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

The effect of sex inequality on solid organ transplantation: A systematic review and meta-analysis

BACKGROUND

Sex disparities are related to biological differences, which may have significant impact on patient and allograft outcomes. The aim was to investigate the impact of sex on clinical and safety outcomes after solid organ transplantation (SOT).

METHODS

A systematic review and meta-analysis was performed. Observational studies comparing females vs. males after SOT were considered for inclusion after a systematic search of the Pubmed, Cochrane Library, and Web of Science databases conducted from 2016 to 2021. Primary outcome was mortality. PROSPERO register number: CRD42021282615.

RESULTS

After retrieving 1103 studies, 22 observational studies (1,045,380 subjects) were finally deemed eligible for inclusion. Females accounted 36.3% of SOT recipients, but presented significantly lower mortality (odds ratio (OR): 0.87, 95% confidence interval (CI): 0.83-0.92, I2=78%). In subgroup analyses, mortality was significantly lower in females undergoing liver (OR: 0.89 95%CI: 0.86-0.92, I2=0%) or kidney transplantation (OR: 0.82 95%CI: 0.76-0.89, I2=72%). Male sex was consistently reported as a protective factor against hospital readmission. Among the outcomes, allograft dysfunction was influenced by a combination of donor-recipient sex and age. Data on overall infections were inconclusive. Several reports suggest a higher risk of malignancy among males.

CONCLUSIONS

Females represent one-third of SOT recipients but have higher survival rates than males after liver and kidney transplantation. The impact on graft dysfunction was heterogeneous. While further research is warranted, our findings should encourage clinicians and researchers to consider sex as a factor when taking decisions regarding SOT management.

Female sex and advanced age are associated with invasive cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Limited data exist to describe sex-based differences in the severity of cytomegalovirus (CMV) infection after solid organ transplant (SOT). We sought to identify if a difference exists in likelihood of tissue-invasive disease between male and female SOT recipients and to understand how age affects this relationship.

METHODS

A retrospective cohort of 180 heart, liver, and kidney recipients treated for CMV was examined. A logistic regression model was developed to assess the relationship between female sex and CMV type (noninvasive vs. invasive). A secondary regression analysis looked at the relationship of invasive CMV with a variable combining sex with age above or below 50.

RESULTS

There were 37 cases of proven or probable invasive CMV, occurring in 30% of females versus 16% of males. After adjustment for potential confounders, females with CMV infection were significantly more likely to have invasive disease (odds ratio (OR) 2.69, 95% confidence interval (CI) 1.25-5.90, p = .01). Females 50 years or older were at particular risk compared with males under 50 years (adjusted OR 4.54, 95% CI 1.33-18.83, p = .02).

CONCLUSION

Female SOT recipients with CMV in our cohort were more likely than males to have tissue-invasive disease, with the highest risk among older females. Further prospective studies are warranted to explore underlying immunologic mechanisms.

Relationship between certain HLA alleles and the risk of cytomegalovirus reactivation following allogeneic hematopoietic stem cell transplantation

INTRODUCTION

Evidence is emerging to support an association between certain HLA alleles and the risk of cytomegalovirus (CMV) reactivation following allogeneic HSCT (allo-HSCT). The primary aim of this study was to identify HLA alleles associated with resistance or susceptibility to CMV reactivation.

METHODS

We studied 586 adults who underwent allo-HSCT for high-risk hematological malignancies. High resolution HLA typing data was available for recipient and donor. HLA Class I and II alleles observed at a frequency of > 5% in our population, were included in the analysis. A CMV viremia level of more than 200 IU/ml on weekly monitoring was considered to be indicative of CMV reactivation.

RESULTS

The median follow-up time in surviving patients was 21 months (range 4-74 months). The cumulative incidence of CMV reactivation at 6 months in the entire cohort was 55% (95% CI 50.8%-59.2%). Mismatched donor, increasing recipient age, occurrence of AGVHD and recipient CMV seropositivity were associated with increased risk of CMV reactivation. HLA B*07:02 (HR 0.59, 95% CI 0.40-0.83) was associated with decreased risk of CMV reactivation. Patients who developed CMV reactivation had a lower incidence of relapse, higher transplant related mortality (TRM) and lower overall survival (OS) compared to those without CMV reactivation. There was an adverse correlation of OS and TRM with increasing numbers of CMV reactivations.

CONCLUSION

We observed that HLA B*07:02 was associated with decreased risk of CMV reactivation. CMV reactivation was associated with lower relapse post-transplant, but this did not translate into a survival benefit due to higher transplant related mortality. This article is protected by copyright. All rights reserved.

Cytomegalovirus in renal transplant recipients from living donors with and without valganciclovir prophylaxis and with immunosuppression based on anti-thymocyte globulin or basiliximab

BACKGROUND

In our population, anti-thymocyte globulin (ATG) of 1 mg/Kg/day for 4 days is used; which permits not using valgancyclovir (VGC) prophylaxis in some renal transplant recipients (RTR) with moderate risk (R+), to reduce costs. This study aimed to determine the incidence and risk of developing cytomegalovirus (CMV), with or without prophylaxis, when exposed to low doses of ATG or basiliximab (BSL).

PATIENTS AND METHODS

A retrospective cohort included 265 RTR with follow-up of 12 months. Prophylaxis was used in R-/D+ and some R+. Tacrolimus (TAC), mycophenolate mofetil, and prednisone were used in all patients. Logistic regression analysis was performed to estimate the risk of CMV in RTR with or without VGC.

RESULTS

Cytomegalovirus was documented in 46 (17.3%) patients: 20 (43.5%) with CMV infection, and 26 (56.5%) with CMV disease. Anti-thymocyte globulin was used in 39 patients (85%): 32 R+, six D+/R-, and one D-/R-. ATG was used in 90% (27 of 30) of patients with CMV and without prophylaxis. The multivariate analysis showed an association of risk for CMV with the absence of prophylaxis (RR 2.29; 95% CI 1.08-4.86), ATG use (RR 3.7; 95% CI 1.50-9.13), TAC toxicity (RR 3.77; 95% CI 1.41-10.13), and lymphocytes at the sixth post-transplant month (RR 1.77; 95% CI 1.0-3.16).

CONCLUSIONS

Low doses of ATG favored the development of CMV and a lower survival free of CMV compared with BSL. In scenarios where resources for employing VGC are limited, BSL could be an acceptable strategy.

Delayed graft function and rejection are risk factors for cytomegalovirus breakthrough infection in kidney transplant recipients

Breakthrough cytomegalovirus (CMV) disease during valganciclovir prophylaxis is rare but may cause significant morbidity and even mortality. In order to identify patients at increased risk the incidence of CMV disease was studied in a large population of renal transplant recipients who underwent a kidney transplantation in the Radboud University Medical Center between 2004 and 2015 (n = 1300). CMV disease occurred in 31/1300 patients. Multivariate binary linear regression analysis showed that delayed graft function (DGF) (p = 0.018) and rejection (p = 0.001) significantly and independently increased the risk of CMV disease, whereas CMV status did not. Valganciclovir prophylaxis was prescribed to 281/1300 (21.6%) high-risk patients (defined as CMV IgG-seronegative recipients receiving a kidney from a CMV IgG-seropositive donor (D+/R-)). Of these 281 patients, 51 suffered from DGF (18%). The incidence of breakthrough CMV disease in D + /R- patients with DGF was much higher than in those with immediate function (6/51 (11.8%) vs 2/230, (0.9%), p = 0.0006 Fisher's exact test), despite valganciclovir prophylaxis. This higher incidence of CMV disease could not be explained by a higher incidence of rejection (and associated anti-rejection treatment) in patients with DGF. D + /R- patients with DGF are at increased risk of developing CMV disease despite valganciclovir prophylaxis. These findings suggest that underexposure to ganciclovir occurs in patients with DGF. Prospective studies evaluating the added value of therapeutic drug monitoring to achieve target ganciclovir concentrations in patients with DGF are needed.

Evaluation of cytomegalovirus prophylaxis in low and intermediate risk kidney transplant recipients receiving lymphocyte-depleting induction

Cytomegalovirus (CMV) is a significant cause of morbidity in kidney transplant recipients (KTR). Historically at our institution, KTR with low and intermediate CMV risk received 6 months of valganciclovir if they received lymphocyte depleting induction therapy. This study evaluates choice and duration of CMV prophylaxis based on donor (D) and recipient (R) CMV serostatus and the incidence of post-transplant CMV viremia in low (D-/R-) and intermediate (R+) risk KTR receiving lymphocyte-depleting induction therapy. A protocol utilizing valacyclovir for 3 months for D-/R- and valganciclovir for 3 months for R+ was evaluated. Adult D-/R- and R+ KTR receiving anti-thymocyte globulin, rabbit or alemtuzumab induction from 8/20/2016 to 9/30/2018 were evaluated through 1 year post-transplant. Patients were excluded if their CMV serostatus was D+/R-, received a multi-organ transplant, or received basiliximab. Seventy-seven subjects met the inclusion criteria: 25 D-/R- (4 historic group, 21 experimental group) and 52 R+ (31 historic, 21 experimental). No D-/R- patients experienced CMV viremia. Among the R+ historic and experimental groups, there was no significant difference in viremia incidence (35.5% vs 52.4%; P = .573). Of these cases, the peak viral load was similar between the groups (median [IQR], 67 [<200-444] vs <50 [<50-217]; P = .711), and there was no difference in the incidence of CMV syndrome (16.1% vs 14.3%; P = 1.000) or CMV related hospitalization (12.9% vs 14.3%; P = 1.000). No patient experienced tissue invasive disease. These results suggest limiting valganciclovir exposure may be possible in low and intermediate risk KTR receiving lymphocyte-depleting induction therapy with no apparent impact on CMV-related outcomes.

Primary sclerosing cholangitis as an independent risk factor for cytomegalovirus infection after liver transplant

BACKGROUND

Cytomegalovirus (CMV) infection is one of the most common infectious complications after solid organ transplant; it is associated with morbidity and mortality and with many direct and indirect effects. However, monitoring and therapeutic procedures are very heterogeneous across treatment centers. Additionally, factors that place patients at risk of CMV infection are poorly defined.

METHODS

Clinical and demographic data from 833 LT recipients and their donors were retrospectively analyzed. Univariate and multivariate analysis were applied. CMV infection was detected by quantitative nucleic acid testing with a lower limit of detection of 40 IU/mL.

RESULTS

In total, 192 of 833 patients (23%) experienced at least one episode of CMV infection after LT; CMV infection occurred to a large extent during the first year after transplant (70%). Multivariate analysis demonstrated that CMV donor-recipient risk constellation (OR 2.05, 95% CI) and primary sclerosing cholangitis (PSC) before LT (OR 3.76, 95% CI) are independent risk factors for CMV infection after LT.

CONCLUSION

Patients with high-risk serostatus, PSC, or both should be monitored more thoroughly and should receive prolonged prophylaxis against CMV infection.

Cytomegalovirus Viremia in Renal Transplant Recipients After Influenza Vaccination

Vaccination with the inactivated influenza vaccine is routinely recommended for all patients before and after transplant, with reduction in complications noted in transplant recipients. The vaccine is relatively well tolerated with few mild side effects. Cytomegalovirus (CMV) infection can reactivate in both solid organ transplant and hematopoietic stem cell transplant recipients, with some patients progressing to disease. There are multiple factors known to contribute to reactivation and subsequent CMV disease, however vaccination has not been reported as a specific risk factor.

We report on two renal transplant recipients who were seen to develop CMV viremia and CMV disease after receiving the Influenza vaccine. We review the literature regarding viremia occurring after vaccination in HIV patients (a similar group of immunocompromised patients).

Risk Factors for Cytomegalovirus Viremia following Liver Transplantation With a Seropositive Donor and Seronegative Recipient Receiving Antiviral Therapy

BACKGROUND

The risk factors for development of viremia in high-risk donor cytomegalovirus (CMV)-seropositive and recipient CMV-seronegative (D+R-) transplant recipients are incompletely defined.

METHODS

The study population comprised patients in the preemptive therapy (PET) arm of a randomized, controlled trial of PET versus prophylaxis using valganciclovir in D+R- liver transplant recipients. Weekly surveillance monitoring for viremia for 100 days was performed using a sensitive CMV-DNA polymerase chain reaction assays. Risk factors for viremia and time to onset (≤4 vs >4 weeks) of viremia were examined using logistic regression models.

RESULTS

Viremia developed in 84% (79/94) of recipients and older donor age was the only independent factor associated with viremia (odds ratio, 2.20 for each quartile increase in donor age; 95% confidence interval [CI], 1.07-4.52; P = .031). Recipients who developed early-onset viremia (within 4 weeks) also had significantly older donors than those with later-onset viremia (difference in age 10.1 years; 95% CI, 2-19; P = .03).

CONCLUSIONS

Older donor age was an independent predictor of viremia and earlier-onset of viremia in D+R- liver transplant recipients. Future studies should assess the mechanistic links underlying this novel association.

CLINICAL TRIAL REGISTRATION

NCT01552369.

Cytomegalovirus prophylaxis in seropositive renal transplant recipients receiving thymoglobulin induction therapy: Outcome and risk factors for late CMV disease

BACKGROUND

Anti-thymocyte globulin (ATG) therapy is a risk factor for cytomegalovirus (CMV) disease in renal transplant (RTx) recipients and therefore antiviral prophylaxis is commonly used. We evaluated the outcome of our current policy of 90 days of CMV prophylaxis in seropositive recipients given ATG and the risk factors for the occurrence of CMV disease after prophylaxis.

METHODS

We studied a retrospective cohort of 423 RTx (2010-2014) CMV-seropositive adults given ATG induction therapy.

RESULTS

54 (13%) patients developed CMV disease at a median of 163 days after transplant, of which 29 (54%) had viral syndrome and 25 (46%) had invasive disease. Median prophylaxis time (94 days) and immunosuppressive drugs were similar between groups (CMV vs no-CMV). Those with CMV disease had more deceased donors and higher donor age, lower lymphocyte count, and lower median eGFR at day 90. Multivariable logistic regression analysis at day 90 and 180 found that eGFR ≤40 ml/min/1.73 m² (but not acute rejection) was associated with late CMV disease. In a separate validation cohort of 124 patients with 8% late CMV disease, eGFR ≤45 and lymphocyte count ≤800 cells/mm³ at the end of prophylaxis remained predictive of late CMV disease occurrence.

CONCLUSIONS

These data indicate that antiviral prophylaxis adequately prevented CMV in seropositive recipients given ATG, but late disease still occurred. Low eGFR and low lymphocyte count at the end of prophylaxis may help identify patients at higher risk of CMV disease.

Sex differences in transplantation

Sex plays a role in the incidence and progression of a wide variety of diseases and conditions related to transplantation. Additionally, a growing body of clinical and experimental evidence suggests that sex can impact the pharmacokinetics and pharmacodynamics of several commonly used immunosuppressive and anti-infective drugs in transplant recipients. A better understanding of these sex differences will facilitate advances in individualizing treatment for patients and improve outcomes of solid organ transplantation. Here, we provide a review of sex-related differences in transplantation and highlight opportunities for future research directions.

The efficacy of valganciclovir for prevention of infections with cytomegalovirus and Epstein-Barr virus after kidney transplant in children

This study evaluated the efficacy of prophylactic ValGCV in preventing CMV and EBV infections in a single-center pediatric kidney transplant population (2008-2014). Therapy duration was determined according to donor/recipient serostatus. EBV monitoring was performed using monthly plasma PCR for 18 months post-transplant and for CMV, monthly for 6 months after prophylaxis cessation. Data were collected on 35 children, median age 10.6 years. There were 15 (42.9%) and 11 (31.4%) recipients seronegative for CMV or EBV, respectively, who received a kidney from a seropositive donor. Prophylaxis was ceased by 6 months in 24 (69%), between seven and 13 months in 10 (29%) children. Fourteen (40%) and eight (23%) children experienced CMV and EBV DNAemia, respectively. Ten of the 14 (71%) episodes of CMV DNAemia occurred in the first 6 months following cessation of prophylaxis. Shorter prophylaxis was associated with increased CMV DNAemia (P = 0.044). There was an inverse correlation between adjusted ValGCV dose and EBV incidence/timing. Neutropenia was more common if ValGCV dosage was ≥10% of the dose predicted (by BSA and creatinine clearance). ValGCV prevents CMV and may modify EBV infection risk. Frequent dosing adjustment for BSA and creatinine clearance is required to optimize safety and efficacy.

Human Leukocyte Antigen Alleles and Cytomegalovirus Infection After Renal Transplantation

Background:

Several studies have been conducted on the relationship between a number of human leukocyte antigen (HLA) alleles and cytomegalovirus infection (CMV), in kidney transplant recipients, after transplantation. However, only a limited number of HLAs have been investigated, so far, and the results have been contradictory.

Objectives:

This study aimed to investigate the relationship between 59 HLA alleles and the CMV infection, in transplant recipients, after kidney transplantation.

Patients and Methods:

This retrospective cohort study was conducted on 200 patients, receiving a kidney transplant, in Baqiyatallah Hospital, in Tehran, during 2013. Throughout a one-year follow-up of kidney transplant recipients, in case of detecting the CMV antigen in patients’ blood, at any time, they were placed in the group of patients with CMV infection, whereas, if no CMV-specific antigen was developed, over a year, patients were placed in the group of patients without CMV infection, after transplantation. This study investigated the relationship between CMV infection in kidney transplant recipients and 59 HLA alleles, including 14 HLA-A, 28 HLA-B, and 17 HLA-DRB1 cases.

Results:

Of all participants, 104 patients (52%) were diagnosed with CMV infection. There was no significant difference between the two groups, with and without CMV infection, in terms of patient’s characteristics. The CMV infection, in patients receiving a transplanted organ from deceased donor, was significantly more prevalent than in those receiving kidney transplant from living donor (63% vs. 39%, respectively, P = 0.001). Recipients with HLA-B44 were more infected with CMV compared with patients without this allele (80% vs. 50%, respectively, P = 0.024); on the contrary, kidney recipients with HLA-DRB1-1 were less infected with CMV than patients without this allele (31% vs. 55%, respectively, P = 0.020). There was no significant relationship between CMV infection and other HLA alleles. Results of multivariate logistic regression analysis showed that deceased donor renal transplantation (OR = 3.018, 95%CI: 1.662 - 5.480, P < 0.001), presence of HLA-B44 (OR = 4.764, 95%CI: 1.259 - 18.032, P = 0.022) and lack of HLA-B8 (OR = 3.246, 95%CI: 1.030 - 10.230, P = 0.044) were the independent risk factors for developing CMV infection, after kidney transplantation.

Conclusions:

The findings of this study showed that deceased donor renal transplantation and the presence of HLA-B44 can make the kidney recipient susceptible to CMV infection after kidney transplantation; on the other hand, the presence of HLA-B8 can have a protective effect.

Risk factors for late-onset cytomegalovirus infection or disease in kidney transplant recipients

BACKGROUND

CMV-D+/R- serostatus is the only well-established risk factor for late-onset cytomegalovirus (CMV) infection/disease (i.e., incident CMV infection/disease after cessation of prophylactic antiviral therapy). This study aimed to explore other potential risk factors for late-onset CMV infection/disease in kidney transplant recipients.

METHODS

We conducted a retrospective cohort study of 641 kidney transplant recipients in Toronto, Canada, from January 1, 2003, to December 31, 2010. The cumulative incidence of late-onset CMV infection/disease was assessed using the Kaplan-Meier product-limit method. Potential risk factors for late-onset CMV infection/disease were examined using Cox proportional hazards regression models.

RESULTS

Cumulative incidence estimates for CMV infection/disease after prophylaxis cessation in D+/R- versus D+/R+ versus D-/R+ patients were 26.2% versus 7.4% versus 3.1% at 6 months and 30.0% versus 7.7% versus 3.7% at 1 year, respectively. D+/R- serostatus (vs. R+ serostatus) and an estimated glomerular filtration rate of less than 45 mL/min (vs. ≥ 60 mL/min) at prophylaxis cessation were independently associated with late-onset CMV infection/disease (hazard ratio, 4.04 [95% confidence interval, 2.39-6.83]; and hazard ratio, 2.03 [95% confidence interval, 1.07-3.88], respectively).

CONCLUSIONS

Patients with lower estimated glomerular filtration rate at prophylaxis cessation may be at an increased risk of late-onset CMV infection/disease and should be considered for more intensive CMV viral load monitoring, particularly within the first year after prophylaxis cessation.

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.

Evaluation of risk factors for cytomegalovirus infection and disease occurring within 1 year of liver transplantation in high-risk patients

BACKGROUND

Recent studies have demonstrated that cytomegalovirus (CMV) infection and disease are associated with increased risk of graft loss and death in high-risk (donor CMV seropositive/recipient CMV seronegative) liver transplant recipients (LTR) despite effective antiviral chemoprophylaxis. Predictors of CMV infection and disease in this important population are incompletely defined.

METHODS

A retrospective cohort study of 227 high-risk first LTR who received primary anti-CMV chemoprophylaxis during the first 100 days after transplant was performed. A large number of patient, donor, operative, and post-transplant potential risk factors were collected. Associations of potential risk factors for CMV infection or disease that occurred during the first year after transplant were assessed using Cox regression models. After Bonferroni adjustment for multiple testing, P-values ≤0.00125 (associations with CMV infection) and ≤0.00122 (associations with CMV disease) were considered as statistically significant.

RESULTS

CMV infection and disease occurred in 91 (40%) and 43 (19%) of LTR, respectively. In multivariable analysis, increased risk of CMV infection was observed for patients with lower model for end-stage liver disease (MELD) score (P = 0.025), lower total bilirubin (P = 0.014), and longer operative time (P = 0.038), whereas increased risk of CMV disease was seen in patients with lower MELD score (P = 0.026), lower total bilirubin (P = 0.044), and lower international normalized ratio (P = 0.043). However, after adjustment for multiple testing, none of these findings approached statistical significance.

CONCLUSION

Our results suggest that interventions designed to prevent CMV infection and disease should be applied to all high-risk LTR until more definitive predictors of these complications are identified.

Advances in cytomegalovirus-preventive strategies in solid organ transplantation: defending pre-emptive therapy

Prevention of cytomegalovirus (CMV) infection is an important part of clinical care provided to patients after solid organ transplantation. While the optimal preventive strategy has not been defined, most centers rely on universal prophylaxis or pre-emptive therapy. This article comments on recent studies designed to identify strategies that effectively reduce the incidence of late-onset CMV disease as the main problem associated with prophylaxis, and on recent data regarding the development of CMV-specific immunity depending on the CMV-preventive regimen used. Despite an apparent trend to prefer prophylaxis in clinical practice, this approach does not seem to be based on robust evidence.

Importance of the cytomegalovirus seropositive recipient as a contributor to disease burden after solid organ transplantation

Background

The incidence of cytomegalovirus (CMV) syndrome/disease after adult solid organ transplantation in the era effective antiviral therapy has not been fully assessed.

Objective

To determines the incidence of CMV syndrome/disease after solid organ transplantation in the UK.

Study design

A retrospective analysis of 1807 solid organ transplants from 12 UK solid organ transplant centres representing 32.7% of all transplant activity occurring in the UK between 1/04/2004 and 31/03/2006. Patients were categorised into those experiencing an episode of symptomatic CMV infection after transplant or those who remained free of symptoms. All patients were followed up for 2 years for the occurrence of CMV syndrome/disease.

Results

The majority of the transplant centres used valganciclovir prophylaxis in the high risk D+R− patients (91.6%) whereas management of the lower risk D+R+ and D−R+ patients was more variable with deployment of both prophylactic and pre-emptive strategies in ∼50% of centres. CMV syndrome/disease occurred in 20.5% of the D+R− patients representing 55 cases whereas the incidence was only 8.1% and 9% in the D+R+ and D−R+ group, respectively (p < 0.001 compared to the D+R− group), but representing a further 58 cases of CMV syndrome/disease. CMV viraemia in the D+R− group was associated with a high probability (65%) of CMV syndrome/disease in renal transplant recipients whereas this was less apparent in the intermediate risk groups.

Conclusions

CMV syndrome/disease remains an important healthcare burden after solid organ transplantation with the intermediate risk groups contributing similar numbers of cases as the high risk group.

Late cytomegalovirus transmission and impact of T-depletion in clinical islet transplantation

The epidemiology of cytomegalovirus infection (CMV) in islet transplantation (IT) is not well defined. This study defines incidence, transmission and clinical sequelae of CMV reactivation or disease in 121 patients receiving 266 islet infusions at a single institution. The donor (D)/recipient (R) serostatus was D+/R- 31.2%, D+/R+ 26.3%, D-/R+ 13.2% and D-/R- 29.3%. CMV prophylaxis with oral ganciclovir/valganciclovir was given in 68%. CMV infection occurred in 14/121 patients (11.6%); six had asymptomatic seroconversion and eight others had positive viremia (six asymptomatic and two with CMV febrile symptoms). Median peak viral loads were 1755 copies/mL (range 625-9 100 000). Risk factors for viremia included lymphocyte depletion (thymoglobulin or alemtuzumab, p < 0.001). Viremia was more common in D+/R+ versus D+/R- (p = 0.12), occurring mostly late after transplant (median 306 days). Presumed transmission from IT occurred in 8/83 of D+/R- procedures (9.6%). Of the two cases of CMV disease, one resulted from islet transmission from a CMV positive donor (D+/R-); the other was due to de novo exogenous infection (D-/R-). Therefore, CMV transmission presents rarely after IT and with low incidence compared to solid organ transplantation, but occurs late posttransplant. The use of lymphocyte depleting therapies is a primary risk factor.

Cytomegalovirus seroprevalence among solid organ donors in Hungary: correlations with age, gender, and blood group

BACKGROUND

Cytomegalovirus (CMV) is endemic throughout the world, affecting most of the population, but the seroprevalence of CMV is known to vary among countries. CMV causes a mild infection in persons with intact immunity; however, CMV infection in organ transplantation is associated with significant morbidity and mortality. The present retrospective study was designed to evaluate the age-, gender-, and blood group-adjusted CMV seroprevalence among solid organ donors, representing fairly the overall Hungarian population (according to Hungarian Central Statistic Institute). This information is important for calculating risk-factors for CMV-seronegative recipients. No nationwide estimates of CMV seroprevalence in Hungary (as a representative of Eastern Middle Europe) have been published yet.

METHODS

We investigated 2070 organ donors for CMV seroprevalence by measuring the CMV-specific immunoglobulin G. The donors were divided into 3 age groups (2-20, 21-50, and 51-70 years old). A study was also conducted on a fourth group consisting of 200 residents from an old age home. CMV seroprevalence differences were searched according to age-, gender- and blood-group distribution.

RESULTS

The CMV seroprevalence of organ donors is 85% and of all investigated persons is 86%. The age-specific prevalence increases, starting from 72% in the first group to 99% in the fourth group. Seroprevalence of females was found to be significantly higher than of males (P=.0001).

CONCLUSION

We have shown that the overall CMV seroprevalence in the Hungarian population is moderately high at 86%. The opportunity for CMV-seronegative recipients to get a graft from a seronegative donor is statistically only 2%. The seroprevalence of the youngest age group is 72% and so it can be concluded that the Hungarian population acquires the infection mainly in childhood or in the early adulthood. Female gender is a risk factor for CMV infection. This fact must be taken into consideration during the planning of patients' follow-up, prophylaxis, and therapy.

Strategies for managing cytomegalovirus in transplant recipients

IMPORTANCE OF THE FIELD

Cytomegalovirus (CMV) is the most important pathogen that affects transplant recipients, by directly causing clinical disease and by indirectly reducing patient and allograft survival.

AREAS COVERED IN THIS REVIEW

This review provides a brief overview of the direct and indirect effects of CMV disease and the traditional and newly described factors that increase the risk of disease after transplantation. Newly acquired data in the diagnostics, prevention and treatment of CMV infection are discussed, with emphasis on guidelines for management as recently endorsed by the American Society of Transplantation and the Transplantation Society.

WHAT THE READER WILL GAIN

The reader will gain up-to-date insights into the contemporary management of CMV after solid organ transplantation. Practical aspects of its diagnosis, prevention and treatment are discussed. Emerging concerns of late-onset CMV disease and antiviral resistance are also highlighted to emphasize the need to optimize CMV-prevention strategies.

TAKE HOME MESSAGE

Prevention of CMV disease is an important goal in the management of solid organ transplant recipients. The efficacy of CMV prevention should be measured not only by the significant reduction in CMV incidence but, as importantly, by the improvement in long-term allograft and patient survival.

Current concepts on cytomegalovirus infection after liver transplantation

Cytomegalovirus (CMV) is the most common viral pathogen that negatively impacts on the outcome of liver transplantation. CMV cause febrile illness often accompanied by bone marrow suppression, and in some cases, invades tissues including the transplanted allograft. In addition, CMV has been significantly associated with an increased predisposition to allograft rejection, accelerated hepatitis C recurrence, and other opportunistic infections, as well as reduced overall patient and allograft survival. To negate the adverse effects of CMV on outcome, its prevention, whether through antiviral prophylaxis or preemptive therapy, is regarded as an essential component to the medical management of liver transplant patients. Two recent guidelines have suggested that antiviral prophylaxis or preemptive therapy are similarly effective in preventing CMV disease in modest-risk CMV-seropositive liver transplant recipients, while antiviral prophylaxis is the preferred strategy over preemptive therapy for the prevention of CMV disease in high-risk recipients [CMV-seronegative recipients of liver allografts from CMV-seropositive donors (D+/R-)]. However, antiviral prophylaxis has only delayed the onset of CMV disease in many CMV D+/R- liver transplant recipients, and at least in one study, such occurrence of late-onset primary CMV disease was significantly associated with increased mortality after liver transplantation. Therefore, optimized strategies for prevention are needed, and aggressive treatment of CMV infection and disease should be pursued. The standard treatment of CMV disease consists of intravenous ganciclovir or oral valganciclovir, and if feasible, one should also reduce the degree of immunosuppression. In one recent controlled clinical trial, valganciclovir was found to be as effective and safe as intravenous ganciclovir for the treatment of mild to moderate CMV disease in solid organ (including liver) transplant recipients. In this article, the authors review the current state and the future perspectives of prevention and treatment of CMV disease after liver transplantation.

Cytomegalovirus infection after kidney transplantation, susceptibility to CMV-infection in association with HLA-genotype — Doctoral dissertation summary

Cytomegalovirus infection is a major infectious complication of transplant recipients, causing significant morbidity and mortality. It is possible to treat this infection effectively only if we know the direct and indirect effects of it, if we take the risk-factors into account, and use sensitive and reliable diagnostic methods for early establishment of diagnosis. In order to avoid severe CMV-infection, it is possible to administer prophylactic therapy. For prophylaxis planning it is important to know the CMV-seroprevalence of Hungarian population and its characteristics. Our results have shown that the seroprevalence of Hungarian population is high: 86%. The primary CMV-infection in Hungary occurs in childhood or in early adulthood, till age of 20 years the seroprevalence is 72%. CMV-seronegative recipients should be transplanted using organs of seronegative donors, however, the chance obtaining the graft from a CMV-seronegative donor was shown to be 2% only. Since such seromatching is rear, we have to know that the constellation of negative recipient and positive donor is the highest risk-factor for developing severe primary CMV-infection. While investigating data of 147 CMV-seronegative recipients from high-risk group it has been established that CMV-infection prophylaxis is essential for high risk patients in the early post-transplant period of 3 months, the administration of any of investigated prophylactic protocols is advantageous in comparing with prophylaxis free management of those patients (P=0.006). The study has also proven that monoprophylaxis with ganciclovir or valganciclovir is the most effective and cost-effective procedure as compared to other protocols (P=0.006). It is important to take into consideration that in prophylactic groups the “late-onset” CMV-infection occurred often (25.4%), and that there were no signs of seroconversion after the primary CMV-infection in 14% of the patients. For the first time it has been found and proven that the female sex is a risk factor for CMV-infection (P=0.0006). Genetic variability influences susceptibility to infectious diseases and HLA-molecules are critical for viral antigen uptaking, processing and presenting. Our data of 129 of high-risk patients suggest that recipients positive for HLA-DQ3 are more susceptible to CMV-infection than a comparable group of patients negative for this HLA-type. This result was not due to rejection and/or treatment for rejection and was not influenced by induction therapy or number of HLA-mismatches. The multivariate Cox Regression analysis has shown that HLA-DQ3 positivity is an independent predictor of primary CMV-infection in CMV-seronegative recipients with seropositive donor grafts (P=0.001). The cognition of HLA-DQ3 is useful in the prediction of acute CMV-infection in high-risk patients, and should influence the planning of the patients' management.

Defining the risks for cytomegalovirus infection and disease after solid organ transplantation

Cytomegalovirus continues to be one of the most clinically significant infections after solid organ transplantation. Classic definitions of patients at high risk for infection and tissue-invasive disease are focused on recipient-donor serostatus, type of organ transplanted, and overall level of immunosuppression. However, recent trends in clinical practice call for a reevaluation of cytomegalovirus infection risks after solid organ transplantation. Indeed, whereas early-onset cytomegalovirus infection is usually controlled by antiviral prophylaxis with ganciclovir and derivatives, delayed- and late-onset cytomegalovirus infection can develop after the completion of a course of preventive therapy. In addition, indirect effects of cytomegalovirus infection may occur as a result of persistent low-level viremia. Suboptimal dosing of antiviral drugs due to specific drug toxicities may result in the development of ganciclovir-resistant cytomegalovirus disease. The relationship between organ allograft rejection and cytomegalovirus infection and disease has been recognized for some time. Transplantation of increasing numbers of extended-criteria donor organs increases the risk of delayed graft function and acute rejection, prompting the use of more intensive immunosuppression. In addition, the trend to spare long-term exposure to calcineurin inhibitors has contributed to a resurgence in the use of polyclonal T-cell induction immunosuppressive agents, which may reduce host anticytomegalovirus immunity. We discuss the current trends in solid organ transplantation that provide a foundation for defining risks for cytomegalovirus infection and disease, including identification of patients who would benefit from more aggressive cytomegalovirus monitoring and prevention strategies.

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.

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.

Cytomegalovirus infection after liver transplantation: Current concepts and challenges

Cytomegalovirus (CMV) is a common viral pathogen that influences the outcome of liver transplantation. In addition to the direct effects of CMV syndrome and tissue-invasive diseases, CMV is associated with an increased predisposition to acute and chronic allograft rejection, accelerated hepatitis C recurrence, and other opportunistic infections, as well as reduced overall patient and allograft survival. Risk factors for CMV disease are often interrelated, and include CMV D+/R- serostatus, acute rejection, female gender, age, use of high-dose mycophenolate mofetil and prednisone, and the overall state of immunity. In addition to the role of CMV-specific CD4+ and CD8+ T lymphocytes, there are data to suggest that functionality of the innate immune system contributes to CMV disease pathogenesis. In one study, liver transplant recipients with a specific polymorphism in innate immune molecules known as Toll-like receptors were more likely to develop higher levels of CMV replication and clinical disease. Because of the direct and indirect adverse effects of CMV disease, its prevention, whether through antiviral prophylaxis or preemptive therapy, is an essential component in improving the outcome of liver transplantation. In the majority of transplant centers, antiviral prophylaxis is the preferred strategy over preemptive therapy for the prevention of CMV disease in CMV-seronegative recipients of liver allografts from CMV-seropositive donors (D+/R-). However, the major drawback of antiviral prophylaxis is the occurrence of delayed-onset primary CMV disease. In several prospective and retrospective studies, the incidence of delayed-onset primary CMV disease ranged from 16% to 47% of CMV D+/R- liver transplant recipients. Current data suggests that delayed-onset CMV disease is associated with increased mortality after liver transplantation. Therefore, optimized strategies for prevention and novel drugs with unique modes of action are needed. Currently, a randomized controlled clinical trial is being performed comparing the efficacy and safety of maribavir, a novel benzimidazole riboside, and oral ganciclovir as prophylaxis against primary CMV disease in liver transplant recipients. The treatment of CMV disease consists mainly of intravenous (IV) ganciclovir, and if feasible, a reduction in the degree of immunosuppression. A recent controlled clinical trial demonstrated that valganciclovir is as effective and safe as IV ganciclovir for the treatment of CMV disease in solid organ (including liver) transplant recipients. In this article, the author reviews the current state and the future perspectives of prevention and treatment of CMV disease after liver transplantation.

Pharmacokinetics of low and maintenance dose valganciclovir in kidney transplant recipients

Valganciclovir is commonly used for cytomegalovirus (CMV) prophylaxis in renal transplant patients. A fixed dose of 900 mg daily is typically recommended, however, there has never been a formal pharmacokinetic study comparing various doses in renal transplant patients. We therefore compared the pharmacokinetic characteristics of intravenous ganciclovir (IV GCV) and oral ganciclovir (GCV) with two different doses of valganciclovir (VGCV) in an open-label crossover study. Ten adult kidney recipients participated in a four-phase crossover treatment schedule of IV GCV (2.5 mg/kg every 12 h), VGCV (900 mg daily), VGCV (450 mg daily) and oral GCV (1000 mg Q8 H). IV GCV and oral VGCV 900 mg daily achieved similar values for AUC(0-24) (median 60.63 vs. 62.86 microg/h/mL). Oral VGCV 450 mg achieved comparable AUC(0-24) values as oral GCV 1000 mg Q8 H (median AUC(0-24) 35.9 vs. 29.04 microg/h/mL). Oral VGCV 900 mg daily provided systemic GCV exposure similar to IV GCV and confirms PV 16 000 study results. Further, VGCV 450 mg daily provided comparable systemic exposure versus oral GCV. Due to its favorable pharmacokinetic profile, data herein suggest that VGCV can be used in the early post-kidney transplant period, and that 450 mg daily provides ample drug exposure for effective CMV prophylaxis in kidney transplant patients.

Improvement in long-term renal graft survival due to CMV prophylaxis with oral ganciclovir: results of a randomized clinical trial

Oral ganciclovir prophylaxis and intravenous preemptive therapy are competitive approaches to prevent cytomegalovirus (CMV) disease after renal transplantation. This trial compared efficacy, safety and long-term graft outcome in 148 renal graft recipients randomized to ganciclovir prophylaxis (N = 74) or preemptive therapy (N = 74). Hierarchical testing revealed (i) patients with CMV infection had more severe periods of impaired graft function (creatinine clearance(max-min) 25.0 +/- 14.2 mL/min vs. 18.1 +/- 12.5 mL/min for patients without CMV infection; p = 0.02),(ii) prophylaxis reduced CMV infection by 65% (13 vs. 33 patients; p < 0.0001) but (iii) creatinine clearance at 12 months was comparable for both regimes (54.0 +/- 24.9 vs. 53.1 +/- 23.7 mL/min; p = 0.92). No major safety issues were observed, and patient survival at 12 months was similar in both groups (5 deaths [6.8%] vs. 4 [5.4%], p = 1.0000). Prophylaxis significantly increased long-term graft survival 4 years posttransplant (92.2% vs. 78.3%; p = 0.0425) with a number needed to treat of 7.19. Patients with donor +/recipient + CMV serostatus had the lowest rate of graft loss following prophylaxis (0.0% vs. 26.8%; p = 0.0035). In conclusion, it appears that routine oral prophylaxis may improve long-term graft survival for most renal transplant patients. Preemptive therapy can be considered in low risk patients in combination with adequate CMV monitoring.

Delayed-onset primary cytomegalovirus disease and the risk of allograft failure and mortality after kidney transplantation

BACKGROUND

During the contemporary era of antiviral prophylaxis, the impact of delayed-onset primary cytomegalovirus (CMV) disease on the outcome of kidney transplantation is not known. We evaluated the incidence, clinical features, risk factors, and outcomes of CMV disease among high-risk kidney transplant recipients.

METHODS

The medical records of CMV-seronegative recipients of kidney transplants from CMV-seropositive donors were reviewed. Cox proportional hazards regression was used to identify factors associated with CMV disease and to assess its impact on allograft loss and mortality.

RESULTS

None of the 176 CMV-seronegative recipients of kidney transplants from CMV-seropositive donors developed breakthrough CMV disease during a median of 92 days (interquartile range, 90-92 days) of oral ganciclovir or valganciclovir prophylaxis. Thereafter, 51 patients (29%) developed CMV disease at a median of 61 days (interquartile range, 40-143 days) after stopping antiviral prophylaxis. Early-onset bacterial and fungal infection (hazard ratio, 3.61; 95% confidence interval, 1.78-7.33; p < .001) and a Charlson comorbidity index > or =3 (hazard ratio, 2.21; 95% confidence interval, 1.15-4.22; p = .011) were associated with a higher risk of delayed-onset primary CMV disease, and postrejection antiviral prophylaxis (hazard ratio, 0.29; 95% confidence interval, 0.09-0.94; P = .039) was associated with a lower risk of such CMV disease. A time-dependent Cox regression analysis revealed a statistically significant association between tissue-invasive CMV disease and allograft loss or mortality (hazard ratio, 2.85; 95% confidence interval, 1.22-6.67; P = .016).

CONCLUSION

This study of a large cohort of CMV-seronegative recipients of kidney transplants from CMV-seropositive donors illustrates the ongoing challenge of delayed-onset primary CMV disease and its impact on transplantation outcomes despite antiviral prophylaxis. Better strategies for CMV disease prevention after kidney transplantation are warranted.

HLA-DQ3 is a probable risk factor for CMV infection in high-risk kidney transplant patients

BACKGROUND

Cytomegalovirus (CMV) infection in transplant patients with special risk factors remains a major hazard. CMV-seronegative recipients with seropositive donors have the highest risk of developing acute CMV disease. We suggest that the HLA-type may influence the occurrence and the severity of primary CMV infection of these recipients and the measurement of the special HLA-types may be useful in the prediction of acute infection.

METHODS

Since 1999 1213 cadaver kidney transplantations have been performed in our clinic. 163 of 1213 recipients were CMV-seronegative (13%) and 129 of them received the kidney from seropositive donors. All 129 patients received CMV infection prophylaxis. Of 129 CMV-seronegative patients 49 developed acute CMV infection (38%) during the first posttransplant year. CMV infection was diagnosed by CMV antigenemia test and serologic measurements (ELISA). The particular HLA-genotypes of the recipients were studied before the transplantation. The occurrence and the severity of CMV infection was investigated in association with HLA-types.

RESULTS

We found different acute CMV infection distribution in the careers and non-careers of investigated HLA-types: HLA-A2, HLA-B12, HLA-Cw7, HLA-DR6 and HLA-DR11, but the differences were not significant in these HLA-types (P = 0.26, P = 0.37, P = 0.83, P = 0.07 and P = 0.37). While investigating HLA-DQ3, we found that of 68 DQ3-positive patients 32 (47%), of 61 DQ3-negative patients 17 (28%) had acute CMV infection and this difference was found to be significant. This result was confirmed by univariate and multivariate Cox Regression (P = 0.001) and the appropriate significance level was considered by Bonferroni correction.

CONCLUSIONS

HLA-DQ3 was found to be an independent predictor of CMV infection. Our data suggest that patients positive for HLA-DQ3 are more susceptible to CMV infection than a comparable group of patients negative for HLA-DQ3. This result was not due to rejection and/or treatment for rejection and was not influenced by induction therapy. Although we found more symptomatic infections among DQ3+ patients the difference was not significant (P = 0.19). Comparing the gender proportion among all 1213 kidney recipients and among CMV-seronegative recipients we found that the proportion of males is significantly higher among CMV-seronegative recipients (P < 0.001).

Cytomegalovirus infection after solid-organ transplantation, its risk factors, direct and indirect effects and prevention strategies

A humán populációban szélesen elterjedt cytomegalovírus által okozott infekció egyike a leggyakrabban előforduló szervátültetést követő virális eredetű fertőzéseknek, amely befolyásolja a transzplantált szerv és a beteg túlélését is. Leggyakrabban a súlyos tünetekkel járó fertőzés olyan transzplantáltaknál alakul ki, akik cytomegalovírus-szeronegatívak az átültetés idejében, és a szervet szeropozitív donortól kapják. A fertőzés előfordulását és súlyosságát egyéb rizikótényezők is befolyásolják: az immunszuppresszió intenzitása, a beültetett szerv típusa, a graftkilökődés és/vagy ennek kezelése, a donor és recipiens közötti „HLA-mismatch”, a recipiens egyes HLA-típusai, női nem stb. A már kialakult cytomegalovírus-infekciónak direkt (tünetek) és indirekt (szövetkárosító és immunmoduláló) hatásai vannak, mindkettő befolyásolja a beteg életminőségét és a további állapot alakulását. Ezért speciális kezelési sémákat és a megelőzésre irányuló intézkedéseket dolgoztak ki, amelyek segítségével a cytomegalovírus károsító hatása csökkenthető vagy elkerülhető. Számos preventív lehetőség közül a gyakorlatban két megelőzési stratégia alkalmazható hatékonyan: az univerzális profilaxis (részét képezi a szelektív profilaxis) és a preemptív terápia. A szerzők – saját és külföldi tapasztalatok alapján – összefoglalják a prevenciós lehetőségeket, összehasonlítják az alkalmazott protokollok előnyeit és hátrányait. Az Amerikai és Kanadai Transzplantációs Társaságok ajánlása alapján a legtöbb amerikai, de sok európai transzplantációs központban is a betegeket három csoportba sorolják: magas, közepes és alacsony rizikójú csoportok; a besorolásnak megfelelően választható a profilaxis. A magas rizikójú betegcsoportoknál (R–/D+ betegek és tüdőtranszplantáltak) nélkülözhetetlen az univerzális profilaxis. Azoknál a betegeknél, akik antilymphocyta-ellenanyagot (ATG, ALG vagy OKT3) kapnak, szükséges az ún. szelektív profilaxis alkalmazása. A közepes rizikójú betegcsoportoknál (R+/D+ vagy R+/D–) lehet választani az univerzális profilaxis és a preemptív terápia között a klinika adottságait figyelembe véve. A nagy forgalmú ambulanciákon, a szoros monitorozás nehézségei és a költséges laboratóriumi vizsgálatok miatt, továbbá a CMV-fertőzés indirekt hatásainak kiküszöbölése érdekében az ajánlások az univerzális profilaxis alkalmazását javasolják. Az alacsony rizikójú csoportban (R–/D–) vese-, máj-, hasnyálmirigy-, szívtranszplantáció esetén a megelőzés szükségességét a transzplantációs centrum dönti el.

Valacyclovir prophylaxis versus preemptive valganciclovir therapy to prevent cytomegalovirus disease after renal transplantation

Both preemptive therapy and universal prophylaxis are used to prevent cytomegalovirus (CMV) disease after transplantation. Randomized trials comparing both strategies are sparse. Renal transplant recipients at risk for CMV (D+/R-, D+/R+, D-/R+) were randomized to 3-month prophylaxis with valacyclovir (2 g q.i.d., n = 34) or preemptive therapy with valganciclovir (900 mg b.i.d. for a minimum of 14 days, n = 36) for significant CMV DNAemia (>/=2000 copies/mL by quantitative PCR in whole blood) assessed weekly for 16 weeks and at 5, 6, 9 and 12 months. The 12-month incidence of CMV DNAemia was higher in the preemptive group (92% vs. 59%, p < 0.001) while the incidence of CMV disease was not different (6% vs. 9%, p = 0.567). The onset of CMV DNAemia was delayed in the valacyclovir group (37 +/- 22 vs. 187 +/- 110 days, p < 0.001). Significantly higher rate of biopsy-proven acute rejection during 12 months was observed in the preemptive group (36% vs. 15%, p = 0.034). The average CMV-associated costs per patient were $5525 and $2629 in preemptive therapy and valacyclovir, respectively (p < 0.001). However, assuming the cost of $60 per PCR test, there was no difference in overall costs. In conclusion, preemptive valganciclovir therapy and valacyclovir prophylaxis are equally effective in the prevention of CMV disease after renal transplantation.

Delayed-onset primary cytomegalovirus disease after liver transplantation

Clinical practice guidelines recommend antiviral prophylaxis to cytomegalovirus (CMV) donor-positive/recipient-negative (D+/R-) liver transplant recipients. We assessed the outcome of this strategy by determining the incidence, clinical features, and risk factors of CMV disease among CMV D+/R- liver transplant recipients who received antiviral prophylaxis. Sixty-seven CMV D+/R- liver transplant recipients (mean age+/-standard deviation: 49.5+/-11.4 years; 75% male) received oral ganciclovir [n=9 (13%)] or valganciclovir [n=58 (87%)] prophylaxis for a median duration of 92 days (interquartile range: 91-100). No breakthrough CMV disease was observed during antiviral prophylaxis. However, primary CMV disease was observed in 2%, 25%, 27%, 27%, and 29% of patients at 1, 3, 6, 12, and 24 months, respectively, after antiviral prophylaxis was stopped. The incidence of delayed-onset primary CMV disease was similar between those who received oral ganciclovir and valganciclovir. Nine (47%) patients had CMV syndrome, 8 (42%) had gastrointestinal CMV disease, and 2 (11%) had CMV hepatitis. Female patients (P=0.01) and younger age at transplant (P=0.03) were associated with an increased risk, whereas diabetes mellitus (P<0.001) was significantly associated with a lower risk of delayed-onset primary CMV disease. Allograft loss or mortality occurred in 8 (12%) patients during the median follow-up period of 3.31 (range: 0.8-5.9) years. No significant association was observed between CMV disease and patient and allograft survival. In conclusion, CMV disease remains a common complication in CMV D+/R- liver transplant patients during the contemporary era of antiviral prophylaxis. Female patients and younger patients are at increased risk of delayed-onset primary CMV disease.

Late-onset cytomegalovirus disease in patients with solid organ transplant

PURPOSE OF REVIEW

To review existing data regarding late cytomegalovirus disease occurring after antiviral prophylaxis.

RECENT FINDINGS

There is a continued debate as to the respective merits of the preemptive and the prophylactic approach to prevent cytomegalovirus disease after transplantation. Arguably, by allowing some infection, the preemptive approach helps build immunity in contrast to prophylaxis, explaining the occurrence of late cytomegalovirus disease in the latter approach. No study comparing directly both approaches is large enough to definitely determine whether the preemptive approach leads to a faster development of immune response protective from late disease nor whether late disease is clinically different after prophylaxis compared to early cytomegalovirus diseases. While risk factors for late cytomegalovirus disease all point to a delay in mounting immune responses, there are no identified markers that would help predict the risk for late disease at the time of prophylaxis discontinuation. Various approaches to prevent late cytomegalovirus disease have been developed: prolonged prophylaxis, microbiological surveillance and preemptive treatment after prophylaxis discontinuation. Considering the identifying risk factors for late disease, it would also make sense to envision vaccinating cytomegalovirus-seronegative recipients.

SUMMARY

The best approach to prevent or manage late cytomegalovirus disease associated with cytomegalovirus prophylaxis remains to be defined.