A Randomized Trial of Valganciclovir Prophylaxis Versus Preemptive Therapy in Kidney Transplant Recipients.

SIGNIFICANCE STATEMENT: Although cytomegalovirus (CMV) infection is an important factor in the pathogenesis of kidney allograft rejection, previous studies have not determined the optimal CMV prevention strategy to avoid indirect effects of the virus. In this randomized trial involving 140 kidney transplant recipients, incidence of acute rejection at 12 months was not lower with valganciclovir prophylaxis (for at least 3 months) compared with preemptive therapy initiated after detection of CMV DNA in whole blood. However, prophylaxis was associated with a lower risk of subclinical rejection at 3 months. Although both regimens were effective in preventing CMV disease, the incidence of CMV DNAemia (including episodes with higher viral loads) was significantly higher with preemptive therapy. Further research with long-term follow-up is warranted to better compare the two approaches. BACKGROUND: The optimal regimen for preventing cytomegalovirus (CMV) infection in kidney transplant recipients, primarily in reducing indirect CMV effects, has not been defined. METHODS: This open-label, single-center, randomized clinical trial of valganciclovir prophylaxis versus preemptive therapy included kidney transplant recipients recruited between June 2013 and May 2018. After excluding CMV-seronegative recipients with transplants from seronegative donors, we randomized 140 participants 1:1 to receive valganciclovir prophylaxis (900 mg, daily for 3 or 6 months for CMV-seronegative recipients who received a kidney from a CMV-seropositive donor) or preemptive therapy (valganciclovir, 900 mg, twice daily) that was initiated after detection of CMV DNA in whole blood (≥1000 IU/ml) and stopped after two consecutive negative tests (preemptive therapy patients received weekly CMV PCR tests for 4 months). The primary outcome was the incidence of biopsy-confirmed acute rejection at 12 months. Key secondary outcomes included subclinical rejection, CMV disease and DNAemia, and neutropenia. RESULTS: The incidence of acute rejection was lower with valganciclovir prophylaxis than with preemptive therapy (13%, 9/70 versus 23%, 16/70), but the difference was not statistically significant. Subclinical rejection at 3 months was lower in the prophylaxis group (13% versus 29%, P = 0.027). Both regimens prevented CMV disease (in 4% of patients in both groups). Compared with prophylaxis, preemptive therapy resulted in significantly higher rates of CMV DNAemia (44% versus 75%, P < 0.001) and a higher proportion of patients experiencing episodes with higher viral load (≥2000 IU/ml), but significantly lower valganciclovir exposure and neutropenia. CONCLUSION: Among kidney transplant recipients, the use of valganciclovir prophylaxis did not result in a significantly lower incidence of acute rejection compared with the use of preemptive therapy. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Optimizing Valganciclovir Efficacy in Renal Transplantation (OVERT Study), ACTRN12613000554763 .

Cytomegalovirus prevention strategies and the risk of BK polyomavirus viremia and nephropathy.

Polyomavirus BK (BKV) is the cause of polyomavirus-associated nephropathy resulting in premature graft loss. There are limited data regarding the role of cytomegalovirus (CMV) infection and its prevention in developing BKV viremia and PVAN. In a prospective study, we analyzed 207 consecutive renal transplant recipients previously enrolled in 2 randomized trials evaluating different CMV prevention regimens with routine screening for BKV and CMV. Of these, 59 received valganciclovir and 100 valacyclovir prophylaxis; 48 patients were managed by preemptive therapy. At 3 years, the incidence of BKV viremia and PVAN was 28% and 5%, respectively. CMV DNAemia developed in 55% and CMV disease in 6%. Both BKV viremia (42% vs 23% vs 21%, P = .006) and PVAN (12% vs 2% vs 2%, P = .011) were increased in patients treated with valganciclovir prophylaxis compared to valacyclovir and preemptive therapy. Using multivariate Cox proportional hazard regression, valganciclovir prophylaxis was independent predictor of BKV viremia (hazard ratio [HR] = 2.38, P = .002) and PVAN (HR = 4.73, P = .026). In contrast, the risk of subsequent BKV viremia was lower in patients with antecedent CMV DNAemia (HR = 0.50, P = .018). These data suggest valganciclovir prophylaxis may be associated with increased risk of BKV viremia and PVAN. CMV DNAemia did not represent a risk for BKV.

Viral load and duration of BK polyomavirus viraemia determine renal graft fibrosis progression: histologic evaluation of late protocol biopsies.

BACKGROUND: Polyomavirus BK (BKV) infection of the renal allograft causes destructive tissue injury with inflammation and subsequent fibrosis. METHODS: Using a prospective cohort of patients after kidney transplantation performed between 2003 and 2012, we investigated the role of BKV viraemia in the development and progression of interstitial fibrosis and tubular atrophy (IFTA). The primary outcome was moderate-to-severe IFTA assessed by protocol biopsy at 36 months. RESULTS: A total of 207 consecutive recipients were enrolled. Of these, 57 (28%) developed BKV viraemia with 10 (5%) cases of polyomavirus-associated nephropathy (PVAN). Transient (<3 months) BKV viraemia occurred in 70% of patients, and persistent (≥3 months) BKV viraemia in 30%. A high viral load (≥10 000 copies/mL) was detected in 18% and a low viral load (<10 000 copies/mL) in 61%, while the viral load could not be determined in 21%. Moderate-to-severe IFTA was significantly increased in high [71%; odds ratio (OR) = 12.1; 95% confidence interval (CI) 1.62-90.0; P = 0.015] or persistent BKV viraemia (67%; OR = 6.33; 95% CI 1.19-33.7; P = 0.031) with corresponding rise in 'interstitial fibrosis + tubular atrophy' scores. Only patients with transient low BKV viraemia showed similar incidence and progression of IFTA to the no-BKV group. Persistent low BKV viraemia was uncommon yet the progression of fibrosis was significant. Only recipients with PVAN experienced inferior graft survival at 5 years. CONCLUSIONS: These data suggest that only transient low BKV viraemia does not negatively affect the progression of allograft fibrosis in contrast to excessive risk of severe fibrosis after high or persistent BKV viraemia.

Less renal allograft fibrosis with valganciclovir prophylaxis for cytomegalovirus compared to high-dose valacyclovir: a parallel group, open-label, randomized controlled trial.

BACKGROUND: Cytomegalovirus (CMV) prophylaxis may prevent CMV indirect effects in renal transplant recipients. This study aimed to compare the efficacy of valganciclovir and valacyclovir prophylaxis for CMV after renal transplantation with the focus on chronic histologic damage within the graft. METHODS: From November 2007 through April 2012, adult renal transplant recipients were randomized, in an open-label, single-center study, at a 1:1 ratio to 3-month prophylaxis with valganciclovir (n = 60) or valacyclovir (n = 59). The primary endpoint was moderate-to-severe interstitial fibrosis and tubular atrophy assessed by protocol biopsy at 3 years evaluated by a single pathologist blinded to the study group. The analysis was conducted in an intention-to-treat population. RESULTS: Among the 101 patients who had a protocol biopsy specimen available, the risk of moderate-to-severe interstitial fibrosis and tubular atrophy was significantly lower in those treated with valganciclovir (22% versus 34%; adjusted odds ratio, 0.31; 95% confidence interval, 0.11-0.90; P = 0.032 by multivariate logistic regression). The incidence of CMV disease (9% versus 2%; P = 0.115) and CMV DNAemia (36% versus 42%; P = 0.361) were not different at 3 years. CONCLUSIONS: Valganciclovir prophylaxis, as compared with valacyclovir, was associated with a reduced risk of moderate-to-severe interstitial fibrosis and tubular atrophy in patients after renal transplantation. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ( ACTRN12610000016033 ). Registered on September 26, 2007.

The impact of viral load and time to onset of cytomegalovirus replication on long-term graft survival after kidney transplantation.

BACKGROUND: Asymptomatic cytomegalovirus (CMV) infection is associated with graft dysfunction and failure. However, no study assessed CMV viral load in terms of the risk for graft failure. METHODS: In a prospective cohort of kidney transplant recipients, we assessed the impact of CMV DNAemia on the overall graft survival and the incidence of moderate-to-severe interstitial fibrosis and tubular atrophy (IF/TA) in protocol biopsy at 36 months. CMV DNAemia was stratified by viral load in whole blood. RESULTS: A total of 180 patients transplanted from October 2003 through January 2011 were included and followed for 4 years; 87 (48%) patients received 3-month prophylaxis with valacyclovir and 45 (25%) with valganciclovir; 48 (27%) were managed by pre-emptive therapy. Within 12 months of transplantation, CMV DNAemia developed in 102 (57%) patients with 36 (20%) having a viral load of ≥2,000 copies/ml. Multivariate Cox analysis identified CMV DNAemia as an independent risk factor for graft loss (hazard ratio 3.42; P=0.020); however, after stratification by viral load, only CMV DNAemia ≥2,000 copies/ml (hazard ratio 7.62; P<0.001) remained significant. Both early-onset (<3 months; P=0.048) and late-onset (>3 months; P<0.001) CMV DNAemia ≥2,000 copies/ml were risk factors for graft loss. The incidence of moderate-to-severe IF/TA was not significantly influenced by CMV DNAemia. CONCLUSIONS: Kidney transplant recipients having CMV DNAemia with a higher viral load irrespective of the time to onset are at increased risk for graft loss.

Randomized trial of valganciclovir versus valacyclovir prophylaxis for prevention of cytomegalovirus in renal transplantation.

BACKGROUND AND OBJECTIVES: Both valganciclovir and high-dose valacyclovir are recommended for cytomegalovirus prophylaxis after renal transplantation. A head-to-head comparison of both regimens is lacking. The objective of the study was to compare valacyclovir prophylaxis with valganciclovir, which constituted the control group. DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS: In a randomized, open-label, single-center trial, recipients of renal transplants (recipient or donor cytomegalovirus-seropositive) were randomly allocated (1:1) to 3-month prophylaxis with valacyclovir (2 g four times daily) or valganciclovir (900 mg daily). Enrollment occurred from November of 2007 to April of 2012. The primary end points were cytomegalovirus DNAemia and biopsy-proven acute rejection at 12 months. Analysis was by intention to treat. RESULTS: In total, 119 patients were assigned to valacyclovir (n=59) or valganciclovir prophylaxis (n=60). Cytomegalovirus DNAemia developed in 24 (43%) of 59 patients in the valacyclovir group and 18 (31%) of 60 patients in the valganciclovir group (adjusted hazard ratio, 1.35; 95% confidence interval, 0.71 to 2.54; P=0.36). The incidence of cytomegalovirus disease was 2% with valacyclovir and 5% with valganciclovir prophylaxis (adjusted hazard ratio, 0.21; 95% confidence interval, 0.01 to 5.90; P=0.36). Significantly more patients with valacyclovir prophylaxis developed biopsy-proven acute rejection (18 of 59 [31%] versus 10 of 60 [17%]; adjusted hazard ratio, 2.49; 95% confidence interval, 1.09 to 5.65; P=0.03). The incidence of polyomavirus viremia was higher in the valganciclovir group (18% versus 36%; adjusted hazard ratio, 0.43; 95% confidence interval, 0.19 to 0.96; P=0.04). CONCLUSIONS: Valganciclovir shows no superior efficacy in cytomegalovirus DNAemia prevention compared with valacyclovir prophylaxis. However, the risk of biopsy-proven acute rejection is higher with valacyclovir.

Long-term outcomes of pre-emptive valganciclovir compared with valacyclovir prophylaxis for prevention of cytomegalovirus in renal transplantation.

Prevention of cytomegalovirus (CMV) is essential in organ transplantation. The two main strategies are pre-emptive therapy, in which one screens for and treats asymptomatic CMV viremia, and universal antiviral prophylaxis. We compared these strategies and examined long-term outcomes in a randomized, open-label, single-center trial. We randomly assigned 70 renal transplant recipients (CMV-seropositive recipient or donor) to 3-month prophylaxis with valacyclovir (n=34) or pre-emptive valganciclovir for significant CMV viremia detected at predefined assessments through month 12 (n=36). Among the 55 patients who had a protocol biopsy specimen available at 3 years to allow assessment of the primary outcome, 9 (38%) of 24 patients in the prophylaxis group and 6 (19%) of 31 patients in the pre-emptive therapy group had moderate to severe interstitial fibrosis and tubular atrophy (odds ratio, 2.50; 95% confidence interval, 0.74-8.43; P=0.22). The prophylaxis group had significantly higher intrarenal mRNA expression of genes involved in fibrogenesis. The occurrence of CMV disease was similar in both groups, but pre-emptive therapy improved 4-year graft survival (92% versus 74%; P=0.049) as a result of worse outcomes in patients with late-onset CMV viremia. In conclusion, compared with valacyclovir prophylaxis, pre-emptive valganciclovir therapy may lead to less severe interstitial fibrosis and tubular atrophy and to significantly better graft survival.

Pharmacoeconomic impact of different regimens to prevent cytomegalovirus infection in renal transplant recipients.

BACKGROUND: The aim of this study was to determine the cost impact of four different strategies for prevention of cytomegalovirus (CMV) disease after renal transplantation. METHODS: Hospitalization data and medical resource utilization data were prospectively collected alongside two randomized trials. In the first trial, the patients were randomized to 3-month prophylaxis with either oral ganciclovir (1 g t.i.d., n = 36) or valacyclovir (2 g q.i.d., n = 35), and to the control group (n = 12) managed by deferred therapy. In the second trial, the patients were randomly assigned to 3-month valacyclovir prophylaxis (n = 34) or preemptive therapy with valganciclovir (900 mg b.i.d. for a minimum of 14 days, n = 36) for significant CMV DNAemia. The cost analysis involved all real costs directly related to CMV during the first year after renal transplantation. RESULTS: The mean CMV-associated costs per patient were EUR 4,581, 2,577, 4,968, and 8,050 in patients in the ganciclovir, valacyclovir, preemptive, and deferred therapy groups, respectively (p < 0.001). Valacyclovir prophylaxis was significantly less expensive than any other regimen. The cost of one episode of CMV disease was EUR 7,510 per patient. Due to excessive incidence of CMV disease, deferred therapy was the most expensive strategy (p < 0.001). CONCLUSIONS: Valacyclovir prophylaxis is less expensive strategy compared with any other regimen.

Valganciclovir prophylaxis against cytomegalovirus impairs lymphocyte proliferation and activation in renal transplant recipients.

BACKGROUND: Antiviral prophylaxis against cytomegalovirus has been associated with reduced risk of allograft rejection and improved allograft survival after renal transplantation. This phenomenon might not be fully explained by preventing the indirect effects of cytomegalovirus. The effect of antiviral agents on lymphocyte function in patients treated with modern immunosuppression has not been studied to date. METHODS: Adult renal transplant recipients were assigned to 3-month prophylaxis with either valganciclovir (900 mg once daily; n=19) or valacyclovir (2 g four times daily; n=17) as part of an ongoing randomized trial. Subsets of lymphocytes, lymphocyte proliferation and/or cytokine production after in vitro mitogen stimulation were evaluated at the end of prophylaxis and 1 month after withdrawal of antiviral drugs. RESULTS: Lymphocyte proliferation was significantly decreased both after phytohemagglutinine (25% ±15% versus 32% ±18%; P=0.025) and concanavalin A stimulation (17% ±9% versus 25% ±16%; P=0.011) during valganciclovir, but not valacyclovir therapy. Moreover, a lower activated T-cell count (CD3(+)HLA-DR(+) cells) was noted in valganciclovir-treated patients (13% ±10% versus 17% ±12% of total CD3(+) T-cells; P=0.005). CONCLUSIONS: Valganciclovir suppresses lymphocyte proliferation and activation in patients after renal transplantation.

Intragraft cytomegalovirus infection: a randomized trial of valacyclovir prophylaxis versus pre-emptive therapy in renal transplant recipients.

BACKGROUND: In a randomized study, we observed a higher incidence of biopsy-proven acute rejection with pre-emptive valganciclovir therapy as compared with valacyclovir prophylaxis for prevention of cytomegalovirus (CMV) disease after renal transplantation (RTx). Persistence of the virus within the allograft could stimulate the alloimmune response. The aim of our study was to evaluate intragraft CMV infection in patients randomized to the trial. METHODS: RTx recipients at risk of CMV were randomized to pre-emptive therapy with valganciclovir (n=36) for significant CMV viraemia (> or =2,000 copies/ml by quantitative PCR in whole blood samples) or 3-month prophylaxis with valacyclovir (n=34). Renal biopsies performed during 12 months post-RTx were analysed for the presence of CMV by real-time PCR and immunohistochemical staining. RESULTS: A total of 35 patients (59 biopsies) in the pre-emptive group and 31 patients (57 biopsies) with valacyclovir prophylaxis had > or =1 biopsy specimen with sufficient material for intragraft CMV determination. Cumulative incidence of intragraft CMV infection was 14% and 7% (P=0.315) with pre-emptive therapy and prophylaxis, respectively. Patients at risk for primary CMV infection (CMV serological donor-positive and recipient-negative) were at higher risk for intragraft CMV infection (40% versus 5%; P=0.008). CMV viraemia at the time of biopsy was associated with the presence of CMV within the allograft (P<0.001). CONCLUSIONS: During the first year after RTx, the incidence of intragraft CMV infection was relatively low with comparable rates in patients managed by pre-emptive valganciclovir therapy and valacyclovir prophylaxis.

Effect of cytomegalovirus viremia on subclinical rejection or interstitial fibrosis and tubular atrophy in protocol biopsy at 3 months in renal allograft recipients managed by preemptive therapy or antiviral prophylaxis.

BACKGROUND: Cytomegalovirus (CMV) is a risk factor for acute renal allograft rejection. The aim of this study was to determine the impact of CMV viremia on subclinical rejection (SCR) and interstitial fibrosis and tubular atrophy (IF/TA) in protocol biopsy at 3 months after transplantation. METHODS: A total of 118 consecutive renal transplant recipients at risk for CMV (donor and recipient CMV seropositive) were included and followed up prospectively. Protocol biopsies with sufficient tissue were obtained in 102 patients. CMV activity was monitored using real-time polymerase chain reaction in whole blood. Three-month prophylaxis with valacyclovir or ganciclovir was given in 60 patients, whereas the remaining 42 patients were managed by preemptive therapy. Multivariate logistic stepwise regression analysis was used to estimate the effect of CMV viremia and other covariates on SCR and IF/TA. RESULTS: CMV viremia occurred in 41% of the patients with a median peak viral load of 1300 copies/mL. The incidence of SCR and IF/TA was 29% and 28%, respectively. CMV viremia was not a risk factor for SCR (OR=0.77, P=0.551); however, viremia of more than or equal to 2000 copies/mL increased the risk of IF/TA (OR=3.83, P=0.023). Biopsy-proven acute rejection (OR=3.34, P=0.009) and sirolimus-based immunosuppression (OR=6.13, P=0.008) were independent predictors of SCR. Delayed-graft function (OR=6.02, P=0.001) and donor age (OR=1.53 per 10-year increase, P=0.009) were associated with IF/TA. CONCLUSIONS: CMV viremia is not an independent risk factor for SCR. CMV viremia with viral load of more than or equal to 2000 copies/mL is associated with increased risk of IF/TA in protocol biopsy at 3 months after transplantation.

A randomized prospective controlled trial of oral ganciclovir versus oral valacyclovir for prophylaxis of cytomegalovirus disease after renal transplantation.

Oral ganciclovir and valacyclovir reduce the incidence of cytomegalovirus (CMV) disease after renal transplantation (RTx). Our study was designed to compare the efficacy, costs, and safety of oral ganciclovir and valacyclovir in the prophylaxis of CMV disease over the first 6 months after RTx. A total of 38 patients was randomized to 3-month treatment with either oral ganciclovir (1 g t.i.d., n=14, GAN group) or oral valacyclovir (2 g q.i.d., n=12, VAL group). A third group (C, n=12) received no prophylaxis. The patients were monitored by CMV-nested PCR in whole blood. No differences were found between the groups in their demographic characteristics, immunosuppressive protocols, or donor and recipient CMV serology. Thirty-six out of 38 (94.7%) recipients were CMV-seropositive. Over the 6-month post-RTx period, there were 13 episodes of CMV disease in eight (66.7%) patients of the C group compared with none in the GAN and VAL groups ( P=0.0005, GAN vs C; P=0.001, VAL vs C). The incidence of CMV viremia was 30.8%, 50.0%, and 91.7% in the GAN, VAL, and C groups, respectively ( P=0.004, GAN vs C; P=0.07, VAL vs C; P=NS, GAN vs VAL). Treatment failure (death, graft loss, CMV disease, or withdrawal from study) occurred in 14.3%, 0% and 66.7% in the GAN, VAL, and C groups, respectively ( P=0.014, GAN vs C; P=0.001, VAL vs C; P=NS, GAN vs VAL). The average CMV-associated costs per patient (in 2001 euros) were 2,449+/-1,178, 2,485+/-581, and 4,259+/-4,616 in the GAN, VAL, and C groups, respectively. Ganciclovir and valacyclovir were well tolerated, with ganciclovir having had to be withdrawn shortly in one patient only because of thrombocytopenia. In conclusion, oral ganciclovir and valacyclovir are equally safe and effective in the prophylaxis of CMV disease after RTx. Both are cost-effective and help reduce CMV-associated costs by some 40% compared with patients without prophylaxis.