Circulating dendritic cells in pediatric patients with nephrotic syndrome

Background: Dendritic cells (DCs) represent one of the most extensively studied topics in immunology, because of their central role in the induction and regulation of adaptive immunity, and because of their therapeutic potential for manipulating immune responses. Objectives: To evaluate circulating DC levels in pediatric patients with idiopathic nephrotic syndrome (NS) and its relation to disease activity in these patients. Methods: Fifteen nephrotic patients in relapse (proteinuria>40mg/m(2)/hour, hypoalbuminemia, and edema) before initiating steroid therapy (Group I), and another15 nephrotic patients in remission after withdrawal of steroid therapy (Group II) were compared to 15 age- and sex-matched healthy children. Besides clinical evaluation and routine laboratory investigations of nephrotic syndrome, circulating DCs were measured by flowcytometry. Results: Circulating DC count was lower in nephrotic patients in both proteinuria and remission groups [(48.89 +/- 13.52) and (64.64 +/- 7.69) X106/liter respectively] than in the control group (78.54 +/- 9.8) X10(6)/liter with highly significant statistical difference (p<0.001), and lower in proteinuria group than the remission group with highly significant statistical difference (p<0.001). There was a positive correlation between DC count and serum albumin (moderate association) (p=0.002) and a negative correlation between DC count and urine protein/creatinine ratio (strong association) (p=0.001). Conclusion: Nephrotic syndrome was associated with decreased number of circulating DCs and the decrease was more apparent in patients with active disease. The positive correlation between DC counts and total protein, and serum albumin, and the negative correlation between DC count and urine protein/creatinine ratio point to the link between the decrease in DC count and the severity of the disease process.