PMC10364118_01
Renal biopsy findings. (A,B) Light microscopy (PAS and Masson's stain, x200 magnification) shows the cellular crescent formation and diffuse inflammatory cell infiltration. (C,D) Immunofluorescence staining shows diffuse, granular deposits of IgG (C) and C3 (D) along the mesangial region and glomerular capillary walls. (E,F) Electron microscopy reveals electron-dense deposits in the segmental subendothelial region (arrows) and glomerular basement membrane (GBM) (triangles).
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F1
Light microscopy revealed that among the 22 glomeruli, eight had cellular crescent formation and one had segmental sclerosis (Figures 1A,B). Immunofluorescence staining revealed diffuse granular deposits of IgG and C3 (IgG +, C3 +++) along the mesangial region and glomerular capillary walls (Figures 1C,D). Electron microscopy revealed electron-dense deposits in the mesangium and glomerular basement membrane (GBM) and intermittently in the sub-endothelial region (Figures 1E,F).
The clinical course of the patient. After hemodialysis and two pulses of methylprednisolone (500 mg/day), followed by 40 mg oral prednisone per day, serum C3 and SCr levels returned to normal, while MPO-ANCA was still positive. Subsequently, the patient developed systemic rashes; prednisone was increased to 40 mg/day, and mycophenolate was prescribed. Two years later, the girl presented with orbital and paranasal sinus abnormalities, the MPO-ANCA level was highly elevated, treatment with one dose of rituximab was unsuccessful, and another pulse of methylprednisolone combined with monthly IVCY brought the disease under control. MP, methylprednisolone pulse; PSL, prednisolone; IVCY, intravenous cyclophosphamide; U-P, urine protein.
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F2
Considering that the laboratory indicators returned to normal, other immunosuppressive agents were not added temporarily, and oral prednisone was tapered (Figure 2). The rash gradually resolved (Figure 2).
Clinical characteristics of the patient. (A,B) Systemic red rash. (C,D) Cartilage involvement, showing saddle nose deformity.
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F3
Approximately five months later, the patient developed recurrent systemic red rashes (Figures 3A,B). The bridge of the nose was low and flat, resembling a saddle nose (Figures 3C,D).