BACKGROUND IgA deficiency associated with glomerulonephritis is rare. In particular, there is no prior report regarding the association between IgA deficiency and membranoproliferative glomerulonephritis (MPGN) in children. Herein, we describe the case of a 5-year-old girl with selective IgA deficiency and MPGN. CASE PRESENTATION The patient presented with persisting urinary abnormality and hypocomplementemia following a group A treptococcal infection. Renal biopsy revealed the presence of diffuse mesangial hypercellularity, endocapillary proliferation, and focal thickening of the walls of the glomerular capillaries using light microscopy, with IgG and moderate C3 deposits observed using immunofluorescence. Electron microscopy images revealed nodular deposits in the subendothelial areas, with hump-shaped subepithelial deposits. The pathological diagnosis was confirmed as MPGN. Treatment using oral prednisolone (PSL), mizoribine (MZR), and angiotensin-converting enzyme inhibitors reduced the proteinuria. The PSL dose was gradually tapered, with the low dose of PSL and MZR continued for 4 years. Histological findings were improved on repeated renal biopsy, and PSL and MZR administration was discontinued. CONCLUSIONS We report a rare case of MPGN related to a streptococcal infection in a child. The clinical presentation included selective IgAD, with several pathological findings and a clinical course typical of glomerulopathy. The patient was successfully treated using multidrug therapy.

中文翻译：

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IgA缺乏症女孩链球菌感染相关的膜增生性肾小球肾炎：病例报告。

背景技术与肾小球肾炎相关的IgA缺乏症很少见。尤其是，目前尚无关于IgA缺乏与儿童膜增生性肾小球肾炎（MPGN）之间的关联的报道。在此，我们描述了一个5岁女孩患有选择性IgA缺乏症和MPGN的情况。病例介绍该患者在A组链球菌感染后表现出持续的尿异常和低补体血症。肾活检显示，使用光学显微镜检查发现肾小球毛细血管壁弥漫性系膜细胞增生，毛细血管内增生和局灶性增厚，免疫荧光观察到IgG和中度C3沉积。电子显微镜图像显示在内皮下区域有结节性沉积物，具有驼峰状的上皮下沉积物。病理诊断确认为MPGN。使用口服泼尼松龙（PSL），咪唑啉碱（MZR）和血管紧张素转换酶抑制剂的治疗可减少蛋白尿。PSL剂量逐渐减少，低剂量的PSL和MZR持续4年。重复进行肾脏活检可改善组织学发现，并停止PSL和MZR给药。结论我们报告了少儿与儿童链球菌感染有关的MPGN病例。临床表现包括选择性IgAD，具有若干病理学发现和典型的肾小球病临床病程。使用多药疗法成功治疗了该患者。PSL剂量逐渐减少，低剂量的PSL和MZR持续4年。重复进行肾脏活检可改善组织学发现，并停止PSL和MZR给药。结论我们报告了少儿与儿童链球菌感染有关的MPGN病例。临床表现包括选择性IgAD，具有若干病理学发现和典型的肾小球病临床病程。使用多药疗法成功治疗了该患者。PSL剂量逐渐减少，低剂量的PSL和MZR持续4年。重复进行肾脏活检可改善组织学发现，并停止PSL和MZR给药。结论我们报告了少儿与儿童链球菌感染有关的MPGN病例。临床表现包括选择性IgAD，具有若干病理学发现和典型的肾小球病临床病程。使用多药疗法成功治疗了该患者。具有一些病理发现和典型的肾小球病变的临床过程。使用多药疗法成功治疗了该患者。具有一些病理发现和典型的肾小球病变的临床过程。使用多药疗法成功治疗了该患者。