SDS : standard deviation score. patients, with the median remission time of 3.65 months. At 12 months Ifenprodil tartrate 2, eight patients in steroid-sensitive group (40%) and four in steroid-resistant group (18%) were drug-free. Total cumulative doses of rituximab were higher in steroid-resistant group (p = 001). Relapse rates and time to first relapse in steroid-sensitive group or remission rates in steroid-resistant group did not differ between the low and high initial dose groups. Conclusion The current study discloses that rituximab therapy may provide a lower relapse rate and prolonged relapse-free survival in the steroid-sensitive group, increased remission rates in the steroid-resistant group, and a significant quantity of drug-free patients in both groups. The optimal regimen for initial treatment and maintenance needs to be decided. strong class=”kwd-title” Keywords: Frequently relapsing nephrotic syndrome, immunosuppressive brokers, steroid-dependent nephrotic syndrome, steroid-resistant nephrotic syndrome, remission 1. Introduction Idiopathic nephrotic syndrome (NS) can be classified according to steroid response into steroid-sensitive nephrotic syndrome (SSNS) or steroid-resistant nephrotic syndrome (SRNS) by the International Study of Kidney Disease in Children (ISKDC) definitions . The most frequent histological lesions in pediatric patients are minimal switch disease (MCD) and focal segmental glomerulosclerosis (FSGS). Children with SSNS who may develop steroid dependency and/or frequent relapses by time and children with SRNS together have been recently called difficult-to-treat NS group. There is no consensus about treatment protocols for difficult-to-treat NS despite the presence of various recommendations [2,3]. Steroids are the main treatment option for children with NS, which can induce remission in the majority of them. Long-term use of corticosteroids in patients with SSNS or SRNS may lead to several complications, including cataract, obesity, hypertension, and decreased bone density. The addition of calcineurin inhibitors (CNIs) or mycophenolate mofetil (MMF) could not provide long-term remission in a group of patients with difficult-to-treat NS. New steroid-sparing brokers have been investigated in recent years. Rituximab (RTX), a mouse-human chimeric monoclonal antibody that binds to the CD20 antigen expressed on B cells, has become a substantial option in difficult-to-treat NS since 2004. Rituximab has been found to be effective in SSNS patients, particularly in those who experienced relapses despite maintenance treatment with CNIs or MMF [4C8]. You will find inconsistent results in the SRNS group around the efficacy of RTX [3,9C11]. Several issues remain uncertain regarding the use of RTX in the treatment of childhood NS, such as Ifenprodil tartrate initial treatment doses, the number of infusions, the Ifenprodil tartrate necessity of additional doses, and dose intervals [5,12,13]. Also, you will find scarce data in the literature on the adverse effects of RTX in children. Besides moderate infusion reactions, life-threatening conditions such as lung injury, myocarditis, and encephalitis have been reported [14,15]. This study aimed to evaluate RTXs efficacy and security at varying doses and intervals in children with difficult-to-treat NS, particularly to assess the prevention of relapses and relapse-free survival in the SSNS group and any improvement Ifenprodil tartrate or remission in the SRNS group. 2. Materials and methods This multicenter retrospective study enrolled children with difficult-to-treat NS on RTX treatment from 11 centers in ?stanbul and two centers from the surroundings of ?stanbul, Turkey. Inclusion criteria were the following: age between 1C18 years and being followed-up at least one year after RTX administration. Exclusion criteria were the presence of genetic abnormalities or secondary NS (hypocomplementemia or immune deposits in kidney biopsy specimens). The study flow-chart is usually shown in Physique 1. Open in a separate window Physique 1 Study flow chart. Of 49 screened patients, 42 fulfilled the selection criteria and consent to study participation. Exclusion criteria were the presence of genetic CD177 mutations, hypocomplementemia, and/or immune deposits in kidney biopsy specimens. T?he NPHS2 gene encodes podocin that is vital.