Monitoring of cytomegalovirus infection in non-transplant pediatric acute lymphoblastic leukemia patients during chemotherapy

Cytomegalovirus (CMV) infection is a significant cause of morbidity and mortality in the posttransplant setting; however, it is increasingly recognized in pediatric leukemia during chemotherapy. This study assessed the prevalence and associated factors of CMV infection in pediatric non-transplant leukemia patients. This was a cross-sectional study of 50 pediatric acute lymphoblastic leukemia (ALL) patients receiving chemotherapy at Ramathibodi Hospital from December 2015 to December 2016. CMV viral load quantified by DNA polymerase chain reaction (PCR) was monitored in different phases of chemotherapy: enrolment, post-induction, post-consolidation, post-intensification, and maintenance. One hundred forty one blood tests were evaluated from 50 patients. Overall prevalence of CMV DNAemia (≥20 copies/mL) and high-level CMV DNAemia (≥1000 copies/mL) was 52% (26 of 50) and 16.0% (8 of 50), respectively. All patients with high-level CMV DNAemia were in the maintenance phase of chemotherapy. One patient had CMV retinitis, while the rest had no end-organ CMV diseases. Increased lymphocyte count was significantly associated with protection from high-level CMV DNAemia (odds ratio 0.997, P = .02). Receiver operating characteristic curve identified a cut-off value of 798 cells/mm³ of absolute lymphocyte count (ALC) as a discriminator for the presence of high-level CMV DNAemia (area under the curve 0.756, 95% CI 0.645–0.867, P = .001) with 88.9% sensitivity and 50.4% specificity. CMV infection predominantly occurred during maintenance chemotherapy. Low ALC was significantly associated with high-level CMV DNAemia. CMV infection surveillance by quantitative CMV DNA PCR during maintenance chemotherapy in patients with ALC <800 cells/mm³ may be considered.