PLASMA-LEVELS OF COMPLEMENT COMPONENTS AND COMPLEMENT HEMOLYTIC ACTIVITY IN PROTEIN-ENERGY MALNUTRITION

Abstract

The plasma levels of complement[C]hemolytic activity (CH50) of some C components and of C3d, a C3 breakdown product, were measured in 59 African children with various types of protein-energy malnutrition (PEM) including kwashiorkor, before and during recovery. A significant decrease of CH50, C3, C9 and factor B was observed in PEM without a concomitant decrease of C4 and C5. Increased plasma levels of C3d were also found in PEM patients. Two mechanisms seem to be involved in the impairment of the complement system in PEM: a decreased synthesis of at least C3 and C9 as suggested by a significant correlation between C3 or C9 levels and those of albumin and cholinesterase; and an increased catabolism of C3 possibly due to an activation of the alternative C pathway, as suggested by the increased level of C3d and the decreased level of factor B which are significantly correlated with C3 levels but not with albumin levels. These data support the possible role of a relative C deficiency in the decreased resistance to infections observed in malnourished children.