Abstract: SA-PO277
IgM Nephropathy, M-Spike, and Chronic EBV Infection with Certolizumab Use
Session Information
- Trainee Case Reports - VI
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Rajasekaran, Arun, University of Central Florida College of Medicine, Kissimmee, Florida, United States
- Mendoza, Mario A., Orlando VA Medical Center, Orlando, Florida, United States
Introduction
IgM Nephropathy is a rare cause of nephrotic syndrome seen in children and young adults. We describe IgM nephropathy causing nephrotic syndrome in an elderly male with normal serum IgM levels and having Rheumatoid Arthritis (RA); who also had tubuloreticular inclusions in his kidney likely caused by chronic EBV infection.
Case Description
A 60 year old male with known RA and ulcerative colitis, on Certolizumab and prednisone therapy, presented with nephrotic range proteinuria. Erosive hand joints and pedal edema were seen. He has known high-titer Rheumatoid factor positive RA with negative anti-CCP antibodies. Labs revealed a normal electrolyte panel, total protein, albumin and renal function. UA showed 3(+) protein. 24-hour-urine specimen revealed 3360 mg of protein. ANA titers were 1:160 (homogenous pattern). Anti-dsDNA, anti-MPO and Proteinase-3 antibodies; and ANCA panel were negative. Complements were low (C3 – 67, C4 – 14). Hepatitis B, C, HIV and CMV serologies were negative. EBV IgM titers were negative, but EBV IgG (728 U/ml) titers were markedly elevated. Serum IgM was normal (178 mg/dl), with a mild increase in IgA (657 mg/dl) and IgG (1858 mg/dl) levels. No monoclonal proteins were seen on UPEP. SPEP revealed an IgG Kappa monoclonal band. Renal biopsy was performed and LM showed mild mesangial hypercellularity, mild to moderate interstitial fibrosis with tubular atrophy. IF showed mesangial regions staining for IgM (3+), IgG (1+), IgA (1+), C3 (1+), and trace kappa and lambda light chains. EM demonstrated patchy podocyte foot processes effacement, several electron dense deposits in an expanded mesangial matrix. Few subepithelial and subendothelial deposits were noted, and many tubuloreticular inclusions were seen. Oncology opined that the IgG Kappa monoclonal band in the SPEP was likely secondary to Certolizumab use, and his Certolizumab was held and a repeat SPEP is pending. Oral diuretics and Lisinopril were started given his edema and proteinuria.
Discussion
Renal IgM deposits can be seen in RA. RA patients’ have impaired control of EBV infection and have high antibody titers against EBV antigens. Our patient had IgM nephropathy with a normal serum IgM level, and our case highlights the need to test for EBV in the setting of RA and IgM nephropathy.