A marked decrease in L-selectin expression by leucocytes in infants with Bordetella pertussis infection: leucocytosis explained?
L-Selectin expression mediates extravasation of leucocytes into tissues and is important for homing of peripheral blood lymphocytes to lymph nodes. The significant down-regulation of L-selectin on leucocytes in pertussis infection may prevent leucocyte migration to areas of infection and homing and adhesion of T and B cells to peripheral lymphoid tissues. The increase in lymphocytes with Th1 phenotype may be required for effective immune response to the infective organism. These data provide a possible explanation for the absolute leucocytosis observed in this disease.
Public health ethical frameworks may be supportive in the evaluation of overweight prevention programs or policy, but seem to lack practical guidance to address ethical conflicts in this particular area.