Immunity to measles in malnourished children

Abstract

This work tests the hypothesis that the increased severity of measles in malnourished children is related to the immune response of the host to the virus. Peripheral blood mononuclear cells (PBM) from well-nourished and malnourished children who had not had measles were infected in vitro with measles virus. The yield of virus from the cells of malnourished children was significantly greater than the yield from well nourished children. This was not due to lack of interferon as both types of cells produced similar amounts on challenge with measles virus. Antibody-independent and antibody-dependent cellular cytotoxicity to Hela cells persistently infected with measles virus was measured on average 1 week after the onset of the measles rash. Mononuclear cells from malnourished children killed infected Hela cells as well as cells from well-nourished children in both types of assay. There was also no significant difference in the ability of serum from the two groups of children to lyse PMB which were infected with measles virus. However, plasma from malnourished children was found to depress proliferation of lymphocytes in the presence of PHA or Candida antigen to a greater degree than plasma from well-nourished children. We conclude that the severity of measles in the malnourished may well be related to the immune response for if their cells are abnormally susceptible to infection and if this infection is followed by a normal cellular and humoral immune response severe and extensive allergic damage would result. The reaction in turn may generate immunosuppressive factors in the patient's plasma thus making the child susceptible to secondary infections.