Spectrum of biopsy-proven kidney diseases in northwest China: a review of 30 years of experiences

Purpose

Large-scale, contemporary studies assessing the spectrum of kidney diseases in northwest China are lacking. Therefore, we aimed to assess the profile of 30-year temporal changes in biopsy-proven kidney diseases in northwest China.

Methods

This cross-sectional study included all patients with a native kidney biopsy specimen in the First Affiliated Hospital of Xi'an Jiaotong University between 1989 and 2018. Data on demographic characteristics and pathological diagnosis were extracted from medical records and pathological reports. Changing patterns of kidney diseases over the study period and disease distributions in different gender and age groups were examined.

Results

This study included 13,620 patients with a mean age of 38.5?±?16.5 years and included 58.2% of men. Primary glomerulonephritis (PGN), second glomerulonephritis (SGN), tubulointerstitial disease, and other renal diseases accounted for 79.1, 18.3, 2.4, and 0.2% of all kidney diseases, respectively. In PGN, IgA nephropathy (IgAN) (25.1%) was the most common type, followed by non-IgA mesangial proliferative glomerulonephritis (MsPGN) (24.9%) and membranous nephropathy (MN) (17.4%). The frequency of MN dramatically increased (p?<?0.001) over the course of the study. Lupus nephritis (6.2%) and Henoch-Schönlein purpura nephritis (HSPN) (4.9%) were leading SGN diagnosis. The frequencies of IgAN, non-IgA MsPGN, and HSPN declined, while those of ANCA/pauci-immune glomerulonephritis and diabetic nephropathy significantly increased.

Conclusion

PGN continues to be the predominant kidney disease in northwest China, and IgAN is the most common type. The frequencies of MN and diabetic nephropathy significantly increased. These findings might be explained by behavioral and environmental exposures and provide implications on future hypothesis-driven research.

     

The spectrum of children's kidney diseases—9925 renal biopsy-proven cases from a single center of China between 2004 and 2017

Objective To analyze the spectrum of children's kidney pathology by renal biopsy. Methods The clinical and pathological data of the cases in Jinling Hospital involving the patients younger than 18 years old who received renal biopsy from April 1st, 2004 to December 31th, 2017 were retrospectively collected, and compared with the renal pathological data of 1611 children aged 0-18 years from June 1982 to March 2004. Results This study included 9925 cases of kidney diseases proven by renal biopsy. The ratio of male to female was 1.79∶1. Primary glomerulonephritis (PGN) accounted for 66.14%, and secondary glomerulonephritis (SGN) accounted for 28.00%. Top five of the PGN were IgA nephropathy (IgAN, 19.11%), mesangial proliferative glomerulonephritis (MsPGN, 16.07%), minimal change disease (MCD, 14.20%), focal segmental glomerulosclerosis (FSGS, 6.19%) and membranous nephropathy (MN, 4.70%) in whole children, IgAN (13.12%), MsPGN (11.20%), MCD(10.63%), FSGS (4.55%) and MN (2.54%) in males, and IgAN (5.99%), MsPGN (4.87%), MCD (3.57%), MN (2.16%) and FSGS (1.63%) in females. Top three of the SGN were Henoch-Schonlein purpura nephritis (HSPN, 17.74%), lupus nephritis (LN, 8.23%) and vasculitis nephropathy (1.82%). The male was in a dominant position in all kinds of pathologic types than female except LN. HSPN was the most frequent type in adolescents between 6-13 years old. LN was the commonest one in 14-18-year-old girls, while IgAN was the the most common in 14-18-year-old boys. Post infective nephritis was the most popular in 12-14-year-old teenagers. It was also found that MN ascended in female. When compared with the data before 2004, HSPN and LN accounted for a greater proportion in SGN, post infective nephritis displayed a smaller proportion. Conclusions PGN is the mainly kind of glomerular disease as before, and immune disorder related to glomerular diseases increase and post infective nephritis decreases in proportion. This study provides the reference and epidemic data for diagnosis, treatment and prevention of children's renal diseases.     

Patterns of renal disease in South Korea: a 20-year review of a single-center renal biopsy database

Background: Several registries and centers have reported the results of renal biopsies from different parts of the world. As there are few data regarding the epidemiology of glomerulonephritis (GN) in South Korea, we conducted this study on renal biopsy findings during the last 20 years from a single center.

Methods: Data for 818 patients who underwent renal biopsy at our center between 1992 and 2011 were collected retrospectively. All kidney specimens were examined with light microscopy (LM) and immunofluorescent microscopy (IF).

Results: There were 818 cases of native kidney biopsies. In cases of primary GN, the most frequent type of renal pathology in adults (18–59 years) was mesangial proliferative GN (MsPGN, 34.5%) followed by IgA nephropathy (IgAN, 33.3%) and membranous GN (MGN, 8.8%). Indications in adults (18–59 years) were asymptomatic urinary abnormalities (75.3%) followed by nephrotic syndrome (19.8%) and acute kidney injury (AKI, 3.4%).

Conclusions: Among 818 renal biopsy specimens, MsPGN and IgAN were the most frequent biopsy-proven renal diseases. MGN was the third most common cause of primary GN and lupus nephritis (LN) was the most common secondary glomerular disease. Our data contribute to the epidemiology of renal disease in South Korea.     

Characteristics of patients with coexisting IgA nephropathy and membranous nephropathy

Background: Coexistence of IgA nephropathy (IgAN) and membranous nephropathy (MN) in the same patient is rare. Few studies have reported the clinical and pathological features of patients with combined IgAN and MN (IgAN–MN).

Methods: The clinico-pathological features, levels of galactose-deficient IgA1 (Gd-IgA1) and autoantibodies against M-type transmembrane phospholipase A₂ receptor (anti-PLA₂R) in sera were compared among IgAN–MN, IgAN, and MN patients.

Results: Twenty-six patients with biopsy-proven IgAN–MN were enrolled. The mean age at biopsy was 43.6?±?15.9?years, and 65.4% were male. Proteinuria and estimated glomerular filtration rate (eGFR) levels in patients with IgAN–MN were similar to that of MN patients. Compared with the IgAN patients, IgAN–MN patients showed a higher median proteinuria level (4.3 vs. 1.2?g/day, p?2, p?p?=?.801). Percentage of IgAN–MN patients with detectable serum levels of anti-PLA₂R was lower than that of MN patients (38.5% vs. 68.6%, p?=?.011).

Conclusions: IgAN–MN patients display similar clinical features to MN patients and milder pathological lesions than IgAN patients. IgAN–MN patients have similar levels of Gd-IgA1 to those of IgAN patients, and a lower proportion of anti-PLA₂R than MN patients.     

豫琼两地原发性肾小球疾病病理类型的变迁对比及临床分析

目的 回顾性分析豫北地区及海南两地近12年原发性肾小球疾病疾病谱的构成演变特点及其意义.方法 分别收集2008年1月至2019年12月于新乡医学院第一附属医院及海南医学院第一附属医院经临床及肾活检诊断为原发性肾小球疾病3985例患者的临床及病理资料,并对其进行对比分析,根据年份分为2008年至2011年、2012年至2...     

四川地区肾活检2330例临床病理分析

目的：探讨四川地区肾穿刺活检病理类型的分布特点以及疾病谱的变迁。方法回顾性分析2330例肾活检患者的临床病理资料,分析本地区肾脏疾病的临床病理特征。结果2330例肾活检患者中,男女比例为1∶1.15,发病高峰年龄为20~40岁。2330例患者中,原发性肾小球疾病1896例（占81.37%）,常见的病理类型依次为 IgA 肾病820例（占35.19%）、系膜增生性肾小球肾炎372例（占15.97%）、膜性肾病298例（占12.79%）、微小病变肾病200例（占8.58%）和局灶节段性肾小球硬化症78例（占3.35%）;继发性肾小球疾病367例（占15.75%）,以狼疮性肾炎最常见（134例,占5.88%）,其次为紫癜性肾炎127例（占5.45%）、糖尿病肾脏疾病35例（占1.5%）和淀粉样变性肾病20例（占0.86%）;肾小管间质疾病50例（占2.15%）;遗传性肾病17例（占0.73%）。2330例肾脏疾病患者的临床表现依次为肾病综合征1015例（占43.56%）、慢性肾炎综合征681例（占29.22%）、急性肾炎综合征392例（占16.82%）、隐匿性肾小球肾炎121例（占5.29%）、慢性肾衰竭72例（占3.09%）、急性肾衰竭47例（占2.02%）。近年来,膜性肾病构成比呈逐渐增加趋势。结论本地区肾脏疾病多见于青壮年,以原发性肾小球疾病最常见,其中 IgA 肾病和系膜增生性肾小球肾炎是最多见的病理类型,膜性肾病的检出率有增高趋势。继发性肾小球疾病以狼疮肾炎和紫癜性肾炎最常见。     

The efficacy of tonsillectomy on clinical remission and relapse in patients with IgA nephropathy: a randomized controlled trial

Background The efficacy of tonsillectomy in immunoglobulin A nephropathy (IgAN) remains controversial. The aim of the study was to conduct a randomized controlled trial to evaluate the effect of tonsillectomy in patients with IgAN. Methods We randomly selected 98 patients with biopsy-proven IgA nephropathy and randomly allocated to receive tonsillectomy combined with drug therapy (Group A) or drug therapy alone (Group B). The participating patients were entered into a 4-year single-center study. Remission and relapse rate were calculated for hematuria and proteinuria using the Kaplan–Meier method. Results No differences were found between the two groups in their baseline clinical and histological characteristics. Patients with tonsillectomy exhibited considerable improvement in the following aspects compared to those patients who did not undergo tonsillectomy: time to reach first remission (3.1 vs. 24.9 months, p?p?p?p?p?=?0.0047) for hematuria and (23.5 vs. 10.5 months, p?=?0.0012) for proteinuria, as well as lower relapse rate for hematuria and proteinuria in Group A. Conclusion Our clinical data demonstrated that tonsillectomy could be beneficial for IgAN patients, particularly by contributing to faster and longer remission, as well as reducing the frequency of possible future relapses.     

儿童孤立性血尿的临床病理分析

目的 探讨儿童孤立性血尿的肾组织病理类型与临床特点。 方法 回顾性分析1995年至2008年间我科肾活检的251例孤立性血尿患儿肾组织病理和临床资料。 结果 肾组织病理类型：轻微病变（ML）93例（37.05%）,基本正常62例（24.70%）,IgA肾病（IgAN）52例（20.72%）,薄基底膜病（TBMN）17例（6.77%）,系膜增生性肾炎（MsPGN）16例（6.37%）,局灶节段肾小球硬化（FSGS）5例（1.99%）,局灶增生性肾炎（FPGN）5例（1.99%）,毛细血管内增生性肾炎（EnPGN）1例（0.40%）。镜下血尿组中IgAN比例低于肉眼血尿组（16.48%比31.88%,P < 0.05）;两组IgAN Hass分级Ⅰ、Ⅱ级（83.33%比95.45%,P > 0.05）,Ⅲ级（16.67%比4.55%, P > 0.05）差异均无统计学意义。35例（共检测102例）尿微量白蛋白升高患儿中,IgANⅢ级比例显著高于尿微量白蛋白正常者（14.28%比0%,P < 0.01）;FSGS和FPGN比例高于尿微量白蛋白正常者（20.00%比1.49%,P < 0.01）;轻微病变比例显著低于尿微量白蛋白正常者（28.57%比58.21%,P < 0.01）。 结论 儿童孤立性血尿肾脏病理以轻微病变、基本正常、IgAN为常见类型。镜下血尿组中IgAN比例较肉眼血尿组低。尿微量白蛋白升高组病理类型较正常组为重。     

呈局灶节段性肾小球硬化的IgA肾病临床病理特点

目的探讨呈局灶节段性肾小球硬化（FSGS）的IgA肾病（IgAN）的临床和病理特点。方法选取我院1988年1月至2002年2月经肾活检确诊为IgAN的患者587例，其中呈FSGS85例，呈弥漫性系膜增生性肾小球肾炎（MsPGN）162例，呈弥漫性系膜增生性肾小球肾炎伴局灶节段性肾小球硬化（MsPGN伴FSGS）185例，比较3种类型IgAN临床和病理资料。结果FSGS型IgAN占同期所有IgAN的14．5％，临床类型以大量蛋白尿型为主，占37．64％。肾小球球囊黏连发生率高达74．12％，小管间质纤维化发生率97．65％，病理分级以LeeⅣ～Ⅴ级为主，免疫病理以IgA—MG型为主，与MsPGN伴FSGS型和MsPGN型的IgAN相比，FSGS型IgAN病程较长，高血压、肾功能不全发生率较高（P〈0．05），而血尿的发生率与后两者无明显区别。结论呈FSGS型IgAN大量蛋白尿、高血压、肾功能不全的发生率高，病变较重，预后较差。     

68例伴有肾组织乙肝病毒抗原沉积的肾炎患者临床和病理分析

目的：探讨血清乙肝病毒（HBV）标志物与肾组织HBV抗原沉积、肾病理之间的关系，了解乙肝病毒相关性肾炎（HBV—GN）的临床和病理特点。方法：收集成人肾组织中检测到HBsAg和／或HBcAg沉积的肾炎患者68例（以下称沉积阳性组）。随机抽取同期肾穿合并有慢性乙型肝炎但肾组织中不伴HBsAg和／或HBcAg沉积的肾炎患者24例作为对照组（以下称沉积阴性组）。两组均采用间接免疫荧光法检测肾活检组织冰冻切片中HBsAg和HBcAg，荧光定量PCR法检测血清HBV—DNA水平。结果：（1）两组患者在血压、血尿和蛋白尿程度以及肾功能水平均无统计学差异；（2）沉积阳性组肾病理以IgA肾病（IgAN，占51．5％）和不典型膜性肾病（MN，占38．2％）为主；沉积阴性组则以系膜增生性肾炎（MsPGN，占50％）为主；（3）68例患者中13例血清HBV标志物阴性或仅有HBsAb阳性，血HBV—DNA病毒载量〈100拷贝／ml的患者肾组织中检测到HBsAg和俄HBcAg沉积，且免疫荧光显示免疫球蛋白和补体沉积均在3种以上，满堂亮者7例（53．8％）：光镜显示不典型MN9例（69．2％），IgAN3例，MPGN1例。结论：对于成年人依据临床难作出HBV—GN诊断。成人HBV—GN病理表现具有多样性，以IgAN和不典型MN为主，其次为MPGN和MsPGN，FSGS少见；肾组织HBV抗原沉积现象可以出现在血清HBV标志物阴性或仅HBsAb阳性的患者，提示应重视肾组织HBV抗原检测，尽可能降低HBV—GN的漏诊率，尤其是血清HBV标志物阴性的患者。     

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。     

IgA肾病520例临床病理分析

目的研究IgA肾病(IgAN)的临床和病理特点及其相互关系。方法对1992年11月～2003年6月温州医学院附属第一医院肾内科病理室肾活检诊断的原发性IgAN520例进行临床与病理分型关系的分析。结果520例IgAN临床表现以无症状性尿检异常最常见,占346例(66.5%),其次是慢性肾炎和肾病综合征,分别占77例(14.8%)和66例(12.7%)。病理类型以局灶节段硬化性肾小球肾炎最常见,占186例(35.8%),其次是系膜增生性肾小球肾炎、轻微病变肾小球肾炎和局灶节段增生性肾小球肾炎,分别为116例(22.3%)、104例(20%)和63例(12.1%)。结论IgAN的临床病理表现多样化并具有一定特点。临床表现最常见为无症状性尿检异常,在病理上最常见的是局灶性肾小球病变类型。     

Clinicopathological features and risk factors analysis of IgA nephropathy associated with acute kidney injury

Objective: The aim of this work is to investigate the distinctive clinicopathological characteristics of AKI in Chinese IgAN population and possible risk factors for AKI. Methods: We performed a retrospective analysis of 1512 patients with biopsy-proven primary IgAN in the period 2006 through 2011 in The First Affiliated Hospital of Sun Yat-sen University. AKI was defined as 2012 KDIGO (Kidney Diseases: Improving Global Outcomes) criteria, and the patients were divided into AKI group (n?=?145) and non-AKI group (n?=?1367). Results: The prevalence of AKI of the IgAN patients in our center was 9.59% (145/1512). Most AKI patients were older age, male, with higher percentage of smoke, hypertension, hyperlipidemia and preexisting impaired kidney function (Scr?>?133?μmol/L), and higher serum creatinine, proteinuria, uric acid, whilst less onset of macroscopic hematuria as well as lower serum albumin and hemoglobin (p?Conclusions: AKI is commonly seen among IgAN population. The clinicopathological features are much more severe in IgAN patients with AKI. Useful clinicopathological predictors are recognized to improve the identification of IgAN patients who are at high risk for AKI.     

Is IgA nephropathy the commonest primary glomerulopathy among young adults in the USA?

Over the past decade, focal segmental glomerulosclerosis (FSGS) has emerged as the most common primary glomerulopathy in adults in the USA. However in our practice, we became aware of increased numbers of patients with IgA nephropathy (IgAN). In order to further examine this, a retrospective analysis of renal biopsy diagnoses from adults was done from our biopsy database. Adult renal biopsies received from 3/1/2001 to 2/28/2005 were analyzed to determine the frequency of common primary glomerulopathies, which included FSGS, IgAN, membranous nephropathy (MN), minimal change disease, and membranoproliferative glomerulonephritis Type I (MPGN). The patients were grouped as all adults (>or=20 years) and young adults (20-39 years). The distribution of common primary glomerulopathies among the two age groups, expressed as a percentage of all non-transplant diagnoses (n = 4,504), was IgAN 6.9/3.4%, FSGS 9.6/3.2%, MN 6.8/1.6%, minimal change disease 2.5/0.9%, MPGN 1.2/0.2%. IgAN was as common as FSGS in young adults in our biopsy population (IgAN/FSGS 154/143 1.08:1). IgAN was the most common primary glomerulopathy in young adult Caucasians (IgAN/FSGS 2.1:1). IgAN was also the most common cause of end-stage renal disease (ESRD) in young adult Caucasians. In contrast, IgAN was rare in African Americans in whom FSGS remains more common (FSGS/IgAN 9.7:1). These findings from a large renal biopsy referral center serving 24 Midwestern and Southern states suggest that IgAN may be the most common primary glomerulopathy and the most common cause of ESRD in young adult Caucasians in the USA.     

Frequency of renal diseases and clinical indication for renal biopsy in children (Report of the Italian National Registry of Renal Biopsies in Children)

Background. Children's renal biopsy data were gathered for 3 consecutive years (1992-1994) by the Group of Renal Immunopathology of the Italian Society of Pediatric Nephrology, which opened a paediatric section of the Italian Registry of Renal Biopsies. Materials. The Registry recorded the histological diagnosis and the clinical data at renal biopsy of 432 children ⩽15 years old (mean age 8.96±3.7 years). Results. The most common glomerulonephritis (GN) at renal biopsy was idiopathic IgAGN (18.8%) and the most frequent secondary GN was Henoch-Schonlein purpura (HSP) nephritis (11.6%). Minimal-change disease (MCD) accounted for 11.6%, focal and segmental sclerosis (FSG) 8.5%, mesangial proliferative GN (MPGN) 9.5%, membranoproliferative GN 5.5%, and thin-membrane disease 5%. Lupus nephritis was diagnosed in 5% and Alport's GN in 3.9% of the cases. The annual incidence of primary GN in Italian children was 11.1 cases per million children population (p.m.c.p.), IgAN accounting for 3.1 cases, MCD 2.3, and HSP nephritis 1.9 cases p.m.c.p. respectively. Italian children underwent renal biopsy because of isolated microscopic haematuria in 19.3% of the cases, non-nephrotic proteinuria with or without microscopic haematuria in 31.2%, and nephrotic-range proteinuria in 34.2%, less frequently (15.3%) because of acute or chronic renal failure. Children with persistent isolated microscopic haematuria had most frequently IgAN (34.9%) or thin-membrane disease (25.3%), while those with non-nephrotic proteinuria had IgAN (30.4%) and HSP nephritis (23%). In cases with nephrotic proteinuria renal biopsy showed MCD in 34.5% of the cases, FSG in 16.9%, and MPGN in 12.2%. When renal biopsy was performed in chronic renal failure chronic interstitial renal disease was detected in 62.5% of the cases. Conclusions. This National Registry provides data on the indications for performing renal biopsy in Italian children and on the frequency and annual incidence of histological lesions detected. IgAN, primary or related to HSP, was the most common nephritis in Italian children undergoing renal biopsy.     

乙型肝炎病毒相关性肾炎的诊治——附20例报告

目的总结乙型肝炎病毒相关性肾炎（HBV-GN）患者的临床及病理特点,以提高HBV-GN的诊治水平。方法经肾活检确诊为HBV-GN的患者20例,回顾性分析患者临床表现、实验室检查（尿常规、24h尿蛋白定量、转氨酶、血清清蛋白、HBV-DNA等）、肾组织光镜改变及免疫荧光（IgG、IgA、IgM、C3、C1q、FRA、HBsAg、HBcAg、HBeAg）染色结果,并分析其临床及病理特点。结果本组20例,其中肾病综合征10例,肾炎综合征9例,无症状镜下血尿1例。病理分型以非典型膜性肾病最多见（MN）,共16例（占78％）,系膜增生性肾小球肾炎（MsPGN）2例（占10％）,系膜毛细血管性肾炎（MPGN）2例（占10％）。7例患者HBV-DNA阴性。给予抗病毒联合激素治疗后,大多数患者肾功能稳定。结论目前HBV-GN的确诊仍依赖肾活检,在乙型肝炎高发区应常规进行肾活检组织乙型肝炎病毒标志物检测。     

Natural history of immunoglobulin A nephropathy and predictive factors of prognosis: a long-term follow up of 204 cases in China

Aim: Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. However, its natural history and risk factors are not well understood. Our aim was to identify the clinical and pathological factors that could predict disease prognosis in Chinese patients. Methods: We studied 204 biopsy‐diagnosed IgAN patients, who were followed for an average of 6.1 years (range, 4–15 years). Chronic kidney disease (CKD) classified according to the Kidney Disease Outcomes Quality Initiative practice guidelines. Renal pathological lesions were graded single‐blindedly according to the Haas classification. The glomerular filtration rate was estimated by the Modification of Diet in Renal Disease equation for Chinese subjects. Results: Patients with CKD were classified as stage 1 (38.10%), stage 2 (35.40%), stage 3 (13.30%), stage 4 (9.90%) and stage 5 (3.30%). During the follow up, 31 patients had progressed to end‐stage renal disease. The renal survival rate following biopsy was 85.1% at the fifth year, and 77.1% at the 10th year. Univariate analysis indicated that patients who were male, had hypertension, proteinuria of more than 1 g/day, renal impairment (estimated glomerular filtration rate, <60 mL/min.1.73 m²), and a high histological grading were associated with poor prognosis. Multivariate analysis indicated that the relative risk of renal failure for patients was 3.9 (P = 0.000) for patients with renal impairment, 2.8 (P = 0.019) for patients with hypertension, and 2.0 (P = 0.003) for patients with high histological grading. Conclusion: We described the natural history of IgAN through follow ups of a relatively large cohort of patients. Most patients were biopsied at an early stage; however, the long‐term prognosis was still poor. Patients with renal impairment, hypertension and advanced histological involvement had the highest risk for disease progression.     

Predictors of poor renal outcome in patients with biopsy‐proven lupus nephritis

Aim: The development of lupus nephritis (LN) is associated with increased morbidity and mortality. In view of scarce data from South Africa on factors affecting renal outcome in LN, the authors' experience was reviewed to identify predictors of poor renal outcome. Methods: This is a retrospective review of 105 patients with biopsy‐proven LN under our care from January 1995 to December 2007. Results: Forty‐three (41.0%) patients reached the composite end‐point of persistent doubling of the serum creatinine over the baseline value, development of end‐stage renal disease (ESRD) or death during a mean follow‐up period of 51.1 months (range 1–137 months). Baseline factors associated with the composite end‐point included presence of systemic hypertension (P = 0.016), mean systolic blood pressure (SBP) (P = 0.004), mean diastolic blood pressure (DBP) (P = 0.001), mean serum creatinine (P = 0.001), estimated glomerular filtration rate (eGFR) (P = 0.003) and diffuse proliferative glomerulonephritis (World Health Organization class IV) (P = 0.024). Interstitial inflammation (P = 0.049), failure of remission in the first year following therapy (P < 0.001), the mean SBP on follow up (P < 0.001) and mean DBP on follow up (P < 0.001) were also associated with composite end‐point. On multivariate analysis, baseline serum creatinine, non‐remission following therapy (P = 0.038) and mean SBP on follow up (P = 0.016) were predictors of poor renal outcome. Conclusion: Baseline serum creatinine, failure of remission in the first year and mean SBP were predictors of poor renal outcome.     

Acute poststreptococcal glomerulonephritis superimposed on IgA nephropathy

Superimposition of poststreptococcal glomerulonephritis (PSGN) on the course of IgA nephropathy (IgAN) is uncommon. A case of PSGN during IgA nephropathy is presented. A 30-year-old man who had alternating gross and microscopic hematuria for 7 months underwent a renal biopsy. The first renal biopsy revealed IgAN with mesangial deposits of IgA and C3. Two months later, the patient suffered generalized edema, proteinuria, hematuria, an increased ASO titer and a decreased C3 level. A second renal biopsy revealed diffuse endocapillary proliferative glomerulonephritis with epimembranous hump-like electron-dense deposits of C3, but the original mesangial IgA deposits had disappeared. A diagnosis of acute PSGN was indicated. Two months after the onset of acute nephritic syndrome, the patient remained asymptomatic, except for microscopic hematuria and proteinuria. Some cases with persistent proteinuria or hematuria after PSGN are probably related to preexisting IgAN.     

Under-grading of <4 cm renal masses on renal biopsy

Study Type – Prognosis (case series) Level of Evidence 4 What's known on the subject? and What does the study add? It is well documented that biopsy of small renal masses is inaccurate and tends to under‐estimate tumour grade compared with surgical specimens. To our knowledge there has not been a study showing grading discrepancy between biopsy and surgical excision in a large population‐based cohort.

OBJECTIVE

• ? To determine whether differences exist in tumour grade between patients who undergo partial nephrectomy (PN) and those who undergo ablation for renal tumours.

PATIENTS AND METHODS

• ? Data was obtained using the Surveillance, Epidemiology and End Results database. Patients with solitary renal tumours of <4 cm treated with ablation or PN and with renal cell carcinoma (RCC) histopathology were identified.
• ? Tissue diagnosis in the ablation specimens was obtained from biopsy reports, whereas tissue from PN specimens was determined from surgical pathology.
• ? Variables analysed included: year of diagnosis, age, sex, race/ethnicity, marital status, population density, education, poverty level, and tumour size.
• ? Stacked bar graphs were created to compare the distributions of grade and histology between the groups. Multinomial logistic regression was used to determine factors independently associated with grade.

RESULTS

• ? In all, 7704 (87.4%) patients underwent PN and 1114 (12.6%) underwent either radiofrequency ablation or cryoablation.
• ? The PN patients were younger at diagnosis (59 vs 68 years, P < 0.001), more likely to be married (70% vs 64%, P < 0.001), and had smaller tumours (2.4 vs 2.6 cm, P < 0.001).
• ? There were no differences in the distribution of histology between the PN and ablation groups.
• ? Tumour grade was significantly lower in tumours treated with ablation.
• ? Compared with grade 1 disease, those undergoing ablation were 30% less likely to have grade 2 (P < 0.001), 30% less likely to have grade 3 (P < 0.001), and 92% less likely to have grade 4 disease (P < 0.01) than those having PN.

CONCLUSIONS

• ? There is a strong association between grade and treatment type in patients with small renal masses after controlling for baseline characteristics.
• ? As grade is determined by different methods, we think that this shows systematic under‐grading in biopsy of small renal masses.