Assessment of renal allograft fibrosis by transient elastography

Transient elastography (TE, Fibroscan) has been established as a noninvasive assessment tool of liver fibrosis. We evaluated potentials and limitations of TE for identifying renal allograft fibrosis. The technical possibility of kidney examination by TE was assessed in two 10‐week‐old German landrace pigs and kidney stiffness (KS) was evaluated in 164 renal transplant patients. KS could be determined in all animals at the pole and pars media (29 ± 10 kPa vs. 31 ± 17 kPa). In human renal allografts KS was successfully performed in 94.5% of the test series with reliable results in 72% of the measurements. Mean KS at the pole or pars media were comparable (35.0 ± 19.9 kPa vs. 33.2 ± 18.6 kPa). Significantly higher KS was detected in renal allografts with histologically confirmed advanced fibrosis. Body‐mass‐index, skin‐allograft distance, and peri or intrarenal fluid accumulation were important confounders of successful KS measurements (BMI: r = ?0.31; P < 0.001; distance: r = ?0.50; P < 0.001). Notably, KS did not correlate with renal function. TE represents a noninvasive approach in selected transplant recipients to identify allografts with severe fibrosis. The heterogeneous kidney morphology and several other confounding factors negatively affect measurability of KS by TE. Further technical modifications are required to improve applicability of TE for kidney assessment.     

肝切除术前实时组织弹性成像评估肝纤维化程度及门静脉压力

目的探讨实时组织弹性成像(real-timetissue elastography,RTE)在术前评估肝纤维化程度及门静脉压力的可行性。方法 2010年6月至2010年8月广西医科大学第一附属医院对34例肝切除病人术前实时超声检测肝组织弹性,术中测量门静脉压力(portalvein pressure,PVP),并结合临床及术后病理进行分析。结果术前实时组织弹性成像定量参数(AREA%)中位数为32.2%(6.8%～77.9%)。术中门静脉压力中位数为19(13～28)cmH2O(1cmH2O=0.098kPa)。肝纤维化分期F04例,F18例,F29例,F31例,F412例。PVP值与肝纤维化分级显著相关(spearman相关系数为0.548,P<0.001)。AREA%随肝纤维分级的升高而显著增加(P<0.01),与肝纤维化分级显著相关(spearman相关系数为0.642,P<0.001)。AREA%与PVP有着显著的线性相关(R=0.753,P<0.001)。AREA%判断重度纤维化的ROC曲线下的面积为0.81。结论实时组织弹性成像可在术前提供一个方便、无创的新方法来评估肝纤维化的程度及门静脉压力。     

实时剪切波弹性成像诊断血吸虫病肝纤维化

目的探讨超声实时剪切波弹性成像诊断血吸虫病肝纤维化的效能。方法采用SurperSonic Imagine AixPlorer型实时剪切波弹性超声诊断仪,检测128例血吸虫肝病患者肝实质弹性模量平均值,根据不同肝纤维化分期将其分为5组,比较5组间弹性模量平均值的差异,并与血清肝纤维化4项指标(血清透明质酸、层黏连蛋白、Ⅲ型前胶原、Ⅳ型胶原)及肝穿刺病理检查结果进行相关性分析;绘制ROC曲线,评价弹性模量平均值诊断肝纤维化的效能。结果血吸虫肝病肝纤维化S0期、S1期、S2期、S3期、S4期肝实质弹性模量平均值总体差异有统计学意义(F=60.810,P=0.035);S0期弹性模量平均值与S2期、S3期、S4期比较差异均有统计学意义(P均0.05)。肝实质弹性模量平均值与血清血清透明质酸、层黏连蛋白、Ⅲ型前胶原、Ⅳ型胶原及肝纤维化病理分期均呈正相关(r=0.461、0.522、0.452、0.381、0.721,P均0.05)。肝实质弹性模量平均值对肝纤维化≥S1期、≥S2期、≥S3期和S4期的诊断阈值分别为6.8、8.9、11.5和14.6kPa,AUC分别为0.941、0.931、0.925和0.912。结论实时剪切波超声弹性成像可较准确、无创地诊断血吸虫病肝纤维化。     

超声实时组织弹性成像诊断颈动脉易损斑块

目的探讨超声实时组织弹性成像(RTE)技术对颈动脉易损斑块的诊断价值。方法选取缺血性脑血管病患者60例,对颈动脉斑块进行超声弹性成像;采用Itoh 5分法对斑块RTE图像进行评分,并与颈动脉内膜切除术(CEA)术后病理学检查进行对照分析。结果超声弹性图彩色编码显示斑块脂质坏死核心为绿色,纤维为蓝色,钙化为蓝白色,出血/血栓为绿色、红绿色相间、蓝绿色相间。60例中,纤维斑块12例,粥样斑块24例,斑块内出血/血栓9例,复杂斑块15例。弹性成像诊断易损斑块的敏感度、特异度、准确率分别为93.75%(45/48)、83.33%(10/12)、91.67%(55/60),阳性预测值、阴性预测值分别为95.74%(45/47)、76.92%(10/13),阳性似然比、阴性似然比分别为5.62、0.075。结论超声弹性成像技术对颈动脉易损斑块有较好的诊断价值。     

Kidney tissue elastography and interstitial fibrosis observed in kidney biopsy

IntroductionKidney interstitial fibrosis is an important risk factor for the progression of chronic kidney disease. Kidney elastography is a noninvasive imaging modality that might be used to assess tissue fibrosis. In this study, we aimed to investigate the relationship between tissue stiffness detected in kidney elastography and interstitial fibrosis observed in kidney biopsy.Materials and methodsPatients who were hospitalized in a tertiary care university hospital with a kidney biopsy indication were included in this study. In all patients, the transverse and sagittal elastography measurements were made using a sonoelastography device before the biopsy. The total histological score was calculated.ResultsFifty-seven native kidney patients with proteinuria were included in the study. Patients were divided into two groups according to the presence (n = 6) and absence of fibrosis (n = 51) as detected by kidney biopsy. A significant correlation was found between the presence of fibrosis detected by biopsy and elastography outcomes (p = .046, r = .192). A significant correlation was found between the urea and creatinine levels and transverse elastography measurements (p = .036, r = .240). No correlation was observed between the transverse elastography measurements and total histological score consisting of glomerular, vascular, and tubular scores (r = .006, p = .967)ConclusionThe findings of our study suggest a significant relationship between the elastography measurements and interstitial fibrosis. Because of the high negative predictive value (91%), we suggest that elastography should mainly be used as an exclusion test for the presence of fibrosis. We also believe that elastography may be useful to evaluate the fibrosis status in kidney diseases.     

超声弹性成像诊断肾纤维化研究进展

肾纤维化包括肾小球硬化和肾间质纤维化,是所有慢性肾病发展到终末期(即尿毒症)的共同病理阶段。肾纤维化早期是一种可逆的病理过程。应用超声弹性成像技术,可精确、快速评估组织硬度。本文主要对超声弹性成像技术对肾纤维化诊断的应用进行综述。     

Noninvasive evaluation of renal allograft fibrosis by transient elastography – a pilot study

Chronic allograft injury (CAI) is the most common cause of graft failure after the first year of transplantation. To date, only protocol biopsies can reveal subclinical disease. Transient elastography (TE) is a novel noninvasive technique that has demonstrated high reliability in the assessment of liver fibrosis. This study evaluates the feasibility of TE for the assessment of renal allograft fibrosis. Fifty‐seven patients underwent TE by the FibroScan® device. Biopsies were performed in 20 patients. Measurement of parenchymal stiffness by TE was successful in 55 of 57 patients (96.5%). Stiffness was significantly correlated to the extent of interstitial fibrosis (Pearson r: 0.67, P: 0.002, R²: 0.45) and inversely related to estimated glomerular filtration rate (eGFR) (Pearson r: ?0.47, P: 0.0003, R²: 0.22). Stiffness values of patients with an eGFR >50 ml/min were significantly lower than in patients with an eGFR ≤50 ml/min (22.2 ± 11.0 vs. 37.1 ± 14.2 kPa, P: 0.0005). The stiffness values of CAI Banff grades 0–1 differed significantly from grade 2 (P: 0.008) and grade 3 (P: 0.046). Parenchymal stiffness measured by TE reflects interstitial fibrosis in kidney allografts. A longitudinal assessment of parenchymal stiffness might be a powerful tool to identify patients with CAI who benefit from biopsy and consequent adaptation of the immunosuppressive regime.     

Relationship between renal hemodynamic status and aging in patients without diabetes evaluated by renal Doppler ultrasonography

Background

Aging is well known as one of the major causes of a reduced glomerular filtration rate (GFR). The resistive index (RI) measured by renal Doppler ultrasonography (RDU) is thought to be a good indicator of renal vascular resistance induced by arteriosclerosis. In this study, we investigated whether RI could be used to evaluate the pathogenesis of renal damage or the mechanisms of reduction of renal function by aging.

Methods

We investigated the correlation between RI and multiple clinical parameters and the influence of aging on the renal hemodynamic status of 194 in-patients (mean age 66.2 years) who underwent RDU at our hospital between February 2009 and July 2010.

Results

RI was significantly correlated with the age, estimated GFR (eGFR), diastolic blood pressure, pulse pressure, and degree of albuminuria. Subjects aged ≥75 years showed a significantly higher correlation coefficient between eGFR and RI. RI showed a stronger correlation with age in subjects aged ≥75 years compared to eGFR.

Conclusion

The present study showed that renal vascular resistance and intra-renal arteriosclerosis had a greater impact on renal function in older than younger subjects, reflecting the possible mechanisms of renal function reduction due to aging.     

The association between congestive heart failure and chronic renal disease

PURPOSE OF REVIEW: Recent findings on the relationship between congestive heart failure and renal failure are summarized in this review. RECENT FINDINGS: Congestive heart failure is found in about one-quarter of cases of chronic kidney disease. The most common cause of congestive heart failure is ischemic heart disease. The prevalence of congestive heart failure increases greatly as the patient's renal function deteriorates, and, at end-stage renal disease, can reach 65-70%. There is mounting evidence that chronic kidney disease itself is a major contributor to severe cardiac damage and, conversely, that congestive heart failure is a major cause of progressive chronic kidney disease. Uncontrolled congestive heart failure is often associated with a rapid fall in renal function and adequate control of congestive heart failure can prevent this. The opposite is also true: treatment of chronic kidney disease can prevent congestive heart failure. There is new evidence showing the cardioprotective effect of carvedilol in patients on dialysis, and of simvastatin and eplerenone in patients with congestive heart failure. Use of non-steroidal anti-inflammatory drugs doubles the rate of hospitalization in patients with congestive heart failure. Anemia has been found in one-third to half the cases of congestive heart failure, and may be caused not only by chronic kidney disease but by the congestive heart failure itself. The anemia is associated with worsening cardiac and renal status and often with signs of malnutrition. Control of the anemia and aggressive use of the recommended medication for congestive heart failure may improve the cardiac function, patient function and exercise capacity, stabilize the renal function, reduce hospitalization and improve quality of life. Congestive heart failure, chronic kidney disease and anemia therefore appear to act together in a vicious circle in which each condition causes or exacerbates the other. Both congestive heart failure and anemia are often undertreated. Cooperation between nephrologists and other physicians in the treatment of patients with anemic congestive heart failure may improve the quality of care and the subsequent prognosis for both congestive heart failure and chronic kidney disease. SUMMARY: Adequate and early detection and aggressive treatment of congestive heart failure and chronic kidney disease and the associated anemia may markedly slow the progression of both diseases.     

The association between renal stones and fasting: A systematic review

IntroductionFasting is a common cultural practice worldwide for both religious and dietary reasons. However, there is concern that fasting may be a risk factor for the development of renal stones. To date, there has not been a systematic assessment of the literature regarding the association between renal stones and fasting.MethodsWe conducted a systematic review following PRISMA guidelines of three databases: Medline-OVID, EMBASE, and CINAHL. All screening and extraction was completed in parallel with two independent reviewers.ResultsOf the 1501 database citations, a total of 10 observational studies with a total of 9906 participants were included. Nine of the studies were conducted in the context of Islamic fasting during Ramadan, with the majority (7/9) finding that renal colic incidence was unaffected by the month of fasting. In contrast, two studies noted an increased incidence among fasting populations. Two other studies noted that urine metabolites and density were altered with fasting but did not translate into clinical outcomes.ConclusionsBased on the available evidence, it is unlikely that fasting significantly increases the risk of renal stones. Physicians should counsel higher-risk patients on safe fasting practices.     

术中剪切波弹性成像测量脊髓弹性模量的初步研究

目的 :探讨术中剪切波弹性成像(shear wave elastography,SWE)测量脊髓型颈椎病患者脊髓弹性模量变化的可行性与应用价值。方法:对17例行颈椎后路椎管扩大成形术的脊髓型颈椎病患者行术中SWE。其中男11例,女6例;年龄58.18±11.49岁(37~78岁);病程2~180个月(62.06±52.54个月);4例C3/4,4例C4/5,5例C5/6,2例C3/4、C4/5,1例C4/5、C5/6,1例C5/6、C6/7;术前JOA评分为6.5~15分(10.74±2.62分),身体质量指数(BMI)为26.02±3.15kg/m2(19.33~30.76kg/m2),病变节段脊髓扁平率为(40.07±9.43)%(24.14%~52.93%)。术中定量测量正常节段和受压节段脊髓弹性模量的均值(Mean)、最大值(Max)、最小值(Min)及标准差(SD),并重复操作两次,对前后两次测量的数据结果使用组内相关系数(ICC)检验其重测信度。应用配对t检验分析两组弹性模量的差异,使用t检验分析不同性别正常脊髓弹性模量的差异,应用Pearson相关分析患者年龄及BMI与正常节段脊髓弹性模量的关系,应用Pearson相关分析患者病程、脊髓扁平率及JOA评分与受压节段脊髓弹性模量的关系。结果:正常节段脊髓弹性模量ICC为0.964(95%CI:0.902~0.987),受压节段脊髓弹性模量的ICC为0.842(95%CI:0.564~0.943)。受压节段脊髓弹性模量的均值、最大值和最小值均显著低于正常脊髓(P0.01)。患者BMI与正常节段脊髓弹性模量间呈正相关(R~2=0.39,P=0.005),年龄与正常脊髓弹性模量无显著相关性(P=0.88)。男性与女性间正常脊髓弹性模量无显著性差异(P=0.68)。病程、脊髓扁平率、JOA评分与受压节段脊髓弹性模量均无显著相关性(分别为:R~2=0.001,P=0.89;R~2=0.004,P=0.80;R~2=0.11,P=0.19)。结论:术中SWE测量脊髓型颈椎病患者脊髓的弹性模量具有可行性,并发现病变脊髓的弹性模量会有所下降。     

Reduction in connective tissue growth factor by antisense treatment ameliorates renal tubulointerstitial fibrosis

Connective tissue growth factor (CTGF/CCN2) is one of the candidate factors mediating fibrogenic activity of TGF-beta. It was shown previously that the blockade of CTGF by antisense oligonucleotide (ODN) inhibits TGF-beta-induced production of fibronectin and type I collagen in cultured renal fibroblasts. The in vivo contribution of CTGF in renal interstitial fibrosis, however, remains to be clarified. With the use of a hydrodynamics-based gene transfer technique, the effects of CTGF antisense ODN are investigated in rat kidneys with unilateral ureteral obstruction (UUO). FITC-labeled ODN injection via the renal vein showed that the ODN was specifically introduced into the interstitium. At day 7 after UUO, the gene expression of CTGF, fibronectin, fibronectin ED-A, and alpha1(I) collagen in untreated or control ODN-treated obstructed kidneys was prominently upregulated. CTGF antisense ODN treatment, by contrast, markedly attenuated the induction of CTGF, fibronectin, fibronectin ED-A, and alpha1(I) collagen genes, whereas TGF-beta gene upregulation was not affected. The antisense treatment also reduced interstitial deposition of CTGF, fibronectin ED-A, and type I collagen and the interstitial fibrotic areas. The number of myofibroblasts determined by the expression of alpha-smooth muscle actin was significantly decreased as well. Proliferation of tubular and interstitial cells was not altered with the treatment. These findings indicate that CTGF expression in the interstitium plays a crucial role in the progression of interstitial fibrosis but not in the proliferation of tubular and interstitial cells during UUO. CTGF may become a potential therapeutic target against tubulointerstitial fibrosis.     

The association between Staphylococcus aureus and subsequent bronchiectasis in children with cystic fibrosis

Background

Staphylococcus aureus (S. aureus) may be related to more rapid progression of cystic fibrosis (CF) lung disease.

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.     

Association between exercise intensity and renal blood flow evaluated using ultrasound echo

Background

High-intensity exercise reduces renal blood flow (RBF) and may transiently exacerbate renal dysfunction. RBF has previously been measured invasively by administration of an indicator material; however, non-invasive measurement is now possible with technological innovations. This study examined variations in RBF at different exercise intensities using ultrasound echo.

Methods

Eight healthy men with normal renal function (eGFR_cys 114?±?19 mL/min/1.73 m²) participated in this study. Using a bicycle ergometer, participants underwent an incremental exercise test using a ramp protocol (20 W/min) until exhaustion in Study 1 and the lactate acid breaking point (LaBP) was calculated. Participants underwent a multi-stage test at exercise intensities of 60, 80, 100, 120, and 140% LaBP in Study 2. RBF was measured by ultrasound echo at rest and 5 min after exercise in Study 1 and at rest and immediately after each exercise in Study 2. To determine the mechanisms behind RBF decline, a catheter was placed into the antecubital vein to study vasoconstriction dynamics.

Results

RBF after maximum exercise decreased by 51% in Study 1. In Study 2, RBF showed no significant decrease until 80% LaBP, and showed a significant decrease (31%) at 100% LaBP compared with at rest (p?<?0.01). The sympathetic nervous system may be involved in this reduction in RBF.

Conclusions

RBF showed no significant decrease until 80% LaBP, and decreased with an increase in blood lactate. Reduction in RBF with exercise above the intensity at LaBP was due to decreased cross-sectional area rather than time-averaged flow velocity.

     

The association between cytomegalovirus infection and atherosclerotic events in renal transplant recipients

Cytomegalovirus (CMV) infection is a risk factor for arteriosclerosis in renal transplant recipients. We sought to investigate the effects of CMV infection on atherosclerotic events (AE) in renal transplant recipients. This retrospective analysis included 200 patients: 52 women and 148 men of overall mean age of 36.18 +/- 10.23 years who were transplanted at our center between 1998 and 2001. We analyzed demographic features, dialysis duration, diabetes, blood pressure level, body mass index (BMI), medications, and lipid parameters. CMV infection was diagnosed in 23.5% of patients in the first 2 years after transplantation; these patients were followed for 4 years. All patients had been assessed for AE, including previous myocardial infarction, angina, revascularization procedures, intermittent claudication, stroke, or transient ischemic attack. AE occurred in 13% during the follow-up period. CMV infection was more frequent among these patients compared to those without AE, namely 42.3% versus 20.6%, respectively. Although the gender, dialysis duration, serum cholesterol level, presence of acute rejection, and BMI were not associated with AE, age, hypertension, and CMV infection did show a relation. A multivariate analysis by logistic regression revealed mean age and CMV infection to be independent risk factors for AE: odds ratio (OR)=5.6, 95% confidence interval (CI)=1.3 to 24.6 (P=0.02) and OR=4, 95% CI = 1.3 to 12.3 (P=.01). This study suggested that the presence of CMV infection may be a triggering factor for AE in renal transplant recipients.