Increased risk of breakthrough infection among cytomegalovirus donor-positive/recipient-negative kidney transplant recipients receiving lower-dose valganciclovir prophylaxis

Efficacy of valganciclovir prophylaxis in kidney transplant recipients following low-dose rituximab induction therapy: a multicenter retrospective study

BACKGROUND

Rituximab (RIT) induction therapy is widely used for desensitization against ABO-incompatible living-donor kidney transplants (KT). However, the efficacy of valganciclovir (VGCV) prophylaxis against cytomegalovirus (CMV) disease and infection in KT recipients (KTRs) following RIT induction remains unclear.

METHODS

The current multicenter retrospective study included 213 KTRs who received low-dose RIT induction between 1998 and 2021, across 6 facilities included in the Michinoku Renal Transplant Network (MRTN). VGCV dosage varied from 450 mg/day (twice weekly) to 900 mg/day (daily), with treatment durations of 3-12 months. The primary and secondary endpoints were the incidence of CMV disease and infection, respectively.

RESULTS

The incidence of CMV disease was significantly higher in the VGCV group (23.5%; 16 patients) than in the non-VGCV group (5.5%; 8 patients) (p < 0.01). The incidence of CMV infection was 54.5% (79 patients) in the non-VGCV group and 48.5% (33 patients) in the VGCV group, with no significant difference (p = 0.42). In the subgroup of CMV-seronegative KTRs receiving allografts from CMV-seropositive donors (CMV IgG (D + /R-)), 18 out of 24 KTRs received VGCV prophylaxis, of whom 10 (55.6%) developed CMV disease. Within this subgroup, only 4 KTRs received VGCV with the standard protocol (900 mg daily for 6 months), and none developed CMV disease.

CONCLUSION

Insufficient VGCV prophylaxis does not reduce the incidence of CMV disease in KTRs following low-dose RIT induction. Despite concerns about leukopenia due to RIT and VGCV, in KTRs with CMV IgG (D + /R-) serostatus, VGCV prophylaxis with a standard protocol may be advisable.

Cytomegalovirus Antiviral Resistance Among Kidney Transplant Recipients in a Phase 3 Trial of Letermovir vs Valganciclovir Prophylaxis

BACKGROUND

In a phase 3 trial, letermovir was noninferior to valganciclovir for cytomegalovirus (CMV) disease prophylaxis in kidney transplant recipients who were CMV-seronegative and received kidneys from donors who were CMV-seropositive. Genotypic antiviral resistance and CMV glycoprotein B (gB) genotype are reported.

METHODS

Plasma samples with detectable CMV DNA were sequenced for the presence of known letermovir and valganciclovir resistance-associated amino acid substitutions (RASs) encoded by CMV gene regions (UL51, UL54, UL56, UL89, UL97) and prevalence of gB (UL55) genotypes (gB1-gB5).

RESULTS

Among participants, 84 of 292 (letermovir) and 93 of 297 (valganciclovir) had evaluable data for ≥1 gene target. Letermovir RASs were not detected in participants who received letermovir prophylaxis; however, 3 had valganciclovir RASs (pUL97). Twelve participants who received valganciclovir prophylaxis had valganciclovir RASs (pUL54, pUL97), and 1 who did not receive letermovir during the trial had letermovir RASs (pUL56). All but 1 participant responded to valganciclovir treatment irrespective of breakthrough CMV DNAemia or frequency of RASs. gB1 was the most frequent genotype across all participants and subgroups.

CONCLUSIONS

Letermovir RASs were not detected with letermovir prophylaxis, supporting a low risk for development of resistance in kidney transplant recipients who were CMV-seronegative and received kidneys from donors who were CMV-seropositive.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov, NCT03443869; EudraCT, 2017-001055-30.

Management of cytomegalovirus in adult solid organ transplant patients: GESITRA-IC-SEIMC, CIBERINFEC, and SET recommendations update

Cytomegalovirus (CMV) infection remains a significant challenge in solid organ transplantation (SOT). The last international consensus guidelines on the management of CMV in SOT were published in 2018, highlighting the need for revision to incorporate recent advances, notably in cell-mediated immunity monitoring, which could alter the current standard of care. A working group including members from the Group for the Study of Infection in Transplantation and the Immunocompromised Host (GESITRA-IC) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Society of Transplantation (SET), developed consensus-based recommendations for managing CMV infection in SOT recipients. Recommendations were classified based on evidence strength and quality using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The final recommendations were endorsed through a consensus meeting and approved by the expert panel.

Management of cytomegalovirus infections - Swedish recommendations 2023

Cytomegalovirus (CMV) infection, which mostly causes a subclinical infection early in life, has important clinical consequences in certain patient groups. CMV is the most common congenital infection and can cause permanent disabilities such as hearing loss and motor- and cognitive deficits in affected infants. In allogeneic haematopoietic stem cell and solid organ transplant recipients, CMV still is an important infectious complication with a risk for life-threatening disease. The previous Swedish recommendations for the management of CMV infections were updated by an expert group under the guidance of The Swedish Reference Group for Antiviral Treatment (RAV) and published at the website of RAV in August 2023 (https://www.sls.se/rav/rekommendationer/cytomegalovirus/). We here provide a translation of the updated recommendations, with minor modifications regarding diagnosis of CMV pneumonia. In the present recommendations, we discuss aspects of old and new CMV antivirals, including dosing for different age groups, and cover the management of congenital infections and CMV in immunocompromised patients. The recommendations are evidence-graded in accordance with the Oxford Centre for Evidence-Based Medicine.

Management of cytomegalovirus infection after liver transplantation

Cytomegalovirus (CMV) infection is one of the primary causes of morbidity and mortality following liver transplantation (LT). Based on current worldwide guidelines, the most effective strategies for avoiding post-transplant CMV infection are antiviral prophylaxis and pre-emptive treatment. CMV- IgG serology is the established technique for pretransplant screening of both donors and recipients. The clinical presentation of CMV infection and disease exhibits variability, prompting clinicians to consistently consider this possibility, particularly within the first year post-transplantation or subsequent to heightened immunosuppression. At annual symposia to discuss CMV prevention and how treatment outcomes can be improved, evidence on the incorporation of immune functional tests into clinical practice is presented, and the results of studies with new antiviral treatments are evaluated. Although there are ongoing studies on the use of letermovir and maribavir in solid organ transplantation, a consensus reflected in the guidelines has not been formed. Determining the most appropriate strategy at the individual level appears to be the key to enhancing outcomes. Although prevention strategies reduce the risk of CMV disease, the disease can still occur in up to 50% of high-risk patients. A balance between the risk of infection and disease development and the use of immunosuppressants must be considered when talking about the proper management of CMV in solid organ transplant recipients. The objective of this study was to establish a comprehensive framework for the management of CMV in patients who have had LT.

Therapeutic Myths in Solid Organ Transplantation Infectious Diseases

Infection management in solid organ transplantation poses unique challenges, with a diverse array of potential pathogens and associated antimicrobial therapies. With limited high-quality randomized clinical trials to direct optimal care, therapeutic "myths" may propagate and contribute to suboptimal or excessive antimicrobial use. We discuss 6 therapeutic myths with particular relevance to solid organ transplantation and provide recommendations for infectious diseases clinicians involved in the care of this high-risk population.

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.

Pitfalls in Valganciclovir Prophylaxis Dose Adjustment Based on Renal Function in Kidney Transplant Recipients

Valganciclovir (VGC) is administered as prophylaxis to kidney transplant recipients (KTR) CMV donor (D)+/recipient (R)- and CMV R+ after thymoglobulin-induction (R+/TG). Although VGC dose adjustments based on renal function are recommended, there is paucity of real-life data on VGC dosing and associations with clinical outcomes. This is a retrospective Swiss Transplant Cohort Study-embedded observational study, including all adult D+/R- and R+/TG KTR between 2010 and 2020, who received prophylaxis with VGC. The primary objective was to describe the proportion of inappropriately (under- or over-) dosed VGC week-entries. Secondary objectives included breakthrough clinically significant CMV infection (csCMVi) and potential associations between breakthrough-csCMVi and cytopenias with VGC dosing. Among 178 KTR, 131 (73.6%) patients had ≥2 week-entries for the longitudinal data of interest and were included in the outcome analysis, with 1,032 VGC dose week-entries. Overall, 460/1,032 (44.6%) were appropriately dosed, while 234/1,032 (22.7%) and 338/1,032 (32.8%) were under- and over-dosed, respectively. Nineteen (14.5%) patients had a breakthrough-csCMVi, without any associations identified with VCG dosing (p = 0.44). Unlike other cytopenias, a significant association between VGC overdosing and lymphopenia (OR 5.27, 95% CI 1.71-16.22, p = 0.004) was shown. VGC prophylaxis in KTR is frequently inappropriately dosed, albeit without meaningful clinical associations, neither in terms of efficacy nor safety.

Prevention of Cytomegalovirus Infection in Solid Organ Transplant Recipients: Guidelines by the Korean Society of Infectious Diseases and the Korean Society for Transplantation

Cytomegalovirus (CMV) is the most important opportunistic viral pathogen in solid organ transplant (SOT) recipients. The Korean guideline for the prevention of CMV infection in SOT recipients was developed jointly by the Korean Society for Infectious Diseases and the Korean Society of Transplantation. CMV serostatus of both donors and recipients should be screened before transplantation to best assess the risk of CMV infection after SOT. Seronegative recipients receiving organs from seropositive donors face the highest risk, followed by seropositive recipients. Either antiviral prophylaxis or preemptive therapy can be used to prevent CMV infection. While both strategies have been demonstrated to prevent CMV infection post-transplant, each has its own advantages and disadvantages. CMV serostatus, transplant organ, other risk factors, and practical issues should be considered for the selection of preventive measures. There is no universal viral load threshold to guide treatment in preemptive therapy. Each institution should define and validate its own threshold. Valganciclovir is the favored agent for both prophylaxis and preemptive therapy. The evaluation of CMV-specific cell-mediated immunity and the monitoring of viral load kinetics are gaining interest, but there was insufficient evidence to issue recommendations. Specific considerations on pediatric transplant recipients are included.

Five-year single-center analysis of cytomegalovirus viremia in kidney transplant recipients and possible implication for novel prophylactic therapy approaches

BACKGROUND

Cytomegalovirus (CMV) infections are a common complication after kidney transplantation (KTx) and negatively affecting patient outcome. Valganciclovir (VGC) prophylaxis is often limited by drug-induced side effects and dose reduction due to decline in kidney function.

METHOD

In the present study, episodes of CMV viremia in the first year after KTx in a cohort of 316 recipients were analyzed retrospectively to identify risk factors linked to persistent infections.

RESULTS

In the studied cohort, 18.7% of patients showed a high-risk (HR) constellation (D+/R-) for CMV infections. CMV viremia affected 22% of our cohort, with HR patients being the most affected cohort (44.1%). Within this group, most viremic events (65.3%) occurred while patients were still on prophylactic therapy, showing significantly higher viral loads and a longer duration compared to seropositive recipients.

CONCLUSION

The analysis at hand revealed that detection of viremia under ongoing antiviral prophylaxis bears an increased risk for sustained viral replication and antiviral drug resistance in HR patients. We identified low estimated glomerular filtration rate (eGFR) and lower dose VGC prophylaxis post-KTx as a risk factor for breakthrough infections in HR patients in our single center cohort. These patients might benefit from a closer CMV monitoring or novel prophylactic agents as letermovir.

Reduced dosing versus full dosing valganciclovir for prophylaxis of cytomegalovirus in high-risk abdominal transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is a common infection in abdominal transplant recipients (ATR). Prevention of CMV in the highest risk population (CMV IgG donor+/recipient-) is critical as CMV is associated with negative outcomes. Guideline recommended prophylactic valganciclovir dosing is 900 mg daily for 6 months in this population. However, reduced dosing strategies are utilized in practice.

METHODS

This single center, retrospective study in adult ATR compared full valganciclovir prophylactic dosing (900 mg daily for 6 months) to reduced dosing (900 mg daily for 3 months, then 450 mg daily for 3 months). The primary endpoint was incidence of CMV infection with viral load >1000 IU/mL. Secondary endpoints included incidence of CMV infection with viral load 200-1000 IU/mL, neutropenia, and leukopenia.

RESULTS

Incidence of CMV infection with viral load >1000 IU/mL (29% vs. 27%, p = 1) or CMV infection with viral load 200-1000 IU/mL (6% vs. 12%, p = .421) did not differ significantly between 68 ATR in reduced and full dosing groups, as well as incidence of leukopenia (94% vs. 97%, p = 1) and neutropenia (77% vs. 70%, p = .586).

CONCLUSIONS

There was no difference in the incidence of CMV infection, neutropenia, or leukopenia of the two dosing regimens, although time to CMV diagnosis was different.

A Systematic Review and Meta-analysis of Optimized CMV Preemptive Therapy and Antiviral Prophylaxis for CMV Disease Prevention in CMV High-Risk (D+R-) Kidney Transplant Recipients

The optimal strategy for cytomegalovirus (CMV) disease prevention in CMV donor/recipient kidney transplant recipients remains uncertain. Conclusions of prior meta-analyses that CMV disease rates with preemptive therapy (PET) and universal prophylaxis (UP) were comparable may have been affected by inclusion of studies lacking key determinants of efficacy of the respective strategies.

Methods

We conducted a systematic review and meta-analysis of PET with weekly CMV polymerase chain reaction monitoring for ≥3 mo and UP with 6 mo of valganciclovir. PubMed and Embase databases were reviewed from January 1, 2010, to April 1, 2022. Risk of bias was assessed with 3 instruments (Cochrane RoB, Cochrane RoBINS-I, and an instrument for assessing risk in observational studies). The primary outcome was CMV disease incidence by 1-y posttransplant. Secondary outcomes by 1-y were graft loss, acute allograft rejection, and mortality. Results were synthesized using generalized linear mixed model meta-analysis. PET studies were stratified into low-threshold (LT) and high-threshold (HT) PET based on the viral load threshold for initiation of antiviral therapy.

Results

Twenty-five studies met inclusion criteria (6 PET, 19 UP). CMV disease incidence was significantly higher in HT (0.30 [95% confidence interval (CI), 0.22-0.39]) versus LT PET (0.06 [95% CI, 0.03-0.12]). LT PET was associated with a significantly lower CMV disease incidence (0.06 [95% CI, 0.03-0.12]) versus UP (0.21 [95% CI, 0.17-0.27]). Incidence of graft loss, acute allograft rejection, or mortality was not significantly different between LT PET and UP (P > 0.05 for all comparisons). Receipt of lymphocyte-depleting antibodies was not associated with a significant difference in CMV disease incidence (odds ratio = 1.34 [95% CI, 0.80-2.25]).

Conclusions

LT PET is associated with a significantly lower incidence of CMV disease compared to UP with similar rates of other clinical outcomes. These findings provide rationale and preliminary data for a randomized superiority trial of optimized LT-PET versus UP in donor seropositive recipient seronegative kidney transplant recipients.

Current Perspectives on the Management of Herpesvirus Infections in Solid Organ Transplant Recipients

Solid organ transplant recipients (SOTRs) are at high risk of human herpesvirus (HHV)-related morbidity and mortality due to the use of immunosuppressive therapy. We aim to increase awareness and understanding of HHV disease burden in SOTRs by providing an overview of current prevention and management strategies as described in the literature and guidelines. We discuss challenges in both prevention and treatment as well as future perspectives.

Burden of neutropenia and leukopenia among adult kidney transplant recipients: A systematic literature review of observational studies

BACKGROUND

Leukopenia and neutropenia (L/N) may affect treatment decisions, potentially resulting in poor clinical and economic outcomes among kidney transplant recipients (KTRs). The burden of L/N is poorly quantified systematically. This systematic literature review aimed to summarize the incidence of, risk factors for, and clinical and economic outcomes associated with L/N post-KT.

METHODS

We systematically searched MEDLINE, Embase, and the Cochrane Library (from database inception-June 14, 2021) and conferences (past 3 years) to identify observational studies examining epidemiology, risk factors, or outcomes associated with L/N among adult KTRs.

RESULTS

Of 2081 records, 82 studies met inclusion criteria. Seventy-three studies reported the epidemiology of L/N post-KT. Pooled incidence of neutropenia, defined as absolute neutrophil counts (ANC) <1000/μl, ranged from 13% to 48% within 1-year post-transplant; ANC <500/μl ranged from 15% to 20%. Leukopenia, defined as white blood cell counts <3500/μl, was 19% to 83%. Eleven studies reported independent risk factors associated with L/N post-KT. D+/R- cytomegalovirus status, mycophenolic acid (MPA), and tacrolimus use were the most consistent risk factors across studies. Fourteen studies reported L/N-associated clinical outcomes. We noted a trend toward a positive association between neutropenia and acute rejection/opportunistic infections. Mixed findings were noted on the association between L/N and graft failure or mortality. Dosage modifications of valganciclovir, MPA, cotrimoxazole, and anti-thymoglobulin and the need for granulocyte colony-stimulating factor (G-CSF) use were common with L/N.

CONCLUSION

Findings suggest post-transplant L/N were common and associated with frequent modifications of immunosuppressive agents, requiring G-CSF use, and rejection or opportunistic infections. Findings highlight the need for interventions to reduce risk of L/N post-KT.

Clinical Manifestations and Outcomes of Renal Transplantation Patients With Pneumocystis jirovecii Pneumonia and Cytomegalovirus Co-infection

Background

Pneumocystis jirovecii pneumonia (PJP) and cytomegalovirus (CMV) infection are common opportunistic infections among renal transplantation (RT) recipients, and both can increase the risk of graft loss and patient mortality after RT. However, few studies had evaluated PJP and CMV co-infection, especially among RT patients. Therefore, this study was performed to evaluate the impact of CMV co-infection with PJP among RT recipients.

Methods

We retrospectively analyzed the clinical data of patients with confirmed diagnosis of PJP between 2015 and 2021 in our hospital. We divided patients into PJP and PJP+CMV groups according to their CMV infection status, and the clinical severity and outcomes of the two groups were evaluated.

Results

A total of 80 patients after RT were diagnosed with PJP. Of these, 37 (46.2%) patients had co-existing CMV viremia. There were no statistically significant intergroup differences in age, sex, diabetes, onset time of PJP after RT and postoperative immunosuppressant. Compared to serum creatinine (Cr) at admission, the serum Cr at discharge in both the PJP and PJP+CMV groups were decreased. The PJP+CMV group had a higher C-reactive protein level, higher procalcitonin level, and lower albumin level than the PJP group. The PJP+CMV group showed a higher PSI score than the PJP group. Moreover, the initial absorption time of the lesion was longer in the PJP+CMV group. However, the duration of hospitalization showed no significant differences between the two groups. The mortality rate was 9.4-times higher in the PJP+CMV group than in the PJP group. The rate of admittance to the intensive care unit was 3.2-times higher in the PJP+CMV group than in the PJP group.

Conclusion

CMV co-infection may result in more serious inflammatory response. RT patients with PJP+CMV infection had more severe clinical symptoms, slower recovery from pneumonia, and higher mortality than those with PJP alone. Therefore, when RT patients present with severe PJP, the possibility of CMV co-infection should be considered. Short-term withdrawal of immunosuppressants in case of severe infection is safe for the renal function of RT patients.

Development of CMV-specific cytotoxic T cells (CMV-Tc) in pediatric renal transplant recipients with CMV viremia

BACKGROUND

Viral infections are controlled primarily by viral-specific T cells, raising concern for adequate T-cell response to clear CMV infection in transplant recipients receiving lymphocyte-depleting agents (LDA). We examined the rates of CMV viremia and clearance, seroconversion, and CMV-specific CD8+ T cell (CMV-Tc) activity with class of induction agent received.

METHODS

Retrospective review of 45 pediatric renal transplant recipients who received induction with LDA (n = 31) or non-LDA (NLDA; n = 14) received valganciclovir prophylaxis for 6 months post-transplant and CMV-PCR monitoring. CMV-Tc was measured by intracellular IFNγ flow cytometry, when possible, at baseline, 1 month after CMV viremia (>5 copies/PCR) and serially until CMV-Tc was positive (≥0.2%).

RESULTS

Viremia rates at 1, 2, and 4 years post-transplant were higher in LDA vs. NLDA (46.3% vs. 7.2%, 64.2% vs. 7.2%, and 64.2% vs. 7.2%, respectively; p = .002). Viremia rates at these time points in seronegative LDA (50.3%, 71.6%, 71.6%) were significantly or near significantly higher than seronegative NLDA (9.1%, 9.1%, 9.1%; p = .004), seropositive-LDA (22.3%, 22.3%, 22.3%; p = .07), or seropositive NLDA (0%, 0%, 0%; p = .07). Eleven of 17 (64.7%) viremic subjects required valganciclovir dose reduction during the prophylaxis period for leukopenia. All viremic LDA patients developed CMV-Tc. One viremic NLDA patient did not develop CMV-Tc. No patients developed CMV disease.

CONCLUSION

CMV seronegative pediatric renal transplant patients receiving LDA are more likely to have valganciclovir prophylaxis dose reduction and develop subclinical CMV viremia; however, all developed CMV-Tc. Larger prospective studies are needed to further understand the effects of induction agents on CMV-Tc and CMV-Tc's role post-transplant.

Low-Dose Valganciclovir Prophylaxis Is Safe and Cost-Saving in CMV-Seropositive Kidney Transplant Recipients

Introduction: Observational studies suggest that low-dose valganciclovir prophylaxis (450 mg daily for normal renal function) is as effective as and perhaps safer than standard-dose valganciclovir (900 mg daily) in preventing CMV infection among kidney transplant recipients. However, this practice is not supported by current guidelines due to concerns for breakthrough infection from resistant CMV, mainly in high-risk CMV donor-seropositive/recipient-seronegative kidney transplant recipients. Standard-dose valganciclovir is costly and possibly associated with higher incidence of neutropenia and BKV DNAemia. Our institution adopted low-dose valganciclovir prophylaxis for intermediate-risk (seropositive) kidney transplant recipients in January 2018. Research Question: To analyze the efficacy (CMV DNAemia), safety (BK virus DNAemia, neutropenia, graft loss, and death), and cost savings associated with this change. Design: We retrospectively compared the above outcomes between CMV-seropositive kidney transplant recipients who received low-dose and standard-dose valganciclovir, transplanted within our institution, between 1/19/2014 and 7/15/2019, using propensity score-adjusted competing risk analyses. We also compared cost estimates between the two dosing regimens, for 3 months of prophylaxis, and for different percentage of patient-weeks with normal renal function, using the current average wholesale price of valganciclovir. Results: We studied 179 CMV-seropositive kidney transplant recipients, of whom 55 received low-dose and 124 standard-dose valganciclovir. The majority received nonlymphocyte depleting induction (basiliximab). Low-dose valganciclovir was at least as effective and safe as, and more cost-saving than standard-dose valganciclovir. Conclusion: This single-center study contributes to mounting evidence for future guidelines to be adjusted in favor of low-dose valganciclovir prophylaxis in CMV-seropositive kidney transplant recipients.

Conversion from cytomegalovirus universal prophylaxis with valganciclovir to the preemptive monitoring approach to manage leukopenia after kidney or pancreas transplantation

PURPOSE

In clinical practice, conversion from universal cytomegalovirus prophylaxis (CMV PPX) with valganciclovir (VGC) to targeted therapy (preemptive monitoring, PEM) is often pursued in the setting of leukopenia. It is unknown if this is an effective strategy.

METHODS

Adult patients receiving a kidney and/or pancreas transplant were included if converted from PPX to PEM between 9/1/19 and 3/1/20 due to leukopenia. A positive CMV viral load (VL) was defined as CMV PCR greater than the lower limit of quantification (LLOQ) based on local lab testing. A CMV VL of >500 IU/mL was chosen as the preemptive treatment (PET) threshold. Primary objective was to describe the impact of conversion on resolution of leukopenia. Secondary objectives were to assess PEM associated outcomes.

RESULTS

There were 49 patients converted from PPX to PEM due to leukopenia in the study period; 88% were KTRs and 96% received lymphocyte-depleting induction; 84% were seropositive at transplant (R+) and 16% were high-risk (D+/R-). Mean WBC at time of enrollment was 1.4 ± 0.4. After PEM conversion, WBC recovered to >3 in 87.8% of the population in a mean of 26.8 ± 24.5 days. Immunosuppression was modified in 96% of the population and GCSF was required in 46.9% of patients. CMV viremia occurred in 36.7% of the population; 78% were KTRs and 94% were R+. Time from PEM enrollment to PET was 64 ± 34 days. Median VL at first detection was 587 IU/mL, median peak was 1920 IU/mL. Five patients (27.8%) presented with symptoms consistent with CMV syndrome, none had end organ disease. Six patients (33%) presented with a VL <500 IU/mL at first detection, but all subsequently surpassed the threshold and required PET. Mean duration of PET was 25 ± 11 days. Mean change in WBC in response to PET was -0.4 ± 1.3. Immunosuppression required further adjustment in 61% of patients. There were no deaths or graft loss due to CMV at last follow-up.

CONCLUSION

In kidney and pancreas transplant recipients who undergo PEM conversion due to leukopenia, withholding of VGC can improve leukopenia, but other concomitant measures are necessary. This population should be considered fairly high risk, with a threshold of treatment of first quantifiable replication. Our findings suggest lack of harm from this approach but highlight the importance of close monitoring to prevent symptomatic replication. Larger studies with longer follow-up are needed to better evaluate the impact of PEM conversion on late-onset CMV and patient and graft outcomes.

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

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Valganciclovir prophylaxis for cytomegalovirus infection in pediatric kidney transplant recipients: a single-center experience

BACKGROUND

There are two approaches for treating cytomegalovirus (CMV) infection occurring after kidney transplantation (KTx). One is preemptive therapy in which treatment is started after confirming positive CMV antigenemia using periodic antigenemia assay. The other approach is prophylactic therapy in which oral valganciclovir (VGCV) is started within 10 days after KTx and continued for 200 days. The Transplantation Society guidelines recommend prophylactic therapy for high-risk (donor's CMV-IgG antibody positive and recipient's negative) pediatric recipients. However, the adequate dose and side effects of VGCV are not clear in children, and there is no sufficient information about prophylaxis for Japanese pediatric recipients.

METHODS

A single-center retrospective analysis was conducted on case series of high-risk pediatric patients who underwent KTx and received oral VGCV prophylaxis at the Department of Pediatric Nephrology, Tokyo Women's Medical University, between August 2018 and March 2019. Data were collected using medical records.

RESULTS

The dose of administration was 450 mg in all the study patients (n = 5). Reduction or discontinuation was required in four of five patients due to adverse events, which included neutropenia in one patient, anemia in two patients, and neutropenia and digestive symptoms in one patient. Late-onset CMV disease occurred in all patients. No seroconversion was observed during prophylaxis.

CONCLUSIONS

Our preliminary study suggests that the dosage endorsed by The Transplantation Society may be an overdose for Japanese pediatric recipients. Further studies are required to examine the safety and efficacy of VGCV prophylaxis in Japanese pediatric recipients.

Impact and outcomes of primary cytomegalovirus disease in seronegative abdominal solid organ transplant recipients of cytomegalovirus unexposed donors (D-/R-)

BACKGROUND

Primary cytomegalovirus (CMV) disease in high-risk (D+/R-) abdominal solid organ transplant recipients (aSOTRs) is well described, however, little is known of primary CMV disease in low-risk (D-/R-) patients.

METHODS

Observational study of adult aSOTRs between 1/1/2009 and 9/1/2019 screened based on serostatus at transplant; D-/R- and D+/R- patients were included.

PRIMARY OBJECTIVE

Describe epidemiology of primary CMV in D-/R- aSOTRs.

SECONDARY OBJECTIVE

Compare infectious and transplant-related outcomes of primary CMV disease in the first 90 days (early CMV) between D-/R- and D+/R-.

RESULTS

Of 782 D-/R- aSOTRs in the study period, 13 developed CMV at any time after transplant to last follow-up. Of 671 D+/R- patients, 186 developed CMV. Early CMV disease was significantly more common in the D-/R- group (54% vs 15.6%, P = .0005) despite populations being similar demographically, including allograft subtype. D-/R- patients with early CMV disease had median viral load >100 000 IU/mL and 42.9% had end-organ manifestations; 71.4% required hospital admission. Immunosuppressive therapy was adjusted in 100% of patients, there was an approximately 14.3% rate of antiviral resistance and 28.6% had concomitant opportunistic infection. These findings were similar to D+/R- patients. There was no difference in risk of rejection or all-cause mortality associated with early CMV disease, however, graft loss was significantly higher in D-/R-.

CONCLUSION

D-/R- aSOTRs infrequently develop CMV, however, when it occurs, they present with disease manifestations similar to and graft outcomes inferior to D+/R- with CMV. Additionally, the majority of CMV disease in D-/R- occurs in the first 90 days after transplant, suggesting possible donor subclinical infection or transfusion source. The complicated course in D-/R- is likely caused by low clinical suspicion. Awareness of disease severity and aggressive upfront management may promote positive outcomes.

Efficacy of low-dose valganciclovir in CMV R+ lung transplant recipients: a retrospective comparative analysis

Background

Cytomegalovirus (CMV) infection is extremely common after lung transplant and can be associated with significant morbidity and mortality. Current practice suggests the use of 900 mg daily of valganciclovir for CMV prophylaxis, but there is no literature assessing whether 450 mg daily of valganciclovir is sufficient in intermediate CMV risk lung transplant recipients. Therefore, we sought to assess the role of low-dose valganciclovir (LDV) versus high-dose valganciclovir (HDV) prophylaxis in intermediate-risk (R+) recipients.

Methods

We conducted a retrospective analysis on lung transplant recipients at the Norton Thoracic Institute in Phoenix, Arizona looking at intermediate-risk patients that received either valganciclovir 450 mg per day (LDV) or 900 mg/day (HDV). All patients were followed for 1 year post-transplant for incidence of CMV viremia. The primary outcome was the rate of CMV viremia as determined by a positive CMV polymerase chain reaction ([PCR] >2.7 log copies/mL). Secondary outcomes included rate of adverse events, acute cellular rejection, and mortality.

Results

The primary analysis included 103 patients (55 in the LDV group, 48 in the HDV group). In the LDV group, 9 patients (16.4%) developed CMV viremia compared to 4 (8.3%) in the HDV group (p=0.221) with no difference observed in adverse event rates between groups.

Conclusion

There was no statistical difference between groups for the primary outcome. However, the effect size demonstrated in this analysis may be of clinical relevance and valganciclovir 450 mg daily would not be recommended in intermediate risk lung transplant recipients at this time. To confirm our results, further prospective studies enrolling larger patient populations are necessary.

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.

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.

The Association Between Cytomegalovirus Infection and Cardiac Allograft Vasculopathy in the Era of Antiviral Valganciclovir Prophylaxis

Supplemental Digital Content is available in the text.

Previous studies on the association between cytomegalovirus (CMV) infection and cardiac allograft vasculopathy (CAV) were conducted on patients transplanted in the prevalganciclovir prophylaxis era. The aim of our study is to evaluate this relation in heart transplantation (HTx) recipients treated according to current prophylactic and immunosuppressive regimens.

Opportunistic Infections in Transplant Patients

Transplants have become common with excellent patient and graft outcomes owing to advances in surgical technique, immunosuppression, and antimicrobial prophylaxis. In 2017, 34,770 solid organ transplants were performed in the United States. For solid organ transplant recipients, infection remains a common complication owing to the regimens required to prevent rejection. Opportunistic infections, which are infections that are generally of lower virulence within a healthy host but cause more severe and frequent disease in immunosuppressed individuals, typically occur in the period 1 month to 1 year after transplantation. This article focuses on opportunistic infections in the solid organ transplant recipient.

Cytomegalovirus Infection in Solid Organ and Hematopoietic Cell Transplantation: State of the Evidence

This review focuses on recent advances in the field of cytomegalovirus (CMV). The 2 main strategies for CMV prevention are prophylaxis and preemptive therapy. Prophylaxis effectively prevents CMV infection after solid organ transplantation (SOT) but is associated with high rates of neutropenia and delayed-onset postprophylaxis disease. In contrast, preemptive therapy has the advantage of leading to lower rates of CMV disease and robust humoral and T-cell responses. It is widely used in hematopoietic cell transplant recipients but is infrequently utilized after SOT due to logistical considerations, though these may be overcome by novel methods to monitor CMV viremia using self-testing platforms. We review recent developments in CMV immune monitoring, vaccination, and monoclonal antibodies, all of which have the potential to become part of integrated strategies that rely on viral load monitoring and immune responses. We discuss novel therapeutic options for drug-resistant or refractory CMV infection, including maribavir, letermovir, and adoptive T-cell transfer. We also explore the role of donor factors in transmitting CMV after SOT. Finally, we propose a framework with which to approach CMV prevention in the foreseeable future.

Clinical outcomes of valganciclovir prophylaxis in high-risk (D+/R-) renal transplant recipients experiencing delayed graft function

BACKGROUND

Cytomegalovirus (CMV) outcomes with valganciclovir prophylaxis in renal transplant recipients experiencing delayed graft function (DGF) are unclear.

METHODS

This single center, retrospective, cohort study of CMV high-risk (D+/R- with alemtuzumab induction) deceased donor renal transplant recipients receiving valganciclovir prophylaxis assessed CMV outcomes in patients experiencing DGF (n = 72) versus those with immediate graft function (IGF; n = 66).

RESULTS

Cytomegalovirus viremia by 12 months occurred at similar rates in the IGF and DGF groups (30.3% vs 26.4%, respectively, P = 0.71) with 89.7% (35/39) of all cases classified as CMV disease. The median time to CMV viremia post transplant was day 141 and 138 in the IGF and DGF groups, respectively (P = 0.30). The incidence of biopsy-proven acute rejection (BPAR) was higher in the DGF group (18.1% vs 4.6%, P = 0.02) with BPAR preceding CMV in only 1 patient. There was no significant difference in graft loss (1.5% vs 4.2%, P = 0.62) or patient survival (98.5% vs 95.8%, P = 0.62) at 1 year between the IGF and DGF groups, respectively.

CONCLUSION

Valganciclovir prophylaxis in patients experiencing DGF yielded similar CMV outcomes up to 1-year post transplant when compared to use in patients with IGF.

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.

Risk Factors for Failure of Primary (Val)ganciclovir Prophylaxis Against Cytomegalovirus Infection and Disease in Solid Organ Transplant Recipients

Background

Rates and risk factors for cytomegalovirus (CMV) prophylaxis breakthrough and discontinuation were investigated, given uncertainty regarding optimal dosing for CMV primary (val)ganciclovir prophylaxis after solid organ transplantation (SOT).

Methods

Recipients transplanted from 2012 to 2016 and initiated on primary prophylaxis were followed until 90 days post-transplantation. A (val)ganciclovir prophylaxis score for each patient per day was calculated during the follow-up time (FUT; score of 100 corresponding to manufacturers’ recommended dose for a given estimated glomerular filtration rate [eGFR]). Cox models were used to estimate hazard ratios (HRs), adjusted for relevant risk factors.

Results

Of 585 SOTs (311 kidney, 117 liver, 106 lung, 51 heart) included, 38/585 (6.5%) experienced prophylaxis breakthrough and 35/585 (6.0%) discontinued prophylaxis for other reasons. CMV IgG donor+/receipient- mismatch (adjusted HR [aHR], 5.37; 95% confidence interval [CI], 2.63 to 10.98; P < 0.001) and increasing % FUT with a prophylaxis score <90 (aHR, 1.16; 95% CI, 1.04 to 1.29; P = .01 per 10% longer FUT w/ score <90) were associated with an increased risk of breakthrough. Lung recipients were at a significantly increased risk of premature prophylaxis discontinuation (aHR, 20.2 vs kidney; 95% CI, 3.34 to 121.9; P = .001), mainly due to liver or myelotoxicity.

Conclusions

Recipients of eGFR-adjusted prophylaxis doses below those recommended by manufacturers were at an increased risk of prophylaxis breakthrough, emphasizing the importance of accurate dose adjustment according to the latest eGFR and the need for novel, less toxic agents.

Very Early Cytomegalovirus Infection After Renal Transplantation: A Single-Center 20-Year Perspective

Background:

Cytomegalovirus (CMV) infection risk in the first month after transplantation is felt to be minimal; however, the epidemiology has not been specifically investigated, particularly in the modern era of potent immunosuppressive regimens and universal CMV prophylaxis.

Objective:

The aim of this study was to describe the incidence of and risk factors associated with CMV occurring less than 30 days after transplant and evaluate the effect of very early CMV on outcomes.

Methods:

Retrospective, single-center study of adult renal transplant (RTX) recipients between January 1, 1994 and December 31, 2014.

Results:

A total of 5225 patients who received a renal transplant in the study time period were reviewed for the presence of CMV infection occurring less than 30 days after transplant. Of these, only 14 patients demonstrated this finding for an overall incidence of 0.27%. Half of these patients were considered to be at heightened risk due to being a recipient of a non-primary transplant or on chronic immunosuppression. This left seven patients without known risk factors for very early CMV to evaluate. In this group, time from transplant to CMV infection was 13.5 ± 7 days. The majority (57.1%, n = 4) were high-risk serostatus (CMV D+/R−) and occurred in the valganciclovir era (71.4%, n = 5). Lymphocyte-depleting induction predominated (57.1%, n = 4). Average cold ischemic time (CIT) was 19.7 ± 7.7 hours. Three patients had post-operative complications, two required exploratory-laparotomy for hemorrhage. When evaluating outcomes, 43% (n = 3) had subsequent episodes of CMV infection, 28.6% (n = 2) developed rejection, and 28.6% (n = 2) died. Outcomes between patients with CMV infection less than 30 days and those with CMV infection more than 30 days after transplant were not significantly different.

Conclusions:

In our review of over 5000 kidney transplants, the incidence of CMV infection in the first 30 days after renal transplant is 0.2%. Notable common patient characteristics include hemorrhage requiring re-operation and prolonged CIT. Outcomes were similar to CMV occurring more than 30 days after transplant. This study should provide the clinician with some reassurance; despite potent immunosuppressive therapy, CMV infection in the first 30 days is unlikely.

Cytomegalovirus in solid organ transplant recipients-Guidelines of the American Society of Transplantation Infectious Diseases Community of Practice

Cytomegalovirus (CMV) is one of the most common opportunistic infections that affect the outcome of solid organ transplantation. This updated guideline from the American Society of Transplantation Infectious Diseases Community of Practice provides evidence-based and expert recommendations for screening, diagnosis, prevention, and treatment of CMV in solid organ transplant recipients. CMV serology to detect immunoglobulin G remains as the standard method for pretransplant screening of donors and transplant candidates. Antiviral prophylaxis and preemptive therapy are the mainstays of CMV prevention. The lack of a widely applicable viral load threshold for diagnosis and preemptive therapy is highlighted, as a result of variability of CMV nucleic acid testing, even in the contemporary era when calibrators are standardized. Valganciclovir and intravenous ganciclovir remain as drugs of choice for CMV management. Strategies for managing drug-resistant CMV infection are presented. There is an increasing use of CMV-specific cell-mediated immune assays to stratify the risk of CMV infection after solid organ transplantation, but their role in optimizing CMV prevention and treatment efforts has yet to be demonstrated. Specific issues related to pediatric transplant recipients are discussed.

The Third International Consensus Guidelines on the Management of Cytomegalovirus in Solid-organ Transplantation

Despite recent advances, cytomegalovirus (CMV) infections remain one of the most common complications affecting solid organ transplant recipients, conveying higher risks of complications, graft loss, morbidity, and mortality. Research in the field and development of prior consensus guidelines supported by The Transplantation Society has allowed a more standardized approach to CMV management. An international multidisciplinary panel of experts was convened to expand and revise evidence and expert opinion-based consensus guidelines on CMV management including prevention, treatment, diagnostics, immunology, drug resistance, and pediatric issues. Highlights include advances in molecular and immunologic diagnostics, improved understanding of diagnostic thresholds, optimized methods of prevention, advances in the use of novel antiviral therapies and certain immunosuppressive agents, and more savvy approaches to treatment resistant/refractory disease. The following report summarizes the updated recommendations.

Persistent Primary Cytomegalovirus Infection After Deceased Donor Kidney Transplant: Ganciclovir Susceptibility of Human Cytomegalovirus With UL97 D605E Mutation: A Case Report

BACKGROUND

Cytomegalovirus (CMV) could cause rejection in immunocompromised patients during early post-renal transplant stage. The American Transplant Society guidelines recommend prophylactic therapy with ganciclovir (GCV) for 3 to 6 months to prevent CMV infections in adult renal transplant patients. However, there is no recommended CMV treatment regimen for pediatric patients.

MAIN FINDINGS

We performed deceased donor kidney transplant from an anti-CMV antibody-positive donor to an anti-CMV antibody-negative 15-year-old female recipient with end-stage renal disease caused by bilateral renal hypoplasia. One month after transplant, increase in positive cells in the CMV antigenemia assay indicated a primary CMV infection in the patient, who immediately received GCV. She was switched to foscarnet after 4 months of anti-CMV therapy because of clinical GCV resistance. CMV was isolated from the peripheral blood mononuclear cells but neutralizing antibody was not detected. Isolated CMV was susceptible to GCV and foscarnet, although it carried the UL97 D605E mutation, assumed to be associated with GCV resistance.

CONCLUSIONS

The primary CMV infection presented a phenotypic clinical drug resistance, but all recovered CMV isolates were drug-susceptible even if isolated after prolonged anti-CMV therapy, indicating that immune status was more important for recovery from primary CMV infection than anti-CMV therapy.

Pediatric transplantation case conference: Update on cytomegalovirus

The prevention and management of cytomegalovirus (CMV) remain challenging in children who have undergone solid organ transplantation, despite the availability of effective antiviral medications and sensitive diagnostic assays. The primary objective of this invited commentary is to provide an updated and multidisciplinary approach to persistently challenging CMV cases that commonly occur in pediatric transplantation candidates and recipients, including cases for which published data are frequently lacking.

Clinical Pharmacodynamics: Principles of Drug Response and Alterations in Kidney Disease

Pharmacokinetics and pharmacodynamics follow the logic of cause and consequence. Receptor-mediated and reversible effects can be distinguished from direct and irreversible effects. Reversible effects are capacity-limited and saturable whereas irreversible effects are limited only by the number of viable targets. In the case of receptor-mediated and reversible effects a threshold and a ceiling concentration can be defined. Antimicrobial drugs with concentration-dependent action are distinguished from drugs with time-dependent action. Concentration-dependent effects are associated with a high ceiling concentration and the target is the high peak. Time-dependent effects are associated with a high threshold concentration and the target is the high trough. During kidney dysfunction, alterations of drug response are usually attributed to pharmacokinetic but rarely to pharmacodynamic changes. Dose adjustment calculations, therefore, tacitly presume that pharmacodynamic parameters remain unchanged while only pharmacokinetic parameters are altered in kidney failure. Kidney dysfunction influences the pharmacokinetic parameters of at least 50% of all essential drugs. Clinicians usually consider pharmacokinetics when kidney disease is found, but pharmacodynamics is as important. Alterations of pharmacodynamic parameters are conceivable but only rarely reported in kidney failure. Sometimes surprising dosing adjustments are needed when pharmacodynamic concepts are brought into the decision process of which dose to choose. Pharmacokinetics and pharmacodynamics should both be considered when any dosing regimen is determined.

Effect of Low-Dose Vs Standard-Dose Valganciclovir in the Prevention of Cytomegalovirus Disease in Kidney Transplantation Recipients: A Systemic Review and Meta-Analysis

BACKGROUND

Valganciclovir is widely used to prevent post-transplant cytomegalovirus (CMV) infection in kidney transplant patients. However, the currently used dose remains controversial because the continuous use of this drug decreases kidney function and can induce leukopenia.

OBJECTIVE

The purpose of this study was to measure the appropriate dose of valganciclovir required to prevent CMV infection.

METHODS

A systematic review and meta-analysis were performed by using a random effects model. The Cochrane Central Register, MEDLINE, EMBASE, and PubMed databases were searched up to April 15, 2017. We conducted analysis on low-dose (450 mg) and standard-dose (900 mg) valganciclovir groups.

RESULTS

After completion of the research, the analysis revealed that the glomerular filtration rate, graft loss, tacrolimus level, antibody-mediated rejection, and fungal and Candida infection rates did not differ between the 2 groups. However, the incidence of CMV tended to decrease in the low-dose group (0.584 [95% confidence interval [CI], 0.352-0.967]; P = .036). The biopsy-proven rejection rate decreased by 0.427 times in the low-dose group compared with the standard-dose group (95% CI, 0.274-0.667; P = .002). Furthermore, the incidence of leukopenia decreased by 0.371 times in the low-dose group compared with the standard-dose group (95% CI, 0.264-0.523; P = .001).

CONCLUSIONS

The 450-mg dose of valganciclovir effectively prevented post-transplantation CMV infection and decreased drug-induced side effects such as leukopenia. In the future, the lower dose of valganciclovir should be considered to prevent CMV infection and enhance cost-effectiveness.

Low-dose valganciclovir for cytomegalovirus prophylaxis in intermediate-risk liver transplantation recipients

Liver transplantation recipients (LTRs) who are seropositive for cytomegalovirus (CMV) (recipient seropositive [R+]) are at intermediate risk for CMV disease. A preventative strategy following transplant is considered standard of care. Current guidelines recommend high-dose valganciclovir (VGCV; 900 mg/day adjusted for renal function) for prophylaxis given limited data on the efficacy and safety of low-dose VGCV (450 mg/day adjusted for renal function). We describe our experience using low-dose VGCV prophylaxis for R+ LTRs at our institution. A single-center, retrospective study was conducted using a database of 364 LTRs over a 4-year period (2011-2014). Adult first-time R+ LTRs receiving low-dose VGCV prophylaxis were included. The primary endpoint was CMV disease at 1 year after transplant. Patients were compared with historical controls receiving high-dose VGCV prophylaxis. Secondary endpoints were biopsy-proven rejection and leukopenia on VGCV. With respect to leukopenia, patients receiving low-dose VGCV were compared with a group of D+R- patients from the database receiving high-dose VGCV. Univariate analyses were performed using chi-squared, Fisher's exact, and Wilcoxon rank sum tests. A total of 200 R+ LTRs met inclusion criteria. Median age was 60 years (interquartile range [IQR], 54-66 years), and 129 (65%) LTRs were male. Median Model for End-Stage Liver Disease score was 22 (IQR, 14-31), and 178 (89%) patients received deceased donor transplants. CMV disease occurred in only 9 (5%) patients, similar to rates in previous studies of LTRs receiving high-dose VGCV. Biopsy-proven rejection occurred in 18 (9%) patients. Patients received VGCV prophylaxis for a median of 3.4 (IQR, 3.1-4.3) months; 151 (76%) R+ LTRs receiving low-dose VGCV developed leukopenia. Premature VGCV discontinuation and granulocyte-colony stimulating factor use were infrequent and not significantly different between the 2 groups. In conclusion, low-dose VGCV was safe and effective for prevention of CMV disease in our cohort of 200 R+ LTR and should be considered as an option in future guidelines. Liver Transplantation 24 616-622 2018 AASLD.

Ganciclovir Dosing Strategies and Development of Cytomegalovirus Resistance in a Kidney Transplant Recipient: A Case Report

In renal transplant recipients, delayed graft function and accompanying renal impairment may lead to therapeutic underexposure of valganciclovir. We describe a case of a cytomegalovirus (CMV)-seronegative kidney transplant recipient from a CMV-seropositive donor, whose course was complicated during valganciclovir prophylaxis by CMV disease, ultimately progressing to ganciclovir, foscarnet, and cidofovir resistance. Assessments and adjustments for renal dysfunction, according to both Cockgroft-Gault and Modification of Diet in Renal Disease study equations, are described. Therapy was complicated by outpatient parenteral therapy with pump-administered antiviral therapy, which may have led to drug underexposure and the fostering of antiviral resistance. Suppression was ultimately achieved in conjunction with reduction in immunosuppressive therapy, CMV immunoglobulin, and initiation of leflunomide. At-risk recipients may benefit from 24 hour creatinine clearance assessments, direct creatinine clearance measurement, or therapeutic drug monitoring. Optimal dosing strategies in recipients with impaired kidney function remain undefined, with limited pharmacokinetic data to date.

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.

Impact of electronic health record-based, pharmacist-driven valganciclovir dose optimization in solid organ transplant recipients

BACKGROUND

Prophylaxis with valganciclovir reduces the incidence of cytomegalovirus (CMV) infection following solid organ transplant (SOT). Under-dosing of valganciclovir is associated with an increased risk of CMV infection and development of ganciclovir-resistant CMV.

METHODS

An automated electronic health record (EHR)-based, pharmacist-driven program was developed to optimize dosing of valganciclovir in solid organ transplant recipients at a large transplant center. Two cohorts of kidney, pancreas-kidney, and liver transplant recipients from our center pre-implementation (April 2011-March 2012, n = 303) and post-implementation of the optimization program (September 2012-August 2013, n=263) had demographic and key outcomes data collected for 1 year post-transplant.

RESULTS

The 1-year incidence of CMV infection dropped from 56 (18.5%) to 32 (12.2%, P = .05) and the incidence of breakthrough infections on prophylaxis was cut in half (61% vs 34%, P = .03) after implementation of the dose optimization program. The hazard ratio of developing CMV was 1.64 (95% CI 1.06-2.60, P = .027) for the pre-implementation group after adjusting for potential confounders. The program also resulted in a numerical reduction in the number of ganciclovir-resistant CMV cases (2 [0.7%] pre-implementation vs 0 post-implementation).

CONCLUSIONS

An EHR-based, pharmacist-driven valganciclovir dose optimization program was associated with reduction in CMV infections.

Low-dose valganciclovir prophylaxis for cytomegalovirus in intermediate-risk (R+) renal transplant recipients: Single-center experience

Renal transplant recipients (RTR) who are seropositive for CMV (R+) are considered to be at intermediate risk for CMV disease. Current guidelines recommend high-dose valganciclovir (VGCV) prophylaxis because of limited data on the efficacy of low-dose VGCV. We describe our experience with using low-dose VGCV in R+ RTR. We retrospectively reviewed a cohort of 316 R+ RTR at our institution between 2002 and 2006. The primary endpoint was CMV disease at 1 year post transplant. The incidence of CMV disease at 12 months after transplantation was only 3% (6/221) in the D+R+ and 4% (4/95) in the D-R+ RTR. Low-dose VGCV was effective at preventing CMV disease in intermediate-risk (R+) RTR.

High-Dose Acyclovir for Cytomegalovirus Prophylaxis in Seropositive Abdominal Transplant Recipients

Background: Following abdominal solid organ transplant (aSOT), valganciclovir (VGC) is recommended for cytomegalovirus (CMV) prophylaxis. This agent is associated with efficacy concerns, toxicity, and emergence of ganciclovir resistance. Objective: To evaluate the incidence of high-dose acyclovir (HD-A) prophylaxis failure in seropositive aSOT recipients (R+). Methods: This was a retrospective, single-center study of R+ transplanted without lymphocyte-depleting induction between January 1, 2000, and June 30, 2013, discharged with 3 months of HD-A prophylaxis (800 mg 4 times daily). The primary outcome was incidence of prophylaxis failure. Secondary outcomes were incidence of biopsy-proven tissue-invasive disease and prophylaxis failure for each allograft subgroup. Results: A total of 1525 patients met inclusion criteria: 944 renal (RTX), 108 simultaneous pancreas-kidneys (SPK), 462 liver (LTX), and 11 pancreas (PTX) transplant recipients. The composite rate of HD-A prophylaxis failure was 7%; incidence of tissue-invasive disease was 0.4%. Failure rates were 4.5%, 6.1%, 11%, and 20% in the RTX, SPK, LTX, and PTX populations, respectively; tissue-invasive disease rates were 0.2%, 0%, 0.7%, and 10%. Failure occurred more frequently in the LTX and PTX populations ( P < 0.0001, HR = 2.6; P = 0.04 HR = 4.4). Incidence of tissue-invasive disease was minimal and not different in the RTX, LTX and SPK populations ( P = 0.34). When evaluating recipients of seronegative allografts (D−), the composite failure rate was 3.4% with no significant difference between allograft subgroups ( P = 0.45). Conclusion: HD-A may be a reasonable prophylaxis alternative for D−/R+ recipients, in the absence of lymphocyte-depleting induction, if low incidence viremia is tolerable. Future studies are needed to determine the long-term impact of CMV viremia in the setting of this prophylaxis approach.

Valganciclovir Dosing for Cytomegalovirus Prophylaxis in Pediatric Solid-organ Transplant Recipients: A Prospective Pharmacokinetic Study

BACKGROUND

Valganciclovir is extensively used for prophylaxis and treatment of cytomegalovirus (CMV) infection in solid-organ transplant recipients. However, pharmacokinetic data in children are scarce, and the pediatric dosing regimen is uncertain. This study sought to prospectively evaluate the pharmacokinetic profile, the clinical efficacy and safety of oral valganciclovir in pediatric transplant recipients and compare different dosing regimens.

METHODS

The cohort included solid-organ transplant recipients treated with valganciclovir for CMV prophylaxis in 2014-2015 at a tertiary pediatric medical center. All received a weight-based once-daily oral dose of 17 mg/kg. Ganciclovir concentrations were measured and the area under the curve (AUC0-24) was calculated.

RESULTS

Thirteen children of median age 7.3 years (interquartile range, 2.2-11.6) were included. Median ganciclovir AUC0-24 was 21.0 mcg·h/mL (interquartile range, 17.1-39.8); 10 patients (77%) attained AUC0-24 <40 mcg·h/mL. Exposure to ganciclovir was about 2-fold lower in young children (<9 years old; P = 0.01) and children with low body surface area (BSA; <0.7 m; P = 0.006) than in their counterparts. Significantly lower doses were recommended with our weight-based protocol than with the manufacturer-recommended BSA- and glomerular filtration rate-based protocol (P = 0.002), reaching a 3-fold difference in infants. No evidence of CMV viremia or disease was observed while prophylaxis was given.

CONCLUSIONS

The weight-based regimen of 17 mg/kg/dose oral valganciclovir results in relatively low ganciclovir exposure, especially in young children with low BSA, yet showed satisfactory clinical efficacy for CMV prophylaxis. The manufacturer's dosing recommendation appears to result in supratherapeutic ganciclovir concentrations. Further studies are needed to establish target AUCs and valganciclovir dosing for CMV prophylaxis in pediatric transplant recipients.