Abstract: SA-PO0774
IgM Monoclonal Gammopathy of Renal Significance with Type I Cryoglobulinemia: A Rare Case of Multiorgan Vasculitis, Hyperviscosity, and Mononeuritis Multiplex
Session Information
- Glomerular Diseases: Lupus Nephritis, Monoclonal Gammopathy-Related Disease, and Transplantation
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Japnoor singh, Fnu, All India Institute of Medical Sciences Bathinda, Bathinda, PB, India
- Nayak, Saurabh, All India Institute of Medical Sciences Bathinda, Bathinda, PB, India
- Panghal, Isha, Government Medical College and Hospital, Chandigarh, CH, India
- Mayank, Fnu, All India Institute of Medical Sciences Bathinda, Bathinda, PB, India
- Singh, Prabhnoor, All India Institute of Medical Sciences Bathinda, Bathinda, PB, India
Introduction
Monoclonal gammopathy of renal significance (MGRS) is a rare disorder where nephrotoxic monoclonal immunoglobulins cause renal injury without overt hematologic malignancy.IgM-associated MGRS accounts for only 7% of MGRS cases. We report an exceptional case of IgM-MGRS complicated by Type I cryoglobulinemia causing multi-organ vasculitis,hyperviscosity syndrome,and mononeuritis multiplex
Case Description
HISTORY:A woman presented with polyarthralgia,palpable purpura, altered sensorium,and nephrotic-range proteinuria with moderate renal dysfunction.She subsequently developed bilateral wrist drop, melena from esophageal vasculitic lesions, and recurrent AKI from bilateral renal infarcts on CT imaging.
INVESTIGATIONS:Workup revealed HCV reactivity, ANA positivity, low complement levels, and a strongly positive serum cryoglobulin with monoclonal IgM-kappa on immunofixation.Bone marrow showed only 2% plasma cells with no CRAB features, confirming MGRS.Biopsy demonstrated MPGN with pseudothrombi and isolated IgM-kappa deposits on IF, establishing Type I cryoglobulinemia.Nerve conduction studies revealed axonal neuropathy consistent with mononeuritis multiplex.
DIFFERENTIAL DIAGNOSIS:Mixed cryoglobulinemia related to hep C infection was considered; however, monoclonal IgM-kappa deposits favored Type I disease. SLE was excluded due to absence of characteristic clinical and IF findings.
MANAGEMENT&OUTCOME:Therapeutic plasma exchange(PLEX) provides rapid improvement in sensorium, skin rash, and renal function by reducing circulating cryoglobulins.Two cycles of bortezomib-based chemotherapy(CYBORD)were initiated targeting the clonal plasma cell population. Treatment was complicated by HCV reactivation, recurrent UTIs,catheter-related bacteremia,and healthcare-associated pneumonia.Following partial recovery, the patient and family opted for comfort-focused care.
Discussion
IgM-MGRS is rare (<0.5% myeloma).Cryoglobulinemic vasculitis is the 2nd M/C renal manifestation after amyloidosis.This case demonstrates Type I cryoglobulin-driven infarction across kidneys, GI tract, nerves, and skin all responding to plasmapheresis.
KEY TEACHING
HCV with monoclonal IgM-kappa indicates Type I cryoglobulinemia, not mixed
Diagnosis requires renal biopsy with IF
PLEX effectively treats hyperviscosity and vasculitis
Early multidisciplinary intervention is vital to prevent permanent organ damage
Acknowledgment
The author acknowledge the Department of Nephrology and Department of Pathology for their support and management of this case.