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During the congress, E-Posters will be accessible to all participants on the congress website 24/7, as well as in the E-poster stations in the congress center.
Preparing your E-Poster
Please review the E-Poster format requirements carefully when preparing your E-Poster. Should your E-Poster not meet the mentioned requirements, it may not be displayed as described above.
E-Poster Submission Deadline
Please prepare and upload your E-Poster no later than March 14, 2026 11.59PM CET. After this date, you will no longer be able to prepare and upload your E-poster and it will not be displayed and accessible on the congress website.
Please follow the instructions below to input your abstract title.
Abstract titles should be brief and reflect the content of the abstract.
IgA vasculitis nephritis (IgAV-N) can present in severe forms that may rapidly progress to end-stage renal disease, as well as in refractory cases that are resistant to aggressive treatments such as methylprednisolone pulse therapy (MPT). This study aimed to investigate the clinical and pathological characteristics of refractory cases unresponsive to MPT or cyclosporine (CsA), and to explore treatment strategies based on pathological findings and their underlying mechanisms.
We retrospectively analyzed 25 pediatric cases diagnosed with IgAV-N (ISKDC histological grade III or higher) via renal biopsy at our institution and affiliated centers. The cases were divided into two groups: a refractory group (n=5), in which remission was achieved only after the introduction of cyclophosphamide (CYP) following failure of MPT and CsA; and a non-refractory group (n=20), in which remission was achieved without CYP. Clinical and histopathological features were compared between the two groups.
There were no significant differences between the groups in age at disease onset, age at biopsy, renal function at biopsy, or degree of proteinuria or hematuria. However, the time from IgAV-N onset to renal biopsy was significantly shorter in the refractory group. No significant differences were observed in the percentage of glomeruli showing mesangial cell proliferation, cellular/fibro-cellular crescents, or segmental/global sclerosis. However, glomeruli with endocapillary hypercellularity accompanied by narrowing of the glomerular capillary lumina were significantly more frequent in the refractory group (77.3% vs. 36.7%, p<0.01). Immunofluorescence staining of biopsy from refractory group revealed proliferating leukocytes (PCNA⁺CD45⁺ cells) within the glomeruli, many of which were CD68⁺ macrophages.
Although the ISKDC classification is based on the extent of crescent formation, our findings suggest that endocapillary hypercellularity may be associated with treatment resistance. Furthermore, severe cases demonstrated the presence of proliferating inflammatory cells—primarily macrophages—within the glomeruli, indicating that these cells may be potential therapeutic targets for alkylating agents such as CYP.
