Etiology of endemic Burkitt's lymphoma.

There is a considerable volume of evidence linking Epstein-Barr virus (EBV) etiologically with Burkitt's lymphoma (BL). BL has satisfied the Henle-Koch criteria. Thus BL patients have significantly higher EBV antibody titres than normal or tumour controls. EBV DNA and EBV-determined nuclear antigen (EBNA) have been demonstrated in a high proportion (greater than 90%) of endemic BL tissues. EBV can transform and immortalize human B-lymphocytes and is known to cause lymphoreticular tumours in New World monkeys. The fact that endemic BL is almost invariably associated with EBV while this is rarely true of the non-endemic form suggests disease heterogeneity in spite of morphological uniformity. The role of malaria as a co-factor in causing immunosuppression and promoting proliferation of EBV-transformed cell is discussed. The identification of specific chromosomal abnormalities in both endemic and non-endemic BL underscores the importance of a suitable genetic background.