Microgeographic variations in Burkitt's lymphoma incidence correlate with differences in malnutrition, malaria and Epstein-Barr virus

Abstract

Background: Endemic Burkitt's lymphoma (eBL) has been associated with Epstein-Barr virus (EBV) and holoendemic Plasmodium falciparum malaria. But recent evidence suggests that other risk factors are involved.

Methods: We hypothesised that selenoprotein glutathione peroxidase (GPx), a surrogate of nutritional status, is an important biomarker for eBL risk. We measured plasma GPx, anthropometric markers of malnutrition, EBV viral loads and malaria parasitaemia in children aged 1-9 years (n=258) from two locations in Nyanza Province, Kenya, with higher-than-expected and lower-than-expected incidence of eBL. The study participants were malaria asymptomatic children from the community.

Results: Children from eBL high-incidence areas had significantly lower GPx levels, high EBV viral load and more evidence of chronic malnutrition than children from eBL low-incidence areas (all P<0.001). Additionally, GPx levels were significantly lower in children with the highest EBV viral load and for those with P. falciparum infections (P=0.035 and P=0.004, respectively).

Conclusions: These results suggest that selenium deficiency may be a risk factor for eBL.

Figure 1

Plasma levels of glutathione peroxidase enzyme (GPx) from children residing in regions with low and high eBL incidence. Plasma levels of GPx in individuals from eBL low-incidence (n=65) and eBL high-incidence (n=93) regions were measured by enzyme-linked immunosorbent assay (ELISA). The dots represent individual GPx selenium levels and the line through the dots represents the mean level. Differences between groups were statistically significant by t-test (P<0.0001).

Figure 2

EBV viral load in children residing in regions with low and high eBL incidence. EBV viral load in individuals from eBL low-risk and eBL high-risk region were determined by Q-PCR. The dots represent individual viral loads, whereas the line through the dots represents the mean. Only those study participants with a positive viral load were analysed (n=74, eBL low risk and n=59, eBL high risk) and are shown. Differences between groups were statistically significant by t-test (P<0.0001).