Abstract: PUB169
Two Clinical Cases of IgM Nephropathy
Session Information
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Johar, Leepakshi, Alta Bates Summit Medical Center - Summit Campus, Oakland, California, United States
- Elattma, Ahmed, Alameda Health System, Oakland, California, United States
- Gilani, Hussain A., Alta Bates Summit Medical Center - Summit Campus, Oakland, California, United States
- Jain, Neha, Alameda Health System, Oakland, California, United States
Introduction
IgM nephropathy is an intermediate between minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS). It is typically an idiopathic glomerulonephritis. Demonstrates diffuse mesangial deposition of IgM on immunofluorescence and mesangial hypercellularity and electron-dense deposits on electron microscopy. Median age is around 42 years old with male predominance. Prevalence is 2.5% with wide variation in presentation including mild to nephrotic range proteinuria along with hematuria.
Case Description
29-year-old female with no prior medical history noted to have proteinuria during pregnancy. No history of NSAID use or herbal medications. She was induced 37 weeks given concern for worsening proteinuria. Physical exam was benign. Urinalysis demonstrated protein with no blood and scant red blood and white blood cells. Protein quantification fluctuated from 0.3 to 1.8 g. Atypical p-ANCA was positive, but the rest of the serologies were negative. Renal biopsy showed IgM nephropathy and glomerulomegaly. Management was with blood pressure control.
Similarly, a 44-year-old female patient with history of inflammatory arthritis (possible RA and SLE), fibromyalgia, obesity, hypothyroidism presented to nephrology clinic for proteinuria. Has had a history of drug induced lupus in 2022 from sulfasalazine. There was concern for Sjogren's per ophthalmology, but serologies negative. Jaccoud's arthropathy of hands, oral ulcers, bleeding gums and epistaxis, edema, painful rash on legs and diffuse arthritis were seen on physical exam. Labs notable for elevated ESR/CRP, 1-2+ protein on UA with baseline creatinine 0.7-0.8. Had positive ANA, dsDNA, histone antibody, antichromatin antibody. ANCA, hepatitis B, hepatitis C, HIV were negative. Patient did not have official lupus diagnosis, but was treated with prednisone. Renal biopsy showed immune complex-mediated mesangial glomerulopathy with IgM mesangial deposits. Electron microscopy with sparse mesangial and paramesangial immune complex deposits. IgM positivity on immunofluorescence microscopy.
Discussion
IgM nephropathy has clinical course similar to MCD, FSGS, and mesangial proliferative GN when appropriately treated. Treatment for IgM nephropathy is not standardized due to limited evidence. First line therapy is corticosteroids. In steroid-resistant cases, calcineurin inhibitors in addition to steroids can be used. Alternatives include rituximab, cyclophosphamide, interferon-alpha.