556 - Clinical Presentation of membranous nephropathy in Children: A single center experience.

Publication Number: 4544.556

Meredith Cox, Lincoln Memorial University DeBusk College of Osteopathic Medicine, Oak Ridge, TN, United States; Alexandra M. Subtirelu, Knoxville Catholic High School, Knoxville, TN, United States; Alexander Venero, University of Tennessee Health Science Center College of Medicine, Knoxville, TN, United States; Sai Sudha Mannemuddhu, 1. East Tennessee Children's Hospital. 2. University of Tennesse, Knoxville, TN, United States

Background: Membranous nephropathy (MN) is an uncommon cause of nephrotic syndrome (NS) in the pediatric and adolescent population, representing approximately 1% of all cases of NS in this age group. In contrast to adults, where primary MN is a leading cause of idiopathic NS, most pediatric cases are secondary, often associated with autoimmune disorders such as systemic lupus erythematosus (SLE), infections, or exposure to certain medications. The diagnosis of primary MN in children and adolescents remains rare, and the clinical course, treatment response, and long-term outcomes are not well characterized. Here, we describe three cases of biopsy-proven primary membranous nephropathy diagnosed over a 20-year period in a single small pediatric nephrology practice, emphasizing the diagnostic process, treatment approaches, and outcomes.

Objective: -

Design/Methods: A retrospective chart review was conducted of all pediatric patients diagnosed with biopsy-proven primary MN over 20 years. Clinical presentation, laboratory findings, treatment regimens, and long-term outcomes were analyzed.

Results: Three adolescents (two females, one male), aged 16 and 17 years, presented with nephrotic-range proteinuria (4+), edema, and hypoalbuminemia (1.3-2.6 mg/dL). All had normal blood pressure and normal renal function, with unremarkable serum electrolytes, complement levels (C3 and C4), inflammatory markers (CRP, ESR), and hematologic profiles. Autoimmune and infectious serologies, including ANA, ASO, ANCA panel, RPR, HIV, Hepatitis B and C, and Quantiferon-TB, were negative. Renal ultrasonography was normal in all patients, and kidney biopsies confirmed primary membranous nephropathy without evidence of secondary causes.
Patients 1 and 2 were treated with a single course of rituximab, while Patient 3 received repository corticotropin injection (Acthar®) for 16 months. All three patients were managed with renin-angiotensin system blockade for 2 months to 5 years. Complete remission, defined by normalization of serum albumin and resolution of proteinuria, was achieved and sustained in all cases at 3-5 years of follow-up. Hypercholesterolemia was observed in Patients 1 and 2; only Patient 1 required statin therapy and low-dose aspirin for thromboprophylaxis.

Conclusion(s): Primary MN in adolescents, though rare, can present as isolated nephrotic syndrome with preserved renal function and negative serologies. These cases demonstrate that alternative immunomodulatory therapies, such as rituximab and ACTH analogs, can induce sustained remission. Early recognition and individualized therapy are crucial for favorable long-term outcomes.

Table 1- Clinical and laboratory parameters, radiology, treatment, and outcomes of patients with primary membranous nephropathy
Table Membranous.pdf