Abstract
INTRODUCTION: Failure to thrive (FTT) refers to failure of expected weight gain, striking lack of well-being and inadequate physical growth in children. The causes vary with geographical and socio-economic factors. In developed countries, FTT is usually a symptom of an underlying disease, often a gastrointestinal or neurological disorder. However, in developing countries, FTT is often associated with inadequate caloric intake and malnutrition. Such children are at an increased risk of infections and infection-related mortality which may be related to altered immune responses. Rarely some Primary immunodeficiencies (PIDs) can manifest as FTT. Not much data regarding neutrophil functions in these children is available. OBJECTIVES: The present study aimed to analyse the functional activity of neutrophils in children with FTT using a highly sensitive and specific flow cytometry-based assay. METHODS: 25 children with FTT (up to 5 years) and 25 healthy controls were assessed for haematological parameters and neutrophil oxidative burst activity by DHR Assay using Flow cytometry. RESULTS: Compared to controls, the cases had significantly lower haemoglobin, hematocrit, RBC count and MCHC but a higher eosinophil count (P<0.0001). On flow cytometry, the Neutrophil Oxidative Index (NOI) was significantly reduced in cases (P<0.0001). 1 of 25 cases (4%) showed no change in neutrophil fluorescence after stimulation, suggesting the presence of CGD, which was later confirmed with molecular assay revealing a CYBB mutation. CONCLUSIONS: To conclude, children with FTT have a decreased Neutrophil Oxidative Burst, suggesting defective killing of pathogens by phagocytes. Also, the presence of CGD should be ruled out in such children.