Discriminant analysis of clinical markers before renal biopsy in patients with IgA nephropathy

Discriminant analysis of clinical markers before renal biopsy in patients with IgA nephropathy is described. Sixty eight patients with IgA nephropathy (IgA nephropathy group) and 66 patients with other chronic glomerulonephritis (non-IgA nephropathy group) were examined. The discriminant analysis was applied to separate those two groups by using twenty clinical parameters as well as binding capacity of serum IgA to the glomeruli of renal specimens. Binding of serum IgA of patients to the glomeruli obtained from patients with IgA nephropathy was performed using avidin-biotin immunofluorescence. Among twenty clinical markers, the levels of serum IgA and creatinine, and degree of microhematuria in IgA nephropathy group were significantly higher than those in non-IgA nephropathy group Furthermore, the positive incidence of serum IgA binding of IgA nephropathy group was significantly higher than that of serum IgA binding of non-IgA nephropathy group. The correct classification rate were 79.10% using five clinical markers including serum IgA, microhematuria, serum C4, quantitation of proteinuria and degree of proteinuria. It is indicated that the levels of serum IgA and the binding of serum IgA to the glomeruli were considered to be major markers for clinical diagnosis of patients with IgA nephropathy It was concluded that the discriminant analysis before renal biopsy was useful for diagnosis of IgA nephropathy.     

原发性IgA肾病与非IgA系膜增生性肾小球肾炎的临床病理分析

目的 比较原发性IgA肾病与非IgA系膜增生性肾小球肾炎（non-IgA mesangial proliferative glomerulonephritis,non-IgA MsPGN）的临床及肾脏病理改变特点.方法 选择我科经肾活检确诊的原发性IgA肾病患者（A组）和non-IgA MsPGN患者（B组）进行临床与病理资料对比分析.结果 A、B组的性别、前驱上呼吸道感染诱因、起病时伴发高血压、镜下血尿、血肌酐无统计学差异（P＞0.05）.B组较A组起病年龄小,起病时伴发肉眼血尿比率低,肾病综合征发生率高,血IgG水平低,差异均有统计学意义（P＜0.05）.A组肾小球、肾小管间质、肾小动脉病理改变发生率高于B组（P＜0.05）,IgM、C3沉积、系膜区电子致密物沉积、大块状致密物、足细胞微绒毛化、肾小球基底膜分层发生率均较B组高（P＜0.01）.结论 IgA肾病与non-IgA MsPGN在临床表现、病理改变上存在明显差异,IgA肾病较non-IgA MsPGN病理损伤重.     

IgA肾病牛津病理分型适用性及其与临床关系的研究

目的探讨应用IgA肾病牛津分型法的临床适用性及其与临床指标的关系。方法收集191例原发性IgA肾病患者肾活检前血肌酐（SCr）,24h尿蛋白定量、平均动脉压（MAP）等临床资料;依据IgA肾病牛津分型定义对肾组织切片进行病理分型;对不同牛津分型间肾活检前SCr、MAP、尿蛋白定量进行比较;对随访时SCr〉129．9μmol／L的26例患者就临床有效性进行预后多因素Logistic回归分析。结果肾组织伴有S1、T1—2型的患者比S0、T0型者。肾活检前SCr水平高（P〈0．05）。24h尿蛋白定量在M、S、E分型间无统计学差异。MAP在伴有S1、T1—2型患者中高于S0、T0型患者（P〈0．05）;多因素Logistic回归分析显示伴有T1—2是导致疗效不佳的独立危险因素。结论牛津分型实际应用仍有局限性;IgA肾病患者伴有T1-2是导致疗效不佳的独立危险因素。     

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。     

Serum levels of soluble Fas and disease activity in patients with IgA nephropathy

Using a sandwich ELISA, we studied 48 patients with IgA nephropathy and 10 patients with diffuse mesangial proliferative glomerulonephritis without IgA deposition (non-IgA PGN) to determine if levels of serum soluble Fas (s-Fas) might reflect the disease activity. The levels of serum s-Fas in patients with the advanced stage of IgA nephropathy were significantly higher than those in patients with the mild stage of the disease, in non-IgA PGN or in healthy controls. The results showed that advanced stage IgA nephropathy patients who showed heavy proteinuria and the presence of urinary casts revealed high levels of serum s-Fas. It was thus suggested that the measurement of serum s-Fas is useful in evaluating the degree of renal injury in patients with IgA nephropathy.     

银屑病合并IgA或非IgA系膜增生性肾小球肾炎六例临床病理分析

目的分析银屑病合并肾损害的临床病理特点。方法回顾性分析北京协和医院1983年至2004年有肾活检结果的银屑病并肾损害患者6例，分析其临床及病理特点。结果男性2例，女性4例，平均年龄38岁。肾损害在银屑病发病后平均16年(7—30年)被发现。2例表现为无症状性镜下血尿和蛋白尿；3例表现为慢性肾炎综合征；1例为肾病综合征。6例均有中大量镜下血尿，其中2例有发作性肉眼血尿：蛋白尿平均为2．05g／24h(0．01—5．42g／24h)；血压4例正常，2例升高；Scr均正常。肾组织免疫荧光检查发现系膜区IgA沉积4例，系膜区IgG沉积1例，免疫荧光阴性1例。光镜表现均不严重，轻度系膜增生3例，中度系膜增生3例；均无新月体形成；慢性肾小管间质病变不明显；2例肾内动脉内膜增生、管腔狭窄。结论在银屑病合并肾损害中，系膜增生性。肾小球肾炎并不少见。可能与银屑病存在一定关系。     

IgA nephropathy: prognostic significance of proteinuria and histological alterations

A retrospective study of 166 patients with IgA nephropathy was undertaken to clarify possible correlations between clinical and histological features, and the severity and prognosis of the disease. At the time of biopsy, impaired renal function, with creatinine clearance (Ccr) below 90 ml/min was found in 61 cases. At the final examination, after a mean follow-up period of 34 months, 82 patients had impaired renal function, 12 of these patients went into terminal renal failure requiring hemodialysis treatment. The presence of proteinuria of more than 1.0 g/day was closely correlated with impairment of renal function both at the time of biopsy and at the final observation. An unfavorable outcome was also anticipated in the presence of hypertension. In contrast, microhematuria, macrohematuria or high serum IgA levels did not appear to be related to the outcome. Histologically, sclerotic lesions such as mesangial or global sclerosis, interstitial fibrosis and tubular atrophy, and some active changes such as mesangial hypercellularity and tuft adhesion were more frequent and severe in patients with impaired renal function. Impressive localization of IgA and C3 in the mesangium as well as in capillary loops was observed more often in these patients. These results clearly indicate that IgA nephropathy may follow a slowly progressive course in about half of the patients, and that marked proteinuria and severe histological changes appear to correlate closely with an unfavorable course.     

IgA nephropathy in a young man with primary hyperparathyroidism

We report the first documented case of IgA nephropathy occurring after treatment of primary hyperparathyroidism. A 29-year-old man with a history of kidney stones and primary hyperparathyroidism underwent kidney biopsy for persistent proteinuria and microhematuria 18 months after resection of an ectopic parathyroid adenoma with subsequent normalization of serum calcium and parathyroid hormone levels. On ultrasound, renal intraparenchymal calcifications were noted. Renal biopsy revealed IgA nephropathy in addition to tubulointerstitial microcalcifications. The development of IgA nephropathy may have been influenced by hyperparathyroidism and/or its treatment. The case highlights the role of renal biopsy in patients with a history of kidney stones and abnormal urinary findings.     

贫血加重IgA肾病患者的临床和病理改变

目的 分析IgA肾病合并贫血患者的临床病理特征.方法 收集经肾活检确诊的IgA肾病患者临床资料409例,按照贫血与否分为非贫血组和贫血组,回顾性分析两组患者的临床和病理资料.结果 与非贫血组比较,贫血组患者的肾小球损伤和肾小管间质萎缩程度较重、24 h尿蛋白增多和eGFR降低.Spearman相关分析结果显示,血红蛋白、eGFR与肾脏病理损伤呈负相关(P＜0.05),血尿酸、24h尿蛋白与肾脏病理损伤呈正相关(P＜0.05).多因素Logistic回归分析发现贫血是肾小管间质萎缩的独立危险因素.结论 IgA肾病合并贫血患者的临床和病理损伤重于IgA肾病非贫血的患者,贫血参与IgA肾病的进展.     

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。     

The spectrum of acute renal failure in IgA nephropathy

Background: Acute renal failure rarely complicates the course of IgA nephropathy. In this study, we have tried to define the mode of presentation, the spectrum of morphology, and the prognostic factors for renal outcome. Methods: Twenty patients with biopsy-proven IgA nephropathy who developed acute renal failure were identified from 2000 to 2009 at a medical center in Taiwan. The patients' records were retrospectively reviewed with respect to clinical presentation, morphology of renal biopsy, and outcomes. Results: On histology, glomerular crescents were present in 11 patients (55%), acute tubular necrosis was identified in 11 patients (55%), acute interstitial nephritis was seen in 4 patients (20%), and extensive tubular red blood cell casts were present in 4 patients (20%). At the end of follow-up, 2 patients (10%) had died, 11 patients (55%) were in remission, and 7 patients (35%) developed end-stage renal disease. The prognostic factors for renal outcome were peak serum creatinine, dialysis support requirement, morphology (prominent glomerular/tubular injury), percentage of glomeruli affected by crescents, and interstitial infiltration (p = 0.04, <0.001, 0.013, 0.05, 0.02, respectively). Conclusions: Our findings suggested that there were four pathogenic mechanisms involved in IgA nephropathy with acute renal failure including (1) crescentic IgA nephropathy; (2) acute tubular necrosis associated with microhematuria and red blood cell casts occluding tubules; (3) acute tubular necrosis not related to microhematuria; and (4) acute interstitial nephritis, apparently induced by drugs. In general, patients with prominent tubular injury had a much higher remission rate than patients with prominent glomerular injury.     

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。     

Development and validation of a noninvasive diagnostic model for IgA nephropathy

Objective To explore the development and clinical application value of Nomogram model, a noninvasive early diagnosis model, in IgA nephropathy. Methods The clinical data of 712 patients with primary glomerular disease diagnosed by renal histopathological examination in Affiliated Hospital of Qingdao University during October 1, 2010 to August 31, 2019 were collected retrospectively, including 241 cases of IgA nephropathy and 471 cases of non-IgA nephropathy. According to the time of case inclusion, the patients were divided into the training set (n=426, 156 cases of IgA nephropathy and 270 cases of non-IgA nephropathy) and the validation set (n=286, 85 cases of IgA nephropathy and 201 cases of non-IgA nephropathy). Univariate and multivariate logistic regression equations were used to analyze the risk factors for diagnosing IgA nephropathy in patients of training set. Nomogram model for noninvasive diagnosis of IgA nephropathy was established according to the akichi information criteria (AIC) and applied to the validation set for validation. The discriminant degree, calibration degree and clinical practicability of the model were verified and evaluated by receiver operating characteristic curve (ROC), calibration curve and decision curve analysis (DCA), respectively. Results Multivariate logistic regression results showed that the age (OR=0.966, 95%CI 0.947-0.985, P=0.001), IgA/C3 ratio (OR=1.889, 95%CI 1.468-2.432, P＜0.001), serum albumin (OR=1.091, 95%CI 1.047-1.136, P＜0.001), total cholesterol (OR=0.810, 95%CI 0.694-0.946, P=0.008), and gross hematuria (OR=6.858, 95%CI 1.867-25.189, P=0.004) of patients with primary glomerular disease were independent factors for the diagnosis of IgA nephropathy. Nomogram diagnostic model was constructed based on the above indicators, and the areas under ROC curve were 0.880 and 0.887 respectively in the training set and the validation set. The calibration curve showed that the predicted probability of the model was in good agreement with the actual probability. DCA showed that the safety and clinical net benefit of the model were higher. Conclusions The Nomogram model has high accuracy and clinical practicality in diagnosing IgA nephropathy, and can be used for noninvasive and early diagnosis of IgA nephropathy to enable patients to receive early treatment.     

Clinical and pathological features of IgA nephropathy with macrohematuria in history

Objective To investigate the clinical and pathological characteristics of IgA nephropathy (IgAN) with macrohematuria (MH). Method 1512 consecutive patients with biopsy-proven IgAN diagnosed from January 2006 to December 2011 were enrolled, and divided into MH group and control group respectively, according to whether there existed episodes of MH before renal biopsy. The clinical and pathological characteristics were compared between two groups. Patients in MH group were then divided into three groups according to the interval from the last episode of MH to renal biopsy to clarify the concomitant clinicopathological changes associated with occurrence of MH. Results The rate of MH in history was 22.1%. MH group patients had significantly lower serum creatinine, slighter proteinuria, lower prevalence of hypertension and heavier microhematuria than control group (all P＜0.001). The prebiopsy durations were similar in two groups (P=0.627). In MH group, chronic pathological indicators, including global/segmental sclerosis, tubule atrophy/interstitial fibrosis were all slighter (all P＜0.001), whereas activity indicators, including necrosis lesions, crescents and mesangial proliferation were all more severe compared with control group (all P＜0.05). Those who underwent renal biopsy within 30 days of the last episode of MH had more severe proteinuria and microhematuria, higher prevalence of necrosis lesions, more severe crescents formation, and endothelial proliferation (all P＜0.05). Conclusions IgAN patients with MH in history have relatively milder clinical and chronic pathological manifestations, however more active pathological changes especially in those who suffer episode of MH recently.     

Analysis of clinical and pathological features of HIV associated renal disease

Objective To describe the presentation, pathology, and outcome of biopsy proved renal disease in HIV infected patients. Methods This retrospective study included all HIV infected patients who underwent renal biopsy during the course of their clinical care at PUMC hospital from 2002 to 2012. The pathology and clinical information were abstracted from each patient’s clinical record. Results Eight HIV infected patients had biopsy confirmed renal disease. The commonest presentation was proteinuria in eight patients, and microscopic hematuria in six patients. Two patients had serum creatinine levels abnormal. Renal pathologies included IgA nephropathy in four patients, and lupus-like nephropathy, non-specific focal segmental glomerulosclerosis, membranous nephropathy and Henoch-Schonlein purpura nephritis in one patient each. All 8 patients received highly active antiretroviral treatment (HAART). Urinary protein was decreased significantly in one of them. Another was relieved with ACEI/ARB in addition to HAART. Corticosteroid was given to the other 6 patients. Among them, two got remission. one presented no reaction and was given cyclosporine. One, whose urinary protein didn't decrease with ACEI/ARB, received corticosteroid and needed further observation. One had continued aggravation of the renal disease. One case died of AIDS. One case companied with IgA nephropathy whose proteinuria recurrence was considered having association with tenofovir renal toxicity relieved after adjustment of HAART. Conclusions Classical HIVAN is uncommon in Chinese HIV infected population, a variety of other pathologies were seen in HIV infected patients, renal biopsy can help confirm the diagnosis. In HIV infected patients with evidence of nephropathy should be treated with HAART at diagnosis. Addition of prednisone should be considered if HAART alone does not result in improvement of renal disease.     

Serum IgA/C3 ratio may predict diagnosis and prognostic grading in patients with IgA nephropathy

Recently, the authors reported that the ratio of serum IgA to C3 (serum IgA/C3 ratio) is a good marker to distinguish patients with IgA nephropathy from non-IgA nephropathy patients together with serum IgA levels using an international reference preparation (IFCC/CRM470). In this study, the authors investigated whether the serum IgA/C3 ratio might be an indicator of prognostic grading in patients with IgA nephropathy. Two hundred and thirteen patients with IgA nephropathy and 96 other glomerular diseases including diffuse or focal mesangial proliferative glomerulonephritis without mesangial IgA deposition (non-IgA PGN), membranous nephropathy and thin basement membrane syndrome were examined. The levels of serum IgA and C3 in these patients were adjusted by the specified formula to those using international standard serum (IFCC/CRM470) in this study. The results of this study showed the highest levels of IgA/C3 ratio in patients with IgA nephropathy. The serum IgA/C3 ratio appears to gradually increase according to the prognostic grading of this disease. Therefore, measurement of the serum IgA/C3 ratio may be useful for prediction of diagnosis and prognostic grading in patients with IgA nephropathy.     

Apoptotic cells in six patients with IgA nephropathy in repeat biopsies

SUMMARY: Programmed cell death is a selective process of physiological cell deletion and is known as apoptosis. The purpose of the present study was to determine the relationship between the existence of apoptotic cells in glomeruli and the clinical or histopathological findings obtained in repeat renal biopsies of patients with IgA nephropathy. Repeat renal biopsy specimens were obtained from six patients with IgA nephropathy. The nick end labelling method (TUNEL) was used for the detection of apoptotic cells. Clinical laboratory data, i.e. urinary protein excretion, creatinine clearance (Ccr), blood urea nitrogen (BUN) and serum creatinine, (s‐Cr) were obtained from these patients. At the first renal biopsy, apoptotic cells in the glomeruli were observed in three out of six patients using TUNEL. These patients were classified as the severe glomerular damage group. The other three patients without apoptotic cells were in the mild glomerular damage group. Mean levels of urinary protein excretion at the first renal biopsy in the patients with apoptotic cells were slightly higher than those in patients without apoptotic cells. Levels of Ccr in patients with apoptotic cells were lower than those in patients without apoptotic cells. There were no significant differences in the levels of BUN and s‐Cr in patients with or without apoptotic cells. Two patients with apoptotic cells in glomeruli at the first renal biopsy did not show apoptotic cells at the second renal biopsy. These two patients showed improvement not only in clinical laboratory findings but also in histological findings at the second biopsy. Only one patient with apoptotic cells at the first and second biopsies exhibited deterioration at the second biopsy. All three patients without apoptotic cells at the first renal biopsy also showed deterioration of the clinical laboratory and histopathological findings. It is postulated that various factors other than apoptosis might induce progression of renal injuries in such patients. It appears that the clinical laboratory data, i.e. proteinuria, renal function and histopathological findings, might be influenced by apoptosis in patients with IgA nephropathy. It is postulated that apoptosis may induce reduction of excess proliferative glomerular mesangial cells and/or infiltrating cells and tissue repair.     

肾功能不全的IgA肾病患者临床表现与病理特点分析

目的分析肾脏活体组织检查（简称：肾活检）时肾功能异常的IgA肾病患者的临床表现与病理特点。方法选择我院经肾活检确诊的190例IgA肾病患者为研究对象,以其患者血肌酐（SCr）130μmol／L为界分为2组：肾功能正常组（SCr〈130μmol／L）128例和肾功能异常组（SCr≥130μmol／L）62例。同时对其肾脏病理进行半定量评分,比较2组患者的临床病理特点,并且通过回归分析与其肾功损害相关的因素。结果与肾功能正常组相比,肾功能异常组男性比例明显增高（72．6％1;L28．9％,P〈0．01）,年龄更大[（34±10）岁比（30±9）岁,P〈0．01],病程更短[（11±17）]个月比（20±41）个月],同时收缩压更高[（141±19）比（123±17）mmHg,P〈0．01],24h尿蛋白定量增多[（3．31±2．70）g比（2．25±2．19）g,P〈0．01]。同时其患者肾脏病理反映慢性病变的指数均明显增高。多因素分析还显示,与肾活检时肾功能异常密切相关的危险因素包括男性,年龄增大,收缩压增高,24h尿蛋白定量增多,以及肾小管萎缩和间质纤维化指数增高。结论肾活检时肾功能异常的IgA。肾病患者临床表现和肾脏病理改变均明显加重,肾小管萎缩和间质纤维化指数增高与IgA肾病患者肾活检时肾功能异常独立相关。     

Clinicopathological and prognostic analysis of children with primary IgA nephropathy with C1q deposition

Objective To investigate the clinical and pathological features and prognosis of children with IgA nephropathy with C1q deposition. Methods The children with IgA nephropathy diagnosed by renal biopsy from January 1, 2000 to December 30, 2017 were retrospectively analyzed and divided into C1q deposit group and C1q negative group according to glomerular immunofluorescence examination. Follow-up until the patient's serum creatinine doubled, glomerular filtration rate decreased by more than 50%, entering end-stage kidney disease, renal replacement therapy or death. Kaplan-Meier survival analysis was used to evaluate the renal survival rate in two groups. Univariate and multivariate Cox proportional hazard regression models were used to analyze the effect of C1q deposition on the prognosis of patients with IgA nephropathy. Results There were 60 cases in C1q deposition group and 60 cases in C1q negative group. (1) the initial eGFR and plasma albumin in C1q deposition group were lower than those in C1q negative group, while the levels of serum creatinine, serum cholesterol and 24 hour urinary protein in C1q group were higher than those in C1q negative group (all P＜0.05). (2) pathological indexes: Mesangial cell proliferation, tubular atrophy/interstitial fibrosis, and cell/fibrocytic crescein score in C1q negative group were significantly higher than those in C1q negative group (all P＜0.0.5). (3) Kaplan-Meier analysis showed that there was significant difference in renal cumulative survival rate between the two groups (Log-rank test: χ2=6.801, P=0.009). Cox proportional hazard regression model showed that the risk of renal end-point events in IgAN children with C1q deposition group was 5.772 times higher than that in C1q negative group (HR=5.772, 95%CI: 1.353-24.6211, P=0.018). Conclusion C1q deposition is an independent risk factor for the progress of renal function in IgA nephropathy children.     

No evidence for pathogenic role of IgE in Henoch-Schoenlein purpura nephritis

Background. The incidence of increased plasma IgE levels was reported to be significantly higher in Henoch-Schoenlein purpura nephritis (HSPN) than in IgA nephropathy (IgAN), and IgE deposits were demonstrated on epidermal Langerhans cells and dermal mast cells in four of six patients with HSPN in two European studies. We designed this study to investigate whether levels of clinical and biological markers of atopy in children with HSPN were significantly higher than those in children with IgAN, non-IgA glomerulonephritis (non-IgAGN), or microhematuria. Methods. The incidence of atopic disease, increased IgE levels, and positive radioallergosorbent test (RAST) results was investigated in 28 children with HSPN, 26 with IgAN, 28 with non-IgAGN, and 30 with microhematuria, all aged 8–16 years. All patients except for those in the microhematuria group, had proteinuria greater than100 mg/dl and had had a kidney biopsy. Results. The incidence of atopic disease, increased IgE levels, and positive RAST results in children with HSPN did not differ from findings in children with IgAN, non-IgAGN, or microhematuria. Conclusion. Our results in Japanese children do not support the idea (suggested by the two European studies) that IgE may play an important role in the pathogenesis of HSPN. Received: February 9, 1998 / Accepted: July 3, 1998