Cytomegalovirus infection post-allogeneic stem cell transplant: Experience from a country with high seropositivity.

Cytomegalovirus (CMV) infection is a major cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Limited data is available from developing countries regarding frequency of CMV infection and treatment outcomes. We enrolled 230 consecutive patients undergoing allogeneic HSCT for various hematological disorders at Armed forces bone marrow transplant center / National institute of blood and marrow transplant (AFBMTC/NIBMT) from February 2017 to December 2020. Cytomegalovirus reactivation post HSCT was monitored weekly starting day 30 until day 100 and pre-emptive antiviral administered to prevent CMV disease in all HSCT recipients with ≥2000 CMV copies/ml. Median age of the study cohort was 9.5 years (range 0.6-53 years), male: female was 2.4:1. Most frequent transplant indication was beta thalassemia major (36.1%) followed by aplastic anemia (23.9%). Malignant disorders constituted 20% of all the patients. Pre transplant CMV seropositivity was 99.1% for the recipients and 99.5% for the donors. CMV infection was seen in 66.1% patients and median time to CMV DNAemia was 36 days. Pre-emptive antiviral therapy was administered to 140 (61%) patients with CMV viral load ≥2000 copies/ml. In multivariate analysis, patients' age >12years, steroid administration and use of MMF with or without PTCy was associated with highest probability of CMV reactivation. OS was 97.4% in patients without CMV reactivation as compared to 80.3% in patients with CMV reactivation (p=0.001). Event free survival was 78.7% in study cohort, 89.7% for patients without CMV reactivation as compared to 73% for patients with CMV reactivation (p=0.003). Our study is the first from this region to show frequencies of CMV seropositivity, CMV infection, risk factors for CMV reactivation and outcome of antiviral therapy in hematopoietic stem cell transplant recipients.