24 weeks of valganciclovir prophylaxis in children after renal transplantation: a 4-year experience

Antiviral medications for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

The risk of cytomegalovirus (CMV) infection in solid organ transplant recipients has resulted in the frequent use of prophylaxis to prevent the clinical syndrome associated with CMV infection. This is an update of a review first published in 2005 and updated in 2008 and 2013.

OBJECTIVES

To determine the benefits and harms of antiviral medications to prevent CMV disease and all-cause death in solid organ transplant recipients.

SEARCH METHODS

We contacted the information specialist and searched the Cochrane Kidney and Transplant Register of Studies up to 5 February 2024 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing antiviral medications with placebo or no treatment, comparing different antiviral medications or different regimens of the same antiviral medications for CMV prophylaxis in recipients of any solid organ transplant. Studies examining pre-emptive therapy for CMV infection are studied in a separate review and were excluded from this review.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias and extracted data. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

This 2024 update found four new studies, bringing the total number of included studies to 41 (5054 participants). The risk of bias was high or unclear across most studies, with a low risk of bias for sequence generation (12), allocation concealment (12), blinding (11) and selective outcome reporting (9) in fewer studies. There is high-certainty evidence that prophylaxis with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment is more effective in preventing CMV disease (19 studies: RR 0.42, 95% CI 0.34 to 0.52), all-cause death (17 studies: RR 0.63, 95% CI 0.43 to 0.92), and CMV infection (17 studies: RR 0.61, 95% CI 0.48 to 0.77). There is moderate-certainty evidence that prophylaxis probably reduces death from CMV disease (7 studies: RR 0.26, 95% CI 0.08 to 0.78). Prophylaxis reduces the risk of herpes simplex and herpes zoster disease, bacterial and protozoal infections but probably makes little to no difference to fungal infection, acute rejection or graft loss. No apparent differences in adverse events with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment were found. There is high certainty evidence that ganciclovir, when compared with aciclovir, is more effective in preventing CMV disease (7 studies: RR 0.37, 95% CI 0.23 to 0.60). There may be little to no difference in any outcome between valganciclovir and IV ganciclovir compared with oral ganciclovir (low certainty evidence). The efficacy and adverse effects of valganciclovir or ganciclovir were probably no different to valaciclovir in three studies (moderate certainty evidence). There is moderate certainty evidence that extended duration prophylaxis probably reduces the risk of CMV disease compared with three months of therapy (2 studies: RR 0.20, 95% CI 0.12 to 0.35), with probably little to no difference in rates of adverse events. Low certainty evidence suggests that 450 mg/day valganciclovir compared with 900 mg/day valganciclovir results in little to no difference in all-cause death, CMV infection, acute rejection, and graft loss (no information on adverse events). Maribavir may increase CMV infection compared with ganciclovir (1 study: RR 1.34, 95% CI: 1.10 to 1.65; moderate certainty evidence); however, little to no difference between the two treatments were found for CMV disease, all-cause death, acute rejection, and adverse events at six months (low certainty evidence).

AUTHORS' CONCLUSIONS

Prophylaxis with antiviral medications reduces CMV disease and CMV-associated death, compared with placebo or no treatment, in solid organ transplant recipients. These data support the continued routine use of antiviral prophylaxis in CMV-positive recipients and CMV-negative recipients of CMV-positive organ transplants.

Long-term outcomes of two-dose alemtuzumab induction in pediatric kidney transplantation

BACKGROUND

Alemtuzumab is a lymphocyte depleting agent used for induction in kidney transplant, but long-term information on its use in pediatric recipients remains sparse.

METHODS

We performed a single-center retrospective cohort study of 57 pediatric kidney transplant recipients receiving alemtuzumab 20 mg/m2/dose ×2 doses for induction immunosuppression. All patients underwent surveillance biopsies, and 91.3% underwent steroid withdrawal by day 4 post-transplant. Outcomes of interest included graft survival, development of donor specific antibodies (DSA), incidence of viremia and PTLD, and duration of lymphopenia.

RESULTS

Median follow-up time was 7.9 years (IQR 5-13.6 years). Median graft survival was 16.5 years (95% CI 11.6-unknown). DSA developed in 36.5% at a median of 944 days (IQR 252-2113 days). Incidences of BK polyomavirus DNAemia (BKPyV-DNAemia), CMV DNAemia, and EBV DNAemia were 38.6%, 22.8%, and 14%, respectively; one patient developed PTLD at 13.3 years post-transplant. Median duration of lymphopenia was 365 days (IQR 168-713 days); 19.3% of patients remained lymphopenic at 3 years post-transplant. There was no association between duration of lymphopenia and graft survival, rejection, DSA detection, or viremia.

CONCLUSIONS

A two-dose alemtuzumab induction protocol can have excellent outcomes with a steroid-free maintenance immunosuppression regimen. More comprehensive, multicenter, comparative studies of pediatric kidney transplant are needed to improve long-term outcomes.

Incidence of cytomegalovirus DNAemia in pediatric kidney, liver, and heart transplant recipients: Efficacy and risk factors associated with failure of weight-based dosed valganciclovir prophylaxis

BACKGROUND

Cytomegalovirus (CMV) is associated with morbidity and mortality in solid organ transplant recipients (SOTR). Valganciclovir (VGC) is extensively used for prophylaxis. Optimal dosing in children, risk factors for failure, and the impact of dose adjustments on CMV DNAemia is not well established.

METHODS

This retrospective cohort study of pediatric SOTR transplanted between 2010-2018 evaluated the epidemiology of CMV DNAemia and used Cox-regression to assess the risk factors for CMV DNAemia within one-year following SOTR.

RESULTS

In 393 pediatric SOTR (heart [96, 24.4%], kidney [180, 45.6%], liver [117, 29.8%]; median age 9.5 ± 0.3 years), overall CMV DNAemia incidence was 6.6/10 000 days (95%CI 5.1/10 000-7.9/10 000) and varied by organ groups: heart 8.2/10 000 days (95%CI 4.9/10 000-11.4/10 000), kidney 5.8/10 000 days (95%CI 3.9/10 000-7.8/10 000), liver 6.2/10 000 days (95%CI 3.7/10 000-8.7/10 000). CMV DNAemia was detected in 75 of 275 (27.2%) patients who received prophylaxis (40 cases occurred during prophylaxis and 35 occurred after completion of prophylaxis). The median VGC dose given according to institutional weight-based algorithm was approximately 1.5-fold lower than the manufacturer-recommended dose. This discordance was more prominent at younger age groups (3.2-fold lower in <2-year-old [100 mg versus 325 mg], 2.5-fold lower in <6-year-old [200 mg versus 447 mg]). Dose reduction due to adverse events was an independent risk factor for breakthrough CMV DNAemia (hazard ratio 2.2, 95%CI 1.2-3.8) among patients with similar age, CMV risk stratification, starting VGC dose, immunosuppressive therapy, and organ group.

CONCLUSION

CMV events occurred while on VGC prophylaxis. Weight-based VGC may prevent supratherapeutic VGC exposure especially in younger children. Dose reduction of VGC prophylaxis for adverse event management places patients at an increased risk for CMV DNAemia suggesting other agents with fewer adverse effects should be considered and need to be studied in children.

Incidence of Cytomegalovirus DNAemia in Pediatric Post–Renal Transplant Patients Receiving Weight-Based vs Body Surface Area–Based Valganciclovir Chemoprophylaxis

OBJECTIVE

To determine the incidence of cytomegalovirus (CMV) DNAemia and disease, identify potential risk factors, and assess the safety and efficacy of weight-based valganciclovir dosing in pediatric post–renal transplant patients.

METHODS

This single-center, retrospective study included patients ≤21 years who received a kidney transplant between January 1, 2011, and November 1, 2019, with 3 to 24 months of follow-up data. Demographics and clinical characteristics were collected to assess for potential risk factors. Descriptive statistics and logistic regressions were used to determine rates of CMV DNAemia considering clinical characteristics and chemoprophylaxis.

RESULTS

Fifty-seven patients were included. The incidence of CMV DNAemia was 43.9%. Cytomegalovirus seropositive status was associated with increased risk of CMV DNAemia. Patients receiving valganciclovir for &lt;150 days had 8.33 (95% CI, 1.68–41.29) greater odds of developing CMV DNAemia than patients receiving valganciclovir for 180 ± 30 days, p = 0.01. The median time to detectable CMV PCR after transplant was 140 days (range, 12–511 days). Cytomegalovirus DNAemia was not statistically different between those receiving weight-based vs FDA-approved valganciclovir dosing; however, patients receiving the FDA-approved dosing were more likely to develop neutropenia. Among the intermediate-risk group, the adjusted relative risk of CMV DNAemia was 0.62 (95% CI, 0.36–1.09) for those not receiving chemoprophylaxis compared with those who did.

CONCLUSIONS

Risk of CMV DNAemia is higher among patients receiving valganciclovir for &lt;150 days. Further exploration of weight-based valganciclovir dosing for CMV chemoprophylaxis in high- and intermediate-risk post–renal transplant patients is needed to minimize adverse drug effects while maintaining efficacy.

Characteristics, risk factors, and outcomes of neutropenia after liver or kidney transplantation in children

BACKGROUND

While prior adult studies have shown that approximately 20%-38% of subjects undergoing solid-organ transplant develop neutropenia, similar analyses in pediatric subjects are scarce.

METHODS

We conducted a retrospective chart review of liver transplant (LT) and kidney transplant (KT) recipients at our center during the period 2008-2018. All of the KT and none of the LT subjects during this time period had induction with either anti-thymocyte globulin (ATG) or basiliximab at time of transplant. Neutropenia was defined as absolute neutrophil count (ANC) value ≤1000/mm3 .

RESULTS

One hundred subjects with LT and 82 subjects with KT were included. The incidence of neutropenia within the first year of transplant in KT was higher compared to LT (54.8% vs 39%, p = .01). The median number of hospitalizations (p = .001) and infectious complications (p = .04) was significantly higher only in the KT subjects who developed neutropenia (compared to those who did not). Multivariate analysis identified factors associated with severity of liver disease at transplant, namely h/o upper gastrointestinal bleeding (p = .02), weight deficit (p = .01), and pre-LT ANC (p = .01), along with high or moderate risk cytomegalovirus status (p = .05) as predictors of neutropenia in LT subjects. Female gender (p = .03) predicted neutropenia, while BK virus infection was protective for neutropenia (p = .04) in KT subjects.

CONCLUSIONS

The incidence of and morbidity associated with neutropenia within 1 year post-transplant is higher in KT subjects compared to LT subjects. The likely reason for this is the use of induction therapy (ATG, basiliximab) at the time of transplant in KT subjects.

Considerations and controversies of pharmacologic management of the pediatric kidney transplant recipient

Pediatric kidney transplantation has experienced considerable growth and improvement in patient and allograft outcomes over the past 20 years, in part due to advancements in immunosuppressive regimens and management. Despite this progress, care for this unique population can be challenging due to limited pediatric transplant data and trials, intricacies related to differences in children and adolescents compared with their adult counterparts, and limitations to long-term survival facing all solid organ transplant populations. Immunosuppression and infection prevention practices vary from one pediatric transplant center to another and clinical controversies exist surrounding treatment and dosing. This review aims to summarize key aspects of pharmacologic management in this population and present pertinent data that describe the influence of practice to serve as a resource for practitioners caring for this unique specialty patient population. Additionally, this review highlights select controversies that exist within pediatric kidney transplantation.

Cytomegalovirus infection and allograft rejection among pediatric heart transplant recipients in the era of valganciclovir prophylaxis

CMV infection remains a significant cause of morbidity among pediatric HTx recipients We explored the implications of CMV infection on post-transplant outcomes among CMV risk-stratified pediatric HTx recipients receiving VGC prophylaxis. Children who underwent HTx between January 2010 and October 2016 were stratified according to CMV risk at time of transplant and evaluated for evidence of post-transplant CMV infection, rejection, CAV, and graft loss. Among 97 children, 41 (42%) were considered HR or IR risk for CMV infection and received VGC prophylaxis. CMV DNAemia was observed in 34% of children, including 71% HR, 40% IR, and 18% LR individuals. Median time to CMV DNAemia following VGC prophylaxis was 32D among HR vs 277D in IR subjects (P = .042). No difference in overall graft loss was noted among groups, but CMV HR children had decreased rejection-free survival (3.5 years) compared to IR (6 years, P = .015) and LR children (8 years, P = .0003). CMV was noted on EMB in 13% of children but was not associated with increased CAV, rejection or graft loss. High-risk CMV status was associated with decreased time to CMV infection despite VGC prophylaxis, compared to IR, and decreased rejection-free survival times compared to both IR and LR recipients. Detection of CMV on EMB was not associated with increased rejection, CAV or graft loss. Additional studies are needed to explore the impact of CMV infection on rejection-free survival in HTx recipients.

Evaluation of a change in cytomegalovirus prevention strategy following pediatric solid organ transplantation

BACKGROUND

An optimal cytomegalovirus (CMV) prevention strategy following solid organ transplantation (SOT) remains uncertain. This study reports on the rates of CMV events following a change in a local prevention guideline involving increased surveillance, earlier transition to oral valganciclovir, and decreased CMV-immunoglobulin use.

METHODS

A retrospective cohort study utilizing historical controls evaluated the rates of CMV invasive disease pre- and post-intervention among pediatric heart, liver, and kidney recipients. Outcomes were recorded for the 4 years pre- and post-intervention, 9/2009-10/2017. Logistic regression was used to estimate the risk of a CMV event.

RESULTS

There was no difference in the rates of CMV invasive disease between the two study groups (P = 1). An increase in the detection of CMV events occurred (P = .04), predominantly asymptomatic CMV infection. This increase was independently associated with increased surveillance testing among high-risk heart and liver recipients, aOR 1.08 (1.06-1.12). Surprisingly, 28.9% of CMV events occurred during antiviral prophylaxis.

CONCLUSIONS

Modification of the local CMV prevention guideline did not result in an increase in CMV invasive disease. CMV events occurred while on prophylaxis, highlighting a potential difference from adult solid organ transplant (SOT) and emphasizing the potential need for monitoring on prophylaxis in the pediatric population.

Impact of standardized protocols for cytomegalovirus disease prevention in pediatric solid organ transplant recipients

End-organ disease caused by CMV is a significant cause of morbidity and mortality in pediatric SOT recipients. Pediatric transplant centers have adopted various approaches for CMV disease prevention in this patient population. We observed significant practice variation in CMV testing, prophylaxis, and surveillance across SOT groups in our center. To address this, we implemented evidence-based standardized protocols and measured outcomes pre- and post-implementation of these protocols. We performed retrospective chart review for SOT recipients from 2009 to 2014 at Boston Children's Hospital. Using descriptive statistics, we measured practice improvement in provision of appropriate prophylaxis, occurrence of neutropenia and associated complications, and occurrence of CMV DNAemia and CMV disease pre- and post-intervention. The pre- and post-intervention periods included 141 and 109 patients, respectively. With the exception of kidney transplant recipients, provision of appropriate valganciclovir prophylaxis improved across SOT groups post-intervention (P < .01). Occurrence of >1 episode of neutropenia was greater in the preintervention period (30% vs 10%, P < .001). In both periods, neutropenia was associated with few episodes of invasive infections. The occurrence of CMV disease did not differ and was overall low. However, due to routine surveillance a significantly greater number of asymptomatic CMV DNAemia episodes were identified and treated in the post-intervention period. Implementation of standardized prevention protocols helped to improve the provision of appropriate prophylaxis to patients at risk for CMV acquisition, increased the diagnosis and treatment of asymptomatic CMV DNAemia, and decreased episodes of recurrent neutropenia in patients receiving prophylaxis.

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.

Simultaneous detection of opportunistic viral infections among renal transplant patients from Sina Hospital, Tehran

Aim: A proportion of renal transplant (RT) recipients are at high risk for acquisition of opportunistic infections. Methods: A total of 101 plasma and urine specimens were collected from RT patients with raised plasma creatinine. These were tested for three common viral pathogens under suspicion of post-transplant nephropathy. Results: A total of 19 (18.8%), 15 (14.8%) and 10 (9.9%) tested positive for BK virus, cytomegalovirus and Epstein–Barr virus in their plasma and/or urine, respectively. Out of the 19 BK virus positive patients, 12 (63%) were in the tested plasma samples and 17 (89%) were in the urine samples. Four asymptomatic patients had high levels of Epstein–Barr virus shedding in their urine. No co-infected patients showed nephropathy. Conclusion: Relying on plasma creatinine rising levels alone may be an unreliable indicator for evaluating opportunistic viral infections in post-transplant RT subjects.

Cytomegalovirus and Epstein-Barr virus infections among pediatric kidney transplant recipients at a center using universal Valganciclovir Prophylaxis

BACKGROUND

CMV is associated with adverse effects in renal transplant recipients. The objective of this study was to characterize the incidence and timing of CMV and EBV infections in relation to valGCV prophylaxis in a pediatric renal transplant cohort.

METHODS

Retrospective cohort of pediatric renal transplant patients given universal valGCV prophylaxis and universal viral surveillance was evaluated. Demographics, prophylaxis, acute rejection, and CMV and EBV infections were abstracted.

RESULTS

A total of 92 pediatric renal allograft recipients, 2008-2013, were included. One or more viral infections developed in 77/92 (83.7%) of the patients. EBV was the most common in 62/92 (67%) patients, irrespective of valGCV (82% of episodes occurring on valGCV). CMV DNAemia occurred in 30/92 (33%) patients, 14 episodes (47%) occurring on valGCV. Incidence of breakthrough CMV on prophylaxis was 15% and was associated with persistent DNAemia (OR 7.8, CI:1.6-32.9, P < 0.02). CMV tissue-invasive disease was not seen. CMV syndrome occurred in 10% of the cohort, only in CMV D+ patients, and only one symptomatic breakthrough infection required treatment. Out of 92, 21 (23%) had simultaneous co-infections with 2-3 viruses.

CONCLUSIONS

Viral infections in pediatric renal transplant recipients receiving universal valGCV prophylaxis were common. EBV infections were not reduced by valGCV prophylaxis, and nearly half of CMV infections occurred on valGCV. Symptomatic CMV infection while on prophylaxis was rare. valGCV prophylaxis may prevent symptomatic CMV infection but not EBV infection, and frequent CMV surveillance in pediatric renal transplant recipients on prophylaxis may not be necessary.

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.

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.

Tolerability of up to 200 days of prophylaxis with valganciclovir oral solution and/or film-coated tablets in pediatric kidney transplant recipients at risk of cytomegalovirus disease

This multicenter, open-label study evaluated the tolerability of extended prophylaxis with valganciclovir in pediatric kidney transplant recipients at risk of CMV disease. Fifty-six patients aged 4 months to 16 years received once-daily valganciclovir oral solution and/or tablets, dosed by BSA and renal function, for up to 200 days. The most common AEs on treatment were upper respiratory tract infection (33.9%), urinary tract infection (33.9%), diarrhea (32.1%), leukopenia (25.0%), neutropenia (23.2%), and headache (21.4%). There were fewer AEs during days 101-228 vs days 1-100. Twenty-seven patients (48.2%) had treatment-related AEs during valganciclovir treatment, most commonly leukopenia (21.4%), neutropenia (19.6%), anemia (7.1%), and tremor (5.4%). Treatment-related serious AEs were reported for nine patients (16.1%) and six withdrew due to AEs. Viremia was centrally confirmed in 10 patients; there was no confirmed CMV disease. One patient tested positive for a resistance mutation (UL97 L595F). Biopsy-proven acute rejection occurred in six patients (10.7%), but no graft loss or deaths occurred. In conclusion, up to 200 days of valganciclovir prophylaxis in pediatric kidney allograft recipients showed a safety profile consistent with that established in adult transplant patients.

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

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

A risk-stratified approach to cytomegalovirus prevention in pediatric solid organ transplant recipients

Optimal strategies to prevent cytomegalovirus (CMV) disease following pediatric solid organ transplantation remain controversial. The purpose of this study was to review the outcomes of a risk-stratified strategy that uses a hybrid or prophylactic strategy for donor (D)+ recipient (R)- patients, a preemptive strategy for D+R+/D-R+, and clinical follow-up alone for D-R+ patients. A retrospective chart review was undertaken at the Stollery Children's Hospital in Edmonton, Alberta for pediatric solid organ transplants 2004 through 2010. Transplants were risk-stratified according to D/R CMV serostatus, organ group, and type of induction or rejection immunosuppression. The incidence of DNAemia and CMV disease and adverse effects from prophylaxis were analyzed. The study included 197 recipients. CMV DNAemia was detected in 49 of 197 recipients (24.8%), and CMV disease occurred in eight of 197 (4%) of which all but one were D+R-. All recovered. Seventeen of 142 recipients who received prophylaxis (12%) had hematologic toxicity. No other toxicities were identified. In conclusion, A risk-stratified approach resulted in very low rates of CMV disease with minimal adverse effects. Lowering the dosage rather than stopping antivirals in the face of neutropenia has the potential to further lower the rate of CMV disease.

Risk Factors and Clinical Features of Cytomegalovirus Disease in Children Receiving Anticancer Chemotherapy

This study was conducted to identify risk factors for cytomegalovirus (CMV) infection and demonstrate the spectrum of CMV disease in children receiving anticancer chemotherapy without hematopoietic stem cell transplantation (HSCT). A total of 289 children who received chemotherapy and were tested for CMV infection were included in the study. CMV antigenemia and DNAemia were determined by identifying the pp65 antigen in leukocytes and performing real-time PCR. CMV disease was diagnosed by tissue biopsy, culture, or ophthalmic examination. Of the 289 children, CMV infection was demonstrated in 46 patients (15.9%). Young age at cancer diagnosis was the risk factor for CMV infection by multivariate analysis (7 mo vs. 7 y, P<0.001). Among 46 children with CMV infection, 10 (21.7%) were diagnosed with CMV disease; hepatitis (n=4), retinitis (n=3), hepatitis and pneumonia (n=2), and hepatitis and retinitis (n=1). The age of the patients with CMV disease was significantly younger than those without (3 vs. 16 mo, P=0.023). Retinoblastoma and neuroblastoma were the 2 most common underlying malignancies. There were 2 fatal cases associated with CMV disease, including 1 who died of CMV pneumonia. The findings of this study demonstrated significant morbidity of CMV infection and disease in young children during the course of chemotherapy without HSCT.

Incidence, risk factors, and outcomes of opportunistic infections in pediatric renal transplant recipients

OIs present significant risks to patients following solid organ transplantation. The purpose of this study was to identify risk factors for the development of OIs after kidney transplantation in pediatric patients and to evaluate the impact of OIs on outcomes in this patient population. A single-center retrospective longitudinal cohort analysis including pediatric patients 21 yr of age or younger transplanted from July 1999 to June 2013 at an academic medical center was conducted. Patients were excluded if they received multi-organ transplant. A total of 175 patients were included in the study. Patients who developed OIs were more likely to be female and younger at the time of transplant. A six-factor risk model for OI development was developed. Death, disease recurrence, and PTLD development were similar between groups but trended toward increased incidence in the OI group. Incidence of rejection was significantly higher in the OI group (p = 0.04). Patients who developed OIs had several important risk factors, including younger age, EBV-negative serostatus, CMV donor (+)/recipient (-), biopsy-proven acute rejection, ANC <1000, MMF dose >500 mg/m(2), and any infection. Incidence of rejection was higher in the OI group, but rate of graft loss was not statistically different.

Efficacy of Extended Valganciclovir Prophylaxis in Preventing Cytomegalovirus Infection in Pediatric Kidney Transplantation

Cytomegalovirus (CMV) is one of the most frequent opportunistic infection in renal transplant (RTx) recipients. Valganciclovir (VGC) has been showed to be safe and highly effective in prophylaxis of CMV infection in RTx recipients. Recently, an increase in delayed onset CMV disease has been noted with some arguing that longer prophylaxis may decrease the late-onset disease.

We retrospectively tested the hypothesis that extended term prophylaxis (ETP) of VGC for 12 months is more effective than short term prophylaxis (STP) of 6 months in preventing CMV infection and disease in pediatric RTx performed at the University of Florida from July 2003 to December 2010. In this period, all recipients underwent prospective CMV PCR (Polymerase Chain Reaction) monitoring and were maintained on similar immunosuppression.

Eighty six patients received RTx during that period. All eligible subjects had to have at least 12 months of graft survival and 18 months of follow up, leaving 73 eligible subjects in final study group. CMV infection or disease occurred in 6/29 (20%) in the STP group vs 6/44 (14%) in the ETP group with no statistical significant difference (P= 0.42). Donor positive/recipients negative CMV serology status (D+/R-) were associated with a higher risk of CMV infection in both univariate and multivariate analysis (P=0.01). Anemia and Leucopenia directly associated with VGC were similar in both groups (P=0.58 and P=0.2 respectively). Biopsy-proven acute rejection was also non-significant in both groups (P=0.39).

Although ETP for CMV from 6 months to 12 months is safe and has minimal adverse effect, it did not reduce CMV infection or disease. Further controlled studies in pediatrics age group are considered to compare longer versus shorter periods of prophylaxis and their impact on prevention of CMV infection, resistance, cost, and toxicity.

Prevention of cytomegalovirus following solid organ transplantation: a literature review

CMV is the most common opportunistic infection affecting SOT recipients. Although current strategies to prevent both CMV infection and disease have been effective, CMV related complications continue to occur, particularly late-onset CMV disease. This literature review article examines the benefits and disadvantages of different prevention modalities, and presents emerging strategies to better prevent CMV in organ transplant recipients.

Antiviral medications for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

The risk of cytomegalovirus (CMV) infection in solid organ transplant recipients has resulted in the frequent use of prophylaxis with the aim of preventing the clinical syndrome associated with CMV infection. This is an update of a review first published in 2005 and updated in 2008.

OBJECTIVES

To determine the benefits and harms of antiviral medications to prevent CMV disease and all-cause mortality in solid organ transplant recipients.

SEARCH METHODS

We searched MEDLINE, EMBASE and the Cochrane Central Registry of Controlled Trials (CENTRAL) in The Cochrane Library to February 2004 for the first version of this review. The Cochrane Renal Group's specialised register was searched to February 2007 and to July 2011 for the first and current updates of the review without language restriction.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing antiviral medications with placebo or no treatment, comparing different antiviral medications and comparing different regimens of the same antiviral medications in recipients of any solid organ transplant. Studies examining pre-emptive therapy were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias and extracted data. Results were reported as risk ratios (RR) or risk differences (RD) with 95% confidence intervals (CI) for dichotomous outcomes and by mean difference (MD) with 95% CI for continuous outcomes. Statistical analyses were performed using the random-effects model. Subgroup analysis and univariate meta-regression were performed using restricted maximum-likelihood to estimate the between study variance. Multivariate meta-regression was performed to investigate whether the results were altered after allowing for differences in drugs used, organ transplanted, and recipient CMV serostatus at the time of transplantation.

MAIN RESULTS

We identified 37 studies (4342 participants). Risk of bias attributes were poorly performed or reported with low risk of bias reported for sequence generation, allocation concealment, blinding and selective outcome reporting in 25% or fewer studies.Prophylaxis with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment significantly reduced the risk for CMV disease (19 studies; RR 0.42, 95% CI 0.34 to 0.52), CMV infection (17 studies; RR 0.61, 95% CI 0.48 to 0.77), and all-cause mortality (17 studies; RR 0.63, 95% CI 0.43 to 0.92) primarily due to reduced mortality from CMV disease (7 studies; RR 0.26, 95% CI 0.08 to 0.78). Prophylaxis reduced the risk of herpes simplex and herpes zoster disease, bacterial and protozoal infections but not fungal infection, acute rejection or graft loss.Meta-regression showed no significant difference in the relative benefit of treatment (risk of CMV disease or all-cause mortality) by organ transplanted or CMV serostatus; no conclusions were possible for CMV negative recipients of negative organs.Neurological dysfunction was more common with ganciclovir and valaciclovir compared with placebo/no treatment. In direct comparison studies, ganciclovir was more effective than aciclovir in preventing CMV disease (7 studies; RR 0.37, 95% CI 0.23 to 0.60) and leucopenia was more common with aciclovir. Valganciclovir and IV ganciclovir were as effective as oral ganciclovir. The efficacy and adverse effects of valganciclovir/ganciclovir did not differ from valaciclovir in three small studies. Extended duration prophylaxis significantly reduced the risk of CMV disease compared with three months therapy (2 studies; RR 0.20, 95% CI 0.12 to 0.35). Leucopenia was more common with extended duration prophylaxis but severe treatment associated adverse effects did not differ between extended and three month durations of treatment.

AUTHORS' CONCLUSIONS

Prophylaxis with antiviral medications reduces CMV disease and CMV-associated mortality in solid organ transplant recipients. These data suggest that antiviral prophylaxis should be used routinely in CMV positive recipients and in CMV negative recipients of CMV positive organ transplants.

The contribution of systematic reviews to the practice of pediatric nephrology

The key to accurate decision-making is to use the best available evidence. Systematic reviews aim to identify and combine evidence using systematic methods to minimize bias to provide reliable data for patient care. While systematic reviews can address different clinical questions, the methodology is most developed for systematic reviews of randomized controlled trials. Such systematic reviews include all available trial evidence, enhance the precision of the estimates of treatment effects, and identify where evidence is lacking or where sufficient evidence is already available. However the term "systematic review" does not guarantee that a review covers all the available data, that the validity of included studies has been appropriately assessed, or that data have been combined appropriately in meta-analyses. Biases in systematic review include those related to identifying data (publication bias, language bias, selective reporting of outcomes) and those due to the design and conduct of trials (selection bias, performance bias, detection bias, attrition bias). Thus, readers should read a systematic review carefully before accepting its results and conclusions. This review examines the information that can be provided by systematic reviews of randomized controlled trials together with the biases that can potentially jeopardize the results and conclusions.

Correlation and clinical utility of pp65 antigenemia and quantitative polymerase chain reaction assays for detection of cytomegalovirus in pediatric renal transplant patients

qPCR and pp65 antigenemia assays are used to monitor CMV infection in renal transplant recipients, but correlation of assays in a pediatric population has not been evaluated. Paired CMV real-time qPCR and pp65 antigenemia tests from 882 blood samples collected from 115 pediatric renal transplant recipients were analyzed in this retrospective cohort study for the strength of association and clinical correlates. The assays correlated well in detecting infection (κ = 0.61). Higher qPCR values were demonstrated with increasing levels of antigenemia (p < 0.01). Discordant test results were associated with antiviral treatment (OR 4.33, p < 0.01) and low-level viremia, with odds of concordance increasing at higher qPCR values (OR 3.67, p < 0.01), and no discordance occurring above 8500 genomic equivalents/mL. Among discordant samples, neither test preceded the other in detecting initial infection or in returning to negative while on treatment. Only two cases of disease occurred during the two-yr study period. With strong agreement in the detection of CMV infection, either qPCR or pp65 antigenemia assays can be used effectively for monitoring pediatric renal transplant patients for both detection and resolution of infection.