原发性局灶节段性肾小球硬化的临床病理及预后

目的:分析114例原发性局灶节段性肾小球硬化(FSGS)患者的临床、病理、免疫病理特点及预后.方法:回顾性分析1985～1996年12年间,114例原发性FSGS患者的临床表现,病理,免疫病理特点,以及其中45例长期随访结果. 结果:1985～1996年12年间,原发性FSGS占同期肾活检的2.62%,平均发病年龄28.54±12.34岁.临床表现为蛋白尿者占93.0%(肾病综合征范围蛋白尿占21.9%),血尿51.8%(肉眼血尿14.9%,镜下血尿36.8%),高血压43.8%.肾活检时已发生肾功能不全者占47.4%,随访中22.2%发展至尿毒症,激素治疗有效率小于10%.肾功能不全者与肾功能正常者相比,前者高血压更为常见(P＜0.05),小管间质病变重[尿渗量明显降低(P＜0.05),尿溶菌酶升高(P＜0.001)].肾小球全球硬化的比率显著升高(P＜0.001),节段性硬化病变更为明显,并伴有更为显著的小管间质损伤,大量炎细胞浸润. 结论:①原发性FSGS好发于中青年,病程隐匿,进展较快;②临床上蛋白尿最为常见,其次是血尿,高血压和肾功能不全.高血压,肾小球全球/节段性硬化及肾小管间质病变,肾组织细胞浸润的程度与预后相关;③对激素治疗反应差,临床治疗应着重控制高血压,保护肾功能.     

家族遗传性局灶节段性肾小球硬化临床及预后特征分析

目的探讨家族性局灶节段性肾小球硬化临床预后特征。方法收集2008—2010年上海交通大学医学院附属瑞金医院家族性及散发性局灶节段性肾小球硬化患者临床资料,观察两组患者基线水平以及随访治疗后各指标的变化情况,分析家族遗传性局灶节段性肾小球硬化的临床及预后特征。结果家族性患者共入组83个家系,共计124例患者,其中男71例,女53例;散发性患者共入组124例,其中男76例,女48例。家族性患者发病时24 h尿蛋白定量显著低于散发性患者(P=0.003),血清白蛋白则显著高于散发患者(P0.01),肾病综合征的发生显著低于散发性患者(P=0.029)。病理表现上,家族性患者与散发性患者局灶节段性肾小球硬化差异无统计学意义(P=0.141),而球性硬化比例显著高于散发性患者(P=0.0007);小管损伤方面,家族性患者肾小管损伤程度显著高于散发性患者(P=0.0004)。随访后23.08%的家族性患者和48.39%的散发性患者24 h尿蛋白达部分缓解(下降超过基线的50%)(P=0.01)。生存曲线可见散发性患者较家族性患者预后相对较好。结论家族性局灶节段性肾小球硬化发病早于散发性患者,临床多表现为高血压及不同程度的蛋白尿,少数患者表现为肾病综合征,发病初期肾功能损伤程度两者差异无统计学意义。家族性患者对治疗反应较差,仅少数患者表现为蛋白尿缓解,较多患者进展至终末期肾病,预后相对差。     

老年IgA肾病患者的临床病理特点和长期预后的相关危险因素分析

目的:探讨老年IgA肾病(IgAN)患者的临床病理特点、长期预后及其相关危险因素. 方法:选取2003年1月至2012年12月在南京军区南京总医院肾脏科经肾活检确诊为IgAN且年龄≥65岁的患者82例,随机选取同期经肾活检确诊为IgAN且年龄在18～64岁的患者328例作为对照组,回顾性分析这些患者的临床及随访资料. 结果:老年IgAN患者与对照组相比,肾活检时平均动脉压(MAP) (P=0.001)、24h尿蛋白定量(P=0.011)、血清肌酐(P＜0.001)、估算的肾小球滤过率(eGFR)(P＜0.001)、血尿酸(P=0.012)、总胆固醇水平(P＜0.001)均存在统计学差异.老年IgAN肾小球硬化比例(P=0.001)及肾小管萎缩/间质纤维化(P=0.009)、肾小球节段硬化(P＜0.001)和动脉硬化(P＜0.001)等慢性化病变的发生率均明显高于对照组.老年IgAN患者3年和8年累计肾脏存活率分别为(89.6％和37.7％,P=0.000 2),显著低于对照组(96.5％和79.4％,P=0.000 2).多因素COX回归分析结果表明,肾活检时蛋白尿(HR 1.847;P=0.011)、eGFR(HR 1.080;P=0.006)水平及存在肾小管萎缩/间质纤维化(HR 5.850; P=0.007)是老年IgAN患者肾脏预后的独立危险因素. 结论:本研究表明,老年IgAN患者高血压、血清肌酐升高及肾病范围蛋白尿的发生率均高于同期行肾活检的非老年IgAN患者,肾脏组织的慢性化病变突出.肾活检时蛋白尿、eGFR水平及存在肾小管萎缩/间质纤维化是影响老年IgAN患者预后的独立危险因素.     

人类免疫缺陷病毒相关性肾病

人免疫缺陷病毒相关性肾病 (humanimmunodefi ciencyvirusassociatednephropathy ,HIVAN)是由HIV 1导致的一种特殊类型的肾脏疾病 ,已成为 2 0～ 6 4岁非洲裔美国人终末期肾衰的第三位致病因素[1,2 ] 。HIVAN临床主要表现为蛋白尿和肾功能不全 ,以轻 中度蛋白尿多见 ,少数可达肾病范围 ,绝大多数患者伴中 重度肾功能不全。最特征性的组织学改变为塌陷性局灶节段性肾小球硬化 (FSGS) ,小管微囊样扩张 ,间质淋巴细胞浸润和间质纤维化。HIVAN预后差 ,未经治疗情况下往往诊断后数周或数月进入终末期肾脏病 (ESRD)。近来HIVAN的…     

肾小球肾炎患者肾活检标本中小管间质损害的意义

为评价肾活检标本中皮质区小管间质损害的意义,作者对101例 IgA 肾病,31例 IgA 阴性(非 IgA)增殖性肾小球肾炎及75例特发性膜性肾小球肾炎,用光镜进行半定量检查。小臂损害程度分四个等级(-～(?)),以此估计成人原发性肾小球肾炎的严重程度及其预后。结果在 IgA 肾病小管间质损害((?))时尿蛋白显著增加,而蛋白尿与另二种肾小球肾炎的小管间质损害之间无相关性。高血压及肾功能减退病例则有随     

抗中性粒细胞胞质抗体相关血管炎肾脏病理改变与肾脏预后的关系

目的:探讨抗中性粒细胞胞质抗体(ANCA)相关血管炎(AAV)不同肾脏病理类型的远期肾脏预后及影响预后的危险因素。方法:205例AAV患者,其中男性89例,女性116例,中位年龄52岁(37~59)岁,基线血清肌酐(SCr)380.1μmol/L(194.5~583.4μmol/L),其中84例(41.0%)需行肾脏替代治疗(RRT)。肾脏病理类型包括局灶型(n=23)、混合型(n=71)、新月体型(n=47)和硬化型(n=64)。回顾性分析不同病理类型AAV的肾脏预后及影响因素。结果:34例(40.5%)摆脱RRT(中位时间1月),局灶型、混合型、新月体型和硬化型摆脱RRT比例分别为100%、54.5%、48.0%和22.9%。随访3~160月(中位时间22月),26例(12.7%)死亡,92例(44.9%)进入终末期肾病(ESRD)。局灶型、混合型、新月体型和硬化型的5年肾存活率分别为92.3%、60.8%、42.8%和28.7%(P0.01)。多因素COX回归分析显示病理类型、基线SCr和血清白蛋白水平为影响肾存活的独立危险因素,局灶型(HR 0.1,P=0.01)、混合型(HR 0.4,P=0.002)和新月体型(HR 0.5,P=0.005)较硬化型进入ESRD的风险显著低。SCr≥442μmol/L(HR 4.9,P=0.00)和病变与正常肾小球比例≤10%(HR 2.1,P=0.04)是硬化型AAV进展至ESRD的独立风险因素。结论:欧洲血管炎研究小组病理类型能预测AAV患者远期肾脏预后,除病理类型外,SCr和血清白蛋白水平也为影响肾存活的独立危险因素;对硬化型AAV要结合SCr水平和病变与正常肾小球比例判断肾脏疾病预后。     

肾小管损伤标志物在局灶节段性肾小球硬化患者中的变化及意义

目的:探讨局灶节段性肾小球硬化(FSGS)患者肾小管功能指标的表达变化特点,寻找更为敏感特异的生物学标志物,早期发现肾小管间质损伤。方法:经肾活检确诊的特发性FSGS组60例,对照为特发性膜性肾病组(IMN)36例、微小病变组(MCD)30例。比较三组患者肾损伤分子1(kidney injury molecule-1,KIM-1)、白介素18(IL-18)、中性粒细胞明胶酶相关载脂蛋白(neutrophil-gelatinase-associated lipocalin,NGAL)与临床病情的变化情况,分析FSGS患者不同病理亚型及不同性质小管间质病变时KIM-1、IL-18、NGAL的表达特点。结果:(1)蛋白尿水平相当的情况下,FSGS患者肾小管功能损伤明显,尿KIM-1、NGAL、NAG、RBP水平均高于IMN、MCD患者(P0.05)。(2)尿KIM-1升高的患者较正常者血胱抑素C(CysC)增高(P0.05);尿NGAL升高的患者较正常者蛋白尿、血BUN、尿C3、尿α2-MG均增高,血清总蛋白及白蛋白明显降低(P0.05)。(3)FSGS患者中,存在急性或慢性合并急性肾小管间质病变者与仅有慢性肾小管间质病变者相比,尿KIM-1、NGAL明显增高(P0.01),而血清白蛋白降低(P0.05)。(4)NAG、RBP尚在正常范围的患者KIM-1、NGAL、IL-18已经增高,病理亦证实其肾小管间质存在不同程度的急性病变。尿KIM-1、NGAL、NAG诊断肾小管间质急性病变其ROC曲线下面积大于尿IL-18、RBP、CysC。结论:FSGS患者较IMN、MCD患者存在更为显著的小管间质损伤,其原因独立于蛋白尿严重程度之外。尿KIM-1、NGAL、NAG是诊断肾小管间质急性病变敏感性和特异性较高的生物学标志物。     

局灶节段性肾小球硬化的发病机制

局灶节段性肾小球硬化(FSGS)是由多种病因引起的,以肾小球节段硬化为病理特征的一组疾病.临床主要表现为蛋白尿,并逐步进展为慢性肾功能不全.FSGS早期虽然肾小球硬化较局限,但存在广泛足突融合,提示足细胞是损伤的主要靶细胞.     

影响原发性局灶节段性肾小球硬化预后的因素

局灶节段性肾小球硬化(FSGS)是一类常见的临床病理综合征,临床上以大量蛋白尿或肾病综合征为主要表现,病理学特征性表现是局灶性、节段性、非增殖性毛细血管袢硬化和足细胞损伤。部分患者对于糖皮质激素和免疫抑制剂治疗反应性较差导致预后不佳,最终进展为终末期肾病。若能在早期对FSGS患者预后相关的各个因素进行分析,将有助临床医师综合判断其预后,并指导治疗方案。本文将分别从病理、临床、基因及治疗等四个层面提取与原发性FSGS预后相关的因素,并就这些因素展开探讨。     

肾小球疾病患者肾间质泡沫细胞的分布及其临床意义

目的：观察肾小球疾病患者肾间质泡沫细胞的分布特点,分析其与临床表现及肾组织病理改变之间的联系.方法：选取经临床病理明确诊断的Alport综合征（AS）125例,特发性膜性肾病（IMN）192例,IgA肾病（IgAN）388例,局灶节段性肾小球硬化（FSGS）137例.观察肾组织泡沫细胞的分布,并对肾间质有无泡沫细胞患者的临床和病理进行比较.结果：（1）AS、IMN、IgAN、FSGS四种疾病肾组织中均存在肾间质泡沫细胞,发生率分别为64.8%、21.4%、12.4%、36.5%,其中以AS中最为多见.（2）肾间质泡沫细胞组肾小球节段硬化的发生率及硬化比例均显著高于无泡沫细胞的对照组,AS、IgAN患者泡沫细胞组间质纤维化程度重于对照组.（3）AS、IgAN患者肾间质泡沫细胞组尿蛋白、血脂水平显著高于对照组（P＜0.01）.FSGS患者肾间质泡沫细胞组三酰甘油水平显著高于对照组,但两组间尿蛋白水平未见差异.结论：肾间质泡沫细胞在AS、IMN、IgAN、FSGS患者中均可以发现,但以AS患者最多见.肾间质泡沫细胞的形成与尿蛋白、血脂的水平有关.肾间质泡沫细胞的存在可能与肾组织慢性化病变形成有关.     

Therapie der fokal segmentalen Glomerulosklerose

Focal segmental glomerulosclerosis (FSGS) is one of the leading courses of idiopathic nephrotic syndrome in adults. It is a histological diagnosis rather than a disease and characterized by damage to podocytes. It occurs as a primary form or as a secondary response to glomerular injury. Distinguishing between primary and secondary forms is important because immunosuppressive therapy is not indicated in patients with secondary FSGS. Patients with secondary FSGS often present with non-nephrotic proteinuria and untreated patients with nephrotic syndrome have a poor renal prognosis. Prognostic factors that influence renal survival of patients with FSGS include the degree of proteinuria, renal dysfunction, histological findings and the response to steroid therapy. There are no randomized controlled trials comparing steroids or other agents to placebo for initial therapy of primary FSGS; however, first line treatment of nephrotic patients with primary FSGS is high dose steroids. Steroid resistance is defined by persistence of the nephrotic syndrome after a more prolonged course of steroid therapy over more than 4 months. Alternative therapies include treatment with calcineurin inhibitors, mycophenolate mofetil, cyclophosphamide and rituximab.     

肾小球疾病间质泡沫细胞的分布及其与临床指标的关系

目的观测各种病理类型肾小球疾病间质泡沫细胞的分布特点及其与临床参数间的关系。方法选取2862名肾活检患者为研究对象,观察间质泡沫细胞浸润常见的病理类型及泡沫细胞的分布特点。对诊断明确的Aploa综合征（AS）5例,膜增生性肾小球肾炎（MPGN）28例,局灶节段硬化性肾小球肾炎（FSGS）144例,特发性膜性肾病（IMN）132例,IgA肾病（IgAN）893例按间质是否存在泡沫细胞进行临床参数的比较。结果（1）非继发性肾小球疾病泡沫细胞浸润高发的病理类型依次为AS（100％）、MPGN（46．43％）、FSGS（21．32％）、IMN（13．64％）、IgAN（6．69％）;（2）泡沫细胞浸润组24小时尿蛋白定量、血胆固醇水平以及反映肾小管功能损伤的指标均高于无泡沫细胞组（P〈0．05）。结论肾间质泡沫细胞浸润常见于AS,但在MPGN、FSGS、IMN和IgAN患者中均可出现,大量蛋白尿与高脂血症是导致泡沫细胞浸润的两大因素。间质泡沫细胞的浸润与间质损害有一定的关联。     

成人过敏性紫癜肾炎预后及其危险因素分析

目的 探讨成人过敏性紫癜肾炎(Henoch-Schnlein nephritis,HSPN)预后及其危险因素。方法 对福建医科大学附属第二医院2002年1月至2011年10月经肾活检证实的76例过敏性紫癜肾炎预后及其危险因素进行回顾性分析。结果 平均随访57个月,10例(13.2%)进入终末期肾脏疾病(end-stage renal failure,ESRD)。单因素分析显示,起病时伴高血压、肾功能损害、随访时24 h尿蛋白定量≥1 g和肾小管间质慢性化指数是肾脏预后不良的危险因素,肾脏预后不良与性别、年龄、肾外表现、起病时肉眼血尿、就诊时24 h尿蛋白定量≥1.0 g、肾小球活动及慢性化指数和免疫抑制剂治疗无关。多因素分析显示,肾脏预后不良危险因素包括起病时肾功能损害(OR=10.96,95%CI 1.56~77.26,P<0.05)和肾小管间质慢性化指数(OR=2.77,95%CI 1.20~6.39,P<0.05)。结论 成人HSPN预后较差,预后不良危险因素包括起病时肾功能损害及肾小管间质慢性化指数。     

The prognosis of focal segmental glomerular sclerosis of adulthood

We describe 46 adults with idiopathic focal segmental glomerular sclerosis (FSGS). The mean age was 36.9 years (range, 15 to 80 years). Males represented 61%, and 65.2% were white. Hypertension was a presenting feature in 63% and 32.6% had microscopic hematuria. Twenty-nine patients had nephrotic proteinuria (greater than or equal to 3.0 g/24 h) at presentation, and 13 had renal insufficiency (serum creatinine concentration greater than 1.5 mg/dl). A mean follow-up of 59.8 months (range, 3 to 255 months) was obtained. In addition to segmental sclerosis, glomerular hyalinosis was observed in 65.3% of biopsies, and this was similar irrespective of the severity of proteinuria. Sixteen of the 29 patients with nephrotic proteinuria received prednisone therapy (60 mg/day) for at least 1 month. Three received cytotoxic agents in addition. A response to therapy was observed in 50%, 5 achieving a complete remission and 3 a partial remission. No patient with non-nephrotic proteinuria received prednisone therapy. The clinical course of each patient was evaluated based on the slope calculated by the linear regression method using the inverse of serum creatinine from the time of presentation to follow-up. Patients with non-nephrotic proteinuria had a better prognosis than nephrotics (P less than .05). Nephrotic patients responding to therapy had a better course than non-responders or patients not treated (P less than 0.01). At the time of last follow-up, 8 patients had progressed to end-stage renal disease, 6 of whom had presented with nephrotic proteinuria. No patient responding to therapy had progressed to end-stage renal disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical Significance of Urinary Biomarkers in Patients With Primary Focal Segmental Glomerulosclerosis

Background

Focal segmental glomerulosclerosis (FSGS) is often accompanied with tubulointerstitial lesion. This study aimed to assess the role of urinary biomarkers in predicting tubulointerstitial lesion and treatment response in FSGS patients.

Predictors of survival in Chinese patients with lupus nephritis

The current study was to determine the predictors of survival in 491 Chinese patients with lupus nephritis (LN). All patients were evaluated and consecutively followed up from 2003 to 2010. The female: male ratio was 9.5:1, with a median age of 31.1?±?12 years. Forty-nine (10.0%) patients were lost to follow-up and 47 (10.3%) patients died. The overall cumulative probability of survival at 5, 10, 15 and 20 years by Kaplan-Meier analysis was 88%, 77%, 53% and 45%, respectively. The log-rank test showed that the probability of survival was significantly decreased in the late-onset patients (≥50 years) (P?=?0.036), patients with hypoproteinaemia (≤35?g/l) (P?=?0.014), patients with increased creatinine (≥1.5?mg/dl) (P?=?0.002) and patients with massive proteinuria (≥3.5?g/24?h) (P?=?0.009). However, the probability of survival was significantly higher in patients treated with hydroxychloroquine (HCQ) (P?=?0.003) than those not treated with it. Based on a multivariate model, increased creatinine (hazard ratio (HR)?=?2.041; P?=?0.017) and proteinuria ≥3.5?g/24hours (HR=1.716; P?=?0.016) were independent risk factors. Glucocorticoid (HR?=?0.457; P?=?0.01) and HCQ (HR=0.197; P?=?0.026) were independent protective factors. Our findings suggest that renal dysfunction and massive proteinuria are independent risk factors for mortality. HCQ could improve the survival of patients with LN.     

Effects of steroids in focal segmental glomerulosclerosis in a predominantly African-American population

BACKGROUND: Focal segmental glomerulosclerosis (FSGS) is a common primary glomerulopathy in African Americans. Prolonged treatment with steroids is recommended for FSGS in those with nephrotic-range proteinuria, but strong evidence for this recommendation, especially in African-American adults, is lacking. We reviewed our experience with steroids in FSGS in a predominantly African-American cohort. METHODS: Patients with primary FSGS were identified and their charts were retrospectively reviewed for demographic data, characteristics of renal biopsy, blood pressure, and use of steroids. End-stage renal disease and doubling of creatinine were end-points. RESULTS: Seventy-two patients (65 African Americans) were identified with 48.3 months of follow-up. Patients receiving steroids (n=43) had higher urine protein excretion than those who did not. Seventeen patients reached end-stage renal disease and 26 doubled their creatinine concentration. Factors significant for renal survival on Cox proportional hazards model were initial creatinine level, severity of renal lesion, and blood pressure over the follow-up period. Treatment with steroids did not affect renal survival. About one third of patients receiving steroids developed complications consisting of diabetes (n=4) and greater than 5 kg weight gain (n=10). CONCLUSION: Renal function, severity of the renal lesion, and blood pressure determine renal survival in FSGS. A beneficial effect of steroids was not observed in this predominantly African-American adult cohort.     

老年人原发性膜性肾病肾小动脉病变的特点

目的 观察老年原发性膜性肾病患者肾小动脉病变的发生情况及其特点.方法 选取2000年1月至2005年12月在我院住院并经肾穿刺活检确诊的原发性膜性肾病患者168例,分为老年组(≥60岁)和非老年组(＜60岁),分析两组患者肾小动脉病变的发生情况及其影响因素.结果 老年组收缩压、舒张压、血肌酐水平、血尿发生率显著高于非老年组,而eGFR则显著低于非老年组.肾小球球性或节段硬化的比例以及肾小管萎缩和肾间质纤维化程度老年组重于非老年组.肾脏小动脉病变的发生率以及严重程度均明显重于非老年组.多因素分析显示,高血压、年龄、肾小管间质慢性损伤是肾脏小动脉病变发生的独立影响因素.进一步将血压正常且小管间质病变匹配的老年与非老年组患者比较,老年患者.肾小动脉病变的发生率以及严重程度仍重于非老年患者(P＜0.05),肾小动脉病变表现为肌层增厚,合并玻璃样变的比例高.结论 老年原发性膜性肾病患者肾小动脉病变的发生率以及严重程度均明显高于非老年患者,合并玻璃样变的比率高,其可能是影响老年原发性肾脏病患者预后不良的重要因素.     

Idiopathic focal segmental glomerulosclerosis: a favourable prognosis in untreated patients?

BACKGROUND: Patients with focal segmental glomerulosclerosis (FSGS) are considered to have a poor prognosis and spontaneous remissions are seldom reported. However, FSGS is not a single disease entity. Our aim was to describe the clinical course in initially untreated patients with recently diagnosed idiopathic FSGS. METHODS: This was a retrospective study of patients with a diagnosis of FSGS by histology, who fulfilled the following criteria: proteinuria >3.5 g/day, normal renal function, duration of proteinuria or hypertension of less than one year, normal-sized kidneys, no underlying renal disease, and a negative family history. Renal biopsies were reviewed without knowledge of the clinical course. RESULTS: Twenty patients (13 male, 7 female) fulfilled the study criteria. Median age was 49.3 (range 21.8 to 73.0) years, serum creatinine 90 +/- 20 micromol/l, proteinuria 10.0 +/- 5.5 g/day and serum albumin 24 +/- 6 g/l. After a median follow-up of 9.4 (2.1-18.6) years, 13 patients (65%) were in remission of proteinuria. Renal function deterioration occurred in seven patients, and prompted treatment in four of them. The ten-year death-censored renal survival was 89%. Renal function deterioration and remission rate could be predicted by selectivity index, serum albumin at three months after renal biopsy and the percentage of glomeruli with segmental sclerosis. CONCLUSION: Focal glomerulosclerosis is not a single disease. Case definition using strict clinical criteria identifies a subgroup of patients with idiopathic FSGS who have a good prognosis. In the majority of these patients immunosuppressive therapy is not warranted.     

Chronic kidney diseases in long-term survivors after allogeneic hematopoietic stem cell transplantation: monitoring and management guidelines

Chronic kidney disease (CKD) occurs commonly (prevalence of approximately 20% in a large series) after allogeneic hematopoietic stem cell transplantation (HSCT). There are three distinct clinical entities that occur after HSCT: thrombotic microangiopathy (TMA), nephrotic syndrome (NS), and idiopathic or graft-versus-host disease (GVHD)-related CKD. Acute renal function decline occurs in the majority of patients in the first months after transplantation. This acute kidney injury can persist and is a risk factor for the later development of CKD. However, the potentially independent role of GVHD, chronic inflammation, and chronic exposure to calcineurin inhibitors in the development and progression of CKD warrants further investigation. Careful monitoring of blood pressure, renal function, and proteinuria is mandatory in patients undergoing HSCT, especially older patients with pre-existent renal impairment. Renal function should be evaluated before HSCT and monitoring should occur at least every 6 to 12 months in these patients. Renal biopsies are indicated in patients with proteinuria and persistent or progressive rises in serum creatinine to determine etiology and prevent progression to end-stage renal disease (ESRD).