Creatinine clearance, urinary excretion of glomerular basement membrane antigens and renal histology in congenital nephrotic syndrome of Finnish type

The endogenous creatinine clearance and urinary excretion rate of glomerular basement membrane (GBM) antigens were followed from 2 to 19 months in fifteen patients with congenital nephrotic syndrome (CNF). The quantitative examination of renal morphology was made on fourteen of these patients. Creatinine clearance increased during the first few months of life and thereafter gradually decreased. The urinary excretion rate of GBM antigens rose during the course of the disease. The creatinine clearance did not correlate significantly with glomerular fibrosis but it did correlate with tubular atrophy and interstitial fibrosis. The urinary excretion of GBM antigens correlated significantly with glomerular and interstitial fibrosis and with tubular atrophy. It is concluded that there is a clear progress in the disease and the renal histological changes probably are caused by accumulation of GBM material in glomeruli.     

Targeted expression of a dominant-negative EGF-R in the kidney reduces tubulo-interstitial lesions after renal injury

The role of EGF in the evolution of renal lesions after injury is still controversial. To determine whether the EGF expression is beneficial or detrimental, we generated transgenic mice expressing a COOH-terminal-truncated EGF-R under the control of the kidney-specific type 1 gamma-glutamyl transpeptidase promoter. As expected, the transgene was expressed exclusively at the basolateral membrane of proximal tubular cells. Under basal conditions, transgenic mice showed normal renal morphology and function. Infusion of EGF to transgenic animals revealed that the mutant receptor behaved in a dominant-negative manner and prevented EGF-signaled EGF-R autophosphorylation. We next evaluated the impact of transgene expression on the development of renal lesions in two models of renal injury. After 75% reduction of renal mass, tubular dilations were less severe in transgenic mice than in wild-type animals. After prolonged renal ischemia, tubular atrophy and interstitial fibrosis were reduced in transgenic mice as compared with wild-type mice. The beneficial effect of the transgene included a reduction of tubular cell proliferation, interstitial collagen accumulation, and mononuclear cell infiltration. In conclusion, functional inactivation of the EGF-R in renal proximal tubular cells reduced tubulo-interstitial lesions after renal injury. These data suggest that blocking the EGF pathway may be a therapeutic strategy to reduce the progression of chronic renal failure.     

102例IgA肾病蛋白尿与病理临床分析

目的探讨蛋白尿对IgA肾病病理改变和临床指标的影响及其相关性。方法回顾性分析郑州大学第一附属医院肾内科102例IgA肾病患者的病理和临床资料,探讨其相关性。结果蛋白尿与牛津分型中毛细血管内增生、节段性的肾小球硬化、肾小管萎缩/间质纤维化、球性硬化、新月体病变的病理改变存在相关性,与肾功能、免疫荧光分型存在相关性,而与高血压、血清IgA、C3水平不存在相关性。结论随着蛋白尿的增多,肾脏毛细血管内增生、肾小管萎缩/间质纤维化、球性硬化等病理改变加重,且肾功能也会随之恶化。     

RANTES and Monocyte Chemoattractant Protein–1 (MCP-1) Play an Important Role in the Inflammatory Phase of Crescentic Nephritis,but Only MCP-1 Is Involved in Crescent Formation and Interstitial Fibrosis

The involvement of chemokines in inflammation is well established, but their functional role in disease progression, and particularly in the development of fibrosis, is not yet understood. To investigate the functional role that the chemokines monocyte chemoattractant protein–1 (MCP-1) and RANTES play in inflammation and the progression to fibrosis during crescentic nephritis we have developed and characterized a murine model for this syndrome. Significant increases in T-lymphocytes and macrophages were observed within glomeruli and interstitium, paralleled by an induction of mRNA expression of MCP-1 and RANTES, early after disease initiation. Blocking the function of MCP-1 or RANTES resulted in significant decreases in proteinuria as well as in numbers of infiltrating leukocytes, indicating that both MCP-1 and RANTES (regulated upon activation in normal T cells expressed and secreted) play an important role in the inflammatory phase of crescentic nephritis. In addition, neutralization of MCP-1 resulted in a dramatic decrease in both glomerular crescent formation and deposition of type I collagen. These results highlight a novel role for MCP-1 in crescent formation and development of interstitial fibrosis, and indicate that in addition to recruiting inflammatory cells this chemokine is critically involved in irreversible tissue damage.Rapidly progressive glomerulonephritis (GN)¹ is characterized by glomerular inflammation and the formation of glomerular crescents, composed of a pleiomorphic infiltrate of mononuclear inflammatory cells and proliferating parietal epithelial cells. These crescents encroach on the urinary space and compress the glomerular tuft causing acute renal failure. This process is almost always associated with severe interstitial and periglomerular inflammation. Spontaneous recovery is rare. More typically, the inflammatory infiltrate gives way to a progressive fibrotic process involving the crescents and the periglomerular and peritubular interstitium, accompanied by tubular atrophy and progressive renal failure. Indeed, clinical studies of patients with glomerular diseases have shown a close correlation between the degree of interstitial fibrosis and the likelihood of chronic renal failure (1, 2).Although the pathogenesis of crescentic glomerulonephritis is incompletely understood and likely involves several convergent pathways, there is general agreement that circulating mononuclear phagocytes play a central role (3, 4). Administration of nephrotoxic serum to rats results in a severe proliferative and necrotizing GN that is characterized by glomerular crescent formation and accumulation of leukocytes (5). These infiltrating cells may then release inflammatory mediators that influence the behavior of glomerular, tubular, and interstitial cells. This interaction between infiltrating and resident cells leads to cellular proliferation, matrix expansion, and may ultimately lead to glomerular sclerosis and interstitial fibrosis.Chemokines are a superfamily of small proteins that are important in recruiting and activating leukocytes during inflammation (6). The chemokines RANTES (regulated upon activation in normal T cells expressed and secreted) and monocyte chemoattractant protein–1 (MCP-1) attract mainly T lymphocytes and mononuclear phagocytes, respectively (7, 8). In vivo, stimulated renal cells are capable of generating both of these chemokines (9, 10, 11), and both have been found to be expressed during models of renal injury (12, 13, 14). Several other chemokines including macrophage inflammatory protein-2 (MIP-2), platelet factor 4, interferon-inducible protein 10 kD (IP-10), and cytokine- induced neutrophil chemoattractant (CINC), have been demonstrated to precede the initial neutrophil influx in experimental anti-GBM GN (15, 16). Studies with neutralizing antibodies show that inhibition of CINC, MIP-2, or MCP-1/JE activity decreases neutrophil accumulation with an associated decline in proteinuria during the first 24 h of disease (17). However, all of these studies concentrate on the acute phase of the disease occurring within the first 24 h of the treatment. Moreover, all of these studies have focused on glomerular changes and do not explore the role that interstitial cells are likely to play in the development of disease throughout the whole cortex. Interstitial cells are important mediators of inflammatory and fibrotic pathways, and the factors that they secrete are likely to be integrally involved in the development of pathology during nephritis (18). Therefore, the in vivo role of chemokines in both disease induction and development remains to be established. In particular, the role of chemokines in the progression from inflammation to fibrosis is unclear.In this study, we have developed and characterized a murine model of accelerated nephrotoxic serum nephritis, determined the nature of the leukocytic infiltration, and analyzed the expression of chemokines during the progression of acute glomerular injury to glomerular crescent formation and renal fibrosis. In addition, we have determined the functional role of the β chemokines MCP-1 and RANTES in the development of glomerular and interstitial inflammation and crescent formation, as well as in the evolution of the ensuing fibrosis.     

Relationship between blood neutrophil‐lymphocyte ratio and renal tubular atrophy/interstitial fibrosis in IgA nephropathy patients

BackgroundThe study aimed to explore the relationship between neutrophil‐lymphocyte ratio(NLR) in peripheral blood and renal tubular atrophy/interstitial fibrosis and to evaluate the clinical significance of NLR in IgA nephropathy (IgAN) patients.MethodsA Total of 263 IgAN patients were included. The participants were categorized into four groups based on quartile of NLR. The clinical data, pathological features, and 2‐year renal survival rates were compared among the four groups. The independent factors affecting renal tubular atrophy/interstitial fibrosis in IgAN were determined by multivariate linear regression analysis.ResultsThe percentage of renal tubular atrophy/interstitial fibrosis increased with the increase of NLR level (p=0.003). The tubular atrophy/interstitial fibrosis score T1 and T2 in Group Q4 was 40%, which was higher than that of other groups, especially Group Q1 (22.73%, p=0.033) and Group Q3 (22.39%, p=0.029). NLR [β=1.230, 95%CI (0.081, 2.379), p=0.036] might be an independent factor affecting renal tubular atrophy/interstitial fibrosis in IgAN. The area under curve predicted by NLR was 0.596 (95%CI 0.534~0.656, p=0.007) with the specificity 88.24% and the optimal critical value of NLR 3.25. Fourteen patients progressed to end‐stage renal disease within 2 years, and the 2‐year survival rate of kidney was 93.49%. The renal survival rate in Group Q4 was 87.04%, lower than that in other three groups, especially Group Q1 (98.11%, p=0.029).ConclusionNLR was correlated with the level of renal tubular atrophy/interstitial fibrosis and might be a significant factor for predicting the prognosis in the IgAN.Background: IgA nephropathy (IgAN) is an important cause of the end stage renal disease (ESRD). The study aimed to explore the relationship between neutrophil‐lymphocyte ratio (NLR) in peripheral blood and renal tubular atrophy/interstitial fibrosis, and to evaluate the clinical significance of NLR in IgA nephropathy (IgAN) patients. Methods: Total 263 IgAN patients confirmed by renal biopsy pathology were included from January 2013 to May 2018 in Ningbo Hwamei Hospital, University of Chinese Academy of Sciences. The peripheral blood samples were taken from these participants and the NLR was analyzed. The participants were categorized into four groups based on the median and upper and lower quartile of NLR, which were Group Q1 (NLR<1.64), Group Q2 (1.64≤NLR<2.19), Group Q3 (2.19≤NLR<3.00), and Group Q4 (NLR≥3.00), respectively. The clinical data and pathological features were compared among four groups. The independent factors affecting renal tubular atrophy/interstitial fibrosis in IgAN were determined by multivariate linear regression analysis. The diagnostic ability of NLR for renal tubular atrophy/interstitial fibrosis was evaluated by the area under receiver operating characteristic curve (AUC). The 2‐year renal survival rates were compared among the four groups. Results: The levels of white blood cell count, neutrophil count, highly sensitive C‐reactive protein, and the percentage of renal tubular atrophy/interstitial fibrosis were increased while lymphocyte count and estimated glomerular filtration rate were decreased with the increase of NLR level (P < 0.05). The percentage of tubular atrophy/interstitial fibrosis 26%–50% (T1) and >50% (T2) in Group Q4 was 40%, which was higher than that of other groups, especially Group Q1 (22.73%) and Group Q3 (22.39%), with significant difference (P < 0.05). NLR [β = 1.230, 95%CI (0.081, 2.379), P = 0.036] might be an independent factor affecting renal tubular atrophy/interstitial fibrosis in IgAN according to multivariate linear regression analysis results. The AUC predicted by NLR was 0.596 (95%CI 0.534~0.656, P = 0.007) with the specificity 88.24%, the sensitivity 30.00% and the optimal critical value of NLR 3.25. Fourteen patients progressed to end‐stage renal disease within 2 years; and the 2‐year survival rate of kidney was 93.49%. The renal survival rate in Group Q4 was 87.04%, lower than that in other three groups, especially Group Q1 (98.11%), with significant difference (P < 0.05). Conclusion: NLR was correlated with the level of renal tubular atrophy/interstitial fibrosis and might be an significant factor for predicting the prognosis in IgAN.     

Anti–microRNA-21 oligonucleotides prevent Alport nephropathy progression by stimulating metabolic pathways

MicroRNA-21 (miR-21) contributes to the pathogenesis of fibrogenic diseases in multiple organs, including the kidneys, potentially by silencing metabolic pathways that are critical for cellular ATP generation, ROS production, and inflammatory signaling. Here, we developed highly specific oligonucleotides that distribute to the kidney and inhibit miR-21 function when administered subcutaneously and evaluated the therapeutic potential of these anti–miR-21 oligonucleotides in chronic kidney disease. In a murine model of Alport nephropathy, miR-21 silencing did not produce any adverse effects and resulted in substantially milder kidney disease, with minimal albuminuria and dysfunction, compared with vehicle-treated mice. miR-21 silencing dramatically improved survival of Alport mice and reduced histological end points, including glomerulosclerosis, interstitial fibrosis, tubular injury, and inflammation. Anti–miR-21 enhanced PPARα/retinoid X receptor (PPARα/RXR) activity and downstream signaling pathways in glomerular, tubular, and interstitial cells. Moreover, miR-21 silencing enhanced mitochondrial function, which reduced mitochondrial ROS production and thus preserved tubular functions. Inhibition of miR-21 was protective against TGF-β–induced fibrogenesis and inflammation in glomerular and interstitial cells, likely as the result of enhanced PPARα/RXR activity and improved mitochondrial function. Together, these results demonstrate that inhibition of miR-21 represents a potential therapeutic strategy for chronic kidney diseases including Alport nephropathy.     

Contribution of irreversible morphological changes of different renal structures to development of anemia in immune glomerulopathies

AIM: To find out correlations between severity of sclerotic affection of the glomeruli, tubules, interstitium, vessels and development of anemia in patients with glomerulopathy. MATERIAL AND METHODS: Assay of global and segmentary sclerosis, semiquantitative morphometry of severity of atrophic tubular changes, diffuse interstitial fibrosis, vascular changes (arteriolohyalinosis, elastofibrosis and perivascular sclerosis) were made in parallel with analysis of clinical laboratory data in 276 cases of chronic primary glomerulopathy with morphologically verified diagnosis by vital renal biopsy. RESULTS: Hemoglobin concentration and advance of anemia correlate negatively with severity of diffuse interstitial fibrosis and atrophic tubular alterations. However, no correlation was found between onset of anemia, severity of global and segmental glomerular sclerosis, the presence of vascular changes in the form of arteriolar hyalynosis, elastofibrosis of small arteries and perivascular sclerosis. CONCLUSION: The findings suggest that development of anemia in patients with primary glomerulopathy may be the result of structural-functional disturbances in tubular epithelium and renal stroma.     

Uremic toxins overload accelerates renal damage in a rat model of chronic renal failure

Uremic toxins have been suggested to promote progression of chronic renal failure by damaging tubular cells. Previous in vitro studies have indicated that some uremic toxins induce oxidative stress and activate NF-kappaB to upregulate plasminogen activator inhibitor-1 in tubular cells. These mechanisms may promote tubulointerstitial fibrosis. The present study examined whether uremic toxins induce glomerular and tubulointerstitial damage in vivo. Two uremic toxins, hippuric acid (HA) or indoleacetic acid (IAA), were tested in two independent experiments (HA-treated rats vs. non-HA-treated controls, IAA-treated rats vs. non-IAA-treated controls). The uremic toxins were administered to subtotally nephrectomized rats. Renal functions were measured periodically and glomerular sclerosis and interstitial fibrosis were examined at the end of the experimental period (18 and 24 weeks, respectively, after subtotal nephrectomy for HA and IAA treatments). Glomerular filtration rate (inulin clearance) at the end of the study period was significantly lower in uremic toxin-treated rats than in control rats (HA-treated rats: 0.090 +/- 0.004 ml/min/100 g body weight vs. non-HA-treated controls: 0.125 +/- 0.013, IAA-treated rats: 0.068 +/- 0.006 versus non-IAA-treated controls: 0.100 +/- 0.013; both p < 0.05). Beta-N-acetyl-glucoseamidase excretion was significantly higher in uremic toxin-treated rats than in control rats (HA-treated: 0.55 +/- 0.05 U/day vs. control: 0.39 +/- 0.04 at week 18, IAA-treated: 0.35 +/- 0.02 vs. control: 0.26 +/- 0.07 at week 16; both p < 0.05). Glomerular sclerosis index was significantly higher in uremic toxin-treated rats than in control rats (HA-treated: 0.85 +/- 0.16 versus control: 0.48 +/- 0.10, IAA-treated: 1.13 +/- 0.25 vs. control: 0.57 +/- 0.10; both p < 0.05). Significant enlargement of interstitial fibrosis was observed in indoleacetic acid-treated rats. These results indicate that overload of uremic toxins accelerates the loss of kidney function, glomerular sclerosis and tubulointerstitial injury in a rat model of chronic renal failure. The present study suggests the potential benefit of early intervention to remove various uremic toxins in delaying the onset of end-stage renal failure in patients with progressive renal disease.     

Epstein-Barr virus infection of renal proximal tubule cells: possible role in chronic interstitial nephritis

Chronic interstitial nephritis frequently accompanies renal diseases of different etiologies. Far less common is the entity of primary interstitial nephritis wherein the glomerular and vascular structures of the kidney are not the primary focus of the disease process. Using in situ hybridization and the polymerase chain reaction, we detected DNA from the Epstein-Barr Virus (EBV) exclusively in renal tissue of patients with the idiopathic variety of chronic interstitial nephritis. The EBV genome, but not that of cytomegalovirus or adenovirus, was detected primarily in renal proximal tubule cells. Furthermore, the CD21 antigen, which serves as the receptor for EBV in B lymphocytes, was detected by immunocytochemistry primarily on proximal tubule cells and was markedly upregulated in the EBV-infected tissue. Western blot analysis of primary cultures of normal proximal tubule cells identified a 140-kDa protein, confirming the expression of the CD21 antigen. Colocalization experiments using proximal and distal tubule markers confirmed that EBV DNA and the CD21 antigen are found primarily in proximal tubule cells. EBV infection of renal proximal tubular cells may participate in evoking a cellular immune response that results in a damaged renal interstitium.     

Immunopathology of renal disease

The reviewed information implicates immune mechanisms in a variety of renal glomerular and tubulointerstitial diseases. Antibodies reactive with intrinsic structural or planted endogenous or exogenous antigens, and with circulating endogenous or exogenous antigens can initiate inflammatory capillary injury by localization in glomerular capillary tufts or along tubular basement membranes. This results in activation of mediator systems, including complement, neutrophils and other leukocytes, amines, peptides, and proteases, which result in vascular and tissue alterations. In some instances, nonimmune activation of complement (for instance, by the properdin system) and other mediators of vascular injury may be involved. A role of cellularly mediated immunologic injury in glomerular disease is not clear and remains the subject of considerable current research. More clearly, there is involvement of lymphocytes in tubulointerstitial and interstitial diseases as well as allograft rejection reactions. A rich armamentarium of in-vitro immunologic tests for specific antibodies, immune-complexes, serum complement levels, and renal tissue analysis provides opportunity for enhanced precision of diagnosis and monitoring progress of disease or treatment. Unfortunately, at the present time, there are not many effective therapies specific for most renal glomerular diseases; perhaps in the future better identification of offending environmental or host antigens will result in more effective prevention and treatment. Application of knowledge concerning renal glomerular diseases to the study of hypersensitivity induced tubulointerstitial injury has resulted in increasing understanding of the pathogenesis of interstitial inflammatory disease of the kidney.     

PAX2基因在梗阻性肾病大鼠肾小管上皮细胞重新表达的意义

【目的】探讨PAX2基因在梗阻性肾病大鼠肾小管上皮细胞的重新表达对肾间质纤维化的意义。【方法】80只大鼠随机分为：假手术组（sham组）和模型组（UUO组）各40只。于术后3d、5d、7d、14d（每组10只）处死取肾组织。光镜观察肾脏病理形态改变,免疫组化、Westernblot及realtimePCR检测肾组织PAX2蛋白和mRNA的表达。【结果】①HE和Masson染色观察到UUO组肾间质呈现明显的纤维化。②免疫组化发现sham组肾小管上皮细胞无PAX2表达;UUO组肾小管上皮细胞表达较多;③Westernblot显示PAX2蛋白水平在UU0组术后3d相比sham组明显的增加（P〈0．05）,随着梗阻时间延长PAX2蛋白表达更加明显;④realtimePCR显示,PAX2mRNA与PAX2蛋白的,矗达趋势相同。⑤相关分析：PAX2蛋白水平与肾小管损伤程度呈正相关（r=0．991,P〈0．05）,与肾间质纤维化程度呈正相关（r=0．985,P〈0．05）。【结论】胚胎发育基因PAX2在梗阻性肾病大鼠肾小管存在重新表达;并参与了梗阻性肾病肾小管损伤和肾间质纤维化的过程。     

Macrophage phenotype and renal fibrosis in obstructive nephropathy

Macrophages have classically been recognized as key players that may promote renal fibrosis. However, several recent studies have suggested a beneficial anti-fibrotic role of infiltrating macrophages that acts to preserve renal architecture in the progressive renal scarring associated with obstructive nephropathy. Furthermore, recent investigations indicate a role for macrophages in both inflammation and repair during disease processes and this has superseded the classical injurious view of macrophages. As a result, the exact role of interstitial macrophages upon various facets of renal fibrosis is an important challenge that needs to be addressed. In this article, we discuss the possible beneficial anti-fibrotic role of infiltrating macrophages in obstructive nephropathy and discuss the potential mechanisms that may regulate the effect of macrophages upon renal interstitial fibrosis.     

转化生长因子β1抑制人肾小管上皮细胞的增殖

背景：慢性肾衰竭进展过程中的一个重要病理改变是炎症和纤维化,主要包括肾小球和肾小管的炎症和纤维化。目前大多数研究主要集中于肾小球,对于肾小管病变的研究相对较少。但实际上部分疾病的肾小管病变出现在肾小球病变之前,其对于疾病预后更具有指导意义。目的：观察转化生长因子β1对人类肾小管上皮细胞HK-2增殖的影响,探索转化生长因子β1在肾小管炎症和纤维化方面的作用。方法：将传代培养的HK-2细胞分成空白对照组和转化生长因子β1作用组,分别使用DMEM／F12培养液,以及含转化生长因子β1（2,5,10#g／L）的DMEM／F12培养液培养,在倒置显微镜下观察各组细胞形态的改变,并使用MTT法检测细胞增殖情况。结果与结论：转化生长因子β1能显著抑制人。肾小管上皮细胞的增殖,并促使细胞向纤维样改变,与空白对照组相比差异有显著性意义（P〈0．05）,其抑制增殖作用并不随转化生长因子β1质量浓度的增大而显著增强,作用时间可持续至72h。结果可见转化生长因子β1能够抑制人肾小管上皮细胞的增殖,并具有促进肾间质纤维化的作用。     

Senile nephrosclerosis--does it explain the decline in glomerular filtration rate with aging?

Nephrosclerosis can be defined by the presence of glomerulosclerosis, tubular atrophy, interstitial fibrosis, and arteriosclerosis on renal biopsy. Chronic kidney disease is identified clinically by a reduction in glomerular filtration rate (GFR) and has been characterized histologically by nephrosclerosis. Many relatively healthy older adults have been diagnosed with chronic kidney disease because of a decline in GFR with normal aging. Recent data show that in healthy adults (living kidney donors), nephrosclerosis on renal biopsy does not associate with GFR independent of age. This may be explained by the decline in GFR and nephrosclerosis being universal with aging (i.e. senescence), by structural changes in the kidney other than nephrosclerosis impacting GFR, or by extrarenal factors affecting GFR decline with age. However, the argument that the age-related decline in GFR can be fully explained by the development of nephrosclerosis in a subset of older adults is not supported by existing data.     

血清半胱氨酸蛋白酶抑制剂C与肾脏病理改变的相关性分析

目的通过探讨半胱氨酸蛋白酶抑制剂C(Cys C)、血清肌酐(SCr)与一些重要肾脏病理改变及临床指标的相关性,为Cys C的临床应用提供更多的循证医学证据。方法随机抽取260例肾活检患者,分别分析患者的Cys C、SCr与肾脏病理损害程度(全球硬化、肾小管萎缩、间质纤维化)评分、年龄、血红蛋白(Hb)的相关性。将患者按全球硬化0～4分划分为5组;按肾小管萎缩0～3分划分为4组;按间质纤维化0～3分划分为4组,再分别比较各病理组间Cys C及SCr的变化。结果 Cys C与SCr、全球硬化、肾小管萎缩、间质纤维化、年龄均呈明显正相关(r分别为0.850、0.471、0.592、0.610、0.197,P均<0.01);SCr与全球硬化、肾小管萎缩、间质纤维化均呈明显正相关(r分别为0.501、0.595、0.607,P均<0.01),但SCr与年龄无相关性(r=0.118,P>0.05);Cys C、SCr均与Hb呈明显负相关(r分别为-0.448、-0.369,P均<0.01)。各病理组间Cys C及SCr水平差异均有统计学意义(P均<0.01),随着病理损害程度的增加,各组Cys C及SCr水平也随之增加;当病理损害程度达到1～2分(<50%)时,大多数患者Cys C水平达到或超出参考范围上限,而大多数患者SCr水平仍在参考范围内。结论 Cys C与SCr均能较好地反映患者的肾脏病理损害及肾功能状况,Cys C评价早期肾损伤的敏感性要优于SCr,但两者均存在影响因素。因此在选择评估肾功能的指标时应以患者存在的影响因素为参考,必要时可联合多项指标以提高评估肾功能的准确性。     

Renal tubulointerstitial fibrosis. New thoughts on its development and progression

Current investigation of the pathogenesis of tubulointerstitial injury indicates that both interstitial fibroblasts and renal tubular epithelial cells promote extracellular matrix accumulation. Moreover, two peptides--TGF-beta and angiotensin II--produced locally or delivered in the circulation, appear to play a central role in renal fibrosis. Pharmacologic amelioration of renal fibrosis may require methods directed at multiple factors involved in the fibrotic process, including angiotensin II, TGF-beta, and the proliferation and activation of interstitial fibroblasts.     

IFN-inducible protein 10 (CXCL10) regulates tubular cell proliferation in renal ischemia-reperfusion injury

Although renal tubular cell proliferation after acute tubular necrosis is an important and essential response in the recovery of renal dysfunction in acute renal failure, the precise factors and mechanisms of tubular cell regeneration remain unclear. Here, we describe our studies using a neutralizing antibody (Ab) against interferon-inducible protein of 10 kDa (IP-10; CXCL10) that indicate a role for CXCL10 in tubular cell proliferation after renal ischemia-reperfusion injury. Tissue necrosis and interstitial infiltrating numbers were comparable between anti-CXCL10 Ab-treated and control mice treated with IgG at the 24 and 48 h time points after reperfusion. In contrast, the numbers of Ki67-positive proliferating tubular cells were significantly increased in anti-CXCL10 Ab-treated mice 48 h after reperfusion. In accordance with the in vivo findings,in vitro studies using murine tubular epithelial cells indicated an antiproliferative effect of CXCL10 upon the intensity of cell proliferation and the number of Ki67-positive cells. These data suggest that CXCL10 plays a role in the regulation of tubular cell proliferation following renal ischemia-reperfusion injury.     

Pathophysiology of chronic tubulo-interstitial disease in rats. Interactions of dietary acid load, ammonia, and complement component C3.

The human end-stage kidney and its experimental analogue, the remnant kidney in the rat, exhibit widespread tubulo-interstitial disease. We investigated whether the pathogenesis of such tubulo-interstitial injury is dependent upon adaptive changes in tubular function and, in particular, in ammonia production when renal mass is reduced. Dietary acid load was reduced in 1 3/4-nephrectomized rats by dietary supplementation with sodium bicarbonate (NaHCO3), while control rats, paired for serum creatinine after 1 3/4 nephrectomy, were supplemented with equimolar sodium chloride. After 4-6 wk, NaHCO3-supplemented rats demonstrated less impairment of tubular function as measured by urinary excretory rates for total protein and low molecular weight protein and higher transport maximum for para-aminohippurate per unit glomerular filtration rate, less histologic evidence of tubulo-interstitial damage, less deposition of complement components C3 and C5b-9, and a lower renal vein total ammonia concentration. Such differences in tubular function could not be accounted for simply on the basis of systemic alkalinization, and differences in tubular injury could not be ascribed to differences in glomerular function. Because nitrogen nucleophiles such as ammonia react with C3 to form a convertase for the alternative complement pathway, and because increased tissue levels of ammonia are associated with increased tubulo-interstitial injury, we propose that augmented intrarenal levels of ammonia are injurious because of activation of the alternative complement pathway. Chemotactic and cytolytic complement components are thereby generated, leading to tubulo-interstitial inflammation. Thus, alkali supplementation reduces chronic tubulo-interstitial disease in the remnant kidney of the rat, and we propose that this results, at least in part, from reduction in cortical ammonia and its interaction with the alternative complement pathway.     

Hepatocyte growth factor prevents renal fibrosis and dysfunction in a mouse model of chronic renal disease.

Chronic renal disease (CRD) is generally thought to be incurable, except through renal transplantation, and the number of patients with CRD is on the increase. Glomerulosclerosis and tubulointerstitial fibrosis represent the morphological equivalent of end-stage CRD. In this study, we demonstrated the preventive effect of hepatocyte growth factor (HGF) on the progression of renal dysfunction and fibrosis, using a spontaneous mouse model for CRD (ICGN strain). The mice progressively developed glomerular sclerotic injury, tubular atrophy, and renal dysfunction until they were 17 wk of age. When recombinant HGF was injected into these mice during a 4-wk-period (from weeks 14-17 after birth), DNA synthesis of tubular epithelial cells was found to be 4.4-fold higher than in mice without HGF injection, thereby suggesting tubular parenchymal expansion promoted by HGF. Notably, HGF suppressed the expression of transforming growth factor-beta and of platelet-derived growth factor as well as myofibroblast formation in the affected kidney. Consequently, the onset of tubulointerstitial fibrosis was almost completely inhibited by HGF, while HGF attenuated the progression of glomerulosclerosis, both leading to preventing manifestation of renal dysfunction. From our results, supplement therapy with HGF may be taken into consideration as a novel option for prevention and treatment of CRD.