Case series of low dose rituximab for membranous nephropathy; a single centre experience https://nephropathol.com DOI: 10.34172/jnp.2023.21440 J Nephropathol. 2023;x(x):e21440 Journal of Nephropathology *Corresponding author: Gerry George Mathew, Email: gerrygeorge007@gmail.com, mathewgg@srmist.edu.in Gerry George Mathew * ID , Jayaprakash Varadharajan ID , Sreedhar Sailapathy SRM Medical College Hospital and Research Centre, Kattankulathur, Chengalpattu, Tamil Nadu, India-603203 ARTICLE INFO Article type: Case Series Article history: Received: 18 January 2023 Accepted: 1 April 2023 Published online: 10 April 2023 Keywords: Membranous nephropathy Rituximab PLA2R Low dose rituximab Cost effective Introduction: Rituximab is the recent treatment of choice for primary membranous nephropathy However, dose of rituximab mentioned in literature is high and not economical in middle income countries. Low dose rituximab based on CD 19 cell count can be tried as an alternative for high dose rituximab for inducing clinical remission in appropriate clinical settings. Case Series: Four patients were administered low dose rituximab and initial CD 19 count was monitored for optimal rituximab response. ree males and one female are part of this case series. Renal biopsies showed membranous nephropathy with tissue phospholipase A2 receptor (PLA2R) positivity in two cases. Serum PLA2R was positive for the same two cases. Two patients completely remitted after one year, one male patient required additional rituximab dose based on CD19 count, one patient required single dose of rituximab for partial remission in the background of tacrolimus with steroids. One patient failed to remit on low dose rituximab protocol. Conclusion: Low dose Rituximab can be tried as a favorable alternative for high dose Rituximab in appropriate clinical settings. ABSTRACT Implication for health policy/practice/research/medical education: Low dose rituximab should be considered as a safe, effective and economical treatment strategy in primary membranous nephropathy in selected patients in appropriate clinical settings. Please cite this paper as: Mathew GG, Varadharajan J, Sailapathy S. Case series of low dose rituximab for membranous nephropathy; a single centre experience. J Nephropathol. 2023;x(x):e21440. DOI: 10.34172/jnp.2023.21440. Introduction Membranous nephropathy is a notable cause of adult nephrotic syndrome with spontaneous remission noted in 32% cases even after 14 months of diagnosis (1,2). The clinical course of membranous nephropathy follows a non-uniform and heterogenous pattern indicating that the same treatment strategies may be inappropriate for different ethnicities (3). Rituximab is a monoclonal antibody targeting B cells which was initially utilized in the management of B cell lymphoproliferative disorders . It has now become the treatment of choice for primary membranous nephropathy (4). However the dose of rituximab adopted for the treatment of idiopathic membranous nephropathy by nephrologists are those which are required to treat B cell dyscrasias (5). Low dose rituximab with a minimum dosage of 100 mg has been effective in persistent depletion of B cells (6). Rituximab is a costly molecule and is logistically difficult to afford in middle income countries like India. Our case series sheds a glimmer of light on the effective use of low dose of rituximab for management of idiopathic membranous nephropathy and its future prospects. Case Series Patient 1 A 19-year-old female presented with history of pedal oedema and frothy urination since two weeks in January 2021. Urine showed 3 + albumin with 3-4 RBC/high power field and her proteinuria was greater than 8 grams on presentation. Her anti-nuclear antibody (ANA), anti- double stranded deoxyribonucleic acid (anti-dsDNA), anti-neutrophil cytoplasmic antibodies (ANCA), human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), anti-HCV (hepatitis C virus) reports were negative with normal complement levels. Rest of her baseline investigations are outlined in Table 1. Renal biopsy revealed 17 glomeruli with glomerular basement membrane showing spike formation without any Case Series