Efficacy and safety of valganciclovir vs. oral ganciclovir for prevention of cytomegalovirus disease in solid organ transplant recipients

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.

Viral prophylaxis in organ transplant patients

Viral pathogens have emerged as the most important microbial agents having deleterious effects on solid organ transplant (SOT) recipients. Antiviral chemoprophylaxis involves the administration of medications to abort transmission of, avoid reactivation of, or prevent progression to disease from, active viral infection. Cytomegalovirus (CMV) is the major microbial pathogen having a negative effect on SOT recipients. CMV causes infectious disease syndromes, augments iatrogenic immunosuppression and is commonly associated with opportunistic superinfection. CMV has also been implicated in the pathogenesis of rejection. Chemoprophylactic regimens for CMV have included oral aciclovir (acyclovir) at medium and high doses, intravenous and oral ganciclovir, and the prodrugs valaciclovir (valacyclovir) and valganciclovir. CMV prophylactic strategies should be stratified, with the highest-risk patients receiving the most 'potent' prophylactic regimens. Herpes simplex virus (HSV) reactivation in SOT recipients is more frequent, may become more invasive, takes longer to heal, and has greater potential for dissemination to visceral organs than it does in the immunocompetent host. Prophylactic regimens for CMV are also effective chemoprophylaxis against HSV; in the absence of CMV prophylaxis, aciclovir, valaciclovir or famciclovir should be used as HSV prophylaxis in seropositive recipients. Primary varicella-zoster virus (VZV) after SOT is rare and most commonly seen in the paediatric transplant population because of VZV epidemiology. Zoster occurs in 5-15% of patients, usually after the sixth post-transplant month. Prophylactic regimens for zoster are neither practical nor cost effective after SOT because of the late onset of disease and low proportion of affected individuals. All SOT recipients should receive VZV immune globulin after contact with either varicella or zoster. Epstein-Barr virus has its most significant effect in SOT as the precipitating factor in the development of post-transplant lymphoproliferative disorders. Antiviral agents that could be effective are the same as those used for CMV, but indications for and effectiveness of prophylaxis are poorly established. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are important pathogens in the SOT population as indications for transplantation. So-called 'prophylaxis' for recurrent HBV and HCV after liver transplantation is controversial, suppressive rather than preventive, and potentially lifelong. Influenza infection after SOT is acquired by person-to-person contact. During epidemic periods of influenza, transplant populations experience a relatively high frequency of infection, and influenza may affect immunosuppressed SOT recipients more adversely than immunocompetent individuals. Antiviral medications for prevention of influenza are administered as post-exposure prophylaxis to SOT recipients, in addition to yearly vaccine, in circumstances such as influenza epidemics and nosocomial outbreaks, and after exposure to a symptomatic individual during 'flu season'.

Efficacy of valganciclovir administered as preemptive therapy for cytomegalovirus disease in liver transplant recipients: impact on viral load and late-onset cytomegalovirus disease

BACKGROUND

The efficacy of valganciclovir used as preemptive therapy for cytomegalovirus (CMV) disease in liver transplant recipients is not known.

METHODS

Between 1996 and 2004, surveillance testing using CMV antigenemia was performed at weeks 2, 4, 6, 8, 10, 12, and 16 posttransplant. A total of 28.8% (17/59) of the patients from 2001 to 2004 with antigenemia who received valganciclovir as preemptive therapy were compared with 26.2% (21/80) of the patients from 1996 to 2000 who received oral ganciclovir as preemptive therapy.

RESULTS

The mean decline in the antigenemia level after initiation of valganciclovir and oral ganciclovir was 80.5% versus 50.7% at 1 week, 99.5% versus 89.4% at 2 weeks, and 100% versus 97.7% at 4 weeks, respectively. A higher proportion of patients who received valganciclovir (64.7%) belonged to the high-risk group (R-/D+) than patients who received oral ganciclovir (33.3%, P=0.10). Recurrent shedding was documented in 47.1% (8/17) of the patients in the valganciclovir group and 28.6% (6/21) of the patients in the oral ganciclovir group (P>0.20). Recurrent shedding correlated significantly with R-/D+ CMV serostatus and baseline CMV antigenemia level, regardless of the study group. No patient in either group developed CMV disease during or after the period of surveillance monitoring. The incidence of opportunistic infections and patient outcome did not differ for the valganciclovir group versus the oral ganciclovir group or patients without CMV infection (P>0.20).

CONCLUSION

Antigenemia-directed valganciclovir as preemptive therapy seems to be effective for the prevention of CMV disease in liver transplant recipients, including high-risk patients.

A simplified strategy for clinical management of late cytomegalovirus infection after oral ganciclovir prophylaxis in renal recipients

OBJECTIVES

Late cytomegalovirus disease after completion of prophylactic therapy occurs in 5-21% of renal allograft recipients within the first year post-transplantation. Identifying patients at risk for late infection is clinically difficult; prolonged cytomegalovirus (CMV) monitoring is costly and cumbersome as follow-up intervals lengthen.

PATIENTS AND METHODS

We performed a prospective 1 year study in 54 de novo renal recipients to assess the minimum CMV monitoring frequency for identifying patients at risk.

RESULTS AND CONCLUSIONS

CMV DNA PCR monitoring on the last day, and again 2 weeks after conclusion of oral ganciclovir prophylaxis, seemed sufficient for identifying recipients at risk for developing clinically relevant late CMV disease and for whom closer clinical follow-up is warranted.

Treatment of Cytomegalovirus Infection or Disease in Solid Organ Transplant Recipients With Valganciclovir

Valganciclovir (VGC) has proved efficacious and safe for the prophylaxis against cytomegalovirus (CMV) in high-risk transplant recipients and for the treatment of CMV retinitis in AIDS patients. We used VGC for the treatment of CMV infection (viremia without symptoms) or disease (CMV syndrome or tissue-invasive disease) in kidney, heart, and lung transplant recipients. Fourteen transplant recipients were treated: five for asymptomatic CMV infection and nine for CMV disease. VGC was administered in doses adjusted to renal function for 4 to 12 weeks (induction and maintenance therapy). Clinically, all nine patients with CMV disease responded to treatment. Microbiologically, treatment with VGC turned blood culture negative for CMV within 2 weeks in all patients and was associated with a > or =2 log decrease in blood CMV DNA within 3 weeks in 8 of 8 tested patients. With a follow-up of 6 months (n = 12 patients), asymptomatic recurrent CMV viremia was noted in five cases, and CMV syndrome noted in one case (all cases in the first 2 months after the end of treatment). VGC was clinically well tolerated in all patients; however, laboratory abnormalities occurred in three cases (mild increase in transaminases, thrombocytopenia, and pancytopenia). This preliminary experience strongly suggests that therapy with VGC is effective against CMV in organ transplant recipients; however, the exact duration of therapy remains to be determined: a longer course may be necessary to prevent early recurrence.

Valganciclovir: oral prevention and treatment of cytomegalovirus in the immunocompromised host

Herpes virus infections, particularly those caused by cytomegalovirus (CMV), lead to significant and, sometimes severe, clinical problems for the immunocompromised host. As effective agents have become available, several treatment and prevention strategies have evolved over the past decade, first in intra-venous form and more recently, as oral preparations. Valganciclovir, the valine ester of ganciclovir, is an orally administered, potent, antiviral agent active against all herpes viruses. When taken orally, valganciclovir has much-improved bioavailability compared with oral ganciclovir and achieves ganciclovir exposures similar to intravenous ganciclovir. Clinical trials evaluating the safety and efficacy of valganciclovir for the treatment of new AIDS-associated CMV retinitis showed equivalency to intravenous ganciclovir and prevented progression of quiescent disease. In solid organ recipients, once-daily valganciclovir has been proven equivalent to oral ganciclovir for the prevention of CMV infection. The high bioavailability and convenient dosing formulation make valganciclovir an attractive option for these indications.

Valacyclovir for Cytomegalovirus Prophylaxis Reduces the Risk of Acute Renal Allograft Rejection

BACKGROUND

Both oral ganciclovir and valacyclovir decrease the incidence of cytomegalovirus (CMV) disease after renal transplantation. Moreover, valacyclovir has been shown to reduce the risk of acute rejection. Our study was designed to compare the efficacy and safety of oral ganciclovir and valacyclovir in the prophylaxis of CMV disease after renal transplantation.

METHODS

A total of 83 patients were prospectively randomized to 3-month treatment with oral ganciclovir (3 g/day, n=36, GAN) or oral valacyclovir (8 g/day, n=35, VAL). A control group (DEF, n=12) was managed by deferred therapy.

RESULTS

No differences were found in demography, immunosuppression, or donor/recipient CMV serology. The 12-month incidence of CMV disease was 67% in the DEF group compared with 6% in the GAN group and 3% in the VAL group (P<0.001 GAN or VAL vs. DEF; P=0.575 GAN vs. VAL). The biopsy-confirmed acute rejection rate at 12 months was 12% in the VAL group compared with 34% in the GAN group (P=0.030) and 58% in the DEF group (P<0.001). The difference between the GAN and DEF groups was not significant (P=0.087). The average CMV-associated costs per patient were $3,072, $2,906, and $4,906 in the GAN, VAL, and DEF groups, respectively.

CONCLUSIONS

Valacyclovir and oral ganciclovir are equally effective in the prevention of CMV disease after renal transplantation. Both regimens are cost-effective. Valacyclovir is associated with a significantly reduced risk of acute rejection compared with both ganciclovir prophylaxis and deferred therapy.

Canadian society of transplantation consensus workshop on cytomegalovirus management in solid organ transplantation final report

The Canadian Society of Transplantation sponsored a Cytomegalovirus (CMV) Consensus Working Group that met on March 19, 2003. The objectives of this group were to determine the current burden of CMV-associated disease in the setting of solid organ transplantation in Canada, make recommendations regarding optimal strategies for the diagnosis, treatment and prevention of CMV infection and disease, highlight gaps in knowledge and outline priorities for research and other initiatives that might further reduce the burden of CMV-associated effects in this setting. This report summarizes the recommendations of the working group including ratings of the strength of evidence supporting the recommendations.

Valganciclovir prophylaxis in patients at high risk for the development of cytomegalovirus disease

BACKGROUND

Despite advances in antiviral therapies, cytomegalovirus (CMV) remains the leading opportunistic infection in the transplant population. Valganciclovir (VGC), the L-valyl ester prodrug of ganciclovir (GCV), provides an excellent oral alternative to GCV for the prevention of CMV in transplant recipients. We investigated the use of VGC for CMV prevention in high-risk renal and pancreas transplant recipients.

METHODS

Patients at high risk for development of CMV disease were defined as either those who had donor positive, recipient-negative serostatus (D+/R-), or those who received antilymphocyte antibody (ALA) therapy for either rejection treatment or induction. A retrospective review was conducted of all kidney and pancreas transplants performed between August 2001 and December 2003. A total of 341 transplants were performed, of which 109 received VGC, and 88 were included in this analysis.

RESULTS

The overall incidence of CMV disease was 5.7% (5/88). All of the CMV episodes were in patients who were D+/R- (17.2% [5/29] versus 0% [0/59], P<0.001). Of these patients, all the episodes of CMV were in patients who received VGC prophylaxis for<100 days post transplant (29% [5/17] versus 0% [0/12], P=0.06). The overall incidence of leukopenia was 11% and thrombocytopenia was 7%, with the incidence between the D+/R- group and the ALA group being similar.

CONCLUSION

VGC is an effective agent in preventing CMV disease in kidney and pancreas transplant recipients who are at high risk for developing the disease. The optimal length of prophylaxis in D+/R- patients is still undefined, while 3 months of prophylaxis appears to be sufficient in patients who received ALA therapy.

Analysis of cytomegalovirus DNA polymerase (UL54) mutations in solid organ transplant patients receiving valganciclovir or ganciclovir prophylaxis

We previously reported the absence of CMV UL97 (kinase) gene resistance mutations up to 12 months post-transplant following 100 days of valganciclovir prophylaxis, and a low incidence of resistance mutations following 100 days of oral ganciclovir prophylaxis in a prospective multicenter study in solid organ transplant recipients excluding lung transplants. Herein, we report UL54 (DNA polymerase) gene sequencing results for all patients with previous UL97 PCR-positive samples (n = 99) in our study. One UL54 resistance mutation (L545S known to confer ganciclovir and cidofovir resistance) was detected in a routine day-100 sample from an asymptomatic patient who received oral ganciclovir. Notably, this CMV UL54 mutation occurred in the absence of a UL97 mutation. Additionally, new UL54 variants were observed. Thus, emergence of CMV UL54 mutations in the absence of UL97 mutations is a rare but possible event that is not necessarily associated with detrimental clinical outcome in solid organ transplant recipients.

Similar Reduction of Cytomegalovirus DNA Load by Oral Valganciclovir and Intravenous Ganciclovir on Pre-Emptive Therapy after Renal and Renal–Pancreas Transplantation

Background

Pre-emptive treatment of CMV infection in transplant recipients aims at prevention of clinical disease by early detection. However, current treatment requires the intravenous (iv) administration of ganciclovir for 2 weeks, which is a considerable burden for the patient. In this observational study, the efficacy of the new oral prodrug valganciclovir was compared with iv ganciclovir.

Methods

To facilitate the introduction of valganciclovir, a therapeutic guideline was developed to use this drug under controlled conditions with regard to safety in renal/renal–pancreas transplant recipients requiring CMV therapy. Subsequently, a group of 57 consecutive transplant recipients was evaluated. Onset and treatment of CMV infections were followed by frequent monitoring of CMV DNA in plasma by quantitative real-time PCR. Details of antiviral therapy were documented.

Results

In 15 out of 57 transplant recipients, a total of 27 anti-CMV treatment episodes were recorded: 18 with valganciclovir (900 mg twice daily) and nine with iv ganciclovir (5 mg/kg twice daily) as initial treatment. Median CMV DNA load reduction during treatment was 0.12 log10/day in the valganciclovir group and 0.09 log10/day in the ganciclovir group. There were no haematological side effects in any group and no patient developed signs of clinical CMV disease.

Conclusion

Similar reduction of CMV DNA load was observed during pre-emptive treatment with oral valganciclovir and iv ganciclovir in transplant recipients. Oral valganciclovir would provide an attractive and safe alternative for pre-emptive CMV treatment in renal/renal–pancreas transplant patients, however, confirmation in larger randomized studies would be desirable.

Pharmacokinetic Profile of Ganciclovir After its Oral Administration and From its Prodrug, Valganciclovir, in Solid Organ Transplant Recipients

BACKGROUND

Valganciclovir (Valcyte) has recently been approved for the prevention of cytomegalovirus (CMV) disease in high-risk (CMV donor positive [D+]/recipient negative [R-]) solid organ transplant (SOT) recipients. Large-scale studies describing the pharmacokinetics of valganciclovir in SOT recipients are lacking. A recent randomised, double-blind study of valganciclovir in 364 D+/R- (intent-to-treat population) SOT recipients provided valuable data on which a population pharmacokinetic analysis was performed.

METHODS

The pharmacokinetics of ganciclovir from oral ganciclovir (Cymevene, 1000 mg three times daily) and from valganciclovir (900 mg once daily) were described with plasma levels from 240 patients (1181 datapoints describing 449 pharmacokinetic profiles) using nonlinear mixed-effects modelling (NONMEM) software. A two-compartment pharmacokinetic model with separate absorption/metabolism and absorption parameters for valganciclovir and ganciclovir, respectively, was developed.

RESULTS

Exposure to ganciclovir from valganciclovir averaged 1.65-fold greater than that from oral ganciclovir (95% CI 1.58, 1.81); respective daily area under the plasma concentration-time curve values were 46.3 +/- 15.2 microg . h/mL and 28.0 +/- 10.9 microg . h/mL. The relative systemic exposure of ganciclovir was approximately 8-fold higher from valganciclovir than oral ganciclovir. Exposure to ganciclovir from valganciclovir was similar among liver, heart and kidney transplant recipients (46.0 +/- 16.1, 40.2 +/- 11.8 and 48.2 +/- 14.6 microg . h/ mL, respectively). Adherence to the prescribed dosing regimens, which were reduced for renal impairment, gave consistent exposure to ganciclovir.

CONCLUSION

Oral valganciclovir produces exposures of ganciclovir exceeding those attained with oral ganciclovir, but in line with those reported after standard intravenous administration of ganciclovir. This indicates that oral valganciclovir is suitable in circumstances requiring prophylactic use of ganciclovir and allows for more convenient management of patients at risk of CMV disease.

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.

Risk Factors for Cytomegalovirus Viremia and Disease Developing after Prophylaxis in High-Risk Solid-Organ Transplant Recipients

BACKGROUND

Cytomegalovirus (CMV) D+/R- solid-organ transplant (SOT) recipients carry increased risk of developing CMV disease; however, other risk factors in these patients have not been delineated.

METHODS

We examined 20 demographic and clinical variables for their association with the development of CMV disease, as defined by an independent endpoint committee (IEC) and also by the investigator (investigator treated [IT]), or CMV viremia within 12 months of transplant in D+/R- transplant recipients who received prophylaxis with valganciclovir or oral ganciclovir for 100 days.

RESULTS

Recipients with low creatinine clearance (Ccr,<40 mL/min) at screening had a significantly increased hazard of developing IEC-defined CMV disease (hazards ratio [HR]=4.28, confidence interval [CI] 1.69, 10.83). Females were twice as likely (HR=2.19, CI .21, 3.99) to develop IEC-defined CMV disease than males. These variables were associated with an increased risk of IEC-defined CMV disease in time-dependent models. Recipients with blood group A were also more likely to develop IEC-defined CMV disease than those with group O (HR=2.36 CI 1.24, 4.51) in the logistic regression model only. Prophylactic drug, organ type, recipient age, rejection episodes, and maintenance immunosuppression regimen were not associated with IEC-defined CMV disease. Female sex was the only variable associated with the development of CMV viremia (odds ratio [OR]=1.65; CI 1.03, 2.65) and IT CMV disease (OR=1.78; CI 1.08, 2.93).

CONCLUSIONS

Low Ccr at screening and blood type A are risk factors for IEC-defined CMV disease, and female sex was a risk factor for IEC- and IT-defined CMV disease and viremia in high-risk SOT recipients. These variables should perhaps be considered when optimizing treatment.

Late-Onset Cytomegalovirus Disease in Liver Transplant Recipients Despite Antiviral Prophylaxis1

BACKGROUND

The incidence and impact of cytomegalovirus (CMV) disease that occurs despite CMV prophylaxis among liver transplant recipients have been incompletely defined.

METHODS

The incidence and risk factors for CMV disease during the first posttransplant year in a cohort of liver transplant recipients who received antiviral prophylaxis with oral ganciclovir were retrospectively analyzed using Cox proportional-hazard regression models.

RESULTS

CMV disease developed in 19 of 259 recipients (7% [95% confidence interval 0.04-0.11]) at a median of 4.5 months posttransplant, included syndrome (63%) or tissue-invasive disease (37%), and was independently associated with an increased risk of mortality during the first posttransplant year (hazard ratio 14 [95% confidence interval 3.8-54], P=0.0007). The incidence was higher (10/38 [26%] vs. 8/180 [4.5%], P<0.0001) in seronegative recipients (R-) of an organ from a seropositive donor (D+) compared with seropositive (R+) patients, respectively. D+R- status was the only variable significantly associated with CMV disease in multivariate analysis.

CONCLUSIONS

Late CMV disease develops in a substantial proportion of D+R- recipients after prophylaxis is discontinued, is not accurately predicted by patient factors, and is associated with increased mortality. New strategies to identify D+R- patients at risk and to reduce the incidence and impact of late CMV disease in this group are warranted.

Following universal prophylaxis with intravenous ganciclovir and cytomegalovirus immune globulin, valganciclovir is safe and effective for prevention of CMV infection following lung transplantation

We prospectively determined the safety and efficacy of valganciclovir for prevention of cytomegalovirus (CMV) in at-risk (donor positive/recipient negative [D+/R-] or R+) lung transplant recipients. We also determined the length of prophylaxis required to significantly decrease both CMV infection and disease. Consecutive lung transplant recipients surviving >30 days (n = 90) received combination prophylaxis with intravenous (i.v.) ganciclovir (GCV) 5 mg/kg/day and cytomegalovirus immune globulin (CMV-IVIG) followed by valganciclovir (450 mg twice-daily) to complete 180, 270 or 365 days of prophylaxis. This group was compared to a historical group (n = 140) who received high-dose oral acyclovir following i.v. GCV and CMV-IVIG. CMV disease was significantly lower in patients receiving valganciclovir compared to acyclovir (2.2% vs. 20%; p < 0.0001). Freedom from CMV infection and disease was significantly greater (p < 0.02) in patients receiving 180, 270 or 365 days of prophylaxis (90%, 95% and 90%, respectively) compared to those receiving 100-179 days (64%) or < 100 days (59%). No patient receiving valganciclovir died during the study. Following prophylaxis with i.v. GCV and CMV-IVIG, valganciclovir is safe and effective for prevention of CMV infection and disease in at-risk lung transplant recipients. The required length of prophylaxis was at least 180 days.

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.

Prevention and treatment of cytomegalovirus infection in solid organ transplant recipients

PURPOSE OF REVIEW

Cytomegalovirus remains the single most important pathogen affecting solid organ transplant recipients. Its importance lies both in its effects and as a model for deciphering the clinical impact and management of other agents such as hepatitis C virus and other herpes viruses such as human herpes virus-6 and 7. The effects of cytomegalovirus infection in these patients can be divided into two categories: the direct causation of a wide variety of infectious disease syndromes; and the indirect effects, which include contributing to the net state of immunosuppression, allograft injury, and potentiating posttransplant lymphoproliferative disease.

RECENT FINDINGS

The advent of valganciclovir, with its excellent oral bioavailability, combined with intravenous ganciclovir have provided powerful tools for controlling the direct effects of cytomegalovirus, particularly with the recognition that the intensity of the antiviral therapy has to be linked to the intensity of the immunosuppression required.Unfortunately, far less is known about the efficacy of antiviral therapy in managing the indirect effects of cytomegalovirus. Preliminary data suggest antiviral prophylaxis protects against acute allograft injury, as well as decreasing the incidence of some opportunistic infection.

SUMMARY

A great deal of progress has been made in the prevention and treatment of the infectious disease syndromes caused by cytomegalovirus, with the development of the concept of the therapeutic prescription. This has two components: an immunosuppressive component to prevent and treat rejection and an antimicrobial component to make it safe. Much more information, however, is required.

Pulmonary complications of solid organ and hematopoietic stem cell transplantation

The ability to successfully transplant solid organs and hematopoietic stem cells represents one of the landmark medical achievements of the twentieth century. Solid organ transplantation has emerged as the standard of care for select patients with severe vital organ dysfunction and hematopoietic stem cell transplantation has become an important treatment option for patients with a wide spectrum of nonmalignant and malignant hematologic disorders, genetic disorders, and solid tumors. Although advances in surgical techniques, immunosuppressive management, and prophylaxis and treatment of infectious diseases have made long-term survival an achievable goal, transplant recipients remain at high risk for developing a myriad of serious and often life-threatening complications. Paramount among these are pulmonary complications, which arise as a consequence of the immunosuppressed status of the recipient as well as from such factors as the initial surgical insult of organ transplantation, the chemotherapy and radiation conditioning regimens that precede hematopoietic stem cell transplantation, and alloimmune mechanisms mediating host-versus-graft and graft-versus-host responses. As the population of transplant recipients continues to grow and as their care progressively shifts from the university hospital to the community setting, knowledge of the pulmonary complications of transplantation is increasingly germane to the contemporary practice of pulmonary medicine.