The impact of viral load and time to onset of cytomegalovirus replication on long-term graft survival after kidney transplantation

Challenges for the improvement of valganciclovir prophylaxis in solid organ transplantation and the possible role of therapeutic drug monitoring in adults

Cytomegalovirus (CMV) infection frequently occurs after solid organ transplantation and is associated with an increased morbidity and mortality. Fortunately, the development of valganciclovir prophylaxis has lowered the incidence of CMV infection and its complications in immunosuppressed solid organ transplant recipients. However, breakthrough infections during valganciclovir prophylaxis and late CMV infection after cessation of valganciclovir prophylaxis still occur with the current prophylactic strategy. Additionally, valganciclovir resistance has emerged among CMV strains, which complicates the treatment of CMV infections. Furthermore, the use of valganciclovir is associated with myelotoxicity, which can lead to the premature withdrawal of prophylaxis. It is important to address these current issues in order to improve the standard care after solid organ transplantation. This paper will therefore discuss the clinical practice of valganciclovir prophylaxis, elaborate on its issues and suggest how to improve the current prophylactic strategy with a possible role for therapeutic drug monitoring.

Epidemiology, management, and burden of cytomegalovirus in solid organ transplant recipients in selected countries outside of Europe and North America: A systematic review

BACKGROUND

Cytomegalovirus (CMV) is a frequent infectious complication following solid organ transplantation (SOT). Considering significant differences in healthcare systems, a systematic review was conducted to describe the epidemiology, management, and burden of CMV post-SOT in selected countries outside of Europe and North America.

METHODS

MEDLINE, Embase, and Cochrane databases were searched for observational studies in SOT recipients across 15 countries in the regions of Asia, Pacific, and Latin America (search period: January 1, 2011 to September 17, 2021). Outcomes included incidence of CMV infection/disease, recurrence, risk factors, CMV-related mortality, treatment patterns and guidelines, refractory and/or resistant CMV, patient-reported outcomes, and economic burden.

RESULTS

Of 2708 studies identified, 49 were eligible (n = 43/49; 87.8% in adults; n = 34/49, 69.4% in kidney recipients). Across studies, selection of CMV preventive strategy was based on CMV serostatus. Overall, rates of CMV infection (within 1 year) and CMV disease post-SOT were respectively, 10.3%-63.2% (9 studies) and 0%-19.0% (17 studies). Recurrence occurred in 35.4%-41.0% cases (3 studies) and up to 5.3% recipients died of CMV-associated causes (11 studies). Conventional treatments for CMV infection/disease included ganciclovir (GCV) or valganciclovir. Up to 4.4% patients were resistant to treatment (3 studies); no studies reported on refractory CMV. Treatment-related adverse events with GCV included neutropenia (2%-29%), anemia (13%-48%), leukopenia (11%-37%), and thrombocytopenia (13%-24%). Data on economic burden were scarce.

CONCLUSION

Outside of North America and Europe, rates of CMV infection/disease post-SOT are highly variable and CMV recurrence is frequent. CMV resistance and treatment-associated adverse events, including myelosuppression, highlight unmet needs with conventional therapy.

Cytomegalovirus High-risk Kidney Transplant Recipients Show No Difference in Long-term Outcomes Following Preemptive Versus Prophylactic Management

BACKGROUND

Following kidney transplantation (KT), cytomegalovirus (CMV) infection remains an important challenge. Both prophylactic and preemptive antiviral protocols are used for CMV high-risk kidney recipients (donor seropositive/recipient seronegative; D+/R-). We performed a nationwide comparison of the 2 strategies in de novo D+/R- KT recipients accessing long-term outcomes.

METHODS

A nationwide retrospective study was conducted from 2007 to 2018, with follow-up until February 1, 2022. All adult D+/R- and R+ KT recipients were included. During the first 4 y, D+/R- recipients were managed preemptively, changing to 6 mo of valganciclovir prophylaxis from 2011. To adjust for the 2 time eras, de novo intermediate-risk (R+) recipients, who received preemptive CMV therapy throughout the study period, served as longitudinal controls for possible confounders.

RESULTS

A total of 2198 KT recipients (D+/R-, n = 428; R+, n = 1770) were included with a median follow-up of 9.4 (range, 3.1-15.1) y. As expected, a greater proportion experienced a CMV infection in the preemptive era compared with the prophylactic era and with a shorter time from KT to CMV infection ( P  < 0.001). However, there were no differences in long-term outcomes such as patient death (47/146 [32%] versus 57/282 [20%]; P  = 0.3), graft loss (64/146 [44%] versus 71/282 [25%]; P  = 0.5), or death censored graft loss (26/146 [18%] versus 26/282 [9%]; P  = 0.9) in the preemptive versus prophylactic era. Long-term outcomes in R+ recipients showed no signs of sequential era-related bias.

CONCLUSIONS

There were no significant differences in relevant long-term outcomes between preemptive and prophylactic CMV-preventive strategies in D+/R- kidney transplant recipients.

A Randomized Trial of Valganciclovir Prophylaxis Versus Preemptive Therapy in Kidney Transplant Recipients

SIGNIFICANCE STATEMENT

Although cytomegalovirus (CMV) infection is an important factor in the pathogenesis of kidney allograft rejection, previous studies have not determined the optimal CMV prevention strategy to avoid indirect effects of the virus. In this randomized trial involving 140 kidney transplant recipients, incidence of acute rejection at 12 months was not lower with valganciclovir prophylaxis (for at least 3 months) compared with preemptive therapy initiated after detection of CMV DNA in whole blood. However, prophylaxis was associated with a lower risk of subclinical rejection at 3 months. Although both regimens were effective in preventing CMV disease, the incidence of CMV DNAemia (including episodes with higher viral loads) was significantly higher with preemptive therapy. Further research with long-term follow-up is warranted to better compare the two approaches.

BACKGROUND

The optimal regimen for preventing cytomegalovirus (CMV) infection in kidney transplant recipients, primarily in reducing indirect CMV effects, has not been defined.

METHODS

This open-label, single-center, randomized clinical trial of valganciclovir prophylaxis versus preemptive therapy included kidney transplant recipients recruited between June 2013 and May 2018. After excluding CMV-seronegative recipients with transplants from seronegative donors, we randomized 140 participants 1:1 to receive valganciclovir prophylaxis (900 mg, daily for 3 or 6 months for CMV-seronegative recipients who received a kidney from a CMV-seropositive donor) or preemptive therapy (valganciclovir, 900 mg, twice daily) that was initiated after detection of CMV DNA in whole blood (≥1000 IU/ml) and stopped after two consecutive negative tests (preemptive therapy patients received weekly CMV PCR tests for 4 months). The primary outcome was the incidence of biopsy-confirmed acute rejection at 12 months. Key secondary outcomes included subclinical rejection, CMV disease and DNAemia, and neutropenia.

RESULTS

The incidence of acute rejection was lower with valganciclovir prophylaxis than with preemptive therapy (13%, 9/70 versus 23%, 16/70), but the difference was not statistically significant. Subclinical rejection at 3 months was lower in the prophylaxis group (13% versus 29%, P = 0.027). Both regimens prevented CMV disease (in 4% of patients in both groups). Compared with prophylaxis, preemptive therapy resulted in significantly higher rates of CMV DNAemia (44% versus 75%, P < 0.001) and a higher proportion of patients experiencing episodes with higher viral load (≥2000 IU/ml), but significantly lower valganciclovir exposure and neutropenia.

CONCLUSION

Among kidney transplant recipients, the use of valganciclovir prophylaxis did not result in a significantly lower incidence of acute rejection compared with the use of preemptive therapy.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Optimizing Valganciclovir Efficacy in Renal Transplantation (OVERT Study), ACTRN12613000554763 .

Relationship between Cytomegalovirus Viremia and Long-Term Outcomes in Kidney Transplant Recipients with Different Donor Ages

OBJECTIVES

To explore the Cytomegalovirus (CMV) burden on the long-term post-transplant course in different donor ages, we evaluated the incidence and risk factors for CMV in our kidney-transplanted patients (KTs) with extensive adoption of expanded-criteria donors (ECDs).

METHODS

Retrospective evaluation of 929 consecutive first KTs (49.5% receiving an organ from a donor ≥ 60 years) performed between 01-2003 and 12-2013. Overall survival was estimated using Kaplan-Meier curves; cumulative incidence function was additionally analyzed to consider the potential role of death with a functioning graft as a competitive event with graft dysfunction and to avoid overestimation. Apart from regular DNAemia monitoring in all patients, prophylaxis was adopted in high-risk groups (D+/R- or recipients of anti-thymocyte globulin induction), with pre-emptive therapy in the remaining groups.

RESULTS

CMV incidence was 19.5% (4-34.9% according to serostatus combination: D-/R-, D-/R+, D+/R+, D+/R-). Donor and recipient age, recipient pre-transplant hypertension, DR antigen compatibility, cold ischemia time, and post-transplant early complications, including rejection, urologic and renal artery stenosis, and lower renal function and proteinuria ≥ 0.5 g/day at one year after KT were associated with CMV. CMV determined lower death-censored graft survival (DCGS) (p < 0.01), with a prominent effect in R+ (p < 0.01) and without impact in R- (p = 0.32 in D-/R- and p = 0.006 in D+/R-). Interestingly, CMV occurrence influenced DCGS only in KTs who received grafts from donors < 50 or 50-69 years old (p < 0.01), while it was not significant with older donors (p = 0.07). The analysis of the cumulative incidence of graft loss accounting for death as a competing risk confirmed all these findings. In multivariate analysis, CMV replication/disease in the first year was an independent predictor for DCGS (HR 1.73 [1.3-2.3]).

CONCLUSIONS

In a large population with extensive ECD adoption, CMV viremia in the first year demonstrates its harmful effect with an independent role for graft loss and significant impact among R+ recipients and KTs with donors < 70 years.

Risk factors for cytomegalovirus infection and disease after kidney transplantation: A meta-analysis

OBJECTIVE

To investigate the risk factors for cytomegalovirus (CMV) infection and disease in kidney transplantation recipient, and provide references for the prevention and control of CMV infection and disease in kidney transplantation patients.

METHODS

Chinese and international literature related to risk factors for CMV infection and disease in renal transplant recipients was searched using databases, including China National Knowledge Infrastructure; WanFang Data; Wiper; Chinese Biomedical Literature database; PubMed; Embase; Web of Science, and the Cochrane Register of Controlled Trials. Two researchers independently screened the literature, extracted the data, and evaluated the quality of the literature according to published standards. A meta-analysis was performed using RevMan 5.4 software to extract the risk factors for CMV infection and disease in renal transplant recipients.

RESULTS

A total of 59,847 subjects were included in 24 studies. The risk factors for CMV infection were ATG [OR = 2.76, 95% CI (2.10, 3.63), P < 0.00001], Donor (D) CMV-IgG(+) Receptor (R)(-): (D+/R-) [OR = 2.97, 95% CI (1.63, 5.44), P = 0.004 < 0.05], recipient age [OR = 1.96, 95% CI (1.50, 2.54), P < 0.00001], lymphocytopenia [OR = 3.26, 95% CI (1.46, 7.31), P < 0.00001], and mycophenolate [OR = 3.22, 95% CI (2.02, 5.46), P < 0.00001]. The protective factor for CMV infection was glomerular filtration rate (GFR) [OR = 0.98, 95% CI (0.97, 0.99), P < 0.00001], and the uncertain factors were the use of tacrolimus [OR = 0.91, 95% CI (0.64, 1.28), P = 0.58 > 0.05], rejection [OR = 1.32, 95% CI (0.49, 3.53), P = 0.58 > 0.05], donor age [OR = 1.00, 95% CI (0.99, 1.01), P = 0.67 > 0.5], and preemptive therapy [OR = 0.51, 95% CI (0.11, 2.36), P = 0.86 > 0.05]. The risk factors for CMV disease were D+/R- [OR = 4.78, 95% CI (3.76, 6.07), P < 0.00001], ATG [OR = 1.83, 95% CI (1.25, 2.67), P < 0.00001], rejection [OR = 1.42, 95% CI (1.26, 1.59), P < 0.00001], mycophenolate [OR = 1.67, 95% CI (1.38, 2.02), P < 0.00001], recipient age [OR = 1.03, 95% CI (1.02, 1.03), P < 0.00001], donor age [OR = 1.01, 95% CI (1.00, 1.01), P = 0.001 < 0.05], Donor (D) CMV-IgG(+) Receptor(R)(+): (D+/R+) [OR = 1.92, 95% CI (1.49, 2.46), P < 0.00001], the use of prednisolone [OR = 1.59, 95% CI (1.32, 1.92), P < 0.00001], and diabetes mellitus[OR = 1.18, 95% CI (1.01, 1.37), P = 0.03 < 0.05], and the uncertain factors were donor type [OR = 4.10, 95% CI (0.28, 59.79), P = 0.30 > 0.05], time of transplantation [OR = 0.95, 95% CI (0.78, 1.16), P = 0.64 > 0.05], and the use of cyclosporine [OR = 1.50, 95% CI (0.62, 3.64), P = 0.37 > 0.05].

CONCLUSION

There are many factors influencing CMV infection and disease in kidney transplant patients. Risk factors should be carefully monitored, protective factors strengthened, and more attention paid to uncertain factors.

Time-dependent blood eosinophilia count increases the risk of kidney allograft rejection

Background

Growing evidence suggest that type 2 immune effectors play a role in solid organ transplantation. The aim of this study was to evaluate the impact of blood count eosinophils (BCEo) on immunological outcomes in kidney transplant recipients with stable graft function after 3 months post-transplant.

Method

We performed cause-specific Cox model considering BCEo, the use of calcineurin inhibitors and systemic corticoids as time-dependent explicative variables on a prospective cohort of 1013 kidney transplant patients who experienced kidney allograft rejection and/or the appearance of de novo donor specific antibodies after excluding common causes of increased BCEo..

Findings

BCEo ≥ 0.3 G/L was associated with a 3-fold increased risk of rejection independent of immunosuppressive regimen after 3 months post-transplant in patients without pre-transplant DSAs and with CNI-based immunosuppression. No association between BCEo either with donor specific antibodies or graft survival was noticed.

Interpretation

These observations in this large cohort support the hypothesis of eosinophils in allo-immunity in human and claim for further mechanistic research.

Funding

This study was supported by the French National Research Agency, The “Institut de Recherche en Santé Respiratoire des Pays de la Loire” and the University hospital of Nantes.

Use of Letermovir-Valganciclovir combination as a step-down treatment after Foscarnet for Ganciclovir-resistant CMV infection in kidney transplant recipients

Background

Letermovir (LTV) might be an alternative treatment to nephrotoxic foscarnet (FOS) in Ganciclovir (GCV) resistant cytomegalovirus (CMV) infection. However, its efficacy in controlling active CMV viremia is unclear, as it is only approved for CMV prophylaxis in hematopoietic stem‐cell transplantation.

Methods

This case series describes 14 kidney transplant recipients (KTR) with moderate‐level GCV resistant CMV infection, treated by different step‐down strategies after initial FOS therapy: (1) Observation without antiviral follow‐up or switch to valganciclovir (VGCV) (pre‐LTV era), and (2) Switch to LTV±VGCV (LTV era).

Results

One patient died under FOS. Thirteen patients were followed under step‐down regimens. All but two patients had ongoing CMV viremia when stopping FOS. In pre‐LTV era, 5/9 (56%) experienced a CMV breakthrough > 10 000 IU/ml calling for another course of FOS, as compared to 1/4 (25%) in the LTV era. Addition of VGCV to LTV at low‐level viral breakthrough, addressing a possible developing resistance against LTV, prevented viral surge in two patients. In the pre‐LTV era, CMV‐related death or graft loss occurred in three of nine (33%), compared to no death or graft loss in the LTV era.

Conclusion

A step‐down strategy combining LTV+VGCV, might allow to safely stop FOS at ongoing low‐level viremia.

Cytomegalovirus after kidney transplantation in 2020: moving towards personalized prevention

Cytomegalovirus (CMV)-related complications after kidney transplantation remain a substantial challenge. Rather than applying one preventive strategy to all at-risk patients, we can now adapt our strategy at the individual patient level. Antiviral prophylaxis or a strict pre-emptive strategy may be optimal for patients at the highest risk for CMV, while patients at lower risk may benefit particularly from pre-emptive monitoring and the administration of therapy only if needed. CMV-specific T-cell assays may be useful for further refining the pre-transplant determination of CMV risk, and for guiding decisions about antiviral therapy need or duration. An immunosuppressive regimen including a mammalian target of rapamycin inhibitor reduces CMV risk and may thus be an attractive option in some patients. New antiviral agents may further expand our therapeutic arsenal in the near future, and the prospects of CMV vaccination and adoptive T-cell therapy appear to be on the horizon.

Antiviral treatment approaches for cytomegalovirus prevention in kidney transplant recipients: A systematic review of randomized controlled trials

Various CMV anti-viral (AV) preventive strategies have been utilized in KTRs. We examined efficacy, safety and costs of CMV-AV prevention strategies in KTRs using a systematic literature review (SLR) of randomized controlled trials (RCTs) publications indexed in MEDLINE and Embase (from inception to November 2018). Thirty RCTs met inclusion criteria with 22 unique AV preventive strategies. Prophylaxis was associated with significantly lower rates of CMV infection/disease (CMVi/d) compared to no prophylaxis (pooled odds ratio, pOR with 95% confidence interval (CI): CMVi: 0.33; 0.19, 0.57; CMVd: 0.27; 0.19; 0.39). Preemptive therapy (PET) had lower rates of CMVd (0.29; 0.11, 0.77), and medical costs compared to no PET. Prophylaxis had significantly lower rates of early CMVi/d, and higher rates of late CMVi and hematological adverse events (leukopenia, 2.93; 1.22, 7.04), and similar overall medical costs compared to PET. Studies involving head-to-head comparison of different prophylaxis approaches showed mixed findings with respect to optimum dose, duration and route of administration on CMV outcomes. Although there was heterogeneity across populations and interventions, both prophylaxis and PET strategies reduced CMVi/d compared to no prophylaxis/PET and had differential safety profile in terms of hematological adverse events. For comprehensiveness we did not limit study inclusion based on date; the wide time-period may have contributed to the heterogeneity in prevention approaches which subsequently made pooling studies a challenge. Despite demonstrated efficacy of prophylaxis/PET, our findings highlight the potential need of a novel intervention with a better safety profile and perhaps improved outcomes.

Epidemiology, risk factors, and outcomes associated with cytomegalovirus in adult kidney transplant recipients: A systematic literature review of real-world evidence

Kidney transplant recipients (KTRs) have increased risk for cytomegalovirus (CMV) infection/disease given the necessity of drug-induced immunosuppression. A comprehensive review of published literature reporting real-world data on prevention strategies utilized and associated CMV burden outcomes is limited. Such data could help inform future clinical practice and identify unmet needs in CMV management. We conducted a systematic review of observational studies published in Medline or EMBASE from January 2008 to November 2018 to identify current real-world CMV management approaches, CMV infection/disease risk factors, and outcomes associated with CMV infection. Descriptive statistics and pooled quantitative analyses were conducted. From 1608 records screened, 86 citations, including 69 803 adult KTR, were included. Prophylaxis and preemptive therapy (PET) were predominant approaches among D+/R- and R + CMV serostatus transplants, respectively. Valganciclovir and ganciclovir were frequently utilized across CMV risk strata. Despite prevention approaches, approximately one-fourth of KTR developed CMV infection. Age and D+/R- CMV serostatus were consistent risk factors for CMV infection/disease. CMV infection/disease was associated with increased mortality and graft loss. CMV was similarly associated with acute rejection (AR) risk, but with high heterogeneity among studies. Limited data were available on CMV and opportunistic infections (OIs) risk. CMV remains a significant issue. New strategies may be needed to optimize CMV management.

Clinical consequences of primary CMV infection after renal transplantation: a case-control study

The impact of primary cytomegalovirus infection (pCMV) on renal allograft function and histology is controversial. We evaluated the influence on incidence of acute rejection, allograft loss, allograft function and interstitial fibrosis/tubular atrophy (IF/TA). Retrospective case-control study, recipients transplanted between 2000 and 2014. Risk of acute rejection and allograft loss for those who experienced pCMV infection compared with those who did not, within an exposure period of two months after transplantation. Besides, its influence on allograft function and histology at one to three years after transplantation. Of 113 recipients experienced pCMV infection, 306 remained CMV seronegative. pCMV infection in the exposure period could not be proven as increasing the risk for acute rejection [HR = 2.18 (95% CI 0.80-5.97) P = 0.13] or allograft loss [HR = 1.11 (95%CI 0.33-3.72) P = 0.87]. Combination of pCMV infection and acute rejection posed higher hazard for allograft loss than acute rejection alone [HR = 3.69 (95% CI 1.21-11.29) P = 0.02]. eGFR(MDRD) values did not significantly differ at years one [46 vs. 50], two [46 vs. 51] and three [46 vs. 52]. No association between pCMV infection and IF/TA could be demonstrated [OR = 2.15 (95%CI 0.73-6.29) P = 0.16]. pCMV infection was not proven to increase the risk for acute rejection or allograft loss. However, it increased the risk for rejection-associated allograft loss. In remaining functioning allografts, it was not significantly associated with decline in function nor with presence of IF/TA.

Herpesviruses oral shedding and viremia in renal transplant recipients: A longitudinal study

BACKGROUND

The objective was to assess the oral shedding and viremia of human herpesviruses in renal transplant recipients.

METHODS

This is a cohort study in which the participants were examined in three different periods: the first within 24 hours before renal transplantation and the second and third ones 15-20 and 45-60 days after the transplantation. Mouthwash and blood samples were collected in each period and then submitted to screening for the presence of eight types of human herpesviruses by using multiplex PCR.

RESULTS

HSV-1 and EBV were more frequent in the saliva after renal transplantation, 15- to 20-day period after the transplant. EBV was found in the saliva of 26 (35.6%) patients before renal transplantation and in 56.2% and 46.6% of them, in the 15- to 20-day and 45- to 60-day periods after the transplant, respectively. High detection rates (75.3%-78.1%) were found for HHV-7 despite the lack of significant variations between the study periods. There was no concordance between herpesviruses oral shedding and viremia.

CONCLUSION

We concluded that the pattern of excretion of HSV-1 and EBV in saliva is changed immediately after renal transplantation, increasing in the 15- to 20-day period after the transplant surgery. No concordance between herpesviruses oral shedding and viremia was observed.

Viral load and duration of BK polyomavirus viraemia determine renal graft fibrosis progression: histologic evaluation of late protocol biopsies

BACKGROUND

Polyomavirus BK (BKV) infection of the renal allograft causes destructive tissue injury with inflammation and subsequent fibrosis.

METHODS

Using a prospective cohort of patients after kidney transplantation performed between 2003 and 2012, we investigated the role of BKV viraemia in the development and progression of interstitial fibrosis and tubular atrophy (IFTA). The primary outcome was moderate-to-severe IFTA assessed by protocol biopsy at 36 months.

RESULTS

A total of 207 consecutive recipients were enrolled. Of these, 57 (28%) developed BKV viraemia with 10 (5%) cases of polyomavirus-associated nephropathy (PVAN). Transient (<3 months) BKV viraemia occurred in 70% of patients, and persistent (≥3 months) BKV viraemia in 30%. A high viral load (≥10 000 copies/mL) was detected in 18% and a low viral load (<10 000 copies/mL) in 61%, while the viral load could not be determined in 21%. Moderate-to-severe IFTA was significantly increased in high [71%; odds ratio (OR) = 12.1; 95% confidence interval (CI) 1.62-90.0; P = 0.015] or persistent BKV viraemia (67%; OR = 6.33; 95% CI 1.19-33.7; P = 0.031) with corresponding rise in 'interstitial fibrosis + tubular atrophy' scores. Only patients with transient low BKV viraemia showed similar incidence and progression of IFTA to the no-BKV group. Persistent low BKV viraemia was uncommon yet the progression of fibrosis was significant. Only recipients with PVAN experienced inferior graft survival at 5 years.

CONCLUSIONS

These data suggest that only transient low BKV viraemia does not negatively affect the progression of allograft fibrosis in contrast to excessive risk of severe fibrosis after high or persistent BKV viraemia.

Cytomegalovirus Viremia after Living and Deceased Donation in Kidney Transplantation

Despite screening, effective anti-viral drugs and risk-balanced prophylaxis, cytomegalovirus (CMV) remains a major cause of morbidity in transplant patients. The objective of this study was to retrospectively analyze the risk factors associated with CMV viremia after kidney transplantation in a large European cohort with standardized valganciclovir prophylaxis in the present era. A special focus was placed on the comparison of living and postmortal donation. We conducted a longitudinal observational study involving 723 adult patients with a total of 3292 patient-years who were transplanted at our center between 2007 and 2015. Valganciclovir prophylaxis was administered over 100 days for CMV+ donors (D) or recipients (R), over 200 days for D+/R−, and none in D−/R−. A CMV+ donor, rejection episodes, and deceased donor transplantation were identified to be associated with increased incidences of CMV viremia. Although we did not find a reduced overall survival rate for patients with CMV viremia, it was associated with worse graft function. Since we observed a relevant number of CMV infections despite prescribing valganciclovir prophylaxis, a pre-emptive strategy in patients with (suspected) adherence restrictions could be favored. Our data can help transplant physicians educate their patients about their individual CMV risk and choose the most appropriate CMV treatment approach.

Relationship between early proteinuria and long term outcome of kidney transplanted patients from different decades of donor age

Background

Proteinuria after kidney transplantation portends a worse graft survival. However the magnitude of proteinuria related to patient and graft survival and its correlation with donor and recipient characteristics are poorly explored.

Methods

This study investigated the impact of post transplant proteinuria in the first year in 1127 kidney transplants analyzing the impact of different donor ages. Proteinuria cut off was set at 0.5 g/day.

Results

Transplants with proteinuria > 0.5 g/day correlated with poor graft and patient outcome in all donor age groups. In addition, 6-month-1-year proteinuria increase was significantly associated with graft outcome, especially with donors > 60 years old (p <  0.05; Odd Ratio 1.8). 1-year graft function (eGFR < or ≥ 44 ml/min) had similar impact to proteinuria (≥ 0.5 g/day) on graft failure (Hazard Ratio 2.77 vs Hazard Ratio 2.46). Low-grade proteinuria (0.2–0.5 g/day) demonstrated a trend for worse graft survival with increasing donor age. Also in kidney-paired analysis proteinuria ≥0.5 effect was more significant with donors > 50 years old (Odd Ratio 2.3).

Conclusions

Post-transplant proteinuria was increasingly harmful with older donor age. Proteinuria ≥0.5 g/day correlates with worse outcomes in all transplanted patients. Prognostic value of proteinuria and eGFR for graft and patient survival was comparable and these two variables remain significant risk factors even in a multivariate model that take into consideration the most important clinical variables (donor age, rejection, delayed graft function and cytomegalovirus viremia among others).

Cytomegalovirus prevention strategies and the risk of BK polyomavirus viremia and nephropathy

Polyomavirus BK (BKV) is the cause of polyomavirus-associated nephropathy resulting in premature graft loss. There are limited data regarding the role of cytomegalovirus (CMV) infection and its prevention in developing BKV viremia and PVAN. In a prospective study, we analyzed 207 consecutive renal transplant recipients previously enrolled in 2 randomized trials evaluating different CMV prevention regimens with routine screening for BKV and CMV. Of these, 59 received valganciclovir and 100 valacyclovir prophylaxis; 48 patients were managed by preemptive therapy. At 3 years, the incidence of BKV viremia and PVAN was 28% and 5%, respectively. CMV DNAemia developed in 55% and CMV disease in 6%. Both BKV viremia (42% vs 23% vs 21%, P = .006) and PVAN (12% vs 2% vs 2%, P = .011) were increased in patients treated with valganciclovir prophylaxis compared to valacyclovir and preemptive therapy. Using multivariate Cox proportional hazard regression, valganciclovir prophylaxis was independent predictor of BKV viremia (hazard ratio [HR] = 2.38, P = .002) and PVAN (HR = 4.73, P = .026). In contrast, the risk of subsequent BKV viremia was lower in patients with antecedent CMV DNAemia (HR = 0.50, P = .018). These data suggest valganciclovir prophylaxis may be associated with increased risk of BKV viremia and PVAN. CMV DNAemia did not represent a risk for BKV.

GCV/VCVG prophylaxis against CMV DNAemia in pediatric renal transplant patients: A systematic review and meta-analysis

CMV disease continues to stand as a significant threat to the longevity of renal transplants in children. More pediatric recipients are CMV-negative with CMV-positive donor serologies resulting in a HR mismatch. The length of prophylaxis with GCV or VGCV required to optimally prevent recurrence of CMVDNAemia remains unknown. This study is a meta-analysis comparing GCV/VGCV prophylaxis regimens provided for <6 months, from 6 to <12 months, and ≥12 months after transplant in order to prevent CMVDNAemia. The search conducted involved PubMed, EMBASE, ISI Web of Science, and Cochrane Central Register from inception through December 2017. Search terms Kidney Transplantation, CMV, GCV, and VGCV provided 204 studies for abstract review. Studies excluded were those which did not itemize pediatric data separately, single case reports, and duplicate studies. Pooled analysis of five retrospective studies and one prospective study identified that there is no statistically significant difference in the incidence of CMV DNAemia when comparing <6 months of prophylaxis and >12 months of prophylaxis (23% and 15%, respectively, P = 0.23). Regardless of the length of prophylaxis, there was no statistical difference in the incidence of CMV DNAemia in the HR patients (6 to <12 months vs <6 months, P = 0.62; 6 to <12 months vs ≥12 months, P = 0.78; ≥12 months vs <6 months, P = 0.83). This study identifies no optimal length of prophylaxis for HR mismatch pediatric renal transplant patients as many develop CMV DNAemia.

Persistent primary cytomegalovirus infection in a kidney transplant recipient: Multi-drug resistant and compartmentalized infection leading to graft loss

Cytomegalovirus (CMV) is one of the most common opportunistic infections after transplantation. To prevent CMV infections, universal prophylaxis and pre-emptive therapy with ganciclovir or its prodrug valganciclovir is applied. However, prolonged antiviral therapy may result in drug-resistance emergence. We describe a case of a 43-year-old CMV-seronegative patient who underwent kidney transplantation from a CMV-seropositive donor and developed CMV disease despite valganciclovir prophylaxis. CMV viral load increased even though valgangiclovir dose was augmented and immunosuppressive therapy reduced. CMV genotyping revealed mutations in the viral UL97 protein kinase, explaining ganciclovir-resistant CMV infection. The viral load failed to respond to foscavir, cidofovir and CMV-neutralizing immunoglobulins. Kidney allograft dysfunction developed 3 months post-transplantation with a histopathologic diagnosis of CMV nephropathy and potentially concomitant T-cell mediated rejection. A transplantectomy was performed on day 164 post-transplantation since the patient had uncontrollable CMV disease associated with a circulating multidrug-resistant DNA polymerase-mutant virus. Detailed monitoring in this patient demonstrated hallmarks of complicated CMV disease: (i) relatively rapid evolution of drug-resistant CMV mutants in the setting of persistent high blood viral loads, (ii) emergence of viral drug-resistance linked to acute graft rejection, (iii) transient and, thereafter, lack of response to various anti-CMV treatments, (iv) compartmentalization and heterogeneity of CMV viral populations, (v) possible differential ability of viral mutants to cause disease in the graft, and (vi) detection of minor viral variants by next generation sequencing. Translational research platforms that provide rapid molecular genotyping for detection of CMV drug-resistance are essential in guiding CMV disease management in high-risk transplant recipients.

Valganciclovir Prophylaxis Versus Preemptive Therapy in Cytomegalovirus-Positive Renal Allograft Recipients: Long-term Results After 7 Years of a Randomized Clinical Trial

BACKGROUND

The VIPP study compared valganciclovir prophylaxis with preemptive treatment regarding efficacy, safety, and long-term graft outcome in cytomegalovirus (CMV)-positive (R+) renal transplant recipients.

METHODS

Multicenter, open-label, randomized clinical study with a 12-month study phase and a follow-up of up to 84 months. Patients in the prophylaxis group received 2 × 450 mg/d oral valganciclovir for 100 days adjusted to renal function. Preemptive treatment with 2 × 900 mg/d valganciclovir was initiated at a viral load of 400 CMV copies/mL or greater (polymerase chain reaction) and maintained over ≥14 days, followed by secondary prophylaxis. Patients were stratified by donor CMV IgG serostatus (donor CMV IgG positive [D+]/R+, donor CMV IgG negative [D-]/R+).

RESULTS

The 12-month results were reported previously (Witzke et al Transplantation 2012). The intent-to-treat/safety population comprised 148 patients in the prophylaxis (61.5% D+/R+) and 151 patients in the preemptive group (52.3% D+/R+). Overall, 47% patients completed the follow-up. Significantly fewer patients in the prophylaxis compared with preemptive group experienced a CMV infection or disease up to month 84 (11.5%; 95% confidence interval [95% CI], 6.8-17.8%] vs 39.7%; 95% CI, 31.9-48.0%; P < 0.0001 and 4.7%; 95% CI, 1.9-9.5% vs 15.9%; 95% CI, 10.5-22.7%; P = 0.002). Incidences of graft loss (7.4% vs 8.6%), death (9.5% vs 11.3%), rejection (29.1% vs 28.5%), and renal function (estimated glomerular filtration rate [mean ± SD]: 58.2 ± 26.3 vs 59.9 ± 25.7 mL/min per 1.73 m) were not significantly different between prophylaxis and preemptive treatment. Tolerability was comparable between groups.

CONCLUSIONS

Prophylaxis was more effective than the preemptive approach, applying a low-intense surveillance protocol in preventing CMV infection and disease in intermediate-risk patients. Both strategies were similarly effective in preventing graft loss and death under the conditions of this long-term trial with a threshold of 400 copies/mL for initiation of anti-CMV treatment.

Less renal allograft fibrosis with valganciclovir prophylaxis for cytomegalovirus compared to high-dose valacyclovir: a parallel group, open-label, randomized controlled trial

BACKGROUND

Cytomegalovirus (CMV) prophylaxis may prevent CMV indirect effects in renal transplant recipients. This study aimed to compare the efficacy of valganciclovir and valacyclovir prophylaxis for CMV after renal transplantation with the focus on chronic histologic damage within the graft.

METHODS

From November 2007 through April 2012, adult renal transplant recipients were randomized, in an open-label, single-center study, at a 1:1 ratio to 3-month prophylaxis with valganciclovir (n = 60) or valacyclovir (n = 59). The primary endpoint was moderate-to-severe interstitial fibrosis and tubular atrophy assessed by protocol biopsy at 3 years evaluated by a single pathologist blinded to the study group. The analysis was conducted in an intention-to-treat population.

RESULTS

Among the 101 patients who had a protocol biopsy specimen available, the risk of moderate-to-severe interstitial fibrosis and tubular atrophy was significantly lower in those treated with valganciclovir (22% versus 34%; adjusted odds ratio, 0.31; 95% confidence interval, 0.11-0.90; P = 0.032 by multivariate logistic regression). The incidence of CMV disease (9% versus 2%; P = 0.115) and CMV DNAemia (36% versus 42%; P = 0.361) were not different at 3 years.

CONCLUSIONS

Valganciclovir prophylaxis, as compared with valacyclovir, was associated with a reduced risk of moderate-to-severe interstitial fibrosis and tubular atrophy in patients after renal transplantation.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ( ACTRN12610000016033 ). Registered on September 26, 2007.

New therapies for human cytomegalovirus infections

The recent approval of letermovir marks a new era of therapy for human cytomegalovirus (HCMV) infections, particularly for the prevention of HCMV disease in hematopoietic stem cell transplant recipients. For almost 30 years ganciclovir has been the therapy of choice for these infections and by today's standards this drug exhibits only modest antiviral activity that is often insufficient to completely suppress viral replication, and drives the selection of drug-resistant variants that continue to replicate and contribute to disease. While ganciclovir remains the therapy of choice, additional drugs that inhibit novel molecular targets, such as letermovir, will be required as highly effective combination therapies are developed not only for the treatment of immunocompromised hosts, but also for congenitally infected infants. Sustained efforts, largely in the biotech industry and academia, have identified additional highly active lead compounds that have progressed into clinical studies with varying levels of success and at least two have the potential to be approved in the near future. Some of the new drugs in the pipeline inhibit new molecular targets, remain effective against isolates that have developed resistance to existing therapies, and promise to augment existing therapeutic regimens. Here, we will describe some of the unique features of HCMV biology and discuss their effect on therapeutic needs. Existing drugs will also be discussed and some of the more promising candidates will be reviewed with an emphasis on those progressing through clinical studies. The in vitro and in vivo antiviral activity, spectrum of antiviral activity, and mechanism of action of new compounds will be reviewed to provide an update on potential new therapies for HCMV infections that have progressed significantly in recent years.

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.

A Markov Analysis of Screening for Late-Onset Cytomegalovirus Disease in Cytomegalovirus High-Risk Kidney Transplant Recipients

BACKGROUND AND OBJECTIVES

Management strategies are unclear for late-onset cytomegalovirus infection occurring beyond 6 months of antiviral prophylaxis in cytomegalovirus high-risk (cytomegalovirus IgG positive to cytomegalovirus IgG negative) kidney transplant recipients. Hybrid strategies (prophylaxis followed by screening) have been investigated but with inconclusive results. There are clinical and potential cost benefits of preventing cytomegalovirus-related hospitalizations and associated increased risks of patient and graft failure. We used decision analysis to evaluate the utility of postprophylaxis screening for late-onset cytomegalovirus infection.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used the Markov decision analysis model incorporating costs and utilities for various cytomegalovirus clinical states (asymptomatic cytomegalovirus, mild cytomegalovirus infection, and cytomegalovirus infection necessitating hospitalization) to estimate cost-effectiveness of postprophylaxis cytomegalovirus screening strategies. Five strategies were compared: no screening and screening at 1-, 2-, 3-, or 4-week intervals. Progression to severe cytomegalovirus infection was modeled on cytomegalovirus replication kinetics. Incremental cost-effectiveness ratios were calculated as a ratio of cost difference between two strategies to difference in quality-adjusted life-years starting with the low-cost strategy. One-way and probabilistic sensitivity analyses were performed to test model's robustness.

RESULTS

There was an incremental gain in quality-adjusted life-years with increasing screening frequency. Incremental cost-effectiveness ratios were $783 per quality-adjusted life-year (every 4 weeks over no screening), $1861 per quality-adjusted life-year (every 3 weeks over every 4 weeks), $10,947 per quality-adjusted life-year (every 2 weeks over every 3 weeks), and $197,086 per quality-adjusted life-year (weekly over every 2 weeks). Findings were sensitive to screening cost, cost of hospitalization, postprophylaxis cytomegalovirus incidence, and graft loss after cytomegalovirus infection. No screening was favored when willingness to pay threshold was <$14,000 per quality-adjusted life-year, whereas screening weekly was favored when willingness to pay threshold was >$185,000 per quality-adjusted life-year. Screening every 2 weeks was the dominant strategy between willingness to pay range of $14,000-$185,000 per quality-adjusted life-year.

CONCLUSIONS

In cytomegalovirus high-risk kidney transplant recipients, compared with no screening, screening for postprophylactic cytomegalovirus viremia is associated with gains in quality-adjusted life-years and seems to be cost effective. A strategy of screening every 2 weeks was the most cost-effective strategy across a wide range of willingness to pay thresholds.