IgM Nephropathy: A Question of Existence in the Domain of Glomerular Diseases; A Case Series

Background: Immunoglobulin M nephropathy (IgMN) is a rare glomerular disease characterized by isolated IgM deposits in the glomeruli. Its clinical presentation and prognosis remain controversial, often overlapping with other glomerular diseases like minimal change disease (MCD). This is a case series describing the clinical and pathological features of patients diagnosed with IgMN at our tertiary care center. Materials and Methods: A retrospective review of renal biopsies performed between January 2023 and December 2023 was conducted. Patients diagnosed as IgMN were included. Clinical data, laboratory parameters, histopathological findings, immunofluorescence results, treatment regimens, and follow-up data were collected. Results: Five patients (four females, one male) were diagnosed with IgMN. The majority presented with nephrotic syndrome with frequent relapses, and steroid dependence. Histopathological examination revealed mesangial hypercellularity and matrix expansion. Immunofluorescence staining showed diffuse 2+/3+ mesangial IgM deposits. Treatment with corticosteroids and rituximab resulted in clinical improvement and stabilization of renal function. Conclusion: IgMN is a distinct clinical entity with a variable clinical course. Early recognition and appropriate treatment, including immunosuppressive therapy, are crucial for achieving remission and preventing disease progression. Further research is needed to better understand the pathogenesis and optimal management of IgMN.