HLA-DR7 association with African Burkitt's lymphoma.

Association between HLA-DR7 and Burkitt's lymphoma previously reported has been confirmed by a second study. Analysis of additional data from a second study of 33 Ghanaian patients with African Burkitt's lymphoma and 54 Ghanaian controls matched for age and ethnic origin showed that 39.4% of cases, but only 14.8% of controls, had HLA-DR7 (p less than 0.01). The relative risk of 3.7 is similar to that observed in the earlier study (3.3). Combining the earlier and present studies, analysis of clinical data from 94 patients with Burkitt's lymphoma and 116 controls shows the relative risk of Burkitt's lymphoma among individuals with HLA-DR7 was 3.4 (p less than 0.001). There was an increased relative risk of the disease associated with HLA-DR7 in: patients under 10 years of age; and patients with advanced stages of disease (Stage III or IV). However, comparison of relative risks by sequential analysis of 2 X 2 tables showed that these differences by age and stage were not statistically significant.