Cytomegalovirus infection in solid organ transplantation: economic implications

Cytomegalovirus infection in heart transplant recipients: Epidemiology, risk factors, and long-term outcomes from a major transplant center in the United States

Background

Despite the use of antiviral prophylaxis, cytomegalovirus (CMV) remains a common opportunistic infection following heart transplantation. This study analyzes the rates, risk factors, and outcomes of CMV among heart transplant recipients.

Methods

A retrospective cohort study was conducted of adults who underwent heart transplantation between January 1, 2011, and March 31, 2019. The primary outcome was clinically significant CMV infection (csCMVi), defined as CMV disease or asymptomatic infection requiring pre-emptive therapy. The secondary outcome was all-cause mortality. Patients received valganciclovir prophylaxis up to 6 months, depending on CMV donor/recipient serostatus. Kaplan-Meier curve and multivariable Cox regression were used for outcome analysis.

Results

Among 553 heart transplant recipients, 101 (18.3%) experienced csCMVi, including 35 (6.3%) with CMV disease. csCMVi was uncommon during prophylaxis. In multivariable analysis, CMV D+/R- status hazard ratio (HR 12.88, 95% CI 6.76-24.56; p < 0.001) and lower absolute lymphocyte counts in seropositive recipients (HR 1.48, 95% CI 1.23-1.79; p < 0.001), but not CMV D+/R- patients (HR 1.18, 95% CI 0.94-1.47; p = 0.162), were significantly associated with csCMVi. Sixty patients died during follow-up, and csCMVi was associated with increased mortality (HR 2.84, 95% CI 1.62-4.98; p < 0.001).

Conclusions

In this large cohort of heart transplant recipients, csCMVi was linked to higher mortality. CMV D+/R- serostatus was associated with an increased risk of csCMVi, with lower absolute lymphocyte counts increasing risk only in CMV seropositive recipients. Strategies for optimizing CMV prevention in serodiscordant heart recipients are warranted.

The Role of the Human Cytomegalovirus UL133-UL138 Gene Locus in Latency and Reactivation

Human cytomegalovirus (HCMV) latency, the means by which the virus persists indefinitely in an infected individual, is a major frontier of current research efforts in the field. Towards developing a comprehensive understanding of HCMV latency and its reactivation from latency, viral determinants of latency and reactivation and their host interactions that govern the latent state and reactivation from latency have been identified. The polycistronic UL133-UL138 locus encodes determinants of both latency and reactivation. In this review, we survey the model systems used to investigate latency and new findings from these systems. Particular focus is given to the roles of the UL133, UL135, UL136 and UL138 proteins in regulating viral latency and how their known host interactions contribute to regulating host signaling pathways towards the establishment of or exit from latency. Understanding the mechanisms underlying viral latency and reactivation is important in developing strategies to block reactivation and prevent CMV disease in immunocompromised individuals, such as transplant patients.

Oral ganciclovir versus valganciclovir for cytomegalovirus prophylaxis in high-risk liver transplant recipients

This retrospective review compared oral valganciclovir (VGCV) 450 mg daily for 6 months versus oral ganciclovir (GCV) 1000 mg 3 times daily for 3 months in preventing cytomegalovirus (CMV) disease in high-risk liver transplant recipients.We evaluated all CMV donor positive-recipient negative liver transplant recipients managed at University Health System in San Antonio,Texas from August 1996 to September 2006. CMV disease was confirmed by polymerase chain-reaction or antigenemia assay, and CMV invasive disease by tissue biopsy. Patient demographics, laboratory results, complications, and therapies were collected via retrospective chart review. Patients < 18 years of age or those who died during transplant admission were excluded. Primary endpoints included incidence, onset, and severity of CMV disease up to 1 year post transplant. Data collection also included patient demographics, immunosuppression, CMV treatment regimens, and relevant lab results. A total of 64 patients (43 VGCV and 21 GCV) were identified. Four patients developed CMV disease:VGCV (3/43,7%) versus GCV (1/21, 5%) (P=1.0), with 1 VGCV patient experiencing tissue-invasive CMV. In all cases, onset of CMV disease occurred after prophylaxis was discontinued. Onset occurred at 24, 27, and 45 weeks post transplant in the VGCVgroup, and at 26 weeks in the 1 patient on GCV. Four patients received rabbit antithymocyte globulin (rATG) induction; 1 patient received rATG and developed CMV disease, with no statistical difference compared with the 3 remaining patients who received rATG but did not develop CMV disease (P=0.09). No difference was found in incidence of CMV disease between patients who received GCV and those who received VGCV at our institution.

Assessing the economic merits of managing cytomegalovirus infection in organ and stem cell transplantation

Two preventative approaches exist to manage cytomegalovirus (CMV), a common infection in recipients of organ and stem cell transplants: prophylaxis--the prevention of viraemia--and pre-emptive therapy--the prevention of manifestation of disease in patients who have viraemia. Economic evaluation may provide a helpful framework to inform the choice between these two approaches. However, several issues arise. Direct comparisons of prophylaxis and pre-emptive therapy are rare and there are few epidemiological data that depict the full natural history of CMV infection and disease. There is a need for large, prospective randomised trials that directly compare these two strategies and are of sufficient duration to assess their overall impact on direct and indirect effects of CMV as well as patient quality of life. These methodological issues are relevant to the economic evaluation of preventative measures in other clinical settings and highlight the need for a rigorous evaluative framework to best inform decision making about the optimal strategy for patients.

Cytomegalovirus Disease Amongst Renal Transplant Recipients in Australia and New Zealand

Cytomegalovirus (CMV) is a significant pathogen causing disease in renal transplant patients. The highest incidence of CMV disease occurs during the first 3 months post-transplant and is most problematic in CMV-naïve transplant recipients. In this study, we conducted a retrospective review of two databases, the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) and the National Hospital Morbidity Database, from the Australian Institute of Health and Welfare (AIHW), to examine CMV in renal transplant recipients. The first source looked at CMV serostatus at the time of transplantation and the second recorded hospital admissions for recipients with invasive CMV disease.

From the ANZDATA registry, we obtained information from 13,530 renal transplants recipients from 1980 to 2004. Of these recipients, 7808 had a known CMV serostatus, of which 65.7% (5134/7808) had a positive sero antibody status and 34.2% (2674/7808) had a negative sero antibody status. In univariate analysis, factors significantly associated with renal rejection were being male, recipient age <50 years, being diabetic, being diagnosed with cancer at some point and having a positive EBV status. Positive CMV serostatus was not a contributing factor. Between 1993 and 2001 there were 1445 renal transplant recipients hospitalized in Australia with a diagnosis of CMV disease, of which 38% (554/1445) had CMV disease as a principal diagnoses. The average annual rate of admissions with any diagnosis was 3871 episodes per 100,000 people living with a functioning graft.

Preventative strategies for CMV in renal transplant recipients should be a priority. New vaccines for CMV may soon be available and renal transplant recipients would be a suitable target group for vaccination.

Sirolimus exposure during the early post-transplant period reduces the risk of CMV infection relative to tacrolimus in renal allograft recipients

INTRODUCTION

There are limited data regarding the role of individual maintenance immunosuppressive agents in the development of cytomegalovirus (CMV) infection. We examined the association between exposure to sirolimus (SRL) and risk of CMV infection after kidney transplantation when compared with tacrolimus (TCL).

METHODS

This is a retrospective observational study of adult renal allograft recipients transplanted between 2001 and 2005 at our center. Patients received anti-lymphocyte antibody induction, and mycophenolate mofetil with either SRL or TCL +/- prednisone. D+/R- patients received valganciclovir 900 mg/d and CMV + patients 450 mg/d for three months. CMV infection was diagnosed with pp65 antigenemia testing prompted by clinical suspicion.

RESULTS

A total of 14 Cases with CMV infection and 129 Controls were identified for primary analysis, and 11 D+/R- Cases and 19 D+/R- Controls for secondary analysis. The groups were comparable in both analyses, except for D+/R- serostatus in the primary analysis. All 14 Cases were on TCL for at least three months prior to diagnosis of CMV infection. In the primary analysis, zero Cases, but 30.2% and 34.9% of Controls (p = 0.009 and 0.004), and in secondary analysis, zero Cases, but 31.6% and 42.1% of Controls (p = 0.046 and 0.013), were on SRL at one and three months, respectively. In the primary analysis, zero Cases vs. 45 Controls (p = 0.004), and in secondary analysis, zero Cases vs. eight Controls (p = 0.013), were on SRL for at least three months early post-transplantation.

CONCLUSION

These findings suggest that SRL as a component of a multidrug immunosuppressive regimen decreases the risk of CMV infection after kidney transplantation when compared with TCL.

Cost of prophylaxis in the management of cytomegalovirus infection in solid organ transplant recipients

BACKGROUND

Limited economic data exist on the use of valganciclovir for the prevention of cytomegalovirus (CMV) infection and disease in solid organ transplant (SOT) recipients. We compared the economics of sequential i.v. and oral ganciclovir prophylaxis vs. oral valganciclovir prophylaxis alone in high-risk (D+/R-) SOT patients.

METHODS

A cost-minimization analysis was performed from the perspective of the Spanish National Health System comparing the cost of sequential ganciclovir prophylaxis (induction with i.v. ganciclovir 10 mg/kg daily for 14 d followed by oral ganciclovir 1 g t.i.d. for 3 months) vs. oral valganciclovir prophylaxis (900 mg once daily for 100 d). Resource utilization data for both regimens were obtained from the literature and from clinical records of 83 patients in nine Spanish hospitals. Results were expressed as average cost per patient treated.

RESULTS

The average cost per patient treated with sequential ganciclovir or valganciclovir prophylaxis was euro3715.51 and euro3295.90, respectively. The higher cost of ganciclovir therapy was due to concomitant administration of anti-CMV immunoglobulin (euro313.73), drug administration costs (euro401.45), catheter culture tests (euro13.64) and adverse events associated with catheter use (euro3.30). Following a sensitivity analysis, taking into account dose and duration of drug, concomitant medications and adverse events, costs for valganciclovir and sequential therapy were similar.

CONCLUSIONS

Valganciclovir prophylaxis is as economical as sequential ganciclovir prophylaxis in high-risk D+/R- SOT patients. In addition, the once-daily dosing regimen of valganciclovir is more convenient, and avoids the complications associated with catheter use.

Cytomegalovirus infection in renal transplant recipients

We have retrospectively analyzed the incidence of cytomegalovirus (CMV) infection in 250 consecutive renal allograft transplants performed in 244 recipients. The mean follow-up was 35.1+/-25.4 months. Immunosuppression was cyclosporine- or tacrolimus-based triple therapy. CMV infection prophylaxis with ganciclovir for 3 months post transplant was prescribed in CMV-seronegative recipients of allografts from seropositive donors (D+R-) and in all recipients treated with OKT3. CMV antigenemia was monitored by the pp65-antigen assay. Thirteen of 57 D+R- recipients (22.8%) developed CMV antigenemia. One recipient had a breakthrough of CMV antigenemia during ganciclovir prophylaxis; 12 D+R- recipients developed CMV antigenemia 147.5+/-173.8 days after transplantation. Four of 13 (30.7%) D+R- recipients had asymptomatic CMV infection, 8 (61.6%) had CMV infection with non-specific symptoms including fever, and 1 (7.7%) developed CMV pneumonia. Six of 13 (46.1%) D+R- patients had been treated with intensified immunosuppressive therapy before CMV infection. In the low-risk CMV groups (D+R+; D-R+; D-R-), 28 recipients (14.5%) developed CMV antigenemia 42.5+/-15.2 days post transplantation. Ten of the 28 (35.7%) recipients had asymptomatic CMV infection, 17 (60.7%) developed CMV infection with non-specific symptoms, and 1 (3.6%) developed CMV pneumonia. Twenty-one of 28 (75.0%) had intensified immunosuppressive therapy before CMV infection. In conclusion, ganciclovir prophylaxis diminished and delayed the onset of CMV infection but did not totally prevent it from occurring in D+R- renal transplant recipients. Clinicians should be vigilant to the possibility of CMV infection in both seronegative and seropositive recipients, especially after anti-rejection therapy.

The cost-effectiveness of prophylaxis with valaciclovir in the management of cytomegalovirus after renal transplantation

Prophylaxis-based antiviral treatment and intensive monitoring followed by pre-emptive antiviral treatment are both commonly used management strategies to reduce risk of cytomegalovirus (CMV) infection following renal transplantation. This study employed a decision-model approach using published efficacy data and information from a recent survey of French clinical practice to consider the relative costs and outcomes associated with CMV prevention strategies for high-risk patient groups. The cost per case of treating tissue invasive and symptomatic CMV disease was estimated at euro 15,431 and euro 10,852, respectively. In the highest infection-risk patient group (positive donor with no previous CMV history) prophylactic oral valaciclovir was shown to avoid the greatest number of CMV disease cases (35 cases per 100 transplanted patients) and reduced the overall CMV-related costs per transplanted patient by around 14% over a'wait-and-treat' baseline strategy. In contrast, intensive monitoring and preemptive treatment resulted in a much higher cost per transplanted patient. This analysis suggests that prophylactic treatment remains the most cost-effective approach to the management of CMV in renal-transplanted patients. Further comparative studies between prophylactic and pre-emptive treatment would be a valuable addition to the current evidence based on CMV prevention.

Cytomegalovirus prophylaxis with valganciclovir in African-American renal allograft recipients based on donor/recipient serostatus

There is a paucity of data examining the efficacy of valganciclovir (VGC) for cytomegalovirus (CMV) prophylaxis in kidney transplant patients, particularly with regard to utilization of a risk-stratified dosing regimen. Eighty adult African-American (AA) renal allograft recipients transplanted from November 3, 2001 to May 28, 2003 and followed for 22 +/- 8 months received VGC once daily for 90 d post-transplant dosed according to donor/recipient (D/R) serostatus: high risk (D+/R-) received 900 mg (n = 12); moderate risk (D+/R+, D-/R+) received 450 mg (n = 60); and low risk (D-/R-) received no prophylaxis (n = 8). Thymoglobulin or basiliximab was used for induction, and mycophenolate mofetil, prednisone, and either tacrolimus or sirolimus for maintenance immunosuppression. Only six patients (7.5%) developed symptomatic CMV infection diagnosed by pp65 antigenemia, three in the high-risk (25%) and three in the moderate-risk (5%) group (p = 0.02). All patients were on tacrolimus for at least 3 months prior to diagnosis. There were no cases of tissue-invasive disease, resistance to treatment, or recurrence. D+/R- serostatus was the only significant independent predictor for CMV infection using multivariate analysis (odds ratio 10.5; p = 0.04). Thymoglobulin induction was not associated with CMV infection. None of 43 patients who were exposed to sirolimus for >30 d developed CMV infection, vs. six of 37 who were not (p = 0.006). We conclude that VGC dosed according to D/R serostatus provides safe and effective CMV prophylaxis in AA renal allograft recipients.

Efficacy and Safety of Low-Dose Valganciclovir for Prevention of Cytomegalovirus Disease in Renal Transplant Recipients: A Single-Center, Retrospective Analysis

STUDY OBJECTIVE

To evaluate the safety and efficacy of valganciclovir 450 mg/day for 6 months for cytomegalovirus (CMV) prophylaxis in renal transplant recipients.

DESIGN

Single-center, retrospective analysis.

SETTING

Urban, academic medical center.

PATIENTS

Fifty-eight patients who received de novo renal transplants from August 1, 2001-November 21, 2002.

INTERVENTION

Valganciclovir 450 mg/day was administered to all renal transplant recipients at risk for CMV disease. Therapy was begun postoperatively and was dose adjusted to renal function.

MEASUREMENTS AND MAIN RESULTS

Data collected from renal transplant recipients were demographics, immunosuppressive and antiviral drug therapy, and occurrence of CMV disease, acute rejection, allograft loss, and hematologic adverse events. Donor (D)/recipient (R) CMV serostatus was 37.9% D+/R+, 29.3% D-/R+, 17.3% D+/R-, and 15.5% D-/R-. Antithymocyte globulin (ATG) was administered to 62.1% of patients. Most of the transplant recipients received triple immunosuppression as maintenance therapy. Median follow-up was 20 months. The frequency of CMV disease was 1.7% within 6 months after transplantation and 5.2% at any point after transplantation. All patients who developed CMV disease were D+/R- and had received ATG. Leukopenia and thrombocytopenia associated with valganciclovir were seen in 28% and 24% of patients, respectively. One patient developed acute cellular rejection. No graft losses or deaths occurred. Early discontinuation of valganciclovir occurred in 20% of patients secondary to severe, persistent leukopenia, thrombocytopenia, and/or diarrhea. None of these patients developed CMV disease.

CONCLUSION

A high rate of CMV disease was noted among the D+/R- population. Administration of ATG as an induction agent also increased the frequency of CMV disease. Despite the low dosage of valganciclovir, hematologic adverse events were common. However, valganciclovir, administered at 450 mg/day for 6 months, was effective and relatively safe for prophylaxis of CMV disease in renal transplant recipients.