Cytomegalovirus disease after prophylaxis with oral ganciclovir in renal transplantation: the importance of HLA-DR matching

Cytomegalovirus Matching in Deceased Donor Kidney Allocation: Results From a U.S. National Simulation Model

Background

Cytomegalovirus (CMV) infects >60% of adults and can pose an independent risk factor for allograft loss and mortality in solid organ transplant recipients. The purpose of this study is to evaluate the impact of a nationwide implementation of CMV seromatching (donor/recipient: D-/R- and D+/R+) in the U.S. deceased donor kidney allocation system (KAS).

Methods

Adult candidates on the U.S. kidney-only transplant waiting list and deceased donor kidneys offered to the U.S. transplant centers were considered. A discrete-event simulation model, simulating the pre-COVID-19 period from January 1, 2015, to January 1, 2018, was used to compare the performances of currently employed KAS-250 policy (without CMV matching) to various simulated CMV matching policies parameterized by calculated panel reactive antibody exception threshold. Outcomes included CMV serodistribution, waiting time, access to transplantation among various groups, transplant rate, graft survival, kidney discard rate, and antigen-mismatch distribution, stratified by CMV serostatus.

Results

CMV matching policy with a calculated panel reactive antibody exception threshold of 50% (namely, the CMV">50%" policy) strikes a better balance between benefits and drawbacks of CMV matching. Compared with KAS-250, CMV">50%" reduced CMV high-risk (D+/R-) transplants (6.1% versus 18.1%) and increased CMV low-risk (D-/R-) transplants (27.2% versus 13.1%); increased transplant rate for CMV R- patients (11.54 versus 12.57) but decreased for R+ patients (10.68 versus 10.48), yielding an increase in aggregate (11.09 versus 10.94); and reduced mean time to transplantation (by 6 wk); and reduced kidney discard rate (25.7% versus 26.2%).

Conclusions

Our findings underscore the feasibility and potential advantages of a nationwide CMV seromatching policy in kidney transplantation.

Recurrent Cytomegalovirus Infection Controlled by the Introduction of Everolimus in a Simultaneous Pancreas-Kidney Transplantation Recipient: A Case Report

In simultaneous pancreas-kidney transplantation (SPK) recipients, cytomegalovirus (CMV) infection is a major complication that has been associated with the use of tacrolimus (TAC)-based immunosuppression. As one of the immunosuppressive drug options, the use of mammalian target of rapamycin inhibitors (mTORi) results in reduced rates of CMV infection in the field of solid organ transplantation. However, little is known about mTORi usage in pancreas transplantation. We report a case of recurrent CMV infection that was controlled by the introduction of mTORi (everolimus) in addition to a TAC-based immunosuppression regimen in SPK. A 52-year-old man underwent SPK. Graft duodenal perforation occurred on the 13th day of surgery, and graft duodenal resection was performed after long-term abscess drainage treatment. After graft duodenal resection, he was diagnosed with CMV viremia, and valganciclovir was started. However, because of recurrent febrile neutropenia caused by cytopenia as a side effect of valganciclovir, there was a repeated need for granulocyte-colony stimulating factor treatment. Immunosuppressive drug taper adjustment was attempted to control recurrent CMV viremia, and everolimus was introduced with the aim of reducing the dose of TAC and mycophenolate mofetil. This resulted in a continuously negative CMV antigenemia test and a stable general condition. Understanding the characteristics of various immunosuppressive agents and appropriately controlling and managing infectious diseases is crucial for the good postoperative management of patients with SPK.

Circulating NKG2C + NK cell expressing CD107a/LAMP-1 subsets at the onset of CMV reactivation in seropositive kidney transplant recipients

Cytomegalovirus (CMV) infection contributes to morbidity and mortality among kidney transplant recipients. Natural killer (NK) cells can battle against CMV in kidney transplant recipients (KTRs). This study aimed to analyze the association between CMV reactivation and the proportion of NK cell subsets and their activity. In a cross-sectional study, ten CMV reactivated KTRs, and ten non- CMV reactivated ones were recruited. Ten matched healthy controls were also included in this cohort. The presence of anti-CMV-IgG Ab in both KTR subgroups from seronegative donors and healthy controls was determined. The frequency of distinct subsets of memory-like NK cells was analyzed through NKG2C, NKG2A, and CD57 using flow cytometry. The activity of NK cells was evaluated after stimulation via coculture with K562 cell line and then assessment of the frequency of CD107a and granzyme B. The mRNA levels of transcription factors, including T-bet, EAT, and inflammatory proteins, including IFN-γ and perforin contributing to NK cell activation, were also evaluated. Results showed a significantly lower frequency of NKG2C + NKG2A-CD57+ NK cell population in CMV-reactivated KTRs compared to non-reactivated ones (P-value:0.003). NKG2C+ NK cells expressing CD107a/LAMP-1 significantly was increased in CMV-reactivated KTRs compared to non-reactivated ones (P-value: 0.0002). The mRNA level of IFN-γ had a significant increase in the CMV-reactivated KTRs vs. nonreactive ones (P-value: 0.004). Finally, evaluation of the NK cells' cytotoxicity and activity through assessment of CD107a/LAMP-1 expression and IFN-γ secretion may be helpful for the identification of the risk of CMV reactivation in KTRs.

The impact of everolimus in reducing cytomegalovirus events in kidney transplant recipients on steroid-avoidance strategy: 3-year follow-up of a randomized clinical trial

There is no evidence of whether everolimus (EVR) reduces cytomegalovirus (CMV) events in patients receiving steroid-free regimens. Besides, studies evaluating a tacrolimus (TAC) and EVR regimen are limited to 1-year follow-up. In this single-center prospective randomized trial, the incidence of CMV and 3-year efficacy and safety outcomes of EVR were compared to those of mycophenolate sodium (MPS) in a steroid-free regimen based on low-exposure TAC. Both groups received rabbit anti-thymocyte globulin (r-ATG) induction (6 mg/kg) and the steroids were withdrawn at day 7. Maintenance immunosuppression consisted of TAC (4-7 ng/ml until month 3 and 2-4 ng/ml thereafter) plus EVR (3-8 ng/ml) in the EVR group (n = 59); and TAC (4-7 ng/ml during all follow-up) plus MPS (1440 mg) in the MPS group (n = 56). The EVR group presented with a lower incidence of CMV events (18.6% vs. 50%, P = 0.001). No differences were observed in biopsy-proven acute rejection (6.8% vs. 3.6%, P = 0.680),graft loss (0.0% vs. 1.8%, P = 0.487),death (6.8% vs. 1.8%, P = 0.365), or estimated glomerular filtration rate at 36 months (61.1 ± 25.4 vs. 66.3 ± 24 ml/min/1.73 m² , P = 0.369). A higher proportion of patients discontinued MPS treatment (8.5% vs. 26.8%, P = 0.013) for safety issues. In conclusion, EVR was associated with lower rates of CMV events in patients induced with standard dose r-ATG and a maintenance steroid-free regimen based on TAC. This regimen effectively prevented acute rejection and demonstrated a more favorable safety profile. (ClinicalTrials.gov:NCT02084446).

Incidence and Risk Factors for Leukopenia in Kidney Transplant Recipients Receiving Valganciclovir for Cytomegalovirus Prophylaxis

Context:

Valganciclovir is used not only for cytomegalovirus prophylaxis after kidney transplantation but can also induce leukopenia, thereby making patients more susceptible to other infections. The epidemiology of leukopenia in patients on valganciclovir remains poorly understood.

Objective:

To determine the incidence and risk factors for leukopenia in patients receiving valganciclovir for cytomegalovirus prophylaxis after kidney transplantation.

Methods:

In this single-center, retrospective, cohort study, we included kidney recipients transplanted from January 1, 2003, to December 31, 2010, to determine the incidence and risk factors for leukopenia in patients who received valganciclovir for cytomegalovirus prophylaxis. The Kaplan-Meier product limit method was used to graphically assess time to leukopenia, and risk factors were assessed using Cox proportional hazards models.

Results:

A total of 542 kidney transplant recipients were included in the study cohort. The cumulative incidence of leukopenia at 6 months posttransplant was 39.3% (11.0% for neutropenia). Low baseline white blood cell count (hazard ratio [HR] 2.34 [95% confidence interval [CI], 1.37-4.00]) and high baseline body mass index (HR 1.05 [95% CI, 1.02-1.09]) were independently associated with an increased risk of leukopenia, while higher Cockcroft-Gault creatinine clearance (HR 0.87 [95% CI, 0.78-0.97]) was significantly associated with a decreased risk of leukopenia.

Conclusions:

These data suggest that recipient baseline white blood cell count, baseline body mass index, and kidney function are clinical predictors of new-onset leukopenia after kidney transplantation. Our results may inform the approach to cytomegalovirus prophylaxis to reduce the risk of valganciclovir-induced leukopenia in kidney transplant recipients.

Risk factors for cytomegalovirus disease in seropositive renal transplant recipients; a single-center case-controlled study

Background:

Risk factors for cytomegalovirus (CMV) disease in renal transplant recipients have been evaluated in industrialized countries with relatively low CMV seroprevalence.

Objectives:

We aimed to determine which factors are related to this illness in a high CMV seroprevalence country.

Patients and Methods:

A case-control study was performed with data from a 5-year follow-up of 260 kidney transplant recipients at our center. Odds ratios were calculated using the Mantel-Haenszel method.

Results:

A total of 25 cases of CMV disease occurred during the study period. Recipient age greater than 55 years old (odds ratio: 4.95, 95% CI: 1.44–17.0) and use of thymoglobulin (odds ratio: 4.84; 95% CI: 1.10–21.39) were the only independent predictors for CMV disease. There was not any relationship between the previous serologic status of both donor and receptor and the occurrence of CMV disease. We did not observe any association between the immunosuppressive regimens and CMV disease, except for thymoglobulin.

Conclusions:

Only recipient age and thymoglobulin administration were related to CMV disease. Further studies are needed to determine if prophylactic treatment confers clinical benefit in this subset of patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Clinical significance of the single nucleotide polymorphism TLR2 R753Q in heart transplant recipients at risk for cytomegalovirus disease

BACKGROUND

The toll-like receptor 2 (TLR2) is a significant component of innate immunity against cytomegalovirus (CMV) infection but information on the clinical significance of the single nucleotide polymorphism (SNP) (R753Q) is conflicting.

OBJECTIVES

The inconsistent observations of the immunological and clinical significance of the TLR2 R753Q polymorphism for CMV infection indicates the influence of confounders.

STUDY DESIGN

The presence of the TLR2 polymorphism was determined by a genotyping assay of 175 HTX patients and 281 healthy blood donors and evaluated in relation to selected virological and clinical parameters.

RESULTS

Relative frequency of TLR2 polymorphism was similar in HTX patients and blood donors (homozygous wild-type, 94.3% vs. 94.0%; heterozygous, 5.1% vs. 5.7%; homozygous mutated, <1%). CMV viremia was detectable in 108 (61.7%) of HTX patients. The TLR2 polymorphism was neither associated with occurrence or level of CMV infection nor with survival, graft failure or rejection, or CMV serostatus of patient before transplantation. Nevertheless, CMV viremia occurred in 83.1% of R+/D+, 77.1% of R+/D-, and 64.3% of R-/D+ patients. Time of first CMV viremia was in R-/D+ patients later than in CMV-seropositive patients (median, 182days versus 23 days; P<0.001) corresponding to the duration of antiviral prophylaxis in R-/D+ patients.

CONCLUSIONS

The TLR2 R753Q polymorphism is extremely rare in the general population and HTX patients. Screening for this risk factor of CMV disease may not be cost-effective in contrast to testing for CMV viremia.

Prophylaxis versus pre-emptive treatment for prevention of cytomegalovirus infection in CMV-seropositive orthotopic liver-transplant recipients

This study compared the pre-emptive and the prophylactic strategies used to prevent cytomegalovirus (CMV) infection and disease in CMV-seropositive orthotopic liver-transplant recipients and searched for associated predictive factors. Seventy-three orthotopic liver-transplant recipients who had received a transplant before November 2005 were given ganciclovir IV pre-emptively (group I) and 56 recipients who had received a transplant after November 2005 were given prophylactic valganciclovir for 3 months (group II). Demographic and biochemical parameters did not statistically vary between the groups at baseline. Monitoring of CMV DNAemia was similar in both groups. Forty-two (57.5%) patients presented with CMV infection in group I and 18 (32.1%) in group II (P < 0.004). CMV DNAemia was first detected at a median of 33 days post-transplant in group I and at 98.5 days in group II (P < 0.003), but viral loads were not significantly different. The overall incidence of CMV disease was 9.6% in group I versus 7.1% in group II (ns). Thirty-five (47.9%) patients presented with biopsy-proven acute rejection in group I and 13 (23.2%) in group II (P = 0.004). Forty (55%) patients in group I and 25 (44.6%) in group II presented with de novo post-transplant diabetes (P = 0.057). At 1-year post-transplant, global survival curves were not significantly different. Independent factors associated with CMV reactivation were an absence of CMV prophylaxis, CMV serological status of the donor, cold ischemia time, and HLA A + B + DR compatibility. CMV prophylaxis is efficacious and can prevent safely the direct and indirect effects of CMV infection in CMV-seropositive orthotopic liver-transplant recipients.

Factors affecting eGFR 5-year post-deceased donor renal transplant: analysis and predictive model

AIM

Long-term survival of renal allografts has improved over the last 20 years. However, less is known about current expectations for long-term allograft function as determined by estimated glomerular filtration rate (eGFR). The aim of this study was to investigate factors which affect graft function at 5 years' post-renal transplantation. The statistically significant factors were then used to construct a predictive model for expected eGFR at five years' post-transplant.

METHODS

We retrospectively reviewed all adult patients who received a renal transplant in the Republic of Ireland between 1990 and 2004. Data collected included era of transplantation (1990-1994, 1995-1999, 2000-2004), donor and recipient age and gender, number of human leucocyte antigen mismatches, cold ischemia time (CIT), number of prior renal transplants, immunosuppressive regimen used and acute rejection episodes. Estimated GFR was calculated at 5 years after transplantation from patient data using the Modified Diet in Renal Disease (MDRD) equation. Consecutive sampling was used to divide the study population into two equal unbiased groups of 489 patients. The first group (derivation cohort) was used to construct a predictive model for eGFR five years' post-transplantation, the second (validation cohort) to test this model.

RESULTS

Nine hundred and seventy eight patients were analyzed. The median age at transplantation was 43 years (range 18-78) and 620 (63.4%) were male. One hundred and seventy five patients (17.9%) had received a prior renal transplant. Improved eGFR at five years' post-transplantation was associated with tacrolimus-based combination immunosuppression, younger donor age, male recipient, absence of cytomegalovirus disease and absence of acute rejection episodes as independently significant factors (p < 0.05). The predictive model developed using these factors showed good correlation between predicted and actual median eGFR at five years. The model explained 20% of eGFR variability. The validation model findings were consistent with the derivation model (21% variability of eGFR explained by model using same covariates on new data).

CONCLUSION

The predictive model we have developed shows good correlation between predicted and actual median eGFR at five years' post-transplant. Applications of this model include comparison of current and future therapy options such as new immunosuppressive regimens.

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.

Successful three-way kidney paired donation with compatible pairs to increase donor pool

Despite heightened international interest in performing living donor kidney paired donation (KPD) transplantation after the publication of a research protocol by Ross and colleagues in 1997, only a few hundred have been performed worldwide. The major obstacle is that many individuals in end-stage renal disease are of blood type O and can only receive an organ from a donor of blood type O, whereas blood type O donors are "universal donors" and will be able to donate directly with an intended recipient of any blood type unless there is a positive crossmatch. To overcome this, patients with compatible but non-HLA identical donors over 45 years of age should be approached for inclusion in KPD program especially O blood group donors. Inclusion of all these additional pairs into the algorithm greatly increases chances of possible matches for O blood group recipients. We report successful three-way KPD transplantation resulting in transplantation of O blood group patient using compatible O blood group donor from India. None of the patients had delayed graft function or rejection and all had stable graft function on discharge without any medical and surgical complications. We need to allocate O blood group kidneys from compatible donors to overcome the barrier of HLA, non-HLA antibodies and other donor related factors to improve transplant quality and long term outcomes. This will increase transplantation of O blood group patients.

Impaired direct priming of CD8 T cells by donor-derived cytomegalovirus following kidney transplantation

Cytomegalovirus (CMV) infection increases the risk of complications after renal transplantation, but the mechanisms controlling donor-derived infection are not adequately characterized. Here, we assessed the risk of clinically significant CMV disease in donor-seropositive, recipient-seropositive (D+R+) renal transplantation and examined recipients' CMV antigen-specific cellular immune responses primed directly by donor cells. In a retrospective cohort of 569 patients administered standardized basiliximab-tacrolimus-mycophenolate-corticosteroid immunosuppressive therapy, CMV disease rates increased in D+R+ serostatus pairings compared with D-R+ pairings (hazard ratio [HR], 2.61; 95% confidence interval [CI], 1.36 to 5.01; P=0.004) and associated with increased donor-recipient HLA mismatch in the D+R+ group (HR [per class 1 mismatch], 1.43; 95% CI, 1.12 to 1.82]; P=0.02). D+R+ and D+R- transplants in which the donor and recipient differentially expressed at least one HLA class I allele were followed prospectively from the time of transplantation. During the first year after transplantation, four of eight seropositive recipients and one of three seronegative recipients displayed peripheral blood CD8+ T cell responses to CMV presented by recipient-specific HLA. Notably, no recipients mounted responses to CMV presented by donor-specific HLA, despite the detection of CMV antigen expression in all seropositive donor organs examined (n=10), suggesting that the allograft of Class I HLA-mismatched seropositive donors is inaccessible to CD8+ T cell responses. Finally, pretransplant assays of anti-CMV cellular immunity predicted post-transplant CMV replication less accurately in D+R+ pairings than in D-R+ pairings, possibly reflecting in vitro assay specificity for recipient, rather than donor, HLA. These findings are relevant to the clinical management and immunologic understanding of donor-transmitted viral infection.

Cytomegalovirus disease in African-American kidney transplant patients

BACKGROUND

Cytomegalovirus (CMV) disease is a serious infection after kidney transplantation. The risk factors and the impact of CMV disease in African-American (AA) kidney transplant patients have not been well characterized.

METHODS

We performed a retrospective analysis on 448 AA patients transplanted between 1996 and 2005. A 3-month universal chemoprophylaxis with ganciclovir or valganciclovir was administered to CMV donor-positive/recipient-negative (D+/R-) patients and to those treated with anti-thymocyte globulin for rejection, but not routinely to those with other D/R serostatus.

RESULTS

A total of 31 AA patients (7%) developed clinical CMV disease. Compared with other D/R serostatus groups, the D+/R- group had the highest 3-year cumulative incidence of CMV disease (16.9% vs. 6.3% in D+/R+, 4.9% in D-/R+, and 2.4% in D-/R-). The D+/R- group also had the worst 3-year death-censored allograft survival (75% vs. 92% in D+/R+, 94% in D-/R+, and 96% in D-/R-, log-rank P = 0.01). Multivariate analysis found that D+/R- serostatus (odds ratio [OR] 5.4, 95% confidence interval [CI] 0.6-48.2, P = 0.003) and donor age > 60 years (OR 9.1, 95% CI 1.3-65, P = 0.03) were independent risk factors for CMV disease.

CONCLUSION

The D+/R- group has the highest incidence of CMV disease and the worst 3-year renal allograft survival despite 3-month universal prophylaxis. Prolonged chemoprophylaxis may be needed to prevent the late development of CMV disease and to improve allograft survival in the high-risk group of AA kidney transplant recipients.

Effects of oral valganciclovir prophylaxis for cytomegalovirus infection in heart transplant patients

BACKGROUND

Cytomegalovirus (CMV) infection is a serious complication following heart transplantation. This study (June 2003-January 2010) retrospectively assessed the effects of oral valganciclovir prophylaxis in adult heart transplant recipients during the first year after transplantation.

METHODS

In patients with normal renal function, 900 mg of oral valganciclovir was administered twice daily for 14 days after heart transplant followed by 900 mg per day for following 6 months. In the event of renal insufficiency, valganciclovir was adjusted according to the manufacturer's recommendations. Antigenemia testing for pp65 antigen and simultaneous polymerase chain reaction (PCR) were used to document exposure to CMV. From 2003 to 2010, 146 patients (74.0% men) of mean age 50.7 ± 10.3 years at the time of heart transplant were included.

RESULTS

A total of 16 patients (11.0% of total, 75.0% male) had a positive pp65 and PCR result (ie, CMV infection) during the year following heart transplant; three of these patients had discontinued valganciclovir prophylaxis within the first 6 months following transplant because of leukopenia, including one patient developed CMV colitis. Two further patients developed CMV pneumonia during prophylactic valganciclovir therapy. Eight patients had positive pp65 and PCR tests in the 6-12 months after heart transplant following cessation of routine prophylaxis. One of these patients developed CMV pneumonia and another developed CMV colitis and CMV pneumonia. Thirty-seven of the 146 (25.3%) patients were CMV donor-seropositive/recipient-seronegative, and seven (18.9% of this subgroup) had a positive CMV test. In patients who were CMV donor-seropositive/recipient-seronegative, the risk of a positive CMV test (ie, CMV infection) was significantly elevated (P = 0.023).

CONCLUSION

CMV prophylaxis with oral valganciclovir for 6 months following heart transplant is clinically feasible. In line with previous studies, CMV donor-seropositive/recipient-seronegative patients have a significantly elevated risk of CMV infection. In patients who prematurely discontinue valganciclovir, close monitoring of CMV antigenemia appears warranted. No significantly elevated rate of CMV infection was observed after 6 months of valganciclovir prophylaxis.

Epidemiology of cytomegalovirus infection after pancreas transplantation

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association of mismatches for HLA-DR with incidence of posttransplant hip fracture in kidney transplant recipients

BACKGROUND

Bone fractures are a frequent complication after kidney transplantation, for which various predisposing factors have been identified. It has been suggested that human leukocyte antigen (HLA) mismatch increases the risk.

METHODS

Data on hip fractures occurring in the first 5 years posttransplant were analyzed among kidney transplants from deceased donors performed between 1995 and 2008 and reported to the Collaborative Transplant Study.

RESULTS

In the 20,509 patients analyzed, the cumulative rate of hip fracture by year 5 posttransplant was 0.85%. Cox regression analysis identified the following risk factors: female recipients aged 40 to 59 years (hazard ratio [HR] 2.26, P=0.029), female recipients 60 years or older (HR 5.14, P<0.001), male recipients 60 years or older (HR 2.39, P=0.028), and donor age more than or equal to 60 years (HR 1.75, P=0.009). Using the rate of fractures in recipients with zero HLA-DR mismatch as the reference, the risk of hip fracture increased for grafts with one HLA-DR mismatch to HR 1.85 (95% confidence interval [CI] 1.18-2.89, P=0.007) and with two HLA-DR mismatches to HR 2.24 (CI 1.25-4.02, P=0.007). There was a significant association between the number of HLA-DR mismatches and the diagnosis of osteoporosis 5 years after transplantation: one HLA-DR mismatch risk ratio 1.26 (CI 1.12-1.43, P<0.001) and two HLA-DR mismatches risk ratio 1.45 (CI 1.20-1.74, P<0.001).

CONCLUSION

The risk of hip fracture after kidney transplantation seems to be markedly exacerbated by HLA-DR mismatching. These findings add to the growing base of evidence that HLA-DR matching influences morbidity after kidney transplantation.

Ganciclovir pharmacokinetic parameters do not change when extending valganciclovir cytomegalovirus prophylaxis from 100 to 200 days

BACKGROUND

A 3-month course of prophylaxis is usually recommended for cytomegalovirus (CMV) D+/R- renal transplant recipients. Based on recent data, up to 6 months of prophylaxis may be used. A subanalysis was performed to evaluate the pharmacokinetics of ganciclovir after valganciclovir administration and to perform an exploratory pharmacokinetic/pharmacodynamic analysis.

METHODS

In Improved Protection Against Cytomegalovirus in Transplant, a phase III, randomized, double blind, placebo-controlled, multicenter study, 318 CMV D+/R- kidney transplant recipients received valganciclovir prophylaxis (900 mg once daily) for 200 or 100 days. A population pharmacokinetic analysis was conducted on a subgroup of patients (n=120). The relationships between ganciclovir exposure (AUC0-24 hr) and clinical outcomes were explored.

RESULTS

The final population parameter estimates (95% confidence interval) were as follows: apparent clearance of ganciclovir, 12 L/hr (11.3-12.7 L/hr); volume of distribution, 18.5 L (14.4-22.6 L); and peripheral volume, 44.4 L (40.2-48.6 L). No differences were apparent between the two treatment groups and these estimates. These results are consistent with previously published pharmacokinetic models. There were no direct correlations between the likelihood of developing hematologic adverse events and ganciclovir exposure at the time of the event. The incidence of CMV disease was not correlated with ganciclovir exposure.

CONCLUSION

The pharmacokinetics of ganciclovir were similar between the two dosing groups (100 vs. 200 days), with the majority of patients achieving an area under the concentration time curve in the target therapeutic range (40-60 μg hr/mL). The fact that the majority of patients were within the target therapeutic range and the absence of a control arm (no treatment) precluded any attempt to validate a correlation with clinical parameters (i.e., CMV disease).

Impact of prophylactic versus preemptive valganciclovir on long-term renal allograft outcomes

BACKGROUND

Both prophylactic and preemptive oral valganciclovir therapy are effective for the management of cytomegalovirus (CMV) postrenal transplantation in the short term. The long-term effect of either strategy is less well defined.

METHODS

We analyzed the data on 115 adult recipients previously enrolled in a prospective randomized controlled trial of prophylaxis versus preemptive therapy for CMV. The primary outcome was a composite of freedom from acute rejection, graft loss, or death. Secondary outcomes included individual primary outcomes, posttransplant cardiovascular events, new-onset diabetes mellitus after transplantation, achievement of goal blood pressure, change in body mass index, interstitial fibrosis/tubular atrophy, and change in renal function. The analysis period was a minimum of 48-month posttransplant or a date of death or graft loss, whichever was earlier.

RESULTS

The primary outcome was similar between groups (83% prophylactic vs. 81% preemptive, P=0.754). The secondary outcomes showed similarities between the prophylactic and preemptive groups. Four patients in the prophylactic group (8%) compared with none in the preemptive group (0%) died with a functioning graft, P=0.043.

CONCLUSIONS

Within the limitations of sample size, our data suggest that either strategy for the management of CMV immediately after transplantation seems effective for patient and graft survival in the long term. CMV management is one of the many therapeutic strategies incorporated into a renal transplantation protocol, which often differs among institutions, and the decision as to which approach to use remains center- and resource-specific. The increased incidence of death in the prophylactic group requires further investigation.

The efficacy and safety of 200 days valganciclovir cytomegalovirus prophylaxis in high-risk kidney transplant recipients

Late-onset cytomegalovirus (CMV) disease is a significant problem with a standard 3-month prophylaxis regimen. This multicentre, double-blind, randomized controlled trial compared the efficacy and safety of 200 days' versus 100 days' valganciclovir prophylaxis (900 mg once daily) in 326 high-risk (D+/R-) kidney allograft recipients. Significantly fewer patients in the 200-day group versus the 100-day group developed confirmed CMV disease up to month 12 posttransplant (16.1% vs. 36.8%; p < 0.0001). Confirmed CMV viremia was also significantly lower in the 200-day group (37.4% vs. 50.9%; p = 0.015 at month 12). There was no significant difference in the rate of biopsy-proven acute rejection between the groups (11% vs. 17%, respectively, p = 0.114). Adverse events occurred at similar rates between the groups and the majority were rated mild-to-moderate in intensity and not related to study medication. In conclusion, this study demonstrates that extending valganciclovir prophylaxis (900 mg once daily) to 200 days significantly reduces the incidence of CMV disease and viremia through to 12 months compared with 100 days' prophylaxis, without significant additional safety concerns associated with longer treatment. The number needed to treat to avoid one additional patient with CMV disease up to 12 months posttransplant is approximately 5.

Avoiding pitfalls: what an endoscopist should know in liver transplantation--part II

Over the last decade the number of patients undergoing transplantation has increased. At the same time, effective peri- and postoperative care and better surgical techniques have resulted in greater numbers of recipients achieving long-term survival. Identification and effective management in the form of adequate treatment is essential, since any delay in diagnosis or treatment may result in graft loss or serious threat to patient's life. Various aspects of endoscopic findings that can be commonly encountered among liver transplant recipients are discussed herein. Topics include: persistent and/or recurrent esophageal varices, reflux, Candida or cytomegalovirus (CMV) esophagitis, esophageal neoplasms, posttransplant peptic ulcer, biliary complications, posttransplant lymphoproliferative disorder (PTLD), Kaposi's sarcoma, CMV colitis and inflammatory bowel disease, colonic neoplasms, Clostridium difficile infection, and graft versus host disease (GVHD).

Probabilistic modeling of cytomegalovirus infection under consensus clinical management guidelines

BACKGROUND

Cytomegalovirus (CMV) is the most common viral pathogen after renal transplantation and remains a major therapeutic challenge with important clinical and economic implications from both direct and indirect consequences of infection.

METHODS

This 5-year study modeled the relationship between CMV infection and biopsy-proven graft rejection, graft loss, or death after renal transplantation in an inception cohort using Canadian consensus guidelines for CMV management as a component of a detailed cost-analysis of viral infection.

RESULTS

Probabilities of CMV viremia and syndrome/disease among 270 sequential graft recipients were 0.27 and 0.09, respectively; 91% of cases occurred in the first 6 months. Probability of CMV infection as the first event was 0.29, with a probability of subsequent biopsy-proven acute rejection (BPAR) of 0.05 (mean: 62+/-26 days, range: 32-85 days), whereas the probability of BPAR as the first event was 0.18, with a probability of subsequent CMV infection of 0.38 (mean: 63+/-31, range: 27-119 days). Probability of freedom from both CMV infection and BPAR throughout the period of observation was 0.53. Time-dependent Cox analysis showed that neither donor/recipient CMV risk stratum nor CMV infection influenced the risks of BPAR (P=0.24; P=0.74) or of graft loss or death (P=0.26; P=0.34). In contrast, BPAR significantly increased the risk of both subsequent CMV infection (hazard ratio=1.77, P=0.03) and of graft loss or death (hazard ratio=8.31, P<0.0001).

CONCLUSIONS

Although current antiviral therapy seems to mitigate the reported deleterious effects of CMV infection on BPAR or graft survival, BPAR remains a significantly risk factor for both CMV infection and functional graft survival.

PD-1 expression and IL-2 loss of cytomegalovirus- specific T cells correlates with viremia and reversible functional anergy

Cytomegalovirus (CMV) represents a major cause of infectious complications after transplantation. Recently, chronic infections with lymphocyte choriomeningitis virus (LCMV), HIV or HCV were shown to be associated with functionally exhausted T cells characterized by high expression of the programmed death (PD)-1 molecule and altered cytokine expression patterns. We therefore hypothesized that functional exhaustion of CMV-specific CD4 T cells may determine impaired CMV control in patients after renal transplantation. In viremic transplant recipients, a significantly higher proportion of CMV-specific CD4 T cells was PD-1 positive (median 40.9%, 17.0-88.7%) as compared to nonviremic transplant patients (8.8%, 0.8-80.5%), dialysis patients (8.8%, 0-36.7%) or controls (3.2%, 0.3-15.4%, p < 0.0001). In line with functional impairment, PD-1-positive T cells produced significantly less IFNgamma as compared to PD-1-negative T cells (p < 0.0001). Moreover, unlike controls or nonviremic patients, CMV-specific T cells from viremic patients showed a significant loss of IL-2 production (p < 0.0001). Interestingly, functional anergy of CMV-specific CD4 T cells was reversible in that antibody-mediated blockade of PD-1 signaling with its ligands PD-L1/-L2 led to an up to 10-fold increase in CMV-specific proliferation. In conclusion, expression of PD-1 defines a reversible defect of CMV-specific CD4 T cells that is associated with viremia, and blocking PD-1 signaling may provide a potential target for enhancing the function of exhausted T cells in chronic CMV infection.

A model for human leukocyte antigen-matched donor-swap transplantation in India

BACKGROUND

In developing countries such as India, extending donor-swap transplantation (DSTx) to human leukocyte antigen (HLA)-mismatched patient-donor pairs would increase well-matched living donor kidney transplantation rates, resulting in use of less immunosuppression and less expenses, lower infective morbidity, and better survival. A model for DSTx based on HLA matching is presented.

METHODS

Consecutive HLA class 1 antigen (A, B) tests of prospective renal allograft recipients and their related donors, performed at a single center in India was analyzed retrospectively using an HLA matching program to determine the proportion of prospective recipients with poorly matched related donors who could have benefited by DSTx based on HLA matching.

RESULTS

Over the past 17.5 years, 2,129 prospective renal allograft recipients and 2,890 donors were tested for HLA class I (A and B) antigens. Of the prospective recipients, 33% did not have well-matched donors (defined as blood group compatible and sharing > or =2 of 4 HLA class I antigens). Among such recipients, 19.2% could have found a well-matched donor-swap pair within a year at a single center. This number would increase to 38% if four major national centers were involved with a shared HLA registry.

CONCLUSIONS

Nearly 40% of prospective recipients without well-matched donors would find a donor-swap pair based on HLA matching within a year, with coordination among four national centers and a shared HLA registry, increasing the well-matched living donor renal transplant rates and improving transplant outcomes. This finding is relevant in the context of Indian government amending the Transplantation of Human Organs Act to encourage DSTx.

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.

Acceleration of allograft failure by cytomegalovirus

A number of human herpesviruses are important opportunistic pathogens that have been associated with increased morbidity and mortality in transplant recipients including human cytomegalovirus (HCMV), HHV6, HHV7, HHV8 as well as HSV-1, VZV. However, HCMV has been linked both epidemiologically and through the use of animal models to the acceleration of acute and chronic allograft rejection. This review will cover the pathophysiology, epidemiology, and mechanisms of CMV-associated disease in the setting of transplantation.

Etiology and impact of cytomegalovirus disease on solid organ transplant recipients

PURPOSE

The characteristics, etiology, natural history, and direct and indirect effects of CMV disease in solid organ transplant recipients are described.

SUMMARY

CMV is a common herpesvirus that may be present in the donor or recipient of a solid organ transplant. Even though it is rarely pathogenic in healthy patients, transplant recipients are at risk for CMV viremia and symptomatic disease due to their immune-suppressed status. In addition to symptoms directly attributed to active disease, CMV can have a variety of indirect effects. Indirect effects may include additional infectious complications, posttransplant lymphoproliferative disease, allograft rejection, allograft loss, or death. The three most prevalent risk factors for CMV infection are CMV seronegativity in a recipient of an organ from a CMV-seropositive donor, the type of organ transplanted, and the degree of immune suppression. CMV prophylaxis is effective at preventing disease, but may result in a delayed onset where CMV disease occurs once the prophylaxis is stopped.

CONCLUSION

Knowledge of risk factors for CMV infection and disease, the natural history in transplant recipients, and its direct and indirect effects will help clinicians make appropriate decisions regarding the use of preventive strategies.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cytomegalovirus infection in renal transplant recipients

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

Prophylactic versus preemptive oral valganciclovir for the management of cytomegalovirus infection in adult renal transplant recipients

Prophylaxis reduces cytomegalovirus (CMV) disease, but is associated with increased costs and risks for side effects, viral resistance and late onset CMV disease. Preemptive therapy avoids drug costs but requires frequent monitoring and may not prevent complications of asymptomatic CMV replication. Kidney transplant recipients at risk for CMV (D+/R-, D+/R+, D-/R+) were randomized to prophylaxis (valganciclovir 900 mg q.d. for 100 days, n=49) or preemptive therapy (900 mg b.i.d. for 21 days, n=49) for CMV DNAemia (CMV DNA level>2000 copies/mL in >or=1 whole blood specimens by quantitative PCR) assessed weekly for 16 weeks and at 5, 6, 9 and 12 months. More patients in the preemptive group, 29 (59%) than in the prophylaxis group, 14 (29%) developed CMV DNAemia, p=0.004. Late onset of CMV DNAemia (>100 days after transplant) occurred in 11 (24%) randomized to prophylaxis, and none randomized to preemptive therapy. Symptomatic infection occurred in five patients, four (3 D+/R- and 1 D+/R+) in the prophylactic group and one (D+/R-) in the preemptive group. Peak CMV levels were highest in the D+/R- patients. Both strategies were effective in preventing symptomatic CMV. Overall costs were similar and insensitive to wide fluctuations in costs of either monitoring or drug.

The impact of early cytomegalovirus infection and disease in renal transplant recipients

Human cytomegalovirus (HCMV) infection is the single most frequent infectious complication in the early period after kidney transplantation. The HCMV load in blood, measured by HCMV PCR or the HCMV pp65 antigen test, is a predictor of HCMV disease in seropositive recipients. However, plasma virus load measurements are of only modest value in predicting the risk of HCMV disease in seronegative recipients of kidneys from seropositive donors. HCMV infection is an independent risk-factor for acute kidney graft rejection. There is also evidence that HCMV is associated with an increased long-term mortality and post-transplant diabetes mellitus. Whether pre-emptive or prophylactic therapy should be the preferred strategy is not yet decided. Some studies indicate that HCMV prophylaxis may reduce the risk of acute rejection, and thereby increase long-term graft survival in seronegative recipients of kidneys from seropositive donors.

Prospective comparison of valacyclovir and oral ganciclovir for prevention of cytomegalovirus disease in high-risk renal transplant recipients

AIMS

To compare the efficacy, costs and safety of oral ganciclovir and valacyclovir in the prophylaxis of cytomegalovirus (CMV) disease in renal transplant (RTx) recipients at high risk of CMV disease.

METHODS

A total of 83 patients were prospectively randomized to 3-month treatment with either oral ganciclovir (3 g/day) or oral valacyclovir (8 g/day). A 3rd group received no prophylaxis. Forty-nine patients were considered to be at high risk of CMV disease due to D+R- serologic status, OKT3/ATG treatment and/or acute rejection within 12 months after RTx. Twenty-three high-risk patients were treated with ganciclovir (GAN group), 17 patients with valacyclovir (VAL group), and 9 patients received no prophylaxis (C group).

RESULTS

No significant differences were found among the groups in their demographic characteristics, immunosuppressive protocols, D/R CMV serology, or CMV risk factors. The 12-month incidence of CMV disease was 89% in the C group compared with 9% in the GAN group and 6% in the VAL group (p < 0.001, GAN or VAL vs. C; p = 0.713, GAN vs. VAL). Treatment failure (death, graft loss, CMV disease or withdrawal from study) occurred in 17, 6, and 89% in the GAN, VAL, and C groups, respectively (p < 0.001, GAN or VAL vs. C; p = 0.285, GAN vs. VAL). The average CMV-associated costs per patient were EUR 3,161, 3,757, and 7,247 in the GAN, VAL, and C groups, respectively (p = 0.027).

CONCLUSION

Valacyclovir and oral ganciclovir are equally effective in the prophylaxis of CMV disease in high-risk RTx patients. Both regimens are cost-effective and help reduce CMV-associated costs by nearly 50% compared with patients without prophylaxis.

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.

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.

Outcome of Low-Dose Ganciclovir for Cytomegalovirus Disease Prophylaxis in Renal-Transplant Recipients

To assess the outcome of low-dose-ganciclovir prophylaxis (500 mg twice a day for 3 months) in renal-transplant recipients, a retrospective analysis of 185 patients transplanted between 1998 and 2001 was performed. There were 29 (15.6%) patients who belonged to the highest risk group, donor cytomegalovirus (CMV) positive, recipient negative (D + R-), and 37 (20%) patients in the lowest risk group, D-R-. Induction immunosuppression consisted of polyclonal antibody or OKT3 (n = 62, 33.5%), interleukin-2 receptor antibody (n = 61, 33%), and no induction (n = 62, 33.5%). CMV disease occurred in 13 (7%) patients. Highest incidence was in D + R- group (17.2%), with no cases in D-R- group (P = 0.03). Tissue-invasive CMV occurred in 4 of these 13 patients. In patients developing CMV disease, there was no evidence of ganciclovir resistance and no mortality over a mean follow-up of 42 months. Low-dose ganciclovir was found to be as effective in decreasing the incidence of clinical CMV disease as high-dose ganciclovir (1 gm three times a day for 3-6 months) in previous studies.

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.

HLA mismatching increases the risk of BK virus nephropathy in renal transplant recipients

BK virus (BKV) nephropathy is a serious complication in kidney transplant recipients that may lead to irreversible graft failure. We have analyzed the degree of donor/recipient HLA compatibility and HLA antigen association in 40 kidney transplant patients with BKV nephropathy in comparison with a control group of 404 unaffected transplant recipients who were on tacrolimus-based immunosuppression with no induction. HLA compatibility was assessed by determining the number of HLA-A, -B, -DR-mismatched antigens. BK virus nephropathy was diagnosed histologically and confirmed by immunochemistry. Univariate and multiple logistic regression statistical analyses have shown a significant association between BKV nephropathy and HLA mismatching. This analysis showed also that BKV nephritis is associated with a greater number of rejection episodes and a higher incidence of steroid-resistant rejection requiring antilymphocyte treatment. There was no association between BKV nephropathy and any specific HLA allele. We propose that HLA mismatching promotes the development of BKV nephropathy through rejection-related inflammatory processes and heavy immunosuppression which cause virus reactivation and injury of the tubular epithelium.