Elevated urinary CD80 excretion in children with steroid-responsive nephrotic syndrome

Background: Idiopathic nephrotic syndrome (INS) is one of the most common glomerular diseases in children with different pathological types and different responses to corticosteroids. A definitive diagnosis is essential for planning the treatment and determining the prognosis of these patients and currently, kidney biopsy is the only method for definitive diagnosis. However, this is an invasive procedure. In addition, in some cases, the biopsy is contraindicated or tissue obtained on biopsy is insufficient and may not represent the underlying disease. According to the recent hypothesis about the role of circulating permeability factors in the pathogenesis of INS, urine protein analysis as a noninvasive method to determine the specific biomarkers of the disease is of great interest to nephrologists and can be useful. Methods: In this case - control study, we analyzed urinary CD80 (uCD80) levels in 51 patients with INS using a special CD80 enzyme-linked immunosorbent assay kit and were compared between different groups of patients. Results: The highest urine CD80/creatinine ratio was found in patients with active minimal change disease and steroid-responsive nephrotic syndrome in the relapse stage of the disease. Conclusion: A significant level of uCD80 is correlated with better renal function and a more favorable response to steroids in patients with INS. Therefore, it can be concluded that a high level of uCD80 is correlated with a good prognosis in these patients.