Research Progress on Membranous Nephropathy-Related Antigens and Immune-Targeted Therapy

Chronic Kidney Disease (CKD) has emerged as a significant global public health concern, with membranous Nephropathy (MN) being the most prevalent pathological type of nephrotic syndrome in adults. MN is classified as an antibody-mediated autoimmune disease. There is a growing interest in the research of MN-related antigens. Furthermore, the treatment of MN predominantly relies on the administration of immunosuppressants, with traditional regimens such as corticosteroids and cyclophosphamide, which have significant side effects, and rituximab, having a 35-40% failure rate, highlighting the critical need for the development of specific and effective immunotherapy strategies. In this review, we summarized the research progress on newly discovered MN-related antigens, including exostosin 1/exostosin 2(EXT1/EXT2), Neural Cell Adhesion Molecule 1 (NCAM-1), Neural Epidermal Growth Factor-like 1 (NELL-1), Contactin 1 (CNTN1), Semaphorin 3B, High-Temperature Recombinant Protein A1 (HTRA1), protocadherin FAT atypical cadherin 1(FAT1) and Protocadherin 7(PCDH7). Among them, NELL-1 and HTRA1 primarily serve as target antigens for primary MN, and their serum antibody titers show a strong correlation with disease activity. While EXT1/EXT2, NCAM1, CNTN-1, and FAT1 mainly act as target antigens for secondary MN. In addition, we evaluated the clinical applications and efficacy of novel immunosuppressants and therapeutic approaches, including new anti-CD20 antibodies, proteasome inhibitors, anti-plasma cell therapies, belimumab, complement inhibitors, and immunoadsorption. The new anti-CD20 agents represented by obalimumab and obinutuzumab, along with anti-plasma cell therapies such as daratumumab, have emerged as ideal alternatives for patients with rituximab resistance. Other therapeutic approaches, including complement inhibitors, immunoadsorption, and belimumab, have also exhibited their unique advantages.