Management of Steroid Sensitive Nephrotic Syndrome

Nephrotic syndrome in children is usually primary (85–90%) showing glomerular involvement without an identifiable cause as infection, drugs, malignancy, or autoimmune disease. Evaluation might reveal an underlying systemic illness in 5–10% of patients. Most common histopathology is minimal change disease [1]. Most nephrotic children have steroid-sensitive nephrotic syndrome (SSNS) with MCD pathology, while 20% are steroid-resistant (SRNS), depending on the geographic area [2]. SRNS children show mostly focal segmental glomerulosclerosis (FSGS), minimal change disease (MCD), mesangial proliferative glomerulonephritis, and rarely membranoproliferative (MP) or membranous (MN) pathology [3]. SSNS outcome is satisfactory, 50% show frequent relapses or steroid dependence, and 3–10% show late steroid resistance [3]. A kidney biopsy is performed at disease onset only in children with atypical features and in all children with steroid resistance. Repeated kidney biopsy is indicated when prolonged (> 2 to 3 years) exposure to CNIs or in children with secondary steroid resistance. Egyptian children with idiopathic NS justified for biopsy showed MCD in 32.2%, FSGS in 45.2%, mesangio-proliferative in 9.7%, MP in 9.7%, and membranous in 3.2%. Indications for biopsy were SRNS in 79.5%, positive family history in 12.8%, age < 1  year in 2.5% or > 10 y in 10.3%, hypertension in 5.1%, and FR in 2.5% [4]. Genetic testing is not recommended in first presentation of the disease unless positive family history or syndromic or < 1y age. While it is of little value in SSNS, it is crucial in SRNS. IPNA clinical practice recommendations 2020, and KDIGO 2021 guidelines recommended routine evaluation of genetic mutations in children with SRNS if available [5–10]. Comorbidities of Idiopathic SSNS as infection, thrombosis, drug side effects are less marked than that observed in SRNS. The mainstay of treatment for IPNS is corticosteroids. Most children respond well to steroids within 4 weeks (SSNS); those who do not respond will be defined as SRNS patients at six weeks. Kidney outcomes In SSNS remain excellent, with < 5% risk of progression to chronic kidney diseases at 10 years after diagnosis [11]. In contrast, SRNS increased risk of progression to (ESRD) [5]. SSNS prognosis is correlated with morbidity of prolonged exposure to corticosteroids and steroid-sparing agents prescribed in frequently-relapsing or steroid-dependent disease. Idiopathic SSNS disease has a chronic, relapsing–remitting course, which tends to resolve spontaneously following puberty. However, in 15% to 25% of cases, it may progress to adulthood, maintaining the peculiar rapid response to corticosteroids in relapse. Small percentage of children may, become secondarily steroid-resistant with high chance both of progressing to kidney failure and to relapse after transplantation.