Evaluation of long-term follow-up results in pediatric patients with nephrotic syndrome

Background: Nephrotic syndrome is one of the most important and most common glomerular diseases of childhood characterized by the triad of proteinuria, hypoalbuminemia and edema resulting from damage to the glomerular filtration barrier. The incidence ranges between 1.15-16.9 per 100,000 children. Nephrotic syndrome may be associated with glomerular disease without a systemic disease or with a systemic disease. Approximately 90% of NS in childhood is idiopathic Treatment of nephrotic syndrome is mainly based on corticosteroids. Approximately 90% of patients respond to steroid treatment, while 10% of patients are resistant to steroid treatment. Approximately 50% of patients with steroid-resistant nephrotic syndrome develop end-stage renal failure within 5 years. Second-line steroid-sparing therapies should be used in the treatment of steroid-dependent nephrotic syndrome, recurrent nephrotic syndrome and steroid-resistant nephrotic syndrome. Serious complications such as edema, infections, acute renal failure (AKI), thromboembolism and growth retardation may also occur in patients with nephrotic syndrome. Materials and Methods: Patients diagnosed with nephrotic syndrome in the Pediatric Nephrology Clinic of the Department of Pediatrics between May 2011 and March 2023 at Başkent University Ankara Hospital were retrospectively analyzed. Demographic characteristics, laboratory parameters, biopsy findings and treatment protocols were retrospectively evaluated from the patients' files. Results: In our study, 57.67% of the patients were male, 42.33% were female and the male/female ratio was 1.36. The mean age of the patients at the time of diagnosis was 83±54 months (0-215 months) and when the mean age at diagnosis was analyzed according to gender, it was found that male patients were diagnosed earlier than female patients. It was observed that 29% of the patients followed up with the diagnosis of nephrotic syndrome were focal segmental glomerülosclerosis (FSGS) and 27.35% were minimal change disease (MCD). In patients who underwent renal biopsy, the most common findings were FSGS, systemic lupus erythematosus (SLE) and IgA nephropathy. During the follow-up period, 6.13% of the patients died. Of the patients who died during follow-up, 9 patients died due to sepsis, a complication secondary to nephrotic syndrome. When the spot urine protein/creatinine ratios at baseline and at the last follow-up were compared, it was observed that the spot urine protein/creatinine ratio decreased during the follow-up period. When the relationship between the development of end-stage renal disease and serum creatinine value at baseline was analyzed, it was observed that there was a significant relationship between serum creatinine values at admission and the development of end-stage renal disease at follow-up. When the relapse status of the patients during the follow-up period was analyzed, it was seen that a total of 32 patients relapsed at least once. When the reasons that could trigger relapse in patients were analyzed, relapses were associated with a history of infection in 15 patients. It was observed that upper respiratory tract infection triggered relapse the most. In patients followed up for FSGS, remission was mostly achieved with the addition of cysloprine A (CsA) to the treatment. In patients who achieved remission after the addition of cyclosporine A to the treatment, the mean 0-hour CsA value in blood was 115.30±118.87 µg/l and the median value was 81.05 µg/l (28.3-512). Conclusion: In our study, demographic, clinical and laboratory findings, histopathologic features and treatment protocols of patients with nephrotic syndrome were analyzed. It was revealed that the findings and histopathologic features of the patients at presentation were important in determining effective treatment. Further prospective studies with a larger number of cases are needed to determine the treatment that best provides remission in patients. Key words: child, nephrotic syndrome, relapse, remission