# P-2164. Clinically Significant Cytomegalovirus Infection (csCMVi) After Matched Donor Allogeneic HSCT Using Post-Transplant Cyclophosphamide: A Systematic Review and Meta-Analysis

## TL;DR

This study finds that 40% of patients receiving matched donor transplants with PTCy face significant CMV infection, highlighting a need for better prevention strategies.

## Contribution

The study is the first to systematically analyze CMV infection risk in matched donor transplants using PTCy.

## Key findings

- The pooled incidence of clinically significant CMV infection was 40%.
- No studies reported use of anti-CMV prophylaxis like Letermovir.
- CMV end-organ disease occurred in 3.9% of patients.

## Abstract

Post-transplant cyclophosphamide (PTCy) was initially used for graft-versus-host disease (GVHD) prophylaxis in haploidentical allogeneic hematopoietic stem cell transplantation (allo-HSCT). This strategy is now expanding into matched related and unrelated donor allo-HSCT. However, the risk of clinically significant cytomegalovirus infection (csCMVi) including reactivation and end-organ disease is poorly defined in this population. We aimed to systematically evaluate the cumulative incidence of csCMVi in this subgroup.PRISMA FLOW DIAGRAMBaseline characteristics of the study population

PRISMA FLOW DIAGRAM

Baseline characteristics of the study population

A systematic review was conducted according to PRISMA guidelines and registered in PROSPERO (ID: 1043133). PubMed, Embase, Scopus, and Cochrane CENTRAL were searched for studies of csCMVi incidence in adult patients with hematologic malignancies undergoing matched donor allo-HSCT with PTCy-based GVHD prophylaxis. A proportion meta-analysis was performed using a random-effects model with Freeman-Tukey double arcsine transformation. Heterogeneity was assessed with I² and Tau²; publication bias was evaluated by funnel plot symmetry.Forest plotPublication bias assessed by Funnel Plot

Forest plot

Publication bias assessed by Funnel Plot

Eleven studies comprising 1,637 patients, with study periods ranging from 2007 to 2023, were included. The most common CMV serostatus was D+/R+ (48.2%), followed by D-/R+ (27.4%). None of the studies reported use of anti-CMV prophylaxis. The pooled cumulative incidence of csCMVi was 40% (95% CI: 35–46%). Heterogeneity was substantial (I² = 78.85%, Tau² = 0.03),

and a random-effects model was used. The funnel plot was symmetrical and did not suggest substantial publication bias. CMV end-organ disease occurred in 3.9% of patients; grade 2–4 acute GVHD occurred in 26.3%.

Clinically significant CMV infection remains a substantial burden among matched donor allo-HSCT recipients receiving PTCy, with a pooled incidence of 40%. Our findings highlight a critical evidence gap as PTCy expands into matched donor transplantation. The consistent absence of anti-CMV prophylaxis such as Letermovir underscores the need for standardized prevention protocols. Notably, data on CMV incidence in patients receiving prophylaxis are lacking, warranting further studies.

All Authors: No reported disclosures