Cytomegalovirus prophylaxis with valganciclovir in kidney, pancreas-kidney, and pancreas transplantation

Simultaneous pancreas/kidney transplant recipients are predisposed to tissue-invasive cytomegalovirus disease and concomitant infectious complications

BACKGROUND

Infections have increased in simultaneous pancreas/kidney transplant recipients (SPKTRs) with cytomegalovirus (CMV) infection being the most important viral infection with adverse impact on patient and allograft outcomes.

METHODS

We studied all primary SPKTRs and deceased-donor kidney transplant recipients (KTRs) between 2008 and 2015 for the development of CMV infection. A total of 21/62 SPKTRs (33.9%) and 90/335 KTRs (26.9%) were diagnosed with CMV infection. A control group of 41 SPKTRs without CMV infection was used for comparison.

RESULTS

SPKTRs showed an increased incidence of CMV infection compared with KTRs. SPKTRs were more likely to develop CMV disease, CMV pneumonia, recurrent CMV infection, higher initial and peak CMV loads, and more need for intravenous antiviral therapy compared with KTRs (P<.05). High-risk CMV serostatus (D+R-) and 2 HLA-B/-DR mismatches increased the risk of CMV infection in SPKTRs (P<.05). No differences were observed for patient and allograft outcomes (P>.05). SPKTRs with CMV infection were more likely to show concomitant Epstein-Barr virus (EBV) viremia compared with SPKTRs without CMV infection (P<.05). SPKTRs with CMV infection showed higher incidences of concomitant BK polyomavirus-associated nephropathy, EBV viremia, and sepsis compared with KTRs with CMV infection (P<.05).

CONCLUSION

Our results suggest a higher incidence and more severe course of CMV infection in SPKTRs compared with KTRs. The increased incidence of concomitant infectious complications among SPKTRs with CMV infection suggests an overall impaired immunity, and calls for more intense screening.

Antimicrobial prophylaxis in solid-organ transplantation

Solid-organ transplantation has become a widely accepted treatment modality for end-stage diseases. With the advent of newer and more potent immunosuppressive regimens, graft survival has improved, but at the expense of an increased risk for the development of infections secondary to bacterial, fungal, viral and parasitic pathogens. Prevention of such infectious complications with effective, well-tolerated and cost-effective antimicrobials would be ideal to improve the outcome of transplant patients. Cytomegalovirus is the most common cause of viral infections. Herpes simplex virus, Varicella-zoster virus, Epstein-Barr virus and others are also significant pathogens. Fungal infections are associated with the highest mortality rates. This review summarizes the most relevant data pertaining to the current understanding of infection prevention for solid-organ transplant recipients.

Epidemiology of cytomegalovirus infection after pancreas transplantation

BACKGROUND

Epidemiology of cytomegalovirus (CMV) infection has not been comprehensively studied after all three types of pancreas transplant (PT) including simultaneous pancreas-kidney transplantation (SPK), pancreas transplantation alone (PTA), and pancreas after kidney transplantation (PAK).

METHODS

We evaluated incidence, risk factors, and outcomes of CMV infection after pancreas transplant at our center from January 1, 1998, to December 31, 2009.

RESULTS

The study cohort included 252 recipients (SPK 60, PTA 71, and PAK 121), 53% men, age 43.9±9 years, followed for 6.3 (interquartile range 3-9) years. CMV serostatus was donor (D) seropositive and recipient (R) seronegative (D+/R-) (27%), D+/R+ (32%), D-/R+ (18%), D-/R- (23%), and one unknown/R+ (0.4%). Two hundred six (82%) patients received CMV prophylaxis. Twelve patients experienced CMV viremia, whereas 31 developed CMV disease. The cumulative incidence of CMV infection (viremia and disease) was 15%, 17%, and 20% at 1, 5, and 10 years, respectively, with no events after 10 years. It was higher in D+/R- group (P<0.004) and patients with kidney graft failure (P=0.036). The variables significantly associated with pancreas graft failure were transplant type (PTA vs. SPK, hazard ratio [HR]=2.29, P=0.020; PAK vs. SPK, HR=2.73, P=0.003) and acute pancreas rejection (HR=2.47, P<0.001). In multivariable mortality model, increased age (P<0.001) and pancreas graft failure (P<0.001) were associated with an increased risk of death, whereas CMV infection (P=0.036) was associated with a borderline decreased risk.

CONCLUSIONS

CMV remains a common cause of clinical illness, particularly among the CMV D+/R- mismatched and patients with kidney graft failure. Marginal association was observed between CMV infection and a lower risk of death, but not with allograft failure.

BK virus nephropathy after simultaneous pancreas-kidney transplantation

BACKGROUND

BK virus nephropathy (BKVN) was reported in up to 7.5% of patients after simultaneous pancreas-kidney transplantation (SPK). Its management by reduction in immunosuppression might pre-dispose to pancreatic graft loss.

METHODS

A retrospective analysis of 178 SPK recipients was performed. All patients received thymoglobulin, daclizumab and a maintenance of low-dose steroids, tacrolimus, and either sirolimus or mycophenolate.

RESULTS

Two (1.1%) patients were identified with BKVN. Time of diagnosis was 22 and 45 months after transplant. Both patients had superimposed calcineurin toxicity in their graft biopsies. Immunosuppression was reduced in both patients, and leflunomide (LEF) was used in one patient. Concurrent kidney rejection episodes were treated with steroid pulses in both patients. One kidney graft improved with a last estimated glomerular filtration rate (GFR) of 43 mL/min, and another kidney graft showed limited improvement with a last GFR of 30 mL/min. Pancreatic graft function remained excellent in both patients as assessed by serum c-peptide, glycosylated hemoglobin, amylase-lipase, and urine amylase levels.

CONCLUSION

Low incidence of BKVN was observed in our SPK series. Reduction in immunosuppression and sometimes LEF can be effective. The underlying mechanism of stable pancreatic allograft function despite ongoing kidney rejection warrants further investigation.

Incidence, risk factors, and outcome of cytomegalovirus infection and disease in patients receiving prophylaxis with oral valganciclovir or intravenous ganciclovir after umbilical cord blood transplantation

There is no information on the efficacy and safety of anticytomegalovirus (CMV) prophylaxis with intravenous ganciclovir or oral valganciclovir after unrelated cord-blood transplantation (UCBT). This issue was addressed in 151 adults (117 CMV-seropositive) undergoing UCBT at a single institution. The first 38 CMV-seropositive recipients were assigned to receive prophylactic ganciclovir, and the next 79 were given valganciclovir after engraftment. The cumulative incidence (CI) of CMV infection and disease was similar in patients receiving valganciclovir or ganciclovir (59% versus 55%, P = .59; and 9% versus 18%, P = .33, respectively). The toxicity profile and CI of nonrelapse mortality (CMV) and infection-related mortality did not differ between drugs. Patients receiving valganciclovir required fewer visits to the day hospital (P = .04). The CI of CMV infection and disease in 34 CMV-seronegative recipients was 12% and 6%, indicating that tight CMV monitoring is mandatory in this subset. The recipient's CMV serostatus, acute and extensive chronic graft-versus-host disease (aGVHD, cGVHD) were the main risk factors for CMV infection, and aGVHD for CMV disease. This study suggests that prophylaxis with oral valganciclovir is as safe and effective as intravenous ganciclovir for preventing CMV infection and disease after UCBT, but valganciclovir reduces the use of hospital resources.

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.

Maribavir: a new oral anti-cytomegalovirus drug

Prophylactic drug therapy for cytomegalovirus (CMV) disease in stem cell and solid organ transplant recipients is effective and simple to implement, with oral ganciclovir and oral valganciclovir as the primary agents. The main problems with the ganciclovir derivatives are myelotoxicity and development of resistance. The new antiviral drug, maribavir, in Phase III clinical trials of CMV prophylaxis after stem cell and liver transplantation, works through a mechanism distinct from that of ganciclovir and shows no myelotoxicity or cross-resistance. The primary toxicity is headache and taste disturbance. If the clinical trials are effective, it is expected that maribavir will be available in 2009. The availability of a new antiviral agent will help in the control of the persistent bane of transplant care.

Cytomegalovirus prophylaxis with valganciclovir in cytomegalovirus-seropositive kidney-transplant patients

The aims of this prospective, open-label, single-center pilot study were to assess the efficacy and safety of human cytomegalovirus (HCMV) prophylaxis using valganciclovir in HCMV- seropositive kidney-transplant patients to prevent HCMV infection and disease. Fifty-one HCMV seropositive kidney-transplant patients recipients who received transplants between 1 December 2005 and 30 November 2006 were included in the study. Valganciclovir was given from transplantation up to 114 (37-329) days, and was adapted to renal function, i.e., 900 mg/d if calculated creatinine clearance was >60 ml/min, or 450 mg/day if it was <60 ml/min. HCMV DNAemia was assessed every 2 weeks during prophylaxis, and on the same basis for 3 months post-prophylaxis. Immunosuppression was based on calcineurin inhibitors (ciclosporine A=22; tacrolimus=11), with mycophenolate mofetil (n=51), and low-dose steroids. Eighteen patients received no calcineurin-inhibitors, but Belatacept instead. During valganciclovir prophylaxis, asymptomatic HCMV DNAemia was observed in one patient, and no case of HCMV disease occurred. Within 252 days (45-425) post-valganciclovir prophylaxis, HCMV DNAemia was detected in 23.5% (n=12) of patients, of whom two had two or more consecutive HCMV DNAemias. Valganciclovir prophylaxis in HCMV-seropositive kidney-transplant patients is effective for preventing cytomegalovirus disease.

Long-term outcome of cytomegalovirus infection in simultaneous pancreas–kidney transplant recipients without ganciclovir prophylaxis

As cytomegalovirus (CMV) infection frequently occurs in simultaneous pancreas kidney transplantation (SPKT), most centers use general ganciclovir prophylaxis. The aim of the study was to analyze the impact of CMV in a patient cohort with preemptive therapy only. Incidence, course and risk factors of CMV infection were retrospectively analyzed in 94 adult SPK recipients without prophylaxis. Patients with asymptomatic pp65-antigenemia were treated preemptively with intravenous ganciclovir for 14 days. Survival rates after 1, 3, and 5 years were 98%, 97%, and 94% for patients, 96%, 94%, and 88% for renal grafts and 88%, 85%, and 82% for pancreas grafts. CMV infections occurred in 51% of patients and CMV syndrome in 16%. No tissue-invasive disease was observed. Thirty-eight per cent of patients with CMV infection developed a recurrence. Risk factors for CMV in multivariate analysis were the D+/R- constellation, acute rejections, anti-rejection therapy and coronary heart disease. CMV had no impact on patient or graft survival, occurrence of acute or chronic rejection and bacterial infections. Preemptive therapy seems to be safe and effective in SPK recipients, but as the present study was retrospective, prospective randomized studies are needed to confirm our results.

Oral valganciclovir as preemptive therapy for cytomegalovirus infection post allogeneic stem cell transplantation

Antiviral compounds including ganciclovir, foscarnet, and cidofovir are routinely used in the treatment of cytomegalovirus (CMV) infection and disease; however, these agents have a poor oral bioavailability and have the inconvenience and expense of intravenous administration.

AIM OF THE STUDY

To evaluate the safety and efficacy of oral valganciclovir (VGCV) for preemptive treatment of CMV reactivation in the setting of allogeneic hematopoietic stem cell transplantation (HSCT).

PATIENTS AND METHODS

We treated 15 patients receiving allogeneic HSCT from related (n=9) or unrelated (n=6) donors. In all patients, either the donor, host, or both were CMV Ig G positive pretransplant. Indication for therapy was preemptive treatment of CMV infection defined as one or two consecutive positive tests of pp65 antigenemia assay or CMV-polymerase chain reaction (PCR). VGCV was administered orally in a dosage of 900 mg b.i.d. for 2 weeks, followed by 450 mg b.i.d. for 2 additional weeks.

RESULTS

Patients developed a positive CMV-PCR after a median of 52 days (range 37-427) post HSCT and a positive pp65 antigenemia after a median time of 74 days (range 37-427) post HSCT. Preemptive treatment with VGCV was started a median time of 56 days (range 37-429) after transplant. In all, 11 patients (73%) completed the 28 days of therapy with VGCV. All patients showed a complete clearance of the virus. The median time to achieve a negative CMV-PCR was 6 days (range 4-18). A relapse of CMV infection after VGCV preemptive therapy occurred in 6 patients (40%). No patient developed early or late CMV disease. Six patients (40%) presented hematological toxicity including neutropenia and/or thrombocytopenia that required drug discontinuation in 4 cases.

CONCLUSION

VGCV administered as preemptive therapy for CMV infection in patients receiving an allogeneic HSCT showed promise for treating this frequent complication. Prospective randomized studies in this setting are mandatory to yield more definitive results.

Unexpectedly high inter- and intrapatient variability of ganciclovir levels in children

Few studies report Ganciclovir or Valganciclovir levels in children. Single-center, retrospective study of all available Ganciclovir levels in transplanted children. Ganciclovir monitoring was performed as previously described [G. Filler (1998); Pediatric Nephrology, 12, 6]. For the normalization of dosing to GFR and target trough levels, we assumed first-order kinetics. We analyzed 57 Ganciclovir levels in 20 children (mean age 8.6 +/- 5.5 yr) treated with intravenous or oral Ganciclovir or oral Valganciclovir. Ganciclovir levels were drawn after IV therapy (n = 9), during oral Ganciclovir (n = 5), or during oral Valganciclovir (n = 15). Oral bioavailability of Valganciclovir was 42.0 +/- 21.8%. The dose-normalized intrapatient Valganciclovir variability was 83%. Mean GFR was 92 +/- 22 mL/min/1.73 m(2). Mean Ganciclovir concentration at last available measurement was 0.60 +/- 0.09 mg/L. While target trough Ganciclovir levels have not been established, possibly subtherapeutic Ganciclovir levels <0.5 mg/L on recommended IV doses were found in eight patients. This subset of patients was significantly younger (4.5 +/- 3.1 vs. 11.4 +/- 5.0 yr). Levels <0.5 mg/L were found in 24/57 instances and 10 patients subsequently had their dose increased. The last Valganciclovir dose adjusted to a GFR of 100 mL/min/1.73 m(2) was 842 +/- 323 mg/m(2)/day. A high proportion of patients had low Ganciclovir levels both on intravenous and oral therapy. The oral bioavailability of Valganciclovir was 42%. Our data suggest substantial inter- and intrapatient variability of Ganciclovir levels after pediatric renal transplantation and may support the need for pharmacokinetic monitoring of Ganciclovir and Valganciclovir therapy for the prevention and treatment of CMV disease after pediatric transplantation. It is currently unclear what target trough level would be most suitable.

Valganciclovir: what is the status in solid organ transplantation?

Prophylactic drug therapy for cytomegalovirus disease in solid organ transplant recipients is effective and simple to implement, but it is associated with patient nonadherence and viral resistance. Recent data show that the efficacy and safety of oral ganciclovir and oral valganciclovir are similar. However, three large daily doses of oral ganciclovir are required, which is inconvenient, and viral resistance can develop to the drug. The single daily dose and lack of viral resistance are advantages of valganciclovir. This has become the primary agent for the prevention of cytomegalovirus disease. Current trials are underway to determine its effectiveness for treatment of cytomegalovirus disease, the optimal length of prophylaxis, and the safety and efficacy of a syrup formulation in children.

A comparative randomised study of valacyclovir vs. oral ganciclovir for cytomegalovirus prophylaxis in renal transplant recipients

An open, prospective, randomised study was conducted to compare the safety and efficacy of valacyclovir vs. oral ganciclovir for cytomegalovirus (CMV) prophylaxis in renal transplant recipients. Eighty-three renal transplant recipients were assigned randomly to receive valacyclovir (n=43) or oral ganciclovir (n=40) for the first 3 months after transplantation. Both groups were similar in terms of demographics, primary renal disease, graft source, HLA matching, immunosuppressive therapy and donor-recipient CMV antibody status. CMV infection was diagnosed by detection of virus DNA in plasma with the Amplicor CMV Test. CMV disease was observed in only one patient belonging to the ganciclovir group, who developed enterocolitis 6 months post-transplantation. No difference was observed between the two treatment groups with respect to detection of CMV DNA, virus infections other than CMV, acute rejection episodes, and serum creatinine levels at 3 and 6 months following transplantation. An increased number of bacterial infections was noted in the ganciclovir group (p 0.003). No adverse reactions with either treatment were reported. The estimated cost of valacyclovir treatment was 20% higher than that of ganciclovir treatment. Overall, both valacyclovir and oral ganciclovir were found to be effective and safe for CMV prophylaxis in renal transplant recipients. Decisions regarding prophylactic regimens should include additional criteria, such as cost or possible development of resistance.

Valganciclovir: a review of its use in the management of CMV infection and disease in immunocompromised patients

Valganciclovir (Valcyte) is an orally administered prodrug of the standard anti-cytomegalovirus (CMV) drug ganciclovir. Valganciclovir is as effective as intravenous ganciclovir for the treatment of AIDS-related CMV retinitis, and oral ganciclovir for the prophylaxis of CMV infection and disease in high-risk solid organ transplant recipients. The drug is generally well tolerated and has a similar tolerability profile to that of oral or intravenous ganciclovir, but is devoid of adverse events related to intravenous or indwelling catheter access associated with the use of intravenous ganciclovir, cidofovir and foscarnet. The simple and convenient once-daily valganciclovir regimen offers potential for improved patient compliance. It provides greater systemic ganciclovir exposure than oral ganciclovir, thus reducing the risk of viral resistance when used for prophylaxis in high-risk solid organ transplant recipients. Furthermore, the use of valganciclovir instead of intravenous ganciclovir may provide significant cost savings, based on data comparing oral versus intravenous regimens for the treatment of AIDS-related CMV retinitis. Overall, valganciclovir appears to have some advantages over ganciclovir. Therefore, when used as prophylaxis against CMV infection and disease in high-risk solid organ transplant recipients or as induction and maintenance therapy of CMV retinitis in patients with AIDS, oral valganciclovir is an attractive alternative to other available anti-CMV drugs.

New agents for the prevention of opportunistic infections in haematopoietic stem cell transplant recipients

Over the past three decades, autologous and allogeneic haematopoietic stem cell transplants (HSCTs) have become effective treatments for a variety of malignant and nonmalignant conditions. Patients who undergo HSCT receive high doses of chemotherapy and/or radiation that induce a prolonged period of profound immunodeficiency, placing them at high risk for infection from a panoply of opportunistic organisms. Although supportive treatment for these patients has markedly improved, 10-20% of allogeneic HSCT recipients will ultimately succumb to infection. Joint guidelines to prevent opportunistic infection were released in 2000 by the Centers for Disease Control, the Infectious Diseases Society of America, and the American Society of Blood and Marrow Transplantation; however, treatment decisions for these patients are often based on limited studies or depend on institution-specific transplant protocols and antibiotic resistance patterns. This paper will discuss new agents for preventing bacterial, fungal and viral infections in HSCT recipients.

Reduction of CMV disease with steroid-free immunosuppresssion in simultaneous pancreas-kidney transplant recipients

The impact of a prednisone-free immunosuppressive regimen was evaluated in simultaneous pancreas-kidney (SPK) recipients. Patient and graft survivals, rejection rates and the incidence of CMV disease were determined. Two hundred consecutive SPK transplant recipients received tacrolimus-based immunosuppression with (n = 100) or without (n = 100) chronic prednisone therapy. Patients were induced with lymphocyte depleting antibodies or IL-2 receptor blockers and received prophylactic antiviral therapy. Patient and graft survivals and rejection rates were not statistically significantly different between treatment groups. Two-year cumulative incidence of CMV in recipients in the prednisone-free protocol was reduced (7.2% vs. 16%; p = 0.15). Considering only recipients at highest risk (D+/R- or D+R+), incidence of CMV disease in the prednisone-free group (n = 61) compared to the steroid-treated group (n = 48) was reduced from 36% to 18% (p < 0.05). Multivariate analysis confirmed the independent effect of prednisone treatment on the incidence of CMV (RR 2.3; p = 0.04). In the prednisone-free protocol, incidence of CMV was less frequent in recipients receiving induction with Campath versus rabbit antilymphocyte globulin (2.4% vs. 12.6%; p = 0.14). Eliminating prednisone immunotherapy did not adversely affect outcomes and was associated with a reduced rate of CMV in SPK recipients of organs from sero-positive donors.

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.

Cytomegalovirus prophylaxis using oral ganciclovir or valganciclovir in kidney and pancreas–kidney transplantation under antibody preconditioning

We investigated retrospectively the risk factors for cytomegalovirus (CMV) infection under ganciclovir or valganciclovir prophylaxis (oral ganciclovir 1 g tid, valganciclovir 450 mg/d) in our kidney and simultaneous pancreas-kidney (SPK) transplant patients undergoing transplantation between July 1, 2001 and February 28, 2003. Two hundred eleven patients receiving prophylactic oral ganciclovir or valganciclovir were included in the study. All patients were given antibody preconditioning (thymoglobulin 178, alemtuzumab 33). Duration of prophylactic treatment was between 3 and 8 months. Fifteen (7.1%) patients developed a positive CMV antigenemia in the first 6 months after transplantation, and 18 of 176 (10.2%) patients developed a positive CMV antigenemia during the first year. No patient developed tissue invasive CMV disease. At 6 months after transplantation, valganciclovir was slightly more effective than ganciclovir prophylaxis (P=.052). Positive donor CMV serology significantly increased the risk of CMV infection compared to CMV-negative donors (P=.014 and P=.003 at 6 and 12 months, respectively). Duration of CMV prophylaxis for more than 3 months decreased the risk of CMV infection (P=.04 and P=.009 at 6 and 12 months, respectively). Either valganciclovir prophylaxis (450 mg/d) or high-dose oral ganciclovir (1 g tid) is effective in preventing tissue-invasive CMV disease, and results in a low incidence of CMV antigenemia in patients undergoing kidney and SPK transplantation.