Abstract：
We herein report a case of IgA nephropathy in a 20-year-old male who maintained a complete remission of minimal change nephrotic syndrome (MCNS) through the administration of rituximab (RTX). He was diagnosed with nephrotic syndrome at 4 years of age. After he relapsed frequently, he was diagnosed with MCNS at 8 years of age based on the findings of a kidney biopsy. At 13 years of age, RTX therapy was initiated to maintain a complete remission after steroid treatment. MCNS recurred twice, including the time in which the interval between the RTX administrations was long. Whenever he relapsed, remission induction was achieved using steroids, and remission maintenance was achieved using RTX. Five months after the 7th RTX administration, the serum IgA level started to increase. After the 9th RTX administration, he demonstrated microhematuria despite the urinary protein level indicating complete remission. At the 10th administration, the urinary protein and the red-blood cell casts were also observed. A renal biopsy was performed 84 months after the initial administration of RTX, and the patient was diagnosed with complications of IgA nephropathy. RTX is not considered to be a useful treatment for IgA nephropathy. The reasons for this are due to the fact that IgA1 does not decrease even following the administration of RTX, because B cells residing in the mucosa may not be deleted by RTX, and IgA production may also continue due to the presence of CD20- long-lived plasma cells. Even when administering RTX, if there are findings of glomerulonephritis on urine testing, the possibility of IgA nephropathy must be considered.
摘要：
我们在此报告了一名20岁男性的IgA肾病病例，该男性通过给予利妥昔单抗（RTX）维持了最小变化性肾病综合征（MCNS）的完全缓解。他在4岁时被诊断为肾病综合征。在他经常复发之后，他在8岁时根据肾脏活检结果被诊断为MCNS.13岁时,在类固醇治疗后开始RTX治疗以维持完全缓解。MCNS复发两次,包括RTX管理之间的间隔很长的时间。每当他复发时，使用类固醇实现缓解诱导，使用RTX实现缓解维持。第七届RTX政府五个月后，血清IgA水平开始升高.在第九届RTX管理之后，尽管尿蛋白水平表明完全缓解，但他仍表现出微血尿。在第十届政府，还观察到尿蛋白和红细胞管型。在初次施用RTX后84个月进行肾活检，诊断为IgA肾病并发症。RTX不被认为是IgA肾病的有用治疗方法。其原因是由于IgA1即使在施用RTX后也不会减少，因为存在于粘膜中的B细胞可能不会被RTX删除，由于CD20-长寿命浆细胞的存在，IgA的产生也可能继续。即使在管理RTX时，如果尿液检查发现肾小球肾炎，必须考虑IgA肾病的可能性。
