Deficiency of immunological and phagocytic function in aboriginal children with protein-calorie malnutrition.

Infection, associated with protein-calorie malnutrition (PCM), is a widespread and important health problem in young Aboriginal children. Clinical obervations have suggested these children to have impaired immune resistance to infection. Children were fivided by anthropometric criteria into three groups: moderately malnourished; showing effects of previous PCM; normally nourished. Numbers and function of T and B lymphocytes and neutrophils were measured in these groups to give an assessment of systemic immune resistance. Primary antigen recognition and blastogenic response of T-lymphocytes were significantly impaired in the malnourished groups. Normal or increased numbers of B and T lymphocytes, and normal secondary antibody response to tetanus toxoid inoculations were found in all groups. Serum opsonin levels, C3 concentrations, immunoglobulin levels, neutrophil numbers and phagocytic activity were normal or increased in all groups. The malnourished children showed relative impairment of neutrophil chemotaxis, metabolic response to phagocytosis and intraphagocytic bactericidal activity. The findings suggested that children with moderate or lasting effects of PCM had multiple dificiencies in the funnction of their immune defence mechanism which may profoundly influence the prevalence, chronicity and mortality of infections diseases in Aboriginal communities.