Abstract: SA-PO648
The Clinical and Pathological Features of Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitides Concomitant with IgG4-Related Disease
Session Information
- Glomerular Diseases: ANCA, Anti-GBM, Kidney Biopsy
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Chen, Liangliang, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
- Ma, Yanhong, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
- Han, Fei, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
Background
Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV) and IgG4-related disease (IgG4-RD) have similarities in clinical features. The characteristics and the pathogenesis of the concomitant AAV and IgG4-RD disease have not been elucidated.
Methods
We included 92 AAV patients with renal biopsy results. Among them, 10 patients met both AAV and IgG4-RD criteria (concomitant group). The IgG subclasses of myeloperoxidase (MPO)-ANCA in both serum and renal tissue were measured and complement activation components were detected in serum.
Results
Patients in concomitant group had both elevated serum IgG4 level and positive MPO-ANCA. They had higher levels of eosinophil counts, serum globulin, IgG, IgE and CRP than patients in AAV alone group. All 10 patients had glomerulonephritis with crescents and 7 patients also had segmental necrosis of glomerular capillary wall. Most of them also presented storiform fibrosis and lymphoplasmocytic infiltration in renal interstitium with IgG4 positive plasma cells more than 10/HPF. The percentages of glomerular global sclerosis and crescent were 36.6%±25.7% and 23.2%±15.4% respectively. Eight patients received combined therapy of glucocorticoids and cyclophosphamide, one patient received glucocorticoids only and another patient received glucocorticoids and rituximab. Eight patients achieved remission with improved renal function, the other two patients were on maintaining dialysis. The IgG4 subclass of MPO-ANCA was higher in concomitant group than that in AAV alone group. A merge of IgG4 and MPO immunofluorescence was observed in parts of glomerular mesangium of concomitant AAV and IgG4-RD patients. For complement components, Bb and mannose-binding lectin (MBL) were elevated in serum of concomitant AAV and IgG4-RD patients.
Conclusion
We showed a new overlap syndrome of AAV and IgG4-RD, in which the IgG4 subclass of ANCA may be a pathogenic factor, and alternative complement pathway and MBL pathway may be involved.