IgM Mesangial Deposition Predicts Relapses of Adult-Onset Minimal Change Disease

Abstract Background: Immunoglobulin M (IgM) mesangial deposition in pediatric minimal change disease (MCD) has been reported to be associated with steroid dependence and poor renal outcomes. However, the evidence regarding the impact of IgM mesangial deposition on the treatment responses or outcomes in adult-onset MCD is lacking.Methods: In this retrospective cohort study, 37 adult patients with MCD received kidney biopsy from January 2010 to May 2020. According to IgM mesangial deposition by immunofluorescence microscopy, the patients were divided into two groups (12 patients with positive IgM deposition; 25 patients with negative IgM deposition). We analyzed the clinical features, the dosage of immunosuppressive agents, and the response to treatment for two years between the two groups.Results: Regarding the clinical symptoms, the dosage of immunosuppressive treatment, and the time to remission, there was no statistically significant difference between the two groups. Compared to the negative IgM group, the frequency of relapses was significantly higher in the positive IgM group within the two-year follow-up period (the negative IgM group 0.25 episodes/year; the positive IgM group 0.75 episodes/year, p = 0.029). Furthermore, multivariate linear regression revealed that the positivity of IgM mesangial deposition is independently associated with the frequency of relapses (regression coefficient B 0.450, 95% CI 0.116-0.784, p = 0.010).Conclusions: Our findings indicated that adult-onset MCD patients with IgM mesangial deposition have a high risk of relapses. Therefore, prolonged and combined immunosuppressive therapy with close follow-up may be considered in MCD adults with IgM mesangial deposition.