Valganciclovir preemptive therapy for the prevention of cytomegalovirus disease in high-risk seropositive solid-organ transplant recipients

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Risk factors for cytomegalovirus infection in patients with antineutrophil cytoplasmic antibody-associated vasculitis

Aims

Cytomegalovirus (CMV) infection under immunosuppression sometimes causes death. This study aimed to elucidate risk factors for CMV infection in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV).

Methods

Patients with AAV who underwent remission induction treatment at Okayama University Hospital between 2006 and 2016 were retrospectively analyzed. The primary outcome was the development of CMV infection within 3 months.

Results

Of the 111 patients, 13 (11.7%) patients developed CMV infection. Patients with CMV infection were older (p = 0.030) and had a higher body mass index (p = 0.029) in comparison to those without CMV infection. A higher proportion had a severe form (p = 0.001) and granulomatosis with polyangiitis (GPA) (p = 0.001), as well as a higher Birmingham Vasculitis Activity Score (p = 0.018) and C-reactive protein (p = 0.018) levels at baseline. Using logistic regression analysis, severe form and GPA were independent risk factors (odds ratio [OR] = 9.68, 95% confidence interval [CI] = 1.92–60.23, and OR = 7.46, 95% CI = 1.46–47.60, respectively). In addition, patients with CMV infection were more likely than those without infection to be glucocorticoid-related diabetes mellitus (p = 0.025).

Conclusion

Our study highlights disease severity and subgroups of AAV as risk factors for CMV infection.

Prevention and management of cytomegalovirus infection in solid-organ transplantation

Cytomegalovirus (CMV) is the most common opportunistic viral infection to occur following solid-organ transplantation. This review will discuss the current strategies of management of CMV in solid-organ transplantation and their challenges. There are two principal approaches for preventing CMV disease in recipients of solid-organ transplants: prophylactic and pre-emptive. Ganciclovir is the most studied and used antiviral for both treatment and prevention, and is the first-line treatment for CMV infection and CMV disease in transplant recipients. There is no consensus regarding the most appropriate prevention method and the approach to CMV disease prevention differs among transplantation centers owing to the paucity of data comparing the two strategies head-to-head. Currently, the recommended treatment for CMV disease is intravenous ganciclovir.

Blood disorders after kidney transplantation

Post transplant anemia (PTA) is a common issue in kidney transplant recipients. Most importantly it is associated with an impaired allograft function. Other important factors associated with PTA are immunosuppressive drugs (MPA, AZA and SRL), iron deficiency, infections (Parvo B19), older donor age, rejection episodes, an increased inflammatory state, and erythropoietin hyporesponsiveness. As there are no adequately powered RCTs in the kidney transplant population on anemia treatment with ESA, we have to rely on what we know from the large RCTs in the CKD population. The recently published KDIGO guidelines do not recommend treatment with ESA if Hb is >10 g/dl. Repletion of iron stores is emphasized. Post transplant leukopenia (PTL) and thrombocytopenia (PTT) are frequent complications especially in the first six months after kidney transplantation. Myelosuppression caused by immunosuppressive agents (MPA, AZA, SRL, rATG), antimicrobial drugs (VGCV), and CMV infection is the predominant cause. There are no widely accepted guidelines on treatment strategies, but most often dose reduction or discontinuation of causative medication is done. Most clinicians tend to decrease MPA dose, but this is eventually associated with an increase in acute rejection episodes. VGCV dose reduction (preemptive treatment instead of CMV prophylaxis) may be a successful strategy. In severe cases G-CSF treatment is an important management option and seems to be safe.

Valganciclovir dosing using area under the curve calculations in pediatric solid organ transplant recipients

Pediatric valganciclovir dosing recommendations have not been extensively validated for prevention or treatment for CMV infection. As such, we performed a pharmacokinetic study to compare different valganciclovir dosing regimens and the potential benefits of individualized dose adjustments in children following organ transplantation. Ganciclovir AUCs were calculated from four plasma drug levels in pediatric SOT recipients aged six months through three yr receiving valganciclovir suspension by mouth. Of the 28 ganciclovir AUC calculations performed, 11 (39%) were outside the therapeutic target range of 40-60 mcg h/L leading to a valganciclovir dose adjustment. Current manufacturer-recommended dosing based on BSA and CrCl was estimated to result in therapeutic AUCs in fewer patients than the simple weight-based formula used in our institution (4 vs. 13; p = 0.017). An AUC calculation using only the two- and five-h measurements was strongly correlated with the AUC using all four time measurements (R(2) = 0.846; p < 0.001). A simple weight-based dosing approach gives a higher probability for therapeutic AUCs compared to the manufacturer-recommended dosing in pediatric transplant patients aged six months through three yr with normal renal function. An AUC calculated using two sample times might allow for fewer blood draws in the future.

[Prophylaxis of cytomegalovirus infection in liver transplantation]

CMV prevention strategies in liver transplant recipients should be stratified according to serological status. In donor (D)-/recipient (R)- combinations, no prophylaxis or preemptive therapy is recommended. In the remaining combinations, the most widely used strategies are universal prophylaxis and preemptive therapy. Both strategies are effective compared with placebo but have not been compared with each other in well-designed clinical trials. Preemptive therapy is the preferred strategy in low-risk patients while prophylaxis is the most widely used option in those at high-risk. Delayed CMV disease is an adverse consequence of universal prophylaxis. Prolongation of prophylaxis from 100 to 200 days does not reduce the incidence of CMV disease. CMV-specific cell mediated immunity, facilitated by preemptive therapy and delayed by prophylaxis, has a therapeutic effect by reducing CMV replication. The drug of choice in both strategies is valganciclovir but the duration and dose differ. When preemptive therapy is used, viremia monitoring is required for the first 4 months. The technique of choice is quantitative polymerase chain reaction. Given the lack of conclusive data, the choice of one or other strategy in these patients should be individualized in each patient and center according to the available resources and possibilities of follow-up.

[Prophylaxis of cytomegalovirus infection in renal transplantation]

Cytomegalovirus (CMV) infection remains a major problem in renal transplant recipients. CMV produces not only febrile syndromes and/or visceral disease but also contributes to the development of acute rejection and chronic graft failure. Valganciclovir prophylaxis has represented a major advance in controlling this infection, but late CMV infection after prophylaxis can occur, especially when universal prophylaxis is used. The use of valganciclovir prophylaxis for 200 days is more effective than prophylaxis for 100 days but does not completely prevent this problem. Prophylaxis based on the detection of CMV viremia (early prophylaxis or preemptive therapy) may prevent the development of delayed CMV disease, but has the disadvantage of requiring more intensive monitoring of viremia and does not prevent the development of viremia and its potential consequences in the long term. This article reviews current recommendations for prophylaxis of CMV disease in renal transplantation.

Pharmacokinetic profile of valganciclovir in pediatric transplant recipients

We evaluated the pharmacokinetic profile of intravenous ganciclovir and oral valganciclovir in transplant children. Median AUC0-24 concentrations obtained after intravenous and oral formulations were 22.9 µg•h/mL (range, 17-65.2) and 34.55 µg•h/mL (range, 20.8-84.2), respectively. After normalization on a 20 mg/kg/d valganciclovir dosage, the median AUC0-24 concentration was 37.6 µg•h/mL (range, 23.6-68).

Valganciclovir to prevent or treat cytomegalovirus disease in organ transplantation

Cytomegalovirus (CMV) is generally considered the most significant pathogen to infect patients following organ transplantation. Significant improvements have been achieved in the management of CMV disease over recent years, especially since the introduction of oral drugs such as oral ganciclovir followed by valganciclovir (VGC), a prodrug of ganciclovir with enhanced bioavailability. Several randomized controlled trials have shown that VGC is an efficacious and convenient oral drug to prevent or treat CMV disease in solid-organ transplant recipients. In this article, we discuss the clinical and pharmacological experience with the use of VGC for the management of CMV in solid-organ transplant recipients. Finally, novel strategies to further reduce the incidence of CMV disease after transplantation are also reviewed.

Impact of a preemptive strategy after 3 months of valganciclovir cytomegalovirus prophylaxis in kidney transplant recipients

BACKGROUND

We assessed the impact of a preemptive strategy after discontinuation of antiviral prophylaxis in the prevention of late-onset cytomegalovirus (CMV) disease in a cohort of kidney transplant recipients.

METHODS

Patients undergoing kidney transplantation at the University Hospital of Lausanne (CHUV) between November 2003 and November 2007 were included if they were donor or recipient (D/R) seropositive for CMV. All patients received 3 months of prophylaxis with valganciclovir, followed by monitoring of CMV DNAemia by polymerase chain reaction (PCR) every 15 days during 3 additional months. Valganciclovir was restarted if CMV PCR was more than or equal to 10,000 copies/mL. The primary endpoint of the study was the incidence of late-onset CMV disease. RESULTS.: Eighty-six kidney transplant recipients were included; 30 patients were D+/R- and 56 patients were R+ for CMV. At 6 months posttransplant, CMV DNAemia had occurred in 31 of 86 (36%) patients: 13 of 30 (43%) in the D+/R- group and 18 of 56 (32%) in the R+ group (P = 0.35). In the D+/R- group, among the 13 patients with CMV DNAemia, 7 (54%) patients developed late-onset CMV disease, simultaneously to the first positive viral load (n = 5) or after detection of low-grade viremia (n = 2). Only two patients received a preemptive treatment. In the R+ group, all positive PCR results were below the established cutoff. Thus, these 18 patients were not treated, and none of them developed late-onset CMV disease (R+ vs. D+/R-: P < 0.001).

CONCLUSIONS

Within the limitations of a noncontrolled study, our data indicate that a preemptive strategy after 3 months of valganciclovir prophylaxis for CMV is not useful in R+ kidney transplant recipients. In D+/R- patients, this approach should be further evaluated.

Impact of prophylactic versus preemptive valganciclovir on long-term renal allograft outcomes

BACKGROUND

Both prophylactic and preemptive oral valganciclovir therapy are effective for the management of cytomegalovirus (CMV) postrenal transplantation in the short term. The long-term effect of either strategy is less well defined.

METHODS

We analyzed the data on 115 adult recipients previously enrolled in a prospective randomized controlled trial of prophylaxis versus preemptive therapy for CMV. The primary outcome was a composite of freedom from acute rejection, graft loss, or death. Secondary outcomes included individual primary outcomes, posttransplant cardiovascular events, new-onset diabetes mellitus after transplantation, achievement of goal blood pressure, change in body mass index, interstitial fibrosis/tubular atrophy, and change in renal function. The analysis period was a minimum of 48-month posttransplant or a date of death or graft loss, whichever was earlier.

RESULTS

The primary outcome was similar between groups (83% prophylactic vs. 81% preemptive, P=0.754). The secondary outcomes showed similarities between the prophylactic and preemptive groups. Four patients in the prophylactic group (8%) compared with none in the preemptive group (0%) died with a functioning graft, P=0.043.

CONCLUSIONS

Within the limitations of sample size, our data suggest that either strategy for the management of CMV immediately after transplantation seems effective for patient and graft survival in the long term. CMV management is one of the many therapeutic strategies incorporated into a renal transplantation protocol, which often differs among institutions, and the decision as to which approach to use remains center- and resource-specific. The increased incidence of death in the prophylactic group requires further investigation.

New developments in the management of cytomegalovirus infection after solid organ transplantation

Despite remarkable advances in the diagnostic and therapeutic modalities for its management, cytomegalovirus (CMV) remains one of the most important pathogens impacting on the outcome of transplantation. Not only does CMV directly cause morbidity and occasional mortality, it also influences many short-term and long-term indirect effects that collectively contribute to reduced allograft and patient survival. Prevention of CMV infection and disease is therefore key in ensuring the successful outcome of solid organ transplantation (SOT). In this regard, antiviral prophylaxis and pre-emptive therapy are similarly effective in preventing CMV disease after transplantation. However, current guidelines prefer antiviral prophylaxis over pre-emptive therapy in preventing CMV disease in high-risk SOT recipients, such as CMV-seronegative recipients of organs from CMV-seropositive donors (CMV D+/R-), and lung, intestinal and pancreas transplant recipients. Antiviral prophylaxis has the benefits of reducing not only the incidence of CMV disease, but also the indirect effects of CMV on allograft and patient survival. The major drawback of antiviral prophylaxis is delayed-onset CMV disease, which occurs in 15-38% of CMV D+/R- SOT recipients who received 3 months of prophylaxis. Allograft rejection, over-immunosuppression and lack of CMV-specific immunity are factors that predispose patients to delayed-onset CMV disease. A recent randomized trial in CMV D+/R- kidney recipients demonstrates a significant reduction in the incidence of CMV disease when valganciclovir prophylaxis is extended to 200 days (compared with the standard 100 days) after transplantation; however, the safety and cost of this prolonged approach has yet to be assessed. In some studies, delayed-onset CMV disease has been significantly associated with allograft loss and mortality. In the vast majority of patients, CMV disease responds to treatment with intravenous ganciclovir. Recently, oral valganciclovir was demonstrated to have an efficacy that is comparable to intravenous ganciclovir in treating mild to moderate cases of CMV disease in SOT recipients. Reduction in the degree of immunosuppression should complement antiviral treatment of CMV disease. Although it remains rare, ganciclovir-resistant CMV disease is increasingly seen in clinical practice, potentially fostered by the prolonged use of antivirals in high-risk over-immunosuppressed transplant recipients. Treatment of drug-resistant CMV is currently non-standardized and may include foscarnet, cidofovir, CMV hyperimmune globulins or leflunomide. The investigational drug marivabir had the potential to treat ganciclovir-resistant CMV disease as it acts through a different mechanism. However, the recent phase III clinical trial in allogeneic bone marrow transplant recipients showed that maribavir was not significantly better than placebo for the prevention of CMV disease. Similarly, the preliminary data in a liver transplant population suggests that maribavir was inferior to oral ganciclovir for the prevention of CMV disease. This article reviews the recent data and other developments in the management of CMV infection after SOT.

Preemptive therapy for cytomegalovirus based on real-time measurement of viral load in liver transplant recipients

BACKGROUND

Real-time PCR has emerged as the preferred diagnostic assay for CMV. However, its utility as a preemptive therapy tool for CMV disease and related outcomes in liver transplant recipients has not been fully defined.

METHODS

Patients comprised 117 consecutive liver transplant recipients who underwent CMV surveillance monitoring using real-time PCR. Preemptive therapy with valganciclovir was employed upon detection of viremia. Baseline viral load was considered high based on log values (median).

RESULTS

CMV viremia developed in 54% (63/117) of the patients, including 77% of R-/D+, 63% of R+/D+, 43% of R+/D-, and 10% of R-/D- patients. Overall, 23% (15/63) of the patients had recurrent viremia; R- serostatus (p=0.065) but not initial viral load correlated with recurrent viremia (p=0.80). At 12 months post-transplant, CMV disease occurred in 0.85% (1/117) of the patients (R+/D+recipient). None (0/30) of the R-/D+patients had CMV disease. Patients with CMV viremia treated preemptively did not differ significantly from those who never developed CMV viremia with regards to bacterial or fungal infections, rejection, graft loss, mortality rate, and probability of survival at 12 months (p>0.05 for all variables). The above outcomes also did not differ for patients with high (>1.9 logs) vs. low viral load (<1.9 logs) (p>0.05 for all outcomes).

CONCLUSIONS

Preemptive therapy guided by real-time PCR based monitoring led to outcomes in all patients or in those with high viral loads that were comparable to outcomes in patients who never developed viremia or had low viral loads, respectively. Late-onset CMV disease at 12 months was observed in <1% of all patients.

Prophylactic therapy with valgancyclovir in high-risk (cytomegalovirus D+/R-) liver transplant recipients: a single-center experience

A retrospective study was performed in liver transplant patients with high risk to develop cytomegalovirus infection (CMV D+/R-) who were treated with valgancyclovir for 3 months as prophylactic therapy. The aim of this study was to determine the safety and efficacy of prophylactic therapy with valgancyclovir. Weekly CMV antigenemia was routinely assessed during the first 3 months posttransplantation, twice a month to month 6, and monthly until the end of the first year, as well as when clinically indicated. The follow-up period was 1 year. From January 2003 to February 2007, 199 liver transplantations were performed at our institution, including 23 (11%) high-risk patients for CMV infection. Median age was 47 +/- 11.6 years. Nineteen patients (70.4%) were men. Five subjects (21.7%) developed CMV infections. Three patients with positive CMV antigenemia at 3, 4, or 6 months posttransplantation were asymptomatic, while 2 (8.7%) showed gastrointestinal CMV disease at 2 months posttransplantation or CMV hepatitis at 1 month after the end of the prophylactic therapy. Treatment with intravenous gancyclovir followed by oral valgancyclovir was successful in both patients. No opportunistic infections were observed and only 1 patient developed leukopenia as an adverse event related to valgancyclovir.

A new strategy of delayed long-term prophylaxis could prevent cytomegalovirus disease in (D+/R-) solid organ transplant recipients

Long-term prophylaxis against cytomegalovirus (CMV) started immediately after transplantation in (D+/R-) poses a higher risk of late-onset CMV disease. Delayed CMV prophylaxis could allow a transitory exposure of the immune system to CMV, which would let the immune system mount an adequate CMV-specific cytotoxic response in (D+/R-) patients and confer protection against CMV disease. We included all (D+/R-) solid organ transplant recipients (SOT) performed at our institution (January 3/October 6) who received CMV prophylaxis (mainly with oral valganciclovir) during 100 d. In the first period (until December 4), prophylaxis was initiated immediately after transplantation (conventional prophylaxis: CP). Since January 5, it was initiated after 14 d (delayed prophylaxis: DP). Incidence and severity of CMV disease was compared between both groups. A total of 44 SOT recipients were included (CP: 26 and DP: 18). CMV disease was diagnosed in eight patients (18%), seven of 26 (27%) in the CP group, and one of 18 (5.5%) in the DP group (p = 0.07). CMV colitis was reported in five of 26 patients in the CP group (19%), whereas there were no cases of visceral CMV disease in the DP group (p = 0.048). A 14-d delay in the beginning of long-term prophylaxis against CMV in (D+/R-) is safe and could prevent the onset of late-CMV disease.

Valganciclovir for cytomegalovirus prevention in solid organ transplant patients: an evidence-based reassessment of safety and efficacy

BACKGROUND

Several anti-viral drugs have demonstrated efficacy in preventing Cytomegalovirus (CMV) infections in solid organ transplant (SOT) patients. The recently approved valganciclovir is the most commonly used and most expensive drug for CMV prevention. The safety and efficacy data have been drawn from a single trial. We hypothesized that valganciclovir may not be as safe as nor more effective than other therapies for CMV prevention.

METHODS

All experimental and analytical studies that compared valganciclovir with other therapies for prevention of CMV infection after SOT were selected. Based on meta-analytic and multivariate regression methodologies we critically analyzed all available evidence.

FINDINGS

Nine studies were included (N = 1,831). In trials comparing valganciclovir with ganciclovir, the risk for CMV disease is 0.98 (95% Confidence Interval (95%CI) 0.67 to 1.43; P = 0.92; I(2) = 0%). Valganciclovir was significantly associated with the risk of absolute neutropenia (<1,500/mm(3)) compared with all therapies (Odds Ratio (OR) 3.63 95%CI 1.75 to 7.53; P = 0.001; I(2) = 0%); with ganciclovir only (OR 2.88, 95%CI 1.27 to 6.53; P = 0.01; I(2) = 0%); or with non-ganciclovir therapies (OR 8.30, 95%CI 1.51 to 45.58; P = 0.01; I(2) = 10%). For a neutropenia cut-off of <1,000/mm(3), the risk remained elevated (OR 1.97, 95%CI 1.03 to 3.67; P = 0.04; I(2) = 0%). For every 24 patients who receive valganciclovir prophylaxis, one more will develop neutropenia compared to other therapies. The risk of late-onset CMV disease with valganciclovir was similar to ganciclovir and higher than those with non-ganciclovir therapies (OR 8.95, 95%CI 1.07 to 74.83; P = 0.04; I(2) = 0%]. One more patient will develop late-onset CMV disease for every 25 who receive valganciclovir compared to treatment with non-ganciclovir therapies. The risk of CMV tissue-invasive disease in liver recipients receiving valganciclovir was 4.5 times the risk seen with ganciclovir [95%CI 1.00 to 20.14] (p = 0.04). All results remained consistent across different study designs, valganciclovir doses, and CMV serostatus.

CONCLUSIONS

Valganciclovir shows no superior efficacy and significantly higher risk of absolute neutropenia, CMV late-onset disease, and CMV tissue-invasive disease compared to other standard therapies. Due to the availability of efficacious, safer, and lower cost drugs (high-dose acyclovir, valacyclovir, ganciclovir), our results do not favor the use of valganciclovir as a first-line agent for CMV preemptive or universal prophylaxis in SOT patients.

Hematologic abnormalities following renal transplantation

Recipients of renal allografts are surviving longer and, consequently, may experience a variety of complications related not only to the transplanted kidney, but also to the hematopoietic system. Common hematologic complications in the renal transplant patient include abnormalities of one cell line, such as post-transplantation erythrocytosis or anemia, that are often treatable with simple measures. Conversely, pathologies involving the leukocyte and platelet population often exist in the context of pancytopenia, which may be a manifestation of systemic infection (e.g., cytomegalovirus, human herpesvirus 8) or malignancy (post-transplantation lymphoproliferative disorders). Uncommon, but life-threatening, processes complicating renal transplantation include hepatosplenic gammadelta T-cell lymphoma and viral-induced hemophagocytic syndrome, both of which are associated with severe pancytopenia and, often, death. Since this patient population is often managed in a multidisciplinary fashion by nephrologists, infection specialists, transplant surgeons, hematologists, and internal medicine physicians, a succinct review of this topic is warranted.

Management of human cytomegalovirus infection in transplant recipients by the pre-emptive therapy approach

Human cytomegalovirus (HCMV) infections are still a major infectious complication in the post-transplant period of both solid organ transplant recipients (SOTRs) and hematopoietic stem cell transplant recipients (HSCTRs). For many years, the major diagnostic assay has been antigenemia, allowing semi-quantification of HCMV load in blood from transplanted patients with disseminated HCMV infection. More recently, the real-time PCR assay has replaced antigenemia for HCMV DNAemia quantification. Prevention of HCMV disease is based on either prophylaxis or pre-emptive therapy with antiviral drugs. The latter approach has been in use in our department for the last 15 years. A cut-off of 300,000 DNA copies/ml whole blood in SOTRs with either primary or reactivated infection, and a cut-off of 10,000 DNA copies/ml blood in HSCTRs proved to be safe and effective in prospective randomized, controlled trials. With this approach, HCMV disease is consistently prevented, except for a limited number of cases of organ localization in the absence of virus in blood. In these cases, HCMV infection/disease must be diagnosed by local biopsy samples.

Prevention of posttransplant cytomegalovirus disease and related outcomes with valganciclovir: a systematic review

The precise impact of valganciclovir as preventive therapy for cytomegalovirus (CMV) in solid organ transplant (SOT) recipients is not fully defined. Data from studies using valganciclovir as preemptive therapy or prophylaxis for CMV in SOT recipients were synthesized for descriptive analysis. CMV disease occurred in 2.6% and 9.9% of the patients receiving valganciclovir as preemptive therapy and prophylaxis, respectively. Although the incidence of early-onset (<or=90 days posttransplant) CMV disease was only 0.8% and 1.2% in all patients and R-/D+ patients receiving valganciclovir prophylaxis, the incidence of late-onset (>90 days posttransplant) CMV disease rose up to 8.9% and 17.7% in the prophylactic group, respectively. On the contrary, no patients developed late-onset CMV disease in preemptive group. Both approaches with valganciclovir have successfully decreased CMV disease in SOT recipients. Late-onset CMV disease is a complication observed uniquely with valganciclovir prophylaxis, particularly in R-/D+ patients, but not with preemptive therapy.

Valganciclovir as treatment for cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Cytomegalovirus (CMV) infection causes morbidity in solid organ transplant (SOT) recipients, either by direct injury or in association with chronic allograft rejection or other opportunistic infections. Ganciclovir is the treatment of choice, but this agent requires intravenous administration, which affects its feasibility for long-term use. Valganciclovir, which has an oral bioavailability of 60%, has proven to be useful for prophylaxis of CMV infection in high-risk SOT recipients and for treating retinitis in persons with acquired immunodeficiency syndrome.

OBJECTIVE

To compare the efficacy of valganciclovir (alone or as sequential therapy after a regimen of intravenous ganciclovir) with intravenous ganciclovir alone for preemptive therapy or treatment of CMV disease (viral syndrome or focal disease) in SOT recipients and to determine the incidence of adverse effects and relapses.

METHODS

In this 2-year prospective, comparative cohort study, 376 episodes of preemptive therapy or treatment of CMV disease were recorded among 334 of 3467 SOT recipients included in the Spanish Network for Research on Infection in Transplantation (RESITRA) database. Intravenous ganciclovir was the first-line treatment in 170 episodes; valganciclovir followed by intravenous ganciclovir was administered in 82 episodes, and valganciclovir alone was administered in 112 episodes.

RESULTS

Valganciclovir was used as preemptive therapy or treatment for CMV disease in 84 and 28 episodes, respectively. Duration of treatment was longer in valganciclovir recipients than in ganciclovir recipients for both preemptive therapy (21 vs. 15 days; P < .001) or viral syndrome treatment (21 vs. 18 days; P < .01). In the valganciclovir arm, 94 (83.9%) of 112 episodes were treated successfully, with no statistical difference in the success rates versus the ganciclovir arm (85.8%) or ganciclovir-valganciclovir arm (95.1%). Eighteen episodes (16.1%) treated with valganciclovir were considered to have resulted in treatment failure (because of persistent antigenemia in 4 [3.6%], on the basis of clinical decision in 7 [6.2%], and because of recurrent disease in 7 [6.2%]). There were no incidents in which valganciclovir treatment was withdrawn because of toxicity.

CONCLUSION

Valganciclovir is safe and useful for preemptive therapy and treatment of CMV disease.

Valganciclovir as preemptive therapy for cytomegalovirus in cytomegalovirus-seronegative liver transplant recipients of cytomegalovirus-seropositive donor allografts

The efficacy of valganciclovir as preemptive therapy for the prevention of cytomegalovirus (CMV) disease and its impact on indirect sequelae of CMV were assessed in recipient-negative/donor-positive (R-/D+) liver transplant recipients. Of 187 consecutive liver transplant recipients at our institution since July 2001, 36 (19.2%) belonged to the R-/D+ group. Surveillance tests for CMV were performed on all patients at weeks 2, 4, 6, 8, 10,12, and 16. In all, 27 patients with asymptomatic viremia received preemptive therapy with valganciclovir. At a total follow-up of 62.8 patient years (median: 19 months, range: 3 months to 5.6 years), no episodes of CMV disease were documented in these patients. The incidence of rejection, retransplantation, and bacterial or fungal infections and the probability of survival did not differ for R-/D+ patients and all non-R-/D+ patients treated preemptively with valganciclovir (P > 0.20 for all variables). Thus, preemptive therapy with valganciclovir in R-/D+ patients was not associated with CMV disease during the period of surveillance monitoring or at anytime thereafter (late-onset CMV disease). The indirect outcomes with the use of valganciclovir in R-/D+ patients were comparable to the outcomes of other subgroups of liver transplant recipients receiving preemptive therapy.

A survey of CMV prevention strategies after liver transplantation

The degree of variability in the use of CMV prevention strategies and choice of antiviral regimens among LT centers has not been previously investigated. An electronic survey on current CMV prevention strategies was sent to all US and Canadian LT centers. A total of 58 (53%) centers completed the survey. Most use CMV PCR for screening or diagnosis. Prophylaxis was the most common prevention strategy for all donor/recipient subtypes except D-/R- who often receive no prophylaxis. Prophylaxis was usually given for 3 months after LT with valganciclovir the most frequently used agent. In the small percentage of centers utilizing the preemptive approach, monitoring for CMV was typically performed with PCR for 3 months and valganciclovir was most frequently used for treatment of detectable CMV viremia. In conclusion, the majority of LT centers utilize CMV prophylaxis over other strategies. Valganciclovir is the most commonly used agent for both antiviral prophylaxis and treatment of CMV viremia in the preemptive approach.

Prophylaxis and treatment of cytomegalovirus disease in recipients of solid organ transplants: current approach and future challenges

PURPOSE OF REVIEW

Cytomegalovirus infection is a major cause of morbidity and mortality in solid-organ transplant recipients, in terms of cytomegalovirus disease itself and the associated outcomes of organ rejection and death. This review focuses on recent literature concerning prevention and treatment of cytomegalovirus disease in this population.

RECENT FINDINGS

Two major strategies for the prevention of cytomegalovirus infection in solid-organ transplant recipients - preemptive and prophylactic treatment - are reviewed. Both strategies result in a lower incidence of cytomegalovirus disease when compared to a 'wait and treat' approach, and are generally considered cost-effective. Neither prophylaxis nor preemption has yet been shown to be superior. Newer trials are also reviewed, which are beginning to evaluate protocols of preemption or prophylaxis representative of current practice, as well as to explore alternative dosing strategies, the benefits of cytomegalovirus immune globulin, and the potential benefit of a longer course of prophylaxis. Concerns for the selection of ganciclovir-resistant strains of cytomegalovirus are also addressed.

SUMMARY

The consensus is that there is benefit for the treatment of solid-organ transplant patients with an antiviral agent before clinical evidence of cytomegalovirus disease. So far, there has been no demonstration of the superiority of prophylactic or preemptive regimens, nor has the exact nature and dosing of the oral antiviral agent of choice been established.