Abstract: FR-PO0946
Rare Case of Macrophage Activation Syndrome Causing Severe Tubulointerstitial Nephritis in Systemic Lupus Erythematosus
Session Information
- Glomerular Case Reports: Lupus, FSGS, Complement, and More
November 07, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Konda, Raghunandan, University of Alabama at Birmingham Health System, Birmingham, Alabama, United States
- Fatima, Huma, University of Alabama at Birmingham Health System, Birmingham, Alabama, United States
- Rizk, Dana V., University of Alabama at Birmingham Health System, Birmingham, Alabama, United States
- Rajasekaran, Arun, University of Alabama at Birmingham Health System, Birmingham, Alabama, United States
Introduction
Macrophage activating syndrome (MAS), a variant of hemophagocytic lymphohistocytosis (HLH), is characterized by an exaggerated inflammatory response with elevated cytokines due to hyperactivation of T lymphocytes and macrophages. MAS is associated with fever, pancytopenia, hepatosplenomegaly, transaminitis; elevated ferritin, triglycerides and soluble IL-2 receptor (sCD25) levels; coagulopathy, hypofibrinogenemia, and low ESR levels. Isolated Tubulointerstitial Nephritis (TIN) in the setting of MAS secondary to Systemic Lupus Erythematosus (SLE) has rarely been described.
Case Description
A 33-year-old female with SLE (joint involvement and cytopenia) on mycophenolate mofetil, prednisone, and hydroxychloroquine with a history of medication non-compliance presented with worsening microscopic hematuria, subnephrotic range proteinuria, but with preserved kidney function. Labs revealed SCr of 0.5 mg/dL, UPCR 600 mg/g, hypocomplementemia [C3 47 and C4 9], ANA titer 1:640, anti-ds-DNA 1:320, with negative ANCA serology. Kidney biopsy demonstrated minimal mesangial lupus nephritis and severe necrotizing TIN with 30% of tubulointerstitial involvement. Special staining and PCR were negative for infections including bacteria, fungi, mycobacteria, spirochetes, and adenovirus. No changes to underlying immunosuppression (IS) was made. After 4 weeks, she presented with severe pyrexia and massive hepatosplenomegaly. Labs showed pancytopenia, significant transaminitis, elevated triglycerides (544 mg/dL), significantly elevated MAS ferritin (>7000 mg/dL) and sCD25 levels (3087 pg/mL), and normal ESR. Thorough infectious workup was negative. Treatment for MAS with underlying SLE included anakinra and high-dose glucocorticoids. Despite this, MAS ferritin levels were extremely high. Subsequent treatment with cyclosporine, rituximab, and IVIG lead to resolution of AKI, proteinuria and normalization of MAS ferritin, serum complements and anti-ds-DNA levels.
Discussion
MAS should be considered when severe inflammation persists despite treatment of the underlying autoimmune condition and infections are ruled out. SLE accounts for 1-5% of MAS. Without aggressive IS, MAS carries a high mortality rate. Our case highlights the rarity of nectroizing TIN with minimal glomerular involvement in a patient with SLE, with improvement in inflammatory markers and kidney function with aggressive IS.