[Risk factors for cytomegalovirus in solid organ transplant recipients]

Cytomegalovirus Viremia in Solid-Organ Transplant Patients in the First Year After Transplantation

OBJECTIVES

Cytomegalovirus infection is an important problem for transplantation. Although effective antivirals for prophylaxis or preemptive therapy have reduced the severity and consequences of infection, cytomegalovirus viremia and cytomegalovirusrelated disease are still matters for patients and for graft survival. The aim of our study was to determine the frequency of cytomegalovirus infections during the first year after transplant.

MATERIALS AND METHODS

In this study, we analyzed the data of 252 liver and kidney transplant patients who had procedures between May 2016 and May 2020. Demographic and laboratory data of patients were recorded retrospectively and analyzed with the SPSS version 25 statistical program.

RESULTS

Our study included 35 liver (14%) and 217 kidney transplant recipients. The ratio of male to female was 3.8, and the median age was 41 years (range, 18-71 years). In our study group, there were 32 patients (12.7%) with cytomegalovirus DNAemia, 13 patients (5%) with cytomegalovirus syndrome, and 6 patients (2.4%) with cytomegalovirus endorgan diseases. Four patients were diagnosed with gastrointestinal disease with histopathology, and 2 patients were diagnosed with cytomegalovirus pneumonia with bronchoscopy and radiology. The mortality rate was 0.8% in the first year.

CONCLUSIONS

Cytomegalovirus reactivations in the first year after transplant play a critical role on graft survival in solid-organ transplant. Regular follow-up of cytomegalovirus DNAemia is crucial for modifying prophylactic and preemptive antiviral regimens.

Development of a Vaccine against Human Cytomegalovirus: Advances, Barriers, and Implications for the Clinical Practice

Human cytomegalovirus (hCMV) is one of the most common causes of congenital infection in the post-rubella era, representing a major public health concern. Although most cases are asymptomatic in the neonatal period, congenital CMV (cCMV) disease can result in permanent impairment of cognitive development and represents the leading cause of non-genetic sensorineural hearing loss. Moreover, even if hCMV mostly causes asymptomatic or pauci-symptomatic infections in immunocompetent hosts, it may lead to severe and life-threatening disease in immunocompromised patients. Since immunity reduces the severity of disease, in the last years, the development of an effective and safe hCMV vaccine has been of great interest to pharmacologic researchers. Both hCMV live vaccines-e.g., live-attenuated, chimeric, viral-based-and non-living ones-subunit, RNA-based, virus-like particles, plasmid-based DNA-have been investigated. Encouraging data are emerging from clinical trials, but a hCMV vaccine has not been licensed yet. Major difficulties in the development of a satisfactory vaccine include hCMV's capacity to evade the immune response, unclear immune correlates for protection, low number of available animal models, and insufficient general awareness. Moreover, there is a need to determine which may be the best target populations for vaccine administration. The aim of the present paper is to examine the status of hCMV vaccines undergoing clinical trials and understand barriers limiting their development.

Contribution of Population Pharmacokinetics to Dose Optimization of Ganciclovir-Valganciclovir in Solid-Organ Transplant Patients

Treatment of solid-organ transplant (SOT) patients with ganciclovir (GCV)-valganciclovir (VGCV) according to the manufacturer's recommendations may result in over- or underexposure. Bayesian prediction based on a population pharmacokinetics model may optimize GCV-VGCV dosing, achieving the area under the curve (AUC) therapeutic target. We conducted a two-arm, randomized, open-label, 40% superiority trial in adult SOT patients receiving GCV-VGCV as prophylaxis or treatment of cytomegalovirus infection. Group A was treated according to the manufacturer's recommendations. For group B, the dosing was adjusted based on target exposures using a Bayesian prediction model (NONMEM). Fifty-three patients were recruited (27 in group A and 26 in group B). About 88.6% of patients in group B and 22.2% in group A reached target AUC, achieving the 40% superiority margin (P< 0.001; 95% confidence interval [CI] difference, 47 to 86%). The time to reach target AUC was significantly longer in group A than in group B (55.9 ± 8.2 versus 15.8 ± 2.3 days,P< 0.001). A shorter time to viral clearance was observed in group B than in group A (12.5 versus 17.6 days;P= 0.125). The incidences of relapse (group A, 66.67%, and group B, 9.01%) and late-onset infection (group A, 36.7%, and group B, 7.7%) were higher in group A. Neutropenia and anemia were related to GCV overexposure. GCV-VCGV dose adjustment based on a population pharmacokinetics Bayesian prediction model optimizes GCV-VGCV exposure. (This study has been registered at ClinicalTrials.gov under registration no. NCT01446445.).