AEs, serious AEs, and pIMDs were similar between groups. CONCLUSIONS: RZV was immunogenic in chronically immunosuppressed RT recipients. Immunogenicity persisted through 12M postvaccination. No safety concerns arose. CLINICAL TRIALS REGISTRATION: NCT02058589.

Prevalence and clinical impact of Streptococcus pneumoniae nasopharyngeal carriage in solid organ transplant recipients.

BACKGROUND: S. pneumoniae is the leading cause of community-acquired pneumonia in the solid organ transplant recipient (SOTR); nevertheless, the prevalence of colonization and of the colonizing/infecting serotypes has not been studied in this population. In this context, the aim of the present study was to describe the rate, characteristics, and clinical impact of S. pneumoniae nasopharyngeal carriage. METHODS: A prospective observational cohort of Solid Organ Transplant recipients (SOTR) was held at the University Hospital Virgen del Rocío, Seville, Spain with the aim to evaluate the S. pneumoniae colonization and the serotype prevalence in SOTR. Two different pharyngeal swabs samples from 500 patients were included in two different seasonal periods winter and spring/summer. Optochin and bile solubility tests were performed for the isolation of thew strains. Antimicrobial susceptibility studies (MICs, mg/l) of levofloxacin, trimethoprim-sulfamethoxazole, penicillin, amoxicillin, cefotaxime, ceftriaxone, erythromycin, azithromycin and vancomycin for each isolate were determined by E-test strips. Capsular typing was done by sequential multiplex PCR reactions. A multivariate logistic regression analysis of factors potentially associated with pneumococcal nasopharyngeal carriage and disease was performed. RESULTS: Twenty-six (5.6%) and fifteen (3.2%) patients were colonized in winter and spring/summer periods, respectively. Colonized SOT recipients compared to non-colonized patients were more frequently men (79.5% vs. 63.1%, P < 0.05) and cohabitated regularly with children (59% vs. 32.2%, P < 0.001). The most prevalent serotype in both studied periods was 35B. Forty-five percent of total isolates were included in the pneumococcal vaccine PPV23. Trimethoprim-sulfamethoxazole and macrolides were the less active antibiotics. Three patients had non-bacteremic pneumococcal pneumonia, and two of them died. CONCLUSIONS: Pneumococcal colonization in SOTR is low with the most colonizing serotypes not included in the pneumococcal vaccines.

Apolipoprotein A-Ib as a biomarker of focal segmental glomerulosclerosis recurrence after kidney transplantation: diagnostic performance and assessment of its prognostic value - a multi-centre cohort study.

Recurrence of idiopathic focal segmental glomerulosclerosis (FSGS) is a serious complication after kidney transplantation. FSGS relapse is suspected by a sudden increase in proteinuria but there is not an accurate noninvasive diagnostic tool to confirm this entity or to detect patients at risk. We aimed to validate the diagnostic performance of ApoA-Ib to detect FSGS relapses by measuring urinary ApoA-Ib in a retrospective cohort of 61 kidney transplanted patients (37 FSGS and 24 non-FSGS). In addition, to assess the ApoA-Ib predictive ability, ApoA-Ib was measured periodically in a prospective cohort of 13 idiopathic FSGS patients who were followed during 1 year after transplantation. ApoA-Ib had a sensitivity of 93.3% and a specificity of 90.9% to diagnose FSGS relapses, with a high negative predictive value (95.2%), confirming our previous results. In the prospective cohort, ApoA-Ib predated the recurrence in four of five episodes observed. In the nonrelapsing group (n = 9), ApoA-Ib was negative in 37 of 38 samples. ApoA-Ib has the potential to be a good diagnostic biomarker of FSGS relapses, providing a confident criterion to exclude false positives even in the presence of high proteinuria. It has also the potential to detect patients at risk of relapse, even before transplantation.

Kinetic of the CMV-specific T-cell immune response and CMV infection in CMV-seropositive kidney transplant recipients receiving rabbit anti-thymocyte globulin induction therapy: A pilot study.

BACKGROUND: Some studies have suggested that rATG treatment may be associated with an increased incidence of CMV infection and delayed CMV immune response. However, the evidences supporting this matter are scarce. This study aims to characterize the kinetic of the CMV-specific T-cell immune response before and after rATG induction therapy and the relationship with the development of CMV infection in CMV-seropositive kidney transplant recipients. METHODS: An observational prospective study of CMV-seropositive kidney transplant patients that received rATG induction therapy was performed. A pretransplant sample was obtained before the surgery to determine the CMV-specific immunity. CMV viral load (by PCR) and CMV-specific T-cell immune response (by flow cytometry) were determined during the follow-up at 0.5, 1, 2, 3, 6, and 12 months post transplantation. RESULTS: A total of 23 patients were included in the study. CMV prophylaxis was administrated for a media of 90 days after transplantation. At the end of follow-up, 18 (78.3%) patients had CMV-specific immunity with a median value of 0.31% CD8+ CD69+ INF-γ+ T cells at a median of 16 weeks post transplantation. Five patients never acquired CMV-specific immunity. No statistically significant association between CMV infection and CMV-specific T-cell immune response (P = .086) was observed. However, patients with positive pretransplant CMV-specific immunity developed earlier immunity and achieved higher levels of CD8+ CD69+ INF-γ+ T-cell post-transplantation than patients with negative pretransplant immunity. CONCLUSIONS: CMV-specific immune monitoring in addition to CMV-serology may be useful to stratify patient's risk of CMV infection before transplantation.

Outcome of Kidney Transplants from Viremic and Non-Viremic Hepatitis C Virus Positive Donors into Negative Recipients: Results of the Spanish Registry.

Historically, donor infection with hepatitis-C virus (HCV) has been a barrier to kidney transplantation. However, in recent years, it has been reported that HCV positive kidney donors transplanted into HCV negative recipients offer acceptable mid-term results. However, acceptance of HCV donors, especially viremic, has not broadened in the clinical practice. This is an observational, multicenter, retrospective study including kidney transplants from HCV positive donors into negative recipients reported to the Spanish group from 2013 to 2021. Recipients from viremic donors received peri-transplant treatment with direct antiviral agents (DAA) for 8-12 weeks. We included 75 recipients from 44 HCV non-viremic donors and 41 from 25 HCV viremic donors. Primary non function, delayed graft function, acute rejection rate, renal function at the end of follow up, and patient and graft survival were not different between groups. Viral replication was not detected in recipients from non-viremic donors. Recipient treatment with DAA started pre-transplant avoids (n = 21) or attenuates (n = 5) viral replication but leads to non-different outcomes to post-transplant treatment with DAA (n = 15). HCV seroconversion was more frequent in recipients from viremic donors (73% vs. 16%, p < 0.001). One recipient of a viremic donor died due to hepatocellular carcinoma at 38 months. Donor HCV viremia seems not to be a risk factor for kidney transplant recipients receiving peri-transplant DAA, but continuous surveillance should be advised.

Factors associated with the humoral response after three doses of COVID-19 vaccination in kidney transplant recipients.

Introduction: Kidney transplant recipients showed a weak humoral response to the mRNA COVID-19 vaccine despite receiving three cumulative doses of the vaccine. New approaches are still needed to raise protective immunity conferred by the vaccine administration within this group of high-risk patients. Methods: To analyze the humoral response and identify any predictive factors within these patients, we designed a prospective monocentric longitudinal study of Kidney transplant recipients (KTR) who received three doses of mRNA-1273 COVID-19 vaccine. Specific antibody levels were measured by chemiluminescence. Parameters related to clinical status such as kidney function, immunosuppressive therapy, inflammatory status and thymic function were analyzed as potential predictors of the humoral response. Results: Seventy-four KTR and sixteen healthy controls were included. One month after the administration of the third dose of the COVID-19 vaccine, 64.8% of KTR showed a positive humoral response. As predictive factors of seroconversion and specific antibody titer, we found that immunosuppressive therapy, worse kidney function, higher inflammatory status and age were related to a lower response in KTR while immune cell counts, thymosin-a1 plasma concentration and thymic output were related to a higher humoral response. Furthermore, baseline thymosin-a1 concentration was independently associated with the seroconversion after three vaccine doses. Discussion: In addition to the immunosuppression therapy, condition of kidney function and age before vaccination, specific immune factors could also be relevant in light of optimization of the COVID-19 vaccination protocol in KTR. Therefore, thymosin-a1, an immunomodulatory hormone, deserves further research as a potential adjuvant for the next vaccine boosters.

Update of the recommendations on the management of the SARS-CoV-2 coronavirus pandemic (COVID-19) in kidney transplant patients.

SARS-CoV-2 infection (COVID-19) has had a significant impact on transplant activity in our country. Mortality and the risk of complications associated with COVID-19 in kidney transplant recipients (KT) were expected to be higher due to their immunosuppressed condition and the frequent associated comorbidities. Since the beginning of the pandemic in March 2020 we have rapidly improved our knowledge about the epidemiology, clinical features and management of COVID-19 post-transplant, resulting in a better prognosis for our patients. KT units have been able to adapt their programs to this new reality, normalizing both donation and transplantation activity in our country. This manuscript presents a proposal to update the general recommendations for the prevention and treatment of infection in this highly vulnerable population such as KT.

Sodium-glucose cotransporter-2 inhibitor therapy in kidney transplant patients with type 2 or post-transplant diabetes: an observational multicentre study.

Background: Sodium-glucose cotransporter-2 inhibitors (SGLT2is) have cardioprotective and renoprotective effects. However, experience with SGLT2is in diabetic kidney transplant recipients (DKTRs) is limited. Methods: This observational multicentre study was designed to examine the efficacy and safety of SGLT2is in DKTRs. The primary outcome was adverse effects within 6 months of SGLT2i treatment. Results: Among 339 treated DKTRs, adverse effects were recorded in 26%, the most frequent (14%) being urinary tract infection (UTI). In 10%, SGLT2is were suspended mostly because of UTI. Risk factors for developing a UTI were a prior episode of UTI in the 6 months leading up to SGLT2i use {odds ratio [OR] 7.90 [confidence interval (CI) 3.63-17.21]} and female sex [OR 2.46 (CI 1.19-5.03)]. In a post hoc subgroup analysis, the incidence of UTI emerged as similar in DKTRs treated with SGLT2i for 12 months versus non-DKTRs (17.9% versus 16.7%). Between baseline and 6 months, significant reductions were observed in body weight [-2.22 kg (95% CI -2.79 to -1.65)], blood pressure, fasting glycaemia, haemoglobin A1c [-0.36% (95% CI -0.51 to -0.21)], serum uric acid [-0.44 mg/dl (95% CI -0.60 to -0.28)] and urinary protein:creatinine ratio, while serum magnesium [+0.15 mg/dl (95% CI 0.11-0.18)] and haemoglobin levels rose [+0.44 g/dl (95% CI 0.28-0.58]. These outcomes persisted in participants followed over 12 months of treatment. Conclusions: SGLT2is in kidney transplant offer benefits in terms of controlling glycaemia, weight, blood pressure, anaemia, proteinuria and serum uric acid and magnesium. UTI was the most frequent adverse effect. According to our findings, these agents should be prescribed with caution in female DKTRs and those with a history of UTI.

Clinical relevance of HLA donor-specific antibodies detected by single antigen assay in kidney transplantation.

BACKGROUND: Clinical relevance of donor-specific antibodies (DSAs) detected by a single antigen Luminex virtual crossmatch in pre-transplant serum samples from patients with a negative cytotoxicity-dependent complement crossmatch is controversial. The aim of this study was to analyse the influence of a pre-transplant positive virtual crossmatch in the outcome of kidney transplantation. METHODS: A total of 892 patients who received a graft from deceased donors after a negative cytotoxicity crossmatch were included. Presence of anti-human leucocyte antigen (HLA) antibodies was investigated using a Luminex screening assay and anti-HLA specificities were assigned performing a Luminex single antigen assay. RESULTS: Graft survival was significantly worse among patients with anti-HLA DSA compared to both patients with anti-HLA with no DSA (P = 0.001) and patients without HLA antibodies (P < 0.001) using a log-rank test. No graft survival differences between anti-HLA with no DSA and no HLA antibodies patient groups were observed (P = 0.595). Influence of both anti-Class I and anti-Class II DSA was detected (P < 0.0001 in both cases). When the fluorescence values were stratified in four groups, no significant differences in graft survival were observed among the groups with fluorescence levels >1500 (global P > 0.05). CONCLUSIONS: The presence of preformed HLA DSA in transplanted patients with a negative cytotoxicity crossmatch is associated with a lower allograft survival. The detection of anti-HLA with no DSA has no influence in the graft outcome. Finally, there were no demonstrable effects of mean fluorescence intensity (MFI) values >1500 on graft survival.

[Update of the recommendations on the management of the SARS-CoV-2 coronavirus pandemic (COVID-19) in kidney transplant patients.] / Actualización de las recomendaciones en el manejo de la pandemia por coronavirus SARS-CoV-2 (COVID-19) en pacientes con trasplante renal.

SARS-CoV-2 infection (COVID-19) has had a significant impact on transplant activity in our country. Mortality and the risk of complications associated with COVID-19 in kidney transplant recipients (KT) were expected to be higher due to their immunosuppressed condition and the frequent associated comorbidities. Since the beginning of the pandemic in March 2020 we have rapidly improved our knowledge about the epidemiology, clinical features and management of COVID-19 post-transplant, resulting in a better prognosis for our patients. KT units have been able to adapt their programs to this new reality, normalizing both donation and transplantation activity in our country.This manuscript presents a proposal to update the general recommendations for the prevention and treatment of infection in this highly vulnerable population such as KT.

There Are 33,784 Functioning Kidney Grafts in Spain: Who Monitors Them and How?

BACKGROUND: As of December 31, 2018, Spain's National Transplant Organization estimated that there were 61,764 people under renal replacement therapy across the country. Of this population, 33,784 (54.7%) had a functioning kidney graft. METHODS: Through the use of a survey to all Spanish hospitals involved in kidney transplantations, we studied the distribution of these recipients nationally, along with who was monitoring them and how. Data collected include the ratio of recipients to transplant nephrologists, median number of recipients followed in each center, and median number of transplant nephrologists per hospital. Of the 806 centers in the Spanish hospital network, 43 (5.3%) were involved in kidney transplants, including 39 transplant hospitals and 4 associated hospitals. The median number of transplants per center was 800 (interquartile range [IQR] = 510-1200). There were 3 nephrologists (IQR 2-5), and the ratio of recipients to transplant nephrologists was 270 (IQR = 190-323). RESULTS: There were no significant differences in these data between autonomous communities, except in the case of the Canary Islands, which had a significantly lower ratio of recipients to transplant nephrologists (146; IQR = 100-185) compared with the rest of the country (ratio 277; IQR = 207-329; P < .001). Of the 39 hospitals, 29 (74.4%) referred patients to centers that did not perform transplants. CONCLUSIONS: All in all, few Spanish hospitals perform kidney transplants. The ratio of recipients to transplant nephrologists is very high, compelling most hospitals to refer patients to nontransplant hospitals for follow-up. There are important differences in the distribution of recipients in hospitals in the Canary Islands vs the rest of the country, a difference that is undoubtedly attributable to its geographic peculiarities.

[Recommendations on management of the SARS-CoV-2 coronavirus pandemic (Covid-19) in kidney transplant patients]. / Recomendaciones en el manejo de la pandemia por coronavirus SARS-CoV-2 (Covid-19) en pacientes con trasplante renal.

The SARS-CoV-2 (Covid-19) coronavirus pandemic is evolving very quickly and means a special risk for both immunosuppressed and comorbid patients. Knowledge about this growing infection is also increasing although many uncertainties remain, especially in the kidney transplant population. This manuscript presents a proposal for action with general and specific recommendations to protect and prevent infection in this vulnerable population such as kidney transplant recipients.

Actualización de las recomendaciones en el manejo de la pandemia por coronavirus SARS-CoV-2 (COVID-19) en pacientes con trasplante renal / Update of the recommendations on the management of the SARS-CoV-2 coronavirus pandemic (COVID-19) in kidney transplant patients

La infección por el SARS-CoV-2 (COVID-19) ha supuesto un importante impacto en la actividad trasplantadora en nuestro país. Era esperable que la mortalidad y el riesgo de complicaciones asociadas a la COVID-19 en el receptor de trasplante renal (TR) fueran mayores debido a su condición de inmunosupresión y a las frecuentes comorbilidades asociadas. Desde el inicio de la pandemia en marzo del 2020 hemos mejorado rápidamente nuestro conocimiento acerca de la epidemiología, características clínicas y manejo de la COVID-19 postrasplante, redundando en un mejor pronóstico para nuestros pacientes. Las unidades de TR han sabido adaptar sus programas a esta nueva realidad, normalizándose la actividad tanto de donación como de trasplante en nuestro país. Este manuscrito presenta una propuesta de actualización de las recomendaciones generales para la prevención y el tratamiento de la infección en esta población tan vulnerable como son los receptores de un trasplante renal. (AU)

SARS-CoV-2 infection (COVID-19) has had a significant impact on transplant activity in our country. Mortality and the risk of complications associated with COVID-19 in kidney transplant (KT) recipients were expected to be higher due to their immunosuppressed condition and the frequent associated comorbidities. Since the beginning of the pandemic in March 2020 we have rapidly improved our knowledge about the epidemiology, clinical features and management of COVID-19 post-transplant, resulting in a better prognosis for our patients. KT units have been able to adapt their programs to this new reality, normalizing both donation and transplantation activity in our country. This manuscript presents a proposal to update the general recommendations for the prevention and treatment of infection in this highly vulnerable population such as KT. (AU)

l-Carnitine ameliorates the oxidative stress response to angiotensin II by modulating NADPH oxidase through a reduction in protein kinase c activity and NF-κB translocation to the nucleus.

l-Carnitine (LC) exerts beneficial effects in arterial hypertension due, in part, to its antioxidant capacity. We investigated the signalling pathways involved in the effect of LC on angiotensin II (Ang II)-induced NADPH oxidase activation in NRK-52E cells. Ang II increased the generation of superoxide anion from NADPH oxidase, as well as the amount of hydrogen peroxide and nitrotyrosine. Co-incubation with LC managed to prevent these alterations and also reverted the changes in NADPH oxidase expression triggered by Ang II. Cell signalling studies evidenced that LC did not modify Ang II-induced phosphorylation of Akt, p38 MAPK or ERK1/2. On the other hand, a significant decrease in PKC activity, and inhibition of nuclear factor kappa B (NF-kB) translocation, were attributable to LC incubation. In conclusion, LC counteracts the pro-oxidative response to Ang II by modulating NADPH oxidase enzyme via reducing the activity of PKC and the translocation of NF-kB to the nucleus.

Recomendaciones en el manejo de la pandemia por coronavirus SARS-CoV-2 (Covid-19) en pacientes con trasplante renal / Recommendations on management of the SARS-CoV-2 coronavirus pandemic (Covid-19) in kidney transplant patients

La pandemia por coronavirus SARS-CoV-2 (Covid-19) está evolucionando de manera muy rápida y representa un riesgo especial en pacientes inmunodeprimidos y con comorbilidades añadidas. El conocimiento sobre esta infección emergente va también en aumento, si bien, aún sigue habiendo muchas incógnitas, sobre todo en la población con trasplante renal. Este manuscrito presenta una propuesta de actuación con recomendaciones generales y específicas para proteger y prevenir de la infección a esta población tan vulnerable como son los receptores de un trasplante renal

The SARS-CoV-2 (Covid-19) coronavirus pandemic is evolving very quickly and means a special risk for both immunosuppressed and comorbid patients. Knowledge about this growing infection is also increasing although many uncertainties remain, especially in the kidney transplant population. This manuscript presents a proposal for action with general and specific recommendations to protect and prevent infection in this vulnerable population such as kidney transplant recipients

Medical management of pneumonia caused by Rhodococcus equi in a renal transplant recipient.

Rhodococcus equi is an animal pathogen that occasionally causes opportunistic infections in immunocompromised patients. The most common clinical picture is one of necrotizing pneumonia with a tendency toward cavitation and the formation of abscesses. We report a case of pneumonia caused by R equi in a renal transplant patient. An excellent response was shown to antibiotic treatment. Symptoms regressed, and the progressive disappearance of the lesion was confirmed on follow-up computed tomography scans. Surgical intervention or other invasive procedures were not required. To our knowledge, 14 cases of infection by R equi in solid-organ transplant patients have been described to date. Nine were recipients of a renal allograft. Surgery was required in many of these patients, and all the renal transplant recipients required the use of invasive therapeutic techniques, such as pleural drainage. This is the first case of a renal transplant recipient in whom radiologic presentation was as a solid nodule without ensuing cavitation that resolved exclusively with antibiotic treatment.

Clinical impact of neutropenia related with the preemptive therapy of CMV infection in solid organ transplant recipients.

OBJECTIVES: The most frequent adverse events associated with valganciclovir treatment are hematological disturbances such as neutropenia. However, the consequences of neutropenia are unknown. We investigated the clinical impact of neutropenia during CMV preemptive therapy and its relationship with the length of antiviral therapy. METHODS: An observational, prospective cohort of 67 solid organ transplant recipients receiving CMV preemptive therapy was studied. RESULTS: Severe neutropenia occurred in 21.8% of the patients at a median of three weeks after initiating antiviral therapy. No association was observed between neutropenia and infection risk in these patients. Liver transplant recipients had 6.7 fold increased risk of neutropenia during CMV therapy compared to kidney transplant recipients (p = 0.012). Patients who developed severe neutropenia received antiviral therapy a median of six days longer than patient who did not (p = 0.457). CONCLUSIONS: Despite the frequency of neutropenia during CMV preemptive therapy, the incidence of infections is not increased. Adjusting the length of preemptive therapy during the episodes of viremia may be recommended, especially in patients with concurrent risk factors for neutropenia such as liver recipients. Further trials are warranted to confirm the safety of this approach.

Harmful effects of viral replication in seropositive hepatitis C virus renal transplant recipients.

BACKGROUND: Seropositivity for hepatitis C virus (HCV) predicts lower patient and graft survival after renal transplantation (RT). However, the influence of viral replication at transplantation on long-term outcome remains to be determined. METHODS: This was a retrospective study conducted in four Spanish hospitals, from 1997 to 2006. Data of all patients with RT, who displayed HCV+ (enzyme-linked immunosorbent assay), and with negative viremia at RT (NEG group) were collected (n=41). For each NEG patient enrolled, data of two patients with RT nearest in time, HCV+, and positive viremia (POS group) were also collected (n=78). RESULTS: The POS group showed a higher incidence of long-term liver disease (56.4% vs. 24.4%, P=0.0009) and episodes of transaminase elevation (38.5% vs. 7.3%, P=0.0003) and worse renal function (serum creatinine [sCr], 3.0 [2.7] vs. 1.9 [1.6] mg/dl, P=0.032; glomerular filtration rate, 43.7 [22.4] vs. 56.9 [27.9] ml/min, P=0.075). Noteworthy, 24.4% of NEG patients reactivated after RT, showing a worse patient survival (P=0.039). Active viral replication at RT and dialysis requirement in the first week remained as independent predictors of lower graft survival (death censored): hazards ratio, 3.11 (95% confidence interval, 1.34-7.19; P=0.009) and hazards ratio 3.13 (95% confidence interval, 1.53-6.37; P=0.002). CONCLUSIONS: This study shows that active viral replication at transplantation is an independent risk factor for graft failure in patients with positive serology for HCV.