少量蛋白尿IgA肾病患者镜下血尿与病理指标的相关性分析

目的探索少量蛋白尿IgA肾病(IgAN)患者镜下血尿发生与病理指标的相关性。 方法回顾性分析2007年1月1日至2012年12月31日在解放军总医院经肾穿刺活检首次诊断的原发性IgAN、尿蛋白<0.5 g/24 h且无肉眼血尿患者。采集患者肾穿刺活检前1周内的血压、尿蛋白定量、尿红细胞形态及计数、肾功能等指标。肾活检后的病理指标按照IgAN牛津分型更新版评价,采用Poisson回归分析镜下血尿水平与病理指标的相关性。 结果共纳入尿蛋白<0.5 g/24 h的IgAN患者88例,其中无镜下血尿组22例,非满视野镜下血尿组58例,满视野镜下血尿组8例。Poisson回归分析显示在校正患者的尿蛋白和肾功能(eGFR)水平后,新月体形成(OR 6.55,95%CI 2.68～15.98)和系膜细胞增殖(OR 4.92,95%CI 1.75～13.83)与IgAN患者镜下血尿水平相关,系膜细胞增殖病变与节段硬化或球囊粘连病变存在交互作用(OR 3.82,95%CI 1.30～11.25)。 结论在蛋白尿少于0.5 g/d的IgAN患者中,患者镜下血尿水平相关的病理因素主要是增殖性病变,包括系膜细胞增殖和新月体形成。系膜细胞增殖病变合并节段硬化和(或)球囊粘连病变,与镜下血尿水平的相关性显著增加。     

尿液miR-374b表达水平与IgA肾病病情相关性初步研究

目的:观察尿标本miR-374b表达水平与IgA肾病(IgAN)病情相关性。方法:收集2016年01月~2016年10月我科住院病人,且首次经肾活检证实为Ig AN40例(少量蛋白尿(1 g/d)肾脏病理高积分IgAN、少量蛋白尿(1 g/d)肾脏病理低积分IgAN、中等量蛋白尿(1~3.5 g/d)IgAN、大量蛋白尿(3.5 g/d)IgAN各10例)、轻微肾小球病变、膜增生性肾小球肾炎I型、局灶节段性肾小球硬化、过敏性紫癜性肾炎及狼疮性肾炎各10例,我院体检中心正常健康对照组25例,收集上述各组尿液,采用RT-qPCR检测上述各组miR-374b表达水平,并分析miRNA-374b表达水平与肾脏病理Haas分级及尿蛋白的相关性。结果:IgA肾病患者miR-374b表达水平高于其他类型肾小球肾炎及健康对照组(P0.000 1),肾脏病理高积分少量蛋白尿IgAN患者miR-374b表达水平显著升高(P0.01),miR-374b表达水平与患者尿蛋白水平及肾脏病理损伤程度正相关(r~2=0.89,P0.01)。结论:尿液miR-374b表达水平与Ig A肾病病情呈正相关,为少量蛋白尿Ig A肾病的早期诊断及治疗提供新的思路。     

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。     

^99mTc—DTPA肾动态显像在IgA肾病慢性肾功能不全患者的临床应用

目的探讨^99mTc-DTPA肾动态显像在IgA肾病（kAN）慢性肾功能不全患者病情监测及预后判断时的应用价值。方法23例经肾活检确诊为IgAN的患者行常规^99mTc-DTPA肾动态显像，测定肾小球滤过率（GFR，包括总GFR和分肾GFR），同时行肾活检按Lee氏分级标准将肾脏病理改变分级，Katafuchi积分标准对患者的肾脏病理损害，包括肾小球损害、肾小管间质损害和血管损害进行积分，将积分与上述显像指标（GFR）进行相关分析。结果随着病理分级增高，GFR趋于降低，各级组间比较差异有显著性意义（P〈0．05或P〈0．01）；相关分析示GFR与肾脏病理总积分、肾小球损害（尤其是节段损害和全球硬化）、小管间质（尤其是间质纤维化和肾小管萎缩）及血管损害呈负相关（P〈0．05或P〈0．01）；在临床指标方面，GFR与血清肌酐和尿蛋白定量及血压（收缩压和舒张压）呈负相关（P〈0．05或P〈0．01）。结论通过^99mTc-DTPA肾动态显像获得的GFR与IgA肾病肾脏病理学改变及临床指标关系密切，其在IgA肾病患者病情监测、指导治疗及预后判断中具有重要临床应用价值。     

成人紫癜性肾炎的临床病理分析及转归

目的：了解深圳地区成人紫癜性肾炎的临床特征及其与肾脏病理的联系;探讨其转归及影响因素。方法：回顾性分析2001年1月～2009年12月间经我院临床及肾活检确诊的紫癜性肾炎52例,对其临床资料、病理特征及转归进行统计分析。结果：（1）成人紫癜性肾炎多好发于30岁以下,40岁以后患者高血压的发生率较高。（2）临床分型以蛋白尿＋血尿型（59.6%）最多见,其次为单纯性血尿（21.2%）和肾病综合征型（19.2%）;病理分级以Ⅱ级（44.2%）及Ⅲ级（36.5%）多见。（3）肾小管间质病变与肾小球慢性病变及活动病变的相关系数分别为0.587（P〈0.01）和0.260（P〉0.05）;蛋白尿越多的患者,其肾小球活动病变积分就越高。（4）多因素分析显示疗效与肾小球硬化率及肾小管间质病变呈负相关。结论：深圳地区成人紫癜性肾炎发病相对年轻,临床以蛋白尿＋血尿型多见,病理以Ⅱ、Ⅲ级常见;蛋白尿的严重程度与肾小球活动病变关系密切;影响疗效的主要因素为肾小球慢性病变及肾小管间质病变程度。     

肾脏病理高积分的少量蛋白尿IgA肾病激素治疗疗效观察

目的：观察肾脏病理高积分的少量蛋白尿IgA肾病患者给予激素治疗的疗效。方法：45例少量蛋白尿IgA肾病患者随机分为两组,所有患者病例积分Haas分型≥Ⅱ型、Katafuehi积分肾小球损伤积分≥2分和（或）肾小管间质损伤积分≥2分,治疗组（22例）给予激素和常规治疗,对照组（23例）仅给予常规治疗。结果：治疗组尿蛋白量显著减少[（0．48±0．17）g／24hvs（0．93±0．36）g／24h,P〈0．05];中等量蛋白尿、eGFR下降终点事件发生率显著低（P〈0．05）。结论：以肾脏病理积分作为少量蛋白尿IgA肾病的指导依据可以获得更好临床预后。     

原发性IgA肾病患者肾脏局部血管紧张素Ⅱ表达与肾脏纤维化相关

目的 研究原发性IgA肾病患者肾脏局部肾素-血管紧张素系统（RAS）组分的表达及其相互调节,探讨肾内血管紧张素Ⅱ（AngⅡ）表达与临床病理损伤指标间的关系。 方法 采用免疫组织化学方法评价肾脏局部RAS组分的表达。分析36例原发性IgA肾病患者肾脏局部RAS组分表达之间的相关性以及肾内AngⅡ表达与血压、估算肾小球滤过率（eGFR）、24 h尿蛋白量和Katafuchi肾脏病理评分之间的相关性。 结果 肾内肾素、血管紧张素原与AngⅡ表达呈正相关（r ＝ 0.43,P < 0.01;r ＝ 0.34,P < 0.05）。肾内AngⅡ表达与eGFR呈负相关（r ＝ -0.61,P < 0.01）,并与病理慢性积分及间质炎性细胞浸润积分呈正相关（ρ ＝ 0.39,P < 0.05;ρ ＝ 0.52,P < 0.05）。 结论 IgA肾病患者肾内AngⅡ表达与肾内肾素、血管紧张素原表达相关,并且肾内AngⅡ表达与肾脏纤维化程度相关。     

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。     

IgA肾病中医辨证分型治疗新探

IgA肾病（IgAN）系指肾小球系膜区以IgA为主的免疫球蛋白沉积为免疫病理特征的一组肾小球疾病,是我国最常见的原发性肾小球疾病,约占肾活检病例的1／3,在确诊后5～25年内有20％-40％的患者可发展为慢性肾衰竭。IgA肾病临床表现多数以血尿为主,可伴有少量蛋白尿、大量蛋白尿或肾病综合征,少数病人可见急进性肾炎综合征。     

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。     

IgA肾病患者扁桃体B1a细胞和IgA1阳性细胞表达及相关因素分析

目的 研究B1a和IgA1阳性细胞在IgA肾病患者扁桃体中的表达及B1a细胞与血尿、蛋白尿和病理Lee分级的关系。 方法 肾活检确诊为原发性IgA肾病及非肾炎慢性扁桃体炎患者各8例为对象,用免疫荧光法和激光共聚焦显微镜对其扁桃体组织进行B1a及IgA1细胞定位和定量计算,并按蛋白尿程度和Lee分级标准与IgA肾病组B1a细胞数量行统计学分析。 结果 B1a细胞主要分布在扁桃体生发中心和小结帽;IgA1细胞主要分布在上皮内、上皮下,以上皮和淋巴组织交界区为多。与慢性扁桃体炎组比较,IgA肾病组两种细胞表达明显增多（P < 0.01）,且呈正相关（r = 0.778,P = 0.023）。在血尿伴蛋白尿和Lee≥Ⅲ级组B1a细胞显著高于单纯血尿和Lee<Ⅲ级组（P < 0.05）。 结论 IgA肾病患者扁桃体中IgA1可能是B1a细胞分泌的。B1a细胞数量随着患者蛋白尿的出现和病理严重程度的加重而增加,可能在疾病发生和进展过程中起着重要的作用。     

150例原发性IgA肾病临床与病理的回顾性研究

目的 分析原发性IsAN的临床和病理特点,为其诊断和治疗提供依据。方法 对150例原发性IgAN患者的临床和病理特点进行回顾性分析。结果 本组患者伴有血尿者114例,男性44例,女性70例,女性患者多于男性患者(p＜0.01);有44例患者发生肉眼血尿,其中24例肉眼血尿与急性扁桃体炎有关。临床与病理相关性分析显示,肾...     

儿童无症状尿检异常IgA肾病的临床病理和预后分析

目的 探讨儿童无症状尿检异常的IgA肾病的临床病理特征和预后。 方法 对54例IgA肾病儿童的临床和病理特征进行分析。根据起病时有无临床症状分为无症状尿检异常组和有症状肾炎组。组织病理学分级参照Lee氏和Katafuchi氏半定量积分法。 结果 无症状尿检异常组18例，有症状肾炎组36例。有症状肾炎组尿蛋白量（24 h）明显高于无症状尿检异常组[（2.3±2.2） g比（0.4±0.3） g，P < 0.05]。无症状尿检异常的IgA肾病儿童表现为镜下血尿者，87％有尿微量白蛋白增高。无症状尿检异常IgA肾病患儿病理表现以Lee 氏Ⅰ~Ⅱ级为主，2例表现为Lee氏Ⅳ~Ⅴ级和 5例发生Katafuchi Ⅱ~Ⅲ级肾小管间质病变。有症状肾炎组Lee氏病理分级以Ⅱ~Ⅲ级为主，两者病理分级分布差异无统计学意义（P > 0.05）。全组患儿平均随访（26.9±8.8）月后，1例病理为Lee 氏Ⅴ级患儿进入终末期肾衰竭，其余患儿Scr均无升高1倍以上。 结论 无症状尿检异常的儿童IgA肾病虽临床症状轻微，但可出现病理损害严重的病例，并影响其预后。     

移植肾IgA肾病临床病理及预后分析

目的探讨移植肾IgA肾病(IgAN)复发或新发的诱因及移植肾生存的危险因素。方法选取2012年11月至2018年12月浙江大学医学院附属第一医院经肾活检确诊为移植肾IgAN的患者,按照血肌酐(Scr)增高水平、估算肾小球滤过率(eGFR)下降率分为稳定组(Scr升高值<20μmol/L,eGFR下降率<10%)和进展组(Scr增高但未达翻倍值,30%相似文献   

Study on glomerular microvascular injury and repair in patients with IgA nephropathy and its relationship with intermedin

Objective To investigate the glomerular microvascular injury and repair in patients with IgA nephropathy (IgAN) as well as its relationship with intermedin (IMD). Methods Eighty cases of renal tissue taken from patients first diagnosed as IgAN in Shanxi Provincial People's Hospital Affiliated to Shanxi Medical University and 15 cases of normal renal tissue were detected by the expression of glomerular IMD, CD31, and VE-cadherin through immunohistochemical method. ELISA method was used to detect VEGF and IMD of plasm from 31 normal subjects and 36 cases chosen from the IgAN patients. Their changes and internal relationship were analyzed according to Lee's and chronic kidney disease (CKD) classification. Results (1) Compared with the control group the expressions of CD31, IMD, and VE-cadherin in IgAN patients were statistically significant (P＜0.01). Compared with the control group the levels of IMD and VEGF in plasma of IgAN patients in early stage of CKD group and late stage of CKD group were statistically significant (P＜0.01). (2) Correlation analysis: the expression of glomerular CD31 and Lee's classification were negatively correlated (r=-0.232, P＜0.05); glomerular IMD was negatively correlated with Lee's classification (r=-0.241, P＜0.05), while positively correlated with glomerular VE-cadherin (r=0.417, P＜0.01). VEGF in plasma of IgAN patients was positive correlated with CKD classification, BUN (r=0.458, 0.409, P＜0.05), and negatively correlated with serum ALB (r=-0.532, P＜0.01). Conclusion Microvascular injury exists in patients with IgAN. The expression of VE-cadherin and IMD are positively correlated, suggesting that IMD may be involved in the progression of vascular protection and angiogenesis in IgAN. The contents of IMD and VEGF in plasma of IgAN patients increase, indicating that they may play a role in the progression of IgAN.     

RGC-32在儿童IgA肾病肾组织中的表达及意义

目的 研究RGC-32（response gene to complement 32）在IgA肾病(IgAN) 儿童及正常肾组织中的表达及其意义。 方法 用免疫组织化学方法观察IgAN儿童及正常肾组织中RGC-32蛋白的表达与分布,并与α平滑肌肌动蛋白(α-SMA)、转化生长因子β1（TGF-β1）的表达、IgAN肾组织病理损伤程度及临床相关指标进行统计学分析。 结果 RGC-32蛋白在IgAN及正常肾组织的肾小管均明显表达,而在肾小球、肾小管间质及肾血管未见表达。RGC-32 在正常肾组织、IgAN轻度、中度及重度损伤组中的阳性表达指数分别为（18.29±6.22）%、（23.90±9.65）%、（31.23±9.86）%和（34.52±10.63）%。RGC-32在IgAN儿童肾组织的阳性表达指数与肾小球评分、肾小管间质评分均呈正相关（r = 0.385,0.347,P < 0.05）;与α-SMA、TGF-β1表达亦呈正相关（r = 0.594,0.521,P < 0.01）;而与Scr、尿NAG/Cr、尿Alb/Cr、尿 IgG/Cr、尿α1微球蛋白/Cr均无相关（r = 0.117,-0.115,-0.138,-0.176,-0.028,P均>0.05)。 结论 首次发现RGC-32蛋白在IgAN儿童和正常肾组织中表达于肾小管,而在肾小球、肾小管间质及肾血管未见表达。RGC-32可能参与了IgAN患儿的肾小管间质损伤,尤其是TGF-β1诱导的肾小管上皮细胞-间充质转分化（EMT）过程。     

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.     

Clinical significance of phospholipase A2 receptor 1 in patients with idiopathic membranous nephropathy

Objective To explore the role of phospholipase A2 receptor 1 (PLA2R1) in the diagnosis, differential diagnosis and evaluation of idiopathic membranous nephropathy (IMN) in adult patients. Methods A total of 242 renal disease patients diagnosed by renal biopsy from March 2015 to January 2016 were enrolled, consisting of 90 IMN, 20 secondary membranous nephropathy (SMN), 82 IgA nephropathy (IgAN), 30 minimal changed disease (MCD), 16 focal segmental glomerulosclerosis (FSGS) and 4 membranoproliferative glomerulonephritis (MPGN). Their clinical data including age, sex, serum creatinine (Scr), serum albumin and 24 h urinary protein were collected. Serum PLA2R1 was measured by enzyme linked immunosorbent assay. PLA2R and IgG subclasses in glomeruli were detected by indirect immunofluorescence assay. The positive rate of serum PLA2R1 among those groups and its correlation with clinical-pathological parameters were analyzed. Results Compared with IMN patients, SMN, MCD and FSGS patients were younger (all P＜0.01); IgAN patients were younger and had higher serum albumin and lower 24 h proteinuria (all P＜0.001); MPGN patients had higher Scr (all P＜0.01). The positive rate of serum PLA2R1 was 75.6% in IMN patients, while it was 0.0% in non-IMN patients. The distribution between serum PLA2R1 and pathological diagnosis had difference (P＜0.001), their positive coincidence rate was 100%, negative coincidence rate was 87.4%, total coincidence rate was 90.9% and their consistency was well (Kappa=0.795, P＜0.001). Among IgG subtype comparisons between IMN patients and SMN patients in the glomeruli, only moderate or more positive IgG4 had statistical differences (82.2% vs 5.0%, P＜0.001); the positive rate of glomerular PLA2R1 was 41.1% in IMN patients, higher than 10.0% in SMN patients (P=0.009); positive PLA2R1 with moderate or more positive IgG4 in glomeruli in IMN patients was more than that in SMN patients (40.0% vs 0.0%, P＜0.001), which could improve the diagnostic specificity of IMN. In IMN patients serum PLA2R1 and glomerular PLA2R1 had statistical differences (P＜0.001). Spearman rank correlation analysis showed that serum PLA2R1 of IMN patients positively correlated with 24 h proteinuria (r=0.315, P=0.002), negatively correlated with serum albumin (r=-0.228, P=0.030) and didn't correlate with Scr (r=0.199, P=0.059). Conclusions Serum PLA2R can be used as the specific indicator for diagnosis, differential diagnosis of IMN and to reflect the severity of IMN in patients.