Abstract: TH-PO815
Systemic Immunoglobulin G4-Related Disease
Session Information
- Pathology and Lab Medicine - I
November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pathology and Lab Medicine
- 1800 Pathology and Lab Medicine
Authors
- Henderson, Jacob R., The Christ Hospital, Cincinnati, Ohio, United States
- Pembaur, Karl Berthold, The Christ Hospital, Cincinnati, Ohio, United States
Introduction
Immunoglobulin G4-Related Disease (IgG4-RD) is an autoimmune condition that can result in systemic fibrosis and organ damage. Clinical manifestations include lymphadenopathy, atopy like symptoms, and is often found incidentally on imaging with diffuse or focal organ lesions. Serological findings can include elevated levels of immunoglobulins and low complement levels. A tissue biopsy is needed for diagnosis revealing IgG4 lymphoplasmacytic infiltration with variable degrees of fibrosis.
Case Description
A 79 year-old male with a PMHx of HTN, biliary stricture, asthma, and BPH presented with generalized fatigue, pruritus, and difficulty initiating urination for one month. Labs revealed an AKI (Cr 5.19, BUN 47; UA - mild proteinuria), transaminitis (AST 322, ALT 460, ALP 796, TBili 4), and anemia (Hgb 11.2). MRCP revealed a biliary duct stricture, chronic pancreatitis, and soft tissue swelling representing retroperitoneal fibrosis. ERCP with biliary stent placement and biopsies were performed, revealing lymphoplasmacytic infiltration and diffuse fibrosis. Renal biopsy revealed diffuse interstitial inflammatory IgG4 lymphoplasmacytic infiltration with interstitial nephritis. Total protein and globulin levels were elevated. SPEP/IFE revealed increased gamma globulins (2.1) with no monoclonality. Immunoglobulin G4 was elevated at 266.2 (4-86), IgG1 was elevated at 1185 (282-395), and low C4 levels.
Discussion
The patient was diagnosed with IgG4-RD and started on immunosuppression with solumedrol and rituximab, complement levels were used to track responsiveness to treatment. Repeat serologic tests after immunosuppression revealed normalization of IgG4, IgG1 and complement levels, with a CD19/20 count of zero, showing that his IgG4-RD was in remission. Early recognition and treatment of IgG4-RD is of upmost importance due to a fibrotic transition that is poorly responsive to treatment with resultant end organ damage.
Renal biopsy demonstrating IgG4 plasma cells.