Prevalence and risk factors for CMV re-activation in Allogeneic hematopoietic stem cell transplantation pediatric patients at National Stem Cell Center (NSCC-Hayat) in Damascus

Abstract

Background and Aims: Cytomegalovirus (CMV) is a major cause of morbidity and mortality after Allo-HSCT, that can occur during the time of immunosuppression. Our study aims to evaluate the prevalence, risk factors, prevention and treatment outcomes of CMV re-activation in pediatric allogeneic hematopoietic stem cell transplantation recipients at the National Stem Cell Center (NSCC-Hayat) in Children's hospital in Damascus.

Methods: A retrospective analysis survey was conducted aiming pediatric patients who underwent allo-HSCT in the National Stem Cell Center from July 2021 to June 2024. The sample size was found to be 27, aging between 1.5 years and 14 years.

Results: The whole sample, recipients and donors, were siblings with 10/10 HLA matching and CMV IgG sero-positive.  Significantly, 11 patients were found within the CMV re-activation group (40.7%, 11/27) when a prospective monitoring of CMV re-activation by polymerase chain reaction (PCR) was adopted strictly once weekly. The incidence of CMV activation was statistically higher in female children (64%) who had anti-thymocyte globulin (ATG) within the conditioning regimen (72,7%), which matches that incidence of CMV-activation was noticeably higher in Major Thalassemia and severe aplastic anemia HSCT group compared to leukemia HSCT group (45,5 %, 36% vs 18% respectively).

Importantly, resolving from infection was found in the whole CMV activated group by an early initiating of intravenous Foscarnet (54,5%) vs oral valganciclovir. (45,5%)

So that immunosuppressive drugs were one of the main risk factors of CMV reactivation after HSCT, incidence was found to be slightly higher in patients who required multi-immunosuppressive drugs (56%), than mono-immunosuppressive drug.

Conclusion: This study suggests a higher risk of CMV re-activation with median age (7 years old) in female gender, patients with thalassemia / aplastic anemia and those receiving ATG-conditioning and multi-immunosuppressing drugs.

Foscarnet and Valgancyclovir therapy were effective and safe for treating CMV in pediatric Allo-HSCT recipients when initiated early and not discontinued until CMV was no longer detected in blood.