Impact of Protein-Energy Malnutrition on Immune Function Markers in Under-Five Children in Sokoto State

Protein-energy malnutrition remains a significant paediatric health challenge in northern Nigeria, with well-documented effects on immune competence. This study evaluated the impact of protein-energy malnutrition on selected immune function markers among children under five years in Sokoto State, North West Nigeria. Sixty malnourished children admitted to a nutrition stabilisation centre in Sokoto and 30 well-nourished children from the same community were recruited. Nutritional status was classified using World Health Organisation weight-for-height and mid-upper arm circumference criteria. Venous blood was collected for determination of total lymphocyte count, serum immunoglobulin G, and complement C3 levels using automated haematology and enzyme immunoassay techniques. Unpaired t-tests and logistic regression were applied. Results revealed significantly lower total lymphocyte count, immunoglobulin G, and complement C3 in malnourished children compared to controls. Children classified as severely malnourished had the greatest immunological deficits. Length of malnutrition duration further reduced immune indices. The study concludes that protein-energy malnutrition profoundly compromises the cellular and humoral immune response in young children in Sokoto. Accelerated nutritional rehabilitation programmes combined with vaccination support are critical for reducing infection-related mortality in this vulnerable group. Keywords: protein-energy malnutrition, immune function, lymphocyte, children, Sokoto State.