With 6,590 cases and 1,430 deaths this year, acute lymphocytic leukemia (ALL) remains the most common type of childhood cancer, with children under 5 years of age at highest risk for the disease. The disease can progress quickly, and if left untreated, can lead to death. For the first time, researchers have linked ALL with a specific virus in the herpes family: congenital cytomegalovirus (CMV).
In a new study, published in Blood, the official journal of the American Society of Hematology (ASH), researchers took a closer look at the bone marrow of 127 children with ALL and 38 children with acute myeloid leukemia (AML) and identified all of the infections that were present. They then screened all of the samples that were taken for all known viruses. The researchers found that CMV DNA was present in the samples that had been taken from children with ALL, but “rarely” from the samples taken from those with AML, according to a press release.
The researchers also analyzed 268 blood samples taken from children who later developed ALL using an “ultra-sensitive digital droplet screen,” and compared these samples with 270 healthy children. They found that those children who eventually developed ALL were 3.71 times more likely to have had CMV at birth. Furthermore, “stratification by Hispanic ethnicity show[ed] a 5.9-fold increased risk of ALL in Hispanics infected perinatally with CMV.” This finding holds particular importance because Hispanics have the “highest risk” of ALL, according to the press release.
In the press release, lead study author, Stephen Francis, PhD, assistant professor of epidemiology at the University of Nevada and University of California, San Francisco, said, “Our goal in tracking CMV back from the time of diagnosis to the womb was to establish that this infection occurred well before initiation of disease.”
He continued, “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. That’s the real take-home message.”
With a whopping 80% of individuals in the United States infected with CMV, and a number of pregnant women transmitting the virus to their fetuses, CMV remains a public health concern. In fact, it is the most common congenital viral infection; 1 in 150 children born in the United States have it.
CMV infection can have a number of serious health complications ranging from hearing loss to microcephaly in newborns. The researchers hope that the findings of their study will not only inspire additional studies, but will also lead to the creation of a CMV vaccine.
According to Dr. Francis, “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.”