Abstract: PUB269
Clinicopathological Features of Unclassified Immune Complex Glomerulonephritis: A Single-Center Retrospective Study
Session Information
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Tu, Yi-Ran, Linkou Chang Gung Memorial Hospital, Taoyuan, Taoyuan City, Taiwan
- Ma, Li-Yi, Linkou Chang Gung Memorial Hospital, Taoyuan, Taoyuan City, Taiwan
- Chen, Tai-Di, Linkou Chang Gung Memorial Hospital, Taoyuan, Taoyuan City, Taiwan
- Hsueh, Chih Fang, Chang Gung University, Taoyuan, Taoyuan City, Taiwan
- Wu, Tsai-yi, Chang Gung University, Taoyuan, Taoyuan City, Taiwan
- Ku, Cheng-Lung, Chang Gung University, Taoyuan, Taoyuan City, Taiwan
- Tu, Kun-Hua, Linkou Chang Gung Memorial Hospital, Taoyuan, Taoyuan City, Taiwan
Background
Immune complex glomerulonephritis (IC-GN) encompasses a broad range of disorders, many of which are well-defined by underlying etiologies such as lupus nephritis, infection-related GN, or monoclonal gammopathy-associated GN. However, a subset of patients presents with immune complex deposition without fulfilling the diagnostic criteria for any established glomerular disease entity. These unclassified cases remain poorly understood.
Methods
We retrospectively reviewed renal biopsy cases from 2016 to 2024 at a tertiary hospital in Taiwan. Among them, 28 patients were identified as having immune complex glomerulonephritis that did not fulfill the diagnostic criteria for any established glomerular disease entity. Clinical data, laboratory findings, pathological features, and outcomes were analyzed. Patients were further stratified by the presence or absence of a membranoproliferative glomerulonephritis (MPGN) pattern.
Results
Among the 28 cases, potential associations included autoimmune features (28.6%), paraproteinemia (35.7%), hematologic malignancy (14.3%), solid organ tumors (3.6%), and chronic infections (17.9%). Patients with MPGN had significantly higher systolic and diastolic blood pressure at presentation (p = 0.001 and p < 0.001, respectively). Although not statistically significant, the MPGN group tended to have higher proteinuria (mean 4.31 vs. 2.32 g/day), lower serum albumin, and worse renal function.
Overall, renal outcomes were poor across both groups: nearly 40% of patients progressed to dialysis-dependent kidney failure, with several requiring dialysis at the time of diagnosis or shortly thereafter. In addition, mortality during follow-up was notable, highlighting the severity and progressive nature of this condition.
Conclusion
A small but distinct group of patients with immune complex GN lacks an identifiable underlying etiology yet exhibits substantial renal injury and unsatisfactory clinical outcomes. Although these cases cannot be clearly classified into existing glomerular disease entities, many are associated with specific clinical contexts—such as autoimmune diseases, paraproteinemia, hematologic disorders, solid organ tumors, or chronic infections—which may offer diagnostic and therapeutic insights.