Epstein-Barr virus and Burkitt’s lymphoma. Associations in Iraqi Kurdistan and twenty-two countries assessed in the International Incidence of Childhood Cancer

Abstract

Background Burkitt's lymphoma (BL) has worldwide variations in incidence that are related to the age of Epstein-Barr virus (EBV) infection. This study examined the age-specific incidence rate (ASIR) of BL and community EBV seropositivity in Iraqi Kurdistan and compared results with data from countries tabulated in the International Incidence of Childhood Cancer volume 3 (IICC-3). Methods The ASIR (95% confidence intervals) of BL in Sulaimani Governorate of Iraqi Kurdistan were calculated for the years 2010–2020. Specimens from 515 outpatients were tested for IgG and IgM antibodies to EBV viral capsid antigen. Results In Sulaimani, 84% of BL occurred under 20 years of age, with an ASIR of 6.2 (4.7–7.7) per million children. This ASIR was not significantly different than that of Egypt, Morocco, Israel, Spain, or France. It was slightly higher than the ASIR of the United States, the United Kingdom, and Germany and markedly higher than for Asia and South Africa. In Africa and much of Asia, early childhood EBV exposure predominates, with nearly all children being infected by 5 years of age. In Sulaimani, just over 50% of children were EBV seropositive at 3 years old and 90% seropositivity was reached at 15 years of age. In Europe and North America, seropositivity is commonly delayed until adolescence or young adulthood and adult predominates over childhood BL. Conclusion In the Middle East, childhood BL is relatively common and adult BL is rare. In Sulaimani, EBV seropositivity increases progressively throughout childhood and reaches 92% at mid-adolescence. This may reflect the Mid East more widely. We suggest that the high childhood and low adult BL rates may be a regional effect of a pattern of EBV exposure intermediate between early childhood and adolescent and young adult infections.

A Study on Burkitt’ S Lymphoma and Epstein-Barr Virus Latency in Duhok, Iraq

“…Burkitt's lymphoma is the most prevalent lymphoma subtype among Kurdish children 6 with an age incidence rate of 6.2 per million children, which is 2 times the rate reported in the United States at 3.2 per million but significantly less than the reports of an endemic variant in Africa (30.0 per million) 4,5 . indicating that Burkitt's lymphoma in Iraq is distinct from endemic and sporadic variants 5 .…”

“…In developing nations, more than 95% of the population acquires the virus before the age of five 4,5 . In contrast, EBV exposure in developed nations like northern Europe and the United States is postponed until adolescence and early adulthood 6 . In prior research in the region of Iraqi Kurdistan, BL was described as a pediatric disease 5,7 .…”

“…In the pathogenesis of endemic BL, EBV collaborates with malaria falciparum 9 . Whereas in sporadic BL, including the Middle East, no co-existing infection or promoting factor other than EBV has ever been discovered 6 . The expression of the MYC gene, which encodes the C-MYC protein transcription factor and is located on chromosome 8q24, governs cell proliferation, differentiation, and death.…”