Phenotypic Characterization And In Vitro Response Of Lymphocytes Of Ghanaian Children With Burkitt’s Lymphoma To Plasmodium Falciparum Malaria Antigens

A bstract It has been show n in epidem iological studies that m alaria m ay play a role in the pathogenesis o f endem ic B urkitt’s Lym phom a (eBL). The contribution o f m alaria to the pathogenesis o f eBL is believed to be due to the im balances in the im m une regulation during m alaria infection. Studies have show n a loss o f C TL function due to a shift o f the im m une responses from T h l tow ards Th2 T-cell function during m alaria infection. This study sought to investigate the phenotypes o f peripheral blood lym phocytes from eBL patients and their responses in vitro to m alaria antigens. L ym phocyte subset distributions and activation in the peripheral blood w ere studied in 22 B L patients and 15 healthy G hanaian children by flow cytom etry. Plasm a and supernatant levels o f T N F -a and IL-10 w ere m easured by ELISA and com pared betw een the tw o groups. The results show that lym phocytes from B L patients have significantly low frequencies o f C D 3+ (p=0.003) and CD 8+CD 3+ (p=0.013) and both the frequency and the absolute counts o f y8+ T cells (p=0.005 and 0.007 respectively) com pared to the controls. The frequency o f V 51+ yd+ T cells w as significantly higher in the patients com pared to the controls (p=0.047). The data also indicates that lym phocytes from BL patients w ere significantly m ore activated than those from the controls w ith regard to the expression o f the activation m arkers, CD95 and H L A -D R by CD 3T and y5+cells. Plasm a level o f T N F -a w as low er (p=0.002) w hereas that o f IL-10 w as higher in BL patients than in controls (p=0.042). Peripheral blood m ononuclear cells (PBM C) from BL patients produced significantly less T N F-a com pared to the controls w hen stim ulated w ith Plasm odium fa lcip a ru m schizonts (p=0.007) and phytohaem agglutinin (PHA) (p=0.050). Sim ilarly, PB M C from BL patients secreted significantly less IL-10 in response to PH A than cells from controls x v (p=0.016) but w ith regard to the cells stim ulated w ith P. fa lcip a ru m schizonts there was no significant difference in secretion o f IL-10 betw een the tw o groups. Taken together, the data show that there are im balances in the im m une system o f BL patients sim ilar to those found in P. fa lcip a ru m m alaria infection suggesting that recurrent P. falciparum infection can be an additive risk factor for the developm ent and persistence o f eBL.