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

Association of Neutropenia With Valganciclovir Prophylaxis Dosing Practices Within Pediatric Solid Organ Transplant Recipients

BACKGROUND

Prophylactic dosing of valganciclovir for cytomegalovirus prophylaxis in the pediatric solid organ transplant (SOT) population is highly variable among institutions. The purpose of this study was to assess the impact of valganciclovir dosing strategy on neutropenia in SOT recipients at a pediatric academic medical center utilizing a novel method of GFR estimation.

METHODS

A retrospective chart review was conducted to identify differences between patients with and without neutropenia. Regression modeling was used to determine whether valganciclovir dosing strategy could predict posttransplant neutropenia.

RESULTS

Of 80 patients included in the study, 32.5% were neutropenic while prescribed valganciclovir. Most patients were receiving concomitant myelosuppressive medications (sulfamethoxazole-trimethoprim [87.5%] and mycophenolate [66.3%]). Fourteen (53.8%) and 21 (38.9%) patients' doses were determined using their cystatin C-based estimated GFR in the neutropenic and non-neutropenic groups, respectively (p = NS). Rates of CMV DNAemia were < 5% in both groups. Valganciclovir dose was not predictive of the rate, odds, or degree of neutropenia. However, a higher valganciclovir dose adjusted for kidney function was associated with a higher log odds of neutropenia.

CONCLUSIONS

At our institution, where BSA-based dosing using a novel GFR method and appropriate upper limits of GFR for age is used, the rate of neutropenia was lower than previous reports in the literature. Furthermore, valganciclovir dose in milligrams per kilogram was not associated with an increased odds or degree of neutropenia. However, dose accounting for BSA and kidney function was. It is crucial to consider kidney function and the exposure to valganciclovir (vs. dose alone) when determining the risk of neutropenia.

Impact of Hepatoblastoma on Infectious Complications Following Pediatric Liver Transplantation

BACKGROUND

Liver transplantation is the standard therapy for end-stage liver disease in pediatric patients with biliary atresia (BA), congenital and metabolic conditions, and for an unresectable malignant tumor like hepatoblastoma (HB). BA is the leading indication for pediatric liver transplantation, while HB is the most common childhood liver cancer. Despite improved outcomes through advanced surgical techniques and novel immunosuppression, pediatric liver transplantation (pLT) is complicated by post-transplant infections.

METHODS

A retrospective review was performed of pLT recipients at Cincinnati Children's Hospital Medical Center (CCHMC) and stratified patients by underlying disease to assess impact on post-transplant infectious events.

RESULTS

BA patients were youngest at pLT (12.5 months; p < 0.001) compared to other disease cohorts (HB 30.8, other 43.7). All HB patients received organs from deceased donors. In the year following pLT, 93% of the patients experienced at least one infectious event (IE). HB patients had the highest mean number of IE across disease groups (5.5 IE/patient vs. BA 4.5, other 4.0; p = 0.055), with significantly more patients with fever and neutropenia (p < 0.001) and EBV infections (p = 0.012). HB patients were more likely to develop IE earlier after pLT than non-HB groups (p = 0.013), especially Clostridioides difficile (p < 0.01) and fever and neutropenia (p < 0.01). Despite having variable IE experiences, 1-and-5-year survival across disease groups were similar.

CONCLUSIONS

IE were frequently observed in HB patients after pLT, possibly related to pre-and-postoperative chemotherapy and associated neutropenia. Underlying disease may help inform targeted infection-related patient management following pLT.

Accurate Multiplex qPCR Detection of Epstein-Barr Virus/Cytomegalovirus/BK Virus in Kidney Transplant Patients: Pilot Study

Chronic kidney disease is a really important heath issue, and transplantation is an intervention that can greatly increase patient quality of life and survival. The aim of this study was to perform a comprehensive evaluation of the BK virus, CMV, and EBV in kidney transplant recipients (KTRs); to assess the prevalence of infections; and to test if our detection method would be feasible for use in follow-ups with KTRs. A total of 157 KTRs registered at the Clinical Hospital "Dr. C. I. Parhon", Iași, Romania, were selected using specific inclusion/exclusion criteria. We tested the blood samples from each patient for BK, EBV, and CMV using a multiplex real-time PCR (qPCR) assay and the TaqMan PCR principle. The highest prevalence was detected for BKV (11/157, 7%), followed by CMV (9/157, 5.7%) and EBV (5/157, 3.2%). By simultaneously detecting three possible nephropathic viruses and oncogenes in KTRs using multiplex real-time PCR, we aimed to optimize their monitoring and follow-up. The prevalence of the tested nephropathogenic viruses-BKV, CMV, and EBV-was comparable to that analyzed in other studies. We demonstrate that the use of qPCR for viral detection in KTRs is a robust, cost-effective method for case monitoring.

Multicenter Analysis of Valganciclovir Prophylaxis in Pediatric Solid Organ Transplant Recipients

Background

Valganciclovir is the only approved antiviral for cytomegalovirus (CMV) prevention in pediatric solid organ transplantation (SOT). Additional approaches may be needed to improve outcomes.

Methods

A multicenter retrospective study from 2016 to 2019 was conducted of pediatric SOT recipients in whom at least 3 months of valganciclovir prophylaxis was planned. Episodes of CMV DNA in blood (DNAemia), CMV disease, drug-related toxicities, as well as other infections in the first year posttransplant and demographic and clinical data were collected. CMV DNAemia in the first year after prophylaxis or during prophylaxis (breakthrough) was analyzed by multivariate hazard models.

Results

Among the 749 patients enrolled, 131 (17.5%) had CMV DNAemia at any time in the first year; 85 (11.4%) had breakthrough DNAemia, and 46 (6.1%) had DNAemia after prophylaxis. CMV disease occurred in 30 (4%). In a multivariate model, liver transplantation compared to kidney or heart, intermediate or high risk based on donor/recipient serologies, neutropenia, and valganciclovir dose modifications attributed to toxicity were associated with increased risk of total and/or breakthrough DNAemia. Bacteremia was also associated with increased hazard ratio for CMV DNAemia. In a separate multivariate analysis, rejection occurred more often in those with breakthrough CMV DNAemia (P = .002); liver transplants, specifically, had increased rejection if CMV DNAemia occurred in the first year (P = .004). These associations may be bidirectional as rejection may contribute to infection risk.

Conclusions

CMV DNAemia in the first year posttransplantation occurs despite valganciclovir prophylaxis and is associated with medication toxicity, bacteremia, and rejection. Pediatric studies of newer antivirals, especially in higher-risk subpopulations, appear to be warranted.

Body surface area compared to body weight dosing of valganciclovir is associated with increased toxicity in pediatric solid organ transplantation recipients

Optimal dosing of valganciclovir (VGCV) for cytomegalovirus (CMV) prevention in pediatric solid organ transplantation recipients (SOTR) is controversial. Dosing calculated based on body surface area (BSA) and creatinine clearance is recommended but simplified body weight (BW) dosing is often prescribed. We conducted a retrospective 6-center study to compare safety and efficacy of these strategies in the first-year posttransplant There were 100 (24.2%) pediatric SOTR treated with BSA and 312 (75.7%) with BW dosing. CMV DNAemia was documented in 31.0% vs 23.4% (P = .1) at any time during the first year and breakthrough DNAemia in 16% vs 12.2% (P = .3) of pediatric SOTR receiving BSA vs BW dosing, respectively. However, neutropenia (50% vs 29.3%, P <.001), lymphopenia (51% vs 15.0%, P <.001), and acute kidney injury causing treatment modification (8.0% vs 1.8%, P <.001) were documented more frequently during prophylaxis in pediatric SOTR receiving BSA vs BW dosing. The adjusted odds ratio of VGCV-attributed toxicities comparing BSA and BW dosing was 2.3 (95% confidence interval [CI], 1.4-3.7] for neutropenia, 7.0 (95% CI, 3.9-12.4) for lymphopenia, and 4.6 (95% CI, 2.2-9.3) for premature discontinuation or dose reduction of VGCV, respectively. Results demonstrate that BW dosing is associated with significantly less toxicity without any increase in CMV DNAemia.

Update on Epidemiology and Outcomes of Infection in Pediatric Organ Transplant Recipients

Pediatric solid organ transplant (SOT) recipients are at risk for infection following transplantation. Data from adult SOT recipients are often used to guide prevention and treatment of infections associated with organ transplantation in children. This article highlights key recent pediatric SOT-specific publications for an array of infectious complications of organ transplantation. Attention is given to areas of need for future study.

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.

CMV infection and management among pediatric solid organ transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is an important cause of morbidity and mortality in pediatric solid organ transplant (SOT) recipients. However, the impact of asymptomatic CMV infections (ie, DNAemia) on clinical outcomes is not well established.

METHODS

We performed a retrospective cohort study of children undergoing first SOT at our institution from January 2012 to June 2018. We evaluated the epidemiology of CMV infections and performed multivariable Cox regression to assess the association between CMV DNAemia without disease or CMV disease (syndrome or end-organ disease) on negative outcomes (death, re-transplantation, or moderate/severe rejection) within the first year after SOT.

RESULTS

Among 271 individuals, 43 (15.9%) developed ≥1 CMV infection during the first year after SOT. There were 56 unique CMV infections including 14 episodes of CMV disease. In 167 patients offered CMV prophylaxis, only 8 (4.8%) developed their first CMV DNAemia episode while on prophylaxis 32 developed CMV DNAemia after prophylaxis completion; only 1 episode of CMV disease occurred while on antiviral prophylaxis. When accounting for receipt of ATG, oral steroids, and number of immunosuppressives on a given day, CMV disease was more strongly associated with negative outcomes (Hazard Ratio (HR): 3.28, 95% CI: 0.73-14.64; p = .12) than CMV DNAemia without disease (HR 1.42, 95% CI: 0.19- 10.79; p = .74), although not to a statistically significant degree.

CONCLUSIONS

Most CMV infections occurred after completion of antiviral prophylaxis. CMV disease was more strongly associated with negative outcomes than asymptomatic CMV DNAemia and should be the focus of CMV prevention practices.