Clinical Characteristics and Prognostic Analysis of Non-Amyloid Monoclonal Gammopathy of Renal Significance (MGRS) in China

Objective: To analyze the treatment efficacy and prognostic factors of patients with non-amyloid monoclonal gammopathy of renal significance (MGRS) across multiple centers, aiming to inform clinical management and improve patient outcomes. Methods: A retrospective study was conducted on 136 non-amyloid MGRS patients from four major hospitals in China. Patients were diagnosed through kidney biopsy, and clinical data were collected, including demographics, laboratory results, pathology types, genetic testing results, and treatment regimens. Median follow-up period was 33.5 months. The endpoints included renal response, progression, and hematologic efficacy according to the International Society of Amyloidosis (ISA) criteria. Results: The study included 136 patients, with a variety of MGRS pathologies , among which MIDD was the most frequent type (64 patients), followed by 20 PGNMID, 19 LCPT and 19 cryoglobulinemic nephropathy There were 104 patients receiving anti-plasma cell therapies, among which 71 were treated with bortezomib-based regimens. Baseline serum free light chain level >400mg/L were found to be an independent risk factor for poor hematologic response to first-line therapy (P=0.042, HR=5.98). Deep hematologic remission was a significant protective factor (p=0.006, HR=20) for renal response. The presence of t (11; 14) translocation was identified as an independent risk factor (p=0.029, HR=0.138) for poor renal response . Patients achieving deep hematologic remission (not achieved vs 104m, p=0.001) and negative t (11; 14) translocation (104m vs 43m, p=0.001) had better renal progression-free survival rates. Conclusion: Although MGRS composes heterogenous diseases, this study underscores the significance of baseline serum free light chain and t(11; 14) translocation in predicting treatment response in non-amyloid MGRS patients , and the connection between hematological response and renal response. Keywords: Non-amyloid MGRS, renal response, hematologic efficacy, serum free light chain, t (11; 14) translocation, personalized treatment.