Different profiles of fatty acids between leukocytes and whole blood in children with idiopathic nephrotic syndrome

Idiopathic nephrotic syndrome (INS) is the most common pediatric glomerular disease, characterized by proteinuria, hypoalbuminemia and edema and caused by an immune dysregulation of T and B cells. Fatty acids (FA) are involved in immune response, with omega-6 prevailing in pro-inflammatory states and omega-3 promoting anti-inflammatory effects. While previous studies of INS assessed FA profile in blood or serum, which may be influenced by many systemic and dietary factors, the intracellular FA metabolism in white blood cells of children with INS, critical to immune cell activation, remains still unexplored. This pilot study compares the FA profile within leukocytes (endo-leukocyte, EL) and whole blood in 35 children with INS and 34 matched controls. INS patients were stratified by steroid sensitivity vs. steroid resistance and by remission vs. proteinuric state. EL FA profiles were analyzed via gas chromatography and dietary habits were evaluated by the Kid Med questionnaire. While blood FA profile of patients demonstrated both elevated omega-6 and omega-3 levels (P-value < 0.005), EL show an inflammatory dominance, with increased omega-6 (P-value < 0.005), but similar omega-3 levels, compared to controls. Furthermore, EL profiles showed reduced saturated FA and palmitic acid but elevated oleic acid levels (P-value < 0.005), possibly indicating a compensatory anti-inflammatory response. This study suggests that EL FA profile may provide unique insights into intracellular mechanisms of inflammation in INS, complementing data arising from blood FA analysis. Despite some limitations, including the small sample size, the study of FA inside the cellular population directly involved in INS underscores its potential in increasing diagnostic precision of FA anomalies in the course of nephrotic syndrome. This new approach may also represent the prerequisite for a clearcut evaluation of the effectiveness of pharmacologic and dietary therapies, like the supplementation with omega 3 metabolites and a diet rich in omega-3.