258例儿童原发性IgA肾病临床与病理分析

目的分析258例儿童原发性IgA肾病的临床和病理特点。方法收集自2008年12月至2017年12月于成都市妇女儿童中心医院儿童肾脏内科肾活检诊断为IgA肾病患儿258例。所有肾活检样本均行光镜、免疫荧光和电镜检查。比较IgA肾病不同病理分级和临床特点的相关性。结果 258例IgA肾病患儿平均年龄为(9.3±3.2)岁,男女比为2.23∶1。临床表现为孤立性血尿型84例,肾脏病理Lee氏分级以Ⅱ级为主(51.1%);孤立性蛋白尿型45例,Lee氏分级以Ⅱ级为主(40.0%);血尿和蛋白尿型72例,Lee氏分级以Ⅲ级为主(56.9%);急性肾炎型4例,其中Lee氏分级为Ⅲ级者2例,Ⅱ、Ⅳ级各1例;肾病综合征型50例,Lee氏分级以Ⅲ级为主(80.0%);慢性肾炎型3例,其中Lee氏分级为Ⅳ级者2例,Ⅴ级1例。不同临床型IgA肾病患儿的免疫球蛋白主要沉积形式为IgA、IgM、C3共沉积;随着病理分级的加重,IgA、IgM、C3共沉积所占比率显著增多(P0.05)。结论 IgA肾病临床分型与病理分级有一定相关性,急性肾炎型、肾病综合征型及慢性肾炎型患儿病理损伤程度重,通过临床分型间接判断IgA肾病进展情况,对于指导临床治疗及判断疾病预后有一定临床价值。     

强直性脊柱炎相关IgA肾病临床病理分析

目的了解强直性脊柱炎（AS）相关IgA肾病的临床病理特点。方法自1997年1月至2006年12月10年间在北京协和医院接受肾活检确诊为IgA肾病的AS患者10例，回顾性分析其临床及病理特点。结果男性9例，女性l例，平均年龄（28．6＋6．8）岁（16～53岁）。4例患者表现为无症状镜下血尿；6例表现反复血尿合并蛋白尿，其中2例有发作性肉眼血尿。平均尿蛋白量（24h）为（1．56±1．53）g（0．02-5．26g）。2例患者有血压升高。所有患者的血肌酐水平均在正常范围。光镜下，8例患者呈轻度系膜细胞增生，IgA肾病Lee氏分级均为Ⅰ或Ⅱ级；另外2例呈中重度系膜增生性改变，IgA肾病Lee氏分级分别为Ⅲ级和Ⅵ级。结论AS相关IgA肾病临床表现为隐匿性肾炎或慢性肾小球肾炎，病理改变以轻度系膜增生为主。     

成人轻微尿检异常IgA肾病患者的临床与病理分析

目的临床怀疑为IgA肾病的轻微尿检异常患者是否需要肾活检一直有争议,本研究通过分析轻微尿检异常的IgA肾病患者临床表现与病理表现之间是否存在相关性,旨在进一步探讨肾活检对单纯轻微尿检异常IgA肾病患者的临床意义。方法临床表现为单纯轻微尿检异常且肾活检明确诊断的患者91例中,筛选达到明确病理诊断标准的患者77例,其中病理确诊为IgA肾病的患者53例,依其临床表现不同分为蛋白尿合并血尿组、单纯血尿组和单纯蛋白尿组,并采用Lee分级和牛津分类两种IgA肾病病理评估方法对其肾脏病理严重程度进行评价,且分别评价三种不同临床表现IgA肾病患者之间肾脏病理严重程度评分分布有无不同。结果 77例明确病理诊断标准的患者中,被诊断为IgA肾病患者53例(占68.8%),其中蛋白尿并血尿者39例(占73.6%),单纯血尿者5例(占9.4%),单纯蛋白尿者9例(占17.0%);53例轻微尿检异常IgA肾病患者中,病理分级以LeeⅢ级为最多(29例,占54.7%),其他依次为Ⅱ级(14例,占26.4%)和Ⅰ级(5例,占9.4%),而病变严重的Ⅳ级和V级,分别为2例(占3.8%)和3例(占5.7%);不同临床表现IgA肾病患者之间肾脏病理无论Lee分级还是牛津分布均无统计学差异(均P0.05)。结论鉴于临床表现不能作为鉴别肾脏病变轻重的依据,因此,怀疑IgA肾病的单纯尿检异常患者,应在无禁忌症的前提下尽可能行肾活检以明确诊断,以利于及时调整治疗方案。     

儿童IgA肾病病理与临床分型及血尿酸的关系

目的:探讨原发性IgA肾病(IgA nephropathy,IgAN)患儿肾脏病理分级与临床分型及血尿酸水平的关系。方法:对2006年1月～2011年12月经肾活检确诊的84例原发性IgAN患儿的临床和病理资料进行回顾性分析。结果:临床分型为无症状性血尿和(或)蛋白尿者,病理改变最轻;单纯性肾病综合征、急性肾炎综合征和慢性肾炎综合征者,病理改变逐渐加重;肾炎性肾病综合征者,病理改变最重。高尿酸组肾脏病理改变以Ⅲ级为主,正常尿酸组以Ⅱ级为主,高尿酸组Ⅳ级、Ⅴ级病变较正常尿酸组多见,正常尿酸组Ⅰ级病变较高尿酸组多见。结论:病理分级与临床分型和血尿酸水平相关联,通过IgAN患儿的临床分型和血尿酸水平有助于了解其肾脏病理损伤的程度。     

儿童隐匿性肾炎的临床和病理研究

目的：探讨儿童隐匿性肾炎的临床和肾组织病理改变特点及其关系。方法：回顾性分析肾活检的323例隐匿性肾炎患儿的临床和肾组织病理改变情况。结果：323例隐匿性肾炎患儿中，单纯性血尿229例，单纯性蛋白尿19例，血尿伴蛋白尿75例。肾组织病理改变类型包括：轻微病变103例（31，89％）、基本正常74例（22．91％）、IgA肾病（IgAN）73例（22．60％）、薄基底膜病（TBMN）27例（8．36％）、系膜增生性肾炎（MsPGN）18例（5．57％）、局灶增生性肾炎（FPGN）10例（3．10％）、膜性肾病（MN）8例（2，48％）、局灶节段肾小球硬化（舢）8例（2．48％）、微小病变（MCD）1例（0，31％）、IgM肾病（IgMN）1例（0．31％）。单纯性血尿组中肾组织结构基本正常的比例较血尿伴蛋白尿组明显偏高（P〈0，01）；血尿伴蛋白尿组中IgAN的比例高于单纯性血尿组和单纯性蛋白尿组（分别P〈0．01、P〈0．05）。IgAN的Lee分级：单纯性血尿组中Ⅰ、Ⅱ级85．00％，Ⅲ级及以上15．00％；血尿伴蛋白尿组中Ⅰ、Ⅱ级58．10％，Ⅲ级及以上41．90％，明显高于单纯性血尿组（x^2=6．47，P〈0．05）。结论：儿童隐匿性肾炎的病理以轻微病变、基本正常、IgAN为常见表现，血尿伴蛋白尿患儿病变较单纯性血尿患儿为重。     

成人与儿童紫癜性肾炎的临床病理特点及预后分析

目的：探讨成人与儿童紫癜性肾炎的临床病理特点及疾病转归的差异。方法：收集温州医学院附属第一医院肾内科住院确诊为紫癜性肾炎（HSPN）的成人患者（≥18岁）36例,38例紫癜性肾炎患儿为温州医学院附属儿童医院住院病人,分析比较二者的临床病埋改变及疾病的转归。结果：（1）所有患者均有血尿。成人紫癜性肾炎临床分型为单纯性血尿2例．血尿＋蛋白尿23例,肾病综合征11例;儿童患者单纯性血尿6例,血尿＋蛋白尿22例,肾病综合征10例;两组比较无统计学差异（P〉0．05）。成人紫癜性肾炎合并高血压14例,合并肾功能损害9例;而所有儿童患者均无高血压或肾功能损害。（2）成人紫癜性肾炎病理分级：Ⅰ级3例、Ⅱ级2例、Ⅲ级28例、Ⅴ级2例、Ⅵ级1例,而儿童患者Ⅱ级31例、Ⅲ级7例,两组比较具有统计学差异（P〈0．001）。（3）27例成人紫癜性肾炎患者随访结果A组10例、B组14例、C组3例,30例儿童紫癜性肾炎的随访结果A组15例、B组13例、C组2例,两组预后无统计学差异（P〉0．05）。结论：成人与儿童紫癜性肾炎临床分型以血尿＋蛋白尿最多见,与儿童患者相比,成人临床表现偏重,合并高血压及肾功能损害较多见。成人紫癜性肾炎病理分级以Ⅲ级多见,而儿童病理分级以Ⅱ级多见,提示成人紫癜性肾炎病理较儿童严重。在本研究观察期内,我们发现成人与儿童紫癜性肾炎的预后均较好,二者预后无统计学差异。     

123例原发性IgA肾病患者临床特点与病理分析

目的：探讨原发性IgA肾病患者临床表现、病理特点及其相关性。方法：回顾性总结分析123例经肾活检病理确诊为原发性IgA肾病的临床和病理资料。结果：123例IgA肾病患者在21岁～40岁年龄段发病率最高（占65.8%）;临床表现以发作性肉眼血尿最多见（占36.6%）;病理类型分级以Ⅱ级（56.1%）,Ⅲ级（20.3%）为主;病理类型与临床表现呈正相关（P〈0.01）;随着Lee氏病理分级程度的增高,血肌酐、血尿酸、血脂有不同程度的升高（P〈0.05）。结论：IgA肾病临床类型多样,其组织形态学改变轻重不一,宜尽早做肾活检以明确诊断,指导治疗。     

34例儿童肾病综合征型紫癜性肾炎肾脏病理与临床分析

目的：探讨儿童肾病综合征型紫癜性肾炎肾脏病理及临床之间的关系。方法：对1997年～2010年我科34例临床以肾病综合征表现及肾活检病理诊断为紫癜性肾炎的患儿进行回顾性分析,肾小球病理分级根据ISKDC分类标准,肾小管间质病理分级参照Bohle方法。结果：（1）肾脏病理分级如下：Ⅰ级2例（5.88%）,Ⅱ级8例（23.53%）,Ⅲ级17例（50.00%）,Ⅳ级6例（17.65%）,Ⅴ级1例（2.94%）,其中Ⅲ级最常见;肉眼血尿组Ⅳ级和Ⅴ级比例较镜下血尿组高,差异有统计学意义（P〈0.05）。（2）肾小管间质病理分级：（-）级12例（35.30%）,（＋）级15例（44.12%）,（＋＋）级5例（14.71%）,（＋＋＋）级0例,（＋＋＋＋）级2例（5.88%）。（3）肾小管间质病变程度与病程呈正相关（r=0.643,P〈0.01）,与血肌酐呈正相关（r=0.577,P〈0.01）。结论：儿童肾病综合征型紫癜性肾炎肾小球病理损害较重,但肾小管间质损害轻,有肉眼血尿表现的临床及病理均较镜下血尿的重,需结合临床表现及肾脏病理进行综合评估,拟定治疗方案。     

IgA肾病肾病综合征的不同病理改变及预后

目的 探讨IgA肾病肾病综合征（NS）的不同病理改变特点与临床和预后的关系。方法 回顾性分析87例表现为NS的IgA肾病患者的临床，病理资料及治疗预后情况。结果 IgA肾病伴发NS的比例为10．01％,在14岁以下及50岁以上的患者中占有较高比例。与非NS表现的IgA肾病患者比较，病理分级（Lee分级）I级，Ⅳ级，Ⅴ级，的比例增加，Ⅱ级，Ⅲ级的比例减少，其中Ⅱ级以下患者较Ⅲ级以上患者年龄小，血压，血肌酐水平低，补体C3的沉积少见，治疗后缓解的多；与同时期表现为NS而病理诊断为微小病变（MCD）的患者比较，二者在临床指标及治疗效果上均无差异。Ⅲ级以上的IgA肾病患者，NS组较非NS组血肌酐水平明显增高，IgA，IgM的沉积多见，球囊粘体 ，新月体，间质炎细胞浸润，间质纤维化，肾小管萎缩水平明显加重。结论 同样表现为NS，病理改变程度不同，其临床指标，免疫荧光沉积形式及对治疗的反应也不一致。可能存在不同的致病机制，临档上应区别对待。     

表现为大量蛋白尿的儿童原发性IgA肾病临床病理及预后分析

目的探讨表现为大量蛋白尿的儿童原发性IgA肾病(IgA nephropathy, IgAN)的临床病理特点及预后。方法该研究为回顾性队列研究, 回顾性分析2008年1月至2021年12月首都儿科研究所附属儿童医院肾脏内科收治的表现为大量蛋白尿的原发性IgAN患儿的临床资料, 根据初始治疗6个月后尿蛋白是否转阴分为有效组和无效组。随访终点事件定义为蛋白尿减少小于50%或达到终末期肾病(end-stage renal disease, ESRD)。采用MedCalc软件进行Kaplan-Meier生存分析, 并用Log-rank检验比较两组肾脏累积生存率的差异。结果研究期间在该院肾脏内科住院的经肾活检确诊为原发性IgAN的患儿共127例, 其中57例表现为大量蛋白尿, 被纳入本研究, 占总IgAN患儿的44.9%。57例患儿中, 病理分级Lee氏Ⅲ级33例(57.9%), Lee氏Ⅲ级以下11例(19.3%), Lee氏Ⅲ级以上13例(22.8%)。随访时间为4.0(3.0, 5.8)年。57例患儿中46例(80.7%)初始治疗有效(有效组), 11例(19.3%)初始治疗无效(无效组)。...     

A case report suggesting a common pathogenesis for IgA nephropathy and Henoch-Schönlein purpura

A 7-year-old boy who had been followed for asymptomatic haematuria and elevated serum IgA levels developed Henoch-Schönlein purpura (HSP) after a streptococcal infection of the tonsils. Findings on renal biopsy were compatible with mild IgA nephropathy (IgAN); tonsillectomy was also performed as he had chronic tonsillitis. This case suggests that there is a common pathogenesis for IgAN and HSP, at least in some patients.     

IgA肾病患者尿足细胞数及肾组织podocalyxin表达与临床病理的相关分析

目的 探讨尿足细胞数和肾组织中足细胞顶膜区的特异性标记蛋白podocalyxin（PCX）的表达与IgA肾病(IgAN)患者临床和病理改变的关系。 方法 收集50例IgAN患者活检前3 d的每天晨尿和20例体检健康对照者的晨尿各100 ml,离心去上清于TXD3细胞离心涂片机上制成涂片。用抗人PCX单克隆抗体分别对尿沉渣涂片和肾组织切片进行免疫组化染色,于光学显微镜下计数尿足细胞排泄数,以及用计算机图像分析系统测量和计算肾小球PCX平均吸光度值。IgAN按Lee分级分成5组,并用Katafuchi半定量积分法记分。比较各组尿足细胞数和肾组织PCX平均吸光度值,并与各项病理指标评分和临床生化指标进行相关性分析。 结果 IgAN组尿中足细胞数显著高于健康对照组（P < 0.01）。IgAN Lee分级各组组间尿足细胞中位数两两比较,Ⅰ-Ⅱ级组低于Ⅲ、Ⅳ、Ⅴ级组（P < 0.05）;Ⅲ级组显著低于Ⅴ级组（P < 0.05）;Ⅲ级组低于Ⅳ级组和Ⅳ级组低于Ⅴ级组,但差异无统计学意义。尿足细胞阳性率在Ⅳ、Ⅴ级组最高（100%）,在LeeⅠ-Ⅱ级组最低（55%）。IgAN患者随着Lee分级升高,肾小球足细胞PCX表达下调,两两比较结果显示,Ⅰ-Ⅱ级组显著高于Ⅲ、Ⅳ、Ⅴ级组（P < 0.05）;Ⅲ、Ⅳ级组显著高于Ⅴ级组（P < 0.05）;Ⅲ级组稍高于Ⅳ级组（P > 0.05）。IgAN患者尿足细胞排泄数与肾小球PCX表达量呈负相关（r = -0.702,P < 0.01);与24 h尿蛋白量呈正相关（r = 0.465,P < 0.01）;与肾小球和肾小管病理积分均呈正相关（r = 0.233,r = 0.307,均P < 0.05）。肾小球PCX表达量分别与肾小球和肾小管病理积分呈负相关（r = -0.560,r = -0.377,均P < 0.05）;与24 h尿蛋白量呈负相关（r = -0.367,P < 0.05）。 结论 IgAN患者尿足细胞排泄量可反映肾组织足细胞缺失程度,肾小球足细胞损伤脱落可能参与IgAN的发生发展,其尿足细胞数有可能作为反映疾病进展的重要指标。     

血清低半乳糖化IgA1测定对鉴别IgA肾病的临床价值

目的 确定血清低半乳糖化IgA1对鉴别诊断IgA肾病的临床价值。 方法 以原发性肾小球疾病患者91例为研究对象，接受肾活检并留取血清；以健康体检者20例血清作为对照。血清标本先用装有耦联蚕豆凝集素的微球进行微量离心柱法分离并洗脱，获得低半乳糖化IgA1。再以凝集素HAA（Helix aspersa）用ELISA法定量检测异常糖基化IgA1（HAA-IgA1）。分析血清低半乳糖IgA1升高在鉴别诊断IgA肾病方面的临床价值。 结果 48例IgA肾病患者HAA-IgA1水平[（83.7±41.0） U]高于健康对照组[（52.6±22.9） U]及43例其他原发性肾小球疾病患者组[（49.2±27.3） U]（均P < 0.01）。而该43例中，非IgA系膜增殖性肾炎患者22例（51%）的HAA-IgA1水平[（47.6±21.5） U]亦显著低于IgA肾病患者。以肾穿刺病理诊断为金标准，所绘制ROC曲线面积为0.797，面积的标准误为0.047（P < 0.01）；鉴别诊断IgA肾病的灵敏度为72.9%，特异度为72.1%，准确度为72.5%。 结论 应用微量离心柱法联合ELISA法检测IgA肾病患者血清低半乳糖IgA1对于鉴别诊断IgA肾病具有一定临床价值。     

胡桃夹综合征并发IgA肾病临床分析

目的 了解胡桃夹综合征并发IgA肾病的临床特点及提高其相应诊治水平。 方法 回顾分析14例胡桃夹综合征并发IgA肾病患者（病例组）及同期36例单纯胡桃夹综合征患者（对照组）的临床资料。所有胡桃夹综合征病例均由彩色多普勒超声和磁共振血管成像（MRA）诊断;IgA肾病均由病理证实。记录两组实验室、影像学资料并进行t检验分析。 结果 两组患者性别、年龄、血压差异无统计学意义。病例组Scr值高于对照组[（81.2±21.3） μmol/L比（61.2±11.8） μmol/L,P < 0.01],尿蛋白量较多[（1.1±0.6） g/d比（0.3±0.2） g/d,P < 0.01],血尿更明显（尿红细胞计分2.3±0.9比1.5±1.3,P < 0.05）。彩色多普勒超声显示两组左肾静脉狭窄处及近肾门处血流速度和内径差异无统计学意义;磁共振血管成像提示两组患者肠系膜上动脉与腹主动脉之间的夹角差异无统计学意义。 结论 对持续存在血尿和蛋白尿、异常红细胞比例较高的胡桃夹综合征患者应考虑存在并发慢性肾炎特别是IgA肾病的可能,应及早行肾活检明确诊断。     

Clinicopathological features of paediatric renal biopsies in Shanghai over a 31 year period

Aim: To identify the variations in paediatric renal biopsy pathology and clinicopathological features during the past 31 years. Methods: A retrospective analysis of paediatric renal biopsies performed at a single institution in Shanghai from January 1979 to December 2009 was conducted. Results: The major pathologies included minor glomerular abnormalities (MGA, 26.1%), IgA nephropathy (IgAN, 17%) and mesangial proliferative glomerulonephritis (MsPGN) without IgA deposition (11.3%). The major clinical presentations included nephrotic syndrome (NS, 39.4%), haematuria with proteinuria (24.4%) and persistent microscopic haematuria (15.1%). MGA accounted for 46.9% of the cases in NS. IgAN and HSN accounted for 24% and 28.9% of patients with concomitant haematuria and proteinuria, and thin basement membrane nephropathy accounted for 51.2% of cases with persistent microscopic haematuria. The frequency of IgAN (78.6%) was much higher than that of TBMN (29.0%) in patients with persistent microscopic haematuria with abnormal urinary albumin. Conclusion: Minor glomerular abnormalities and IgAN were the major renal diseases in our study population, and the focus of our paediatric nephrologists. The high proportion of TBMN suggested that there should be limited use of renal biopsy for patients with persistent microscopic haematuria and renal biopsy should be performed in the presence of proteinuria or abnormal levels of urinary albumin.     

The association of WISP-1 expression in IgA nephropathy patients with renal interstitial fibrosis

Objective To investigate the relationship between the expression of Wnt induced secreted protein-1 (WISP-1) and the fibrosis of renal biopsy tissue in IgA nephropathy (IgAN) patients. Methods Fifty-three patients firstly diagnosed as IgA nephropathy by renal biopsy were included and classified according to Oxford and Lee's classification. Sixteen patients with MCD entered the fibrosis negative control group, and fourteen healthy adults entered the normal control group. The expression of WISP-1 in renal tissues and serum of all subjects were detected by immunohistochemistry and ELISA respectively. Results Immunohistochemistry results showed that WISP-1 was not expressed in MCD patients and normal human kidney tissues, which was abundantly deposited in renal tissue of patients with focal proliferative IgAN with renal interstitial fibrosis. The serum level of WISP-1 in IgAN patients was significantly higher than that in normal subjects (P=0.015) and MCD patients (P=0.030). In the subgroup analysis of IgAN renal fibrosis, the serum concentration of WISP-1 of fibrosis grade between 0-10% (F1 group) and fibrosis＞25% (F3 group) were significantly higher than that in the normal group and the MCD group (all P＜0.05). There was no significant difference between F2 group (10%＜fibrosis≤25%) and normal group or MCD group (P＞0.05). Conclusions The expression of WISP-1 in serum and renal tissue of renal interstitial fibrosis IgAN patients is higher than that of normal and MCD patients without renal fibrosis, and the IgAN patients' serum level of WISP-1 is significantly increased in fibrosis lower score group. The expressions of WISP-1 in serum and renal tissue are related to the occurrence of IgAN renal interstitial fibrosis, in which WISP-1 may play an important role as an early precursor factor in the pathogenesis of IgAN renal interstitial fibrosis.     

尿激酶联合苯那普利治疗IgA肾病的随访对照研究

目的 观察联合应用尿激酶(UK)和血管紧张素转换酶抑制剂(ACEI)苯那普利治疗IgA肾病(IgAN)的效果。方法 将71例Lee分级≥Ⅲ级的IgAN患者随机分为两组:UK+ACEI组及ACEI组,随访观察两组的疗效。结果 (1)12个疗程后,UK+ACEI组24h尿蛋白定量明显下降(P<0.01),血白蛋白(AIb)水平升高(P<0.05),疗效优于ACEI组。(2)治疗前应用Katafuchi IgA肾病积分系统进行IgAN的病理评分,在肾小球积分≥7分的患者中,治疗至12个疗程时,UK+ACEI治疗效果优于ACEI组(P<0.05)。(3)UK+ACEI组中有10例患者进行了重复肾活检,经治疗后多数患者病理改变保持稳定。结论 UK联合ACEI治疗中重度IgAN安全有效,疗效优于单用ACEI者。肾小球硬化及间质炎细胞浸润的程度可作为估计UK治疗IgAN效果的指标。     

IgA nephropathy is not a rare disease in the United Kingdom

A retrospective analysis of all renal biopsies performed in the Grampian Region of Scotland during 1977-1980 revealed that IgA nephropathy was the most frequently encountered glomerular lesion. The commonest indications for renal biopsy were the presence of asymptomatic urinary abnormalities (90/184; 48.9%) especially asymptomatic haematuria (42/184; 22.8%). A histological diagnosis was made in 36 of the 42 patients presenting with asymptomatic haematuria (85.7%); 16 of the 26 cases of IgA nephropathy presented in this way. Overall, IgA nephropathy was detected in 14.1% of all biopsies and accounted for 21.8% of primary glomerular diseases. This study indicates that IgA nephropathy is apparently more common in Grampian than elsewhere in the United Kingdom. However, it is suggested that this does not represent a true variation in the prevalence of the condition; IgA nephropathy is probably a common cause of haematuria in the United Kingdom.     

A clinicopathological study of adult Japanese IgA nephropathy patients: Early stage cases and cases with exacerbation

Summary: Most cases of adult type IgA nephropathy (IgAN) have an insidious onset and asymptomatic course. However, some patients reveal recurrent macroscopic haematuria following episodes of respiratory or urinary tract infections. In order to clarify the correlation between clinical features and histological alterations or prognosis, 42 cases of early stage IgAN and 40 cases with acute exacerbation episodes were investigated and compared with a control group. Early stage cases were defined as having had a renal biopsy within 1 year after the first detection of urinary abnormalities, and had normal urinary findings within the 12 months before the first detection of urinary abnormalities. Acute exacerbation cases were defined as macroscopic haematuria or worsening of urinary abnormalities after acute infectious episodes and undergoing a renal biopsy within 120 days after the onset of these episodes. the early stage cases had better renal function and lower systolic and diastolic blood pressure than that of control group. They also showed milder changes in mesangial cell proliferation, mesangial matrix increase, totally sclerotic glomeruli, and tubulo-interstitial changes. However, it is important to note that glomerular and interstitial sclerotic changes were observed even in early stage cases. Endothelial detachment was noticed more frequently in the early stage cases. Acute exacerbation cases revealed lesions of endocapillary proliferation, mesangiolysis and endothelial detachment more frequently, although these changes were segmental in each glomerulus. There was no statistical difference in disease prognosis between cases with and without acute exacerbation. These data indicated that there are characteristic histological changes in early stage cases and acute exacerbation cases of IgAN.