Analyzing the Correlation Between Serum IgM Levels and Rituximab's Therapeutic Efficacy in Adult Nephrotic Syndrome：A retrospective cohort study

Abstract

Objective To investigate the relationship between serum IgM level and the efficacy of rituximab (RTX)in the treatment of adult patients with nephrotic syndrome(NS). Methods This study retrospectively analyzed the clinical data of 68 NS patients who received RTX treatment in Shenzhen Second People's Hospital from September 2018 to August 2023. This study employed Cox proportional hazards model, Kaplan-Meier survival curves and other statistical methods to analyze the correlation between IgM level and the efficacy of RTX in NS treatment. Result This study involving 68 patients, 45 were male (66.18%). The Patients were divided into two groups according to the cutoff value of ROC curve analysis. There were 29 cases in the low level group (< 0.81 g/L) and 39 cases in the high level group ( > = 0.81 g/L). Complete remission was achieved in 23 cases (33.82%). Univariate analysis revealed that in the low IgM level group, eGFR was a significant factor influencing the effectiveness of Rituximab treatment for nephrotic syndrome (HR = 1.03, 95%CI 1.01 ~ 1.04).In the Cox regression model, serum IgM levels were positively correlated with the likelihood of complete remission in adults with NS treated with rituximab (HR = 3.080, 95% CI 1.552–6.110).Even after adjusting for age, gender, BMI, albumin, eGFR, urine protein quantification, D-dimer, serum IgG, and complement C3, this relationship remains significant (HR = 3.041, 95%CI 1.242–7.447, P < 0.05). However, we went further and found that serum IgM levels are negatively correlated with the efficacy of patients with membranous nephropathy treated with rituximab, but positively correlated with the complete remission of patients with minimal change disease.In the low and high serum IgM level groups, the median time to remission is 27 months and 11 months, respectively.The possibility of complete remission of nephrotic syndrome in patients with high levels of IgM was 1.967 times higher than that in patients with low levels of IgM. Conclusion Baseline IgM levels significantly correlate with the effectiveness of Rituximab treatment in adult patients with nephrotic syndrome. Specifically, serum IgM levels negatively correlate with treatment outcomes in patients with membranous nephropathy receiving Rituximab, while positively correlating with complete remission in patients with minimal change disease. Trial registration: This is a retrospective cohort study, we temporarily did not apply for clinical trials number.