Low-dose valaciclovir and cytomegalovirus immunoglobulin to prevent cytomegalovirus disease in high-risk renal transplant recipients

Low-Dose Valacyclovir for Cytomegalovirus Infection Prophylaxis After a Heart Transplant

OBJECTIVES

Cytomegalovirus infection is a major cause of morbidity and mortality in solid-organ transplant. Low doses of valacyclovir have been administered as cytomegalovirus prophylaxis in our institution for years. To the best of our knowledge, there is no published study of a low-dose regimen for cytomegalovirus prophylaxis in heart transplant patients. Therefore, our aim was to determine the results of low doses of valacyclovir in heart transplant.

MATERIALS AND METHODS

Between September 2006 and December 2014, sixty-eight patients underwent orthotopic heart transplants. All of the patients received triple immunosuppressive therapy after surgery. During the next 6 months, sulfamethoxazole/trimethoprim was administered for Pneumocystis jiroveci pneumonia, and toxoplasmosis. Additionally all patients received valacyclovir hydrochloride (1000 mg/d, oral) for cytomegalovirus prophylaxis and nystatin oral rinse for prophylaxis of fungal infections.

RESULTS

There was only 1 cytomegalovirus infection at follow-up. The patient had cytomegalovirus pneumonia at 17-month follow-up. In response to treatment with 1-week intravenous ganciclovir, the patient was discharged with a further 6-month oral valacyclovir therapy (1000 mg/d).

CONCLUSIONS

In this study, we hypothesized that daily use of low-dose valacyclovir (1000 mg/d) is not only sufficient for cytomegalovirus prophylaxis but also beneficial in terms of cost.

Immunotherapeutic Approaches To Prevent Cytomegalovirus-Mediated Disease

Human cytomegalovirus (CMV) is the major cause of congenital neurological defects in the United States and also causes significant morbidity and mortality for hematopoietic and solid organ transplant patients. Primary infection in immunocompetent individuals rarely causes disease but resolves as a life-long latent infection, characterized by sustained antibody and cellular responses. Despite considerable efforts over the last 40 years to develop live attenuated and subunit vaccines, none is close to receiving regulatory approval. However, there is evidence that antibodies can prevent primary infection and cytotoxic T cells can suppress secondary infection. Prior maternal infection decreases the risk a fetus will contract CMV, while adoptive transfer of virus-specific CD8+ T cells is highly protective against CMV disease in hematopoietic stem cell transplant recipients. As a result, three polyclonal immunoglobulin preparations are approved for clinical use and one monoclonal antibody has reached phase III trials. Enhanced understanding of the viral life cycle from a biochemical perspective has revealed additional targets for neutralizing antibodies in the gH/gL/UL128-131 pentamer. Until an effective vaccine is licensed, passive immunotherapeutics may present an alternative to maintain viral loads and prevent CMV disease in susceptible populations. This review summarizes the progress and potential of immunotherapeutics to treat CMV infection.

The efficacy and cost-effectiveness of valacyclovir in cytomegalovirus prevention in solid organ transplantation

Prevention of cytomegalovirus infection using antiviral prophylaxis or the pre-emptive therapy approach is an integral part of management of patients after solid organ transplantation. Regarding renal transplantation, valacyclovir is currently the only antiviral agent recommended for prophylaxis as an alternative to valganciclovir. This review article discusses studies documenting the efficacy and safety of valacyclovir prophylaxis as well as those comparing valacyclovir with other prophylactic regimens or with pre-emptive therapy. Also addressed are the economic aspects supporting the cost-effectiveness of valacyclovir prophylaxis and demonstrating lower costs compared with other cytomegalovirus preventive strategies.

CMV: Prevention, Diagnosis and Therapy

Cytomegalovirus (CMV) is the most common infection after organ transplantation and has a major impact on morbidity, mortality and graft survival. Optimal prevention, diagnosis and treatment of active CMV infection enhance transplant outcomes, and are the focus of this section. Methods to prevent CMV include universal prophylaxis and preemptive therapy; each has its merits, and will be compared and contrasted. Diagnostics have improved substantially in recent years, both in type and quality, allowing for more accurate and savvy treatment; advances in diagnostics include the development of an international standard, which should allow comparison of results across different methodologies, and assays for cellular immune function against CMV. Therapy primarily involves ganciclovir, now rendered more versatile by data suggesting oral therapy with valganciclovir is not inferior to intravenous therapy with ganciclovir. Treatment of resistant virus remains problematic, but is enhanced by the availability of multiple novel therapeutic agents.

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.