Patients who develop B-cell precursor acute lymphoblastic leukemia (BCP-ALL) in childhood may have dysregulated immune function at birth, according to a study published in Cancer Research.
Investigators evaluated neonatal concentrations of inflammatory markers and found significant differences between children who were later diagnosed with BCP-ALL and leukemia-free control subjects.
“Our findings suggest that children who develop ALL are immunologically disparate already at birth,” said study author Signe Holst Søegaard, a PhD student at Statens Serum Institut in Copenhagen, Denmark.
“This may link to other observations suggesting that children who develop ALL respond differently to infections in early childhood, potentially promoting subsequent genetic events required for transformation to ALL, or speculations that they are unable to eliminate preleukemic cells.”
“Importantly, our study does not inform about the nature of the associations observed—i.e., whether they are causal or consequential. Accordingly, further studies are needed both to confirm the findings and to identify the underlying mechanisms.”
For this study, Søegaard and her colleagues measured concentrations of 10 inflammatory markers on neonatal dried blood spots from 178 patients with BCP-ALL and 178 matched controls. The patients were diagnosed with BCP-ALL at ages 1 to 9.
The inflammatory markers assessed were interleukin (IL)-6, its soluble receptor sIL-6Rα, IL-8, IL-10, IL-12, IL-17, IL-18, transforming growth factor (TGF)-β1, monocyte chemotactic protein (MCP)-1, and C-reactive protein (CRP).
Compared to controls, children who later developed BCP-ALL had significantly different neonatal concentrations of eight inflammatory markers.
Concentrations of sIL-6Rα, IL-8, TGF-β1, MCP-1, and CRP were significantly lower among the BCP-ALL patients. The adjusted odds ratios (adjusted for birth weight and maternal age) of BCP-ALL were 0.82 for sIL-6Rα, 0.84 for IL-8, 0.83 for TGF-β1, 0.68 for MCP-1, and 0.83 for CRP.
On the other hand, concentrations of IL-6, IL-17, and IL-18 were significantly higher among BCP-ALL patients than controls. The adjusted odds ratios were 1.19 for IL-6, 1.12 for IL-17, and 1.08 for IL-18.
The investigators noted that IL-10 concentrations were too low for accurate measurement in all patients and controls. Additionally, a “large proportion” of patients and controls (31% to 61%) had IL-6 and IL-17 concentrations that were below the limit of detection.
“We also demonstrated that several previously shown ALL risk factors—namely, birth order, gestational age, and sex—were associated with the neonatal concentrations of inflammatory markers,” Søegaard said. “These findings raise the interesting possibility that the effects of some known ALL risk factors partly act through prenatal programming of immune function.”
The investigators found that increasing birth order was associated with significantly higher IL-18 and lower CRP concentrations.
Increasing gestational age was associated with significantly lower sIL-6Rα and TGF-β1 concentrations and higher CRP concentrations. And males had significantly lower sIL-6Rα and IL-8 concentrations and higher CRP concentrations than females.
However, none of the following factors were significantly associated with concentrations of inflammatory biomarkers: maternal age at delivery, maternal hospital contact due to infection during pregnancy, maternal prescription for antimicrobials during pregnancy, birth weight, and mode of delivery.
“Our findings underline the role the child’s baseline immune characteristics may play in the development of ALL,” Søegaard said. “However, we cannot yet use our research results to predict who will develop childhood ALL. In future studies, we will further characterize the relation between immune constitution at birth and risk of childhood ALL with the ultimate goal of developing preventive strategies targeting predisposed children.”
Søegaard noted that this study had its limitations, including the small number of inflammatory markers studied. In addition, the limited sample size made it impossible to detect potential differences between BCP-ALL subtypes.
The study was sponsored by the Dagmar Marshall Foundation, the A.P. Møller Foundation, the Danish Childhood Cancer Foundation, the Arvid Nilsson Foundation, and the Danish Cancer Research Foundation. There were no conflicts of interest disclosed.