Is Cytomegalovirus Linked to Childhood Leukemia Risk?

Prenatal infection with cytomegalovirus (CMV) increases the risk of childhood acute lymphoblastic leukemia (ALL), indicates a study of newborn blood and pretreatment childhood bone marrow published in the journal Blood.

The finding suggests the possibility that ALL could be prevented with antiviral interventions or vaccination.

“If it’s truly that in utero CMV is one of the initiating events in the development of childhood leukemia, then control of the virus has the potential to be a prevention target,” said lead study author Stephen Francis, PhD, assistant professor of epidemiology at the University of Nevada and University of California San Francisco.

Using archived pretreatment bone marrow samples from the California Childhood Leukemia Study at UC Berkeley, the researchers conducted a comprehensive untargeted search for bacteria and all known viruses in marrow from 38 children with acute myeloid leukemia (AML) and 127 children diagnosed with ALL.

Marrow from all of the children with ALL harbored CMV DNA, they discovered. Active CMV transcription was demonstrated in leukemia blasts and intact CMV virions were found in serum.

The research team subsequently screened newborn blood-spot samples for CMV among 268 children who were later diagnosed with ALL and 270 healthy control children. Children who developed ALL were more than three times as likely to have been CMV-positive at birth (odds ratio [OR] 3.71, 95% CI: 1.56-792; P = .0016).

The association between in-utero CMV infection and subsequent development of ALL was particularly strong among Hispanic children (OR 5.90; 95% CI: 1.89-25.96; P = .006).

“This is the first step, but if we do end up finding a causal link to the most common childhood cancer, we hope that will light a fire in terms of stopping mother-to-child transmission of CMV,” said Francis.