Ethnicity and difference in dengue virus-specific memory T cell responses in Cuban individuals.

The different risk factors associated with dengue hemorrhagic fever pathogenesis needs yet additional clarification. The exceptional epidemiological circumstances in Cuba allow their evaluation in a well-defined situation. In the present study the memory T cell response of 80 Cuban donors previously infected with dengue-1 and dengue-2 during the 1977 and 1981 epidemics, and belonging to different ethnic groups, was examined. White people showed, in contrast to black people, stronger and remarkably cross-reactive dengue virus-specific memory CD4(+) T lymphocyte proliferation and interferon-gamma release. The observed variation in T cell response according to ethnicity could be related to the immunopathogenesis of dengue hemorrhagic fever, and may partially explain the epidemiological evidence that black individuals are at lower risk for the most severe dengue clinical course compared with white individuals.