Serum cystatin C,monocyte/high-density lipoprotein-C ratio,and uric acid for the diagnosis of coronary heart disease and heart failure

BACKGROUND Coronary heart disease(CHD)and heart failure(HF)are the major causes of morbidity and mortality worldwide.Early and accurate diagnoses of CHD and HF are essential for optimal management and prognosis.However,conventional diagnostic methods such as electrocardiography,echocardiography,and cardiac biomarkers have certain limitations,such as low sensitivity,specificity,availability,and cost-effectiveness.Therefore,there is a need for simple,noninvasive,and reliable biomarkers to diagnose CHD and HF.AIM To investigate serum cystatin C(Cys-C),monocyte/high-density lipoprotein cholesterol ratio(MHR),and uric acid(UA)diagnostic values for CHD and HF.METHODS We enrolled 80 patients with suspected CHD or HF who were admitted to our hospital between July 2022 and July 2023.The patients were divided into CHD(n=20),HF(n=20),CHD+HF(n=20),and control groups(n=20).The serum levels of Cys-C,MHR,and UA were measured using immunonephelometry and an enzymatic method,respectively,and the diagnostic values for CHD and HF were evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Serum levels of Cys-C,MHR,and UA were significantly higher in the CHD,HF,and CHD+HF groups than those in the control group.The serum levels of Cys-C,MHR,and UA were significantly higher in the CHD+HF group than those in the CHD or HF group.The ROC curve analysis showed that serum Cys-C,MHR,and UA had good diagnostic performance for CHD and HF,with areas under the curve ranging from 0.78 to 0.93.The optimal cutoff values of serum Cys-C,MHR,and UA for diagnosing CHD,HF,and CHD+HF were 1.2 mg/L,0.9×10^(9),and 389μmol/L;1.4 mg/L,1.0×10^(9),and 449μmol/L;and 1.6 mg/L,1.1×10^(9),and 508μmol/L,respectively.CONCLUSION Serum Cys-C,MHR,and UA are useful biomarkers for diagnosing CHD and HF,and CHD+HF.These can provide information for decision-making and risk stratification in patients with CHD and HF.

Correlations between serum kidney injury molecule-1,cystatin C and immunosuppressants:A cross-sectional study of renal transplant patients in Bahrain

Renal transplant patients receive several immunosuppressive drug regimens that are potentially nephrotoxic for treatment.Serum creatinine is the standard for monitoring kidney function;however,cystatin C(Cys C)and kidney injury molecule-1(KIM-1)have been found to indicate kidney injury earlier than serum creatinine and provide a better reflection of kidney function.Here,we assessed Cys C and KIM-1 serum levels in renal transplant patients receiving mycophenolate mofetil,tacrolimus,sirolimus,everolimus,or cyclosporine to evaluate kidney function.We used both the Chronic Kidney Disease Epidemiology Collaboration(CKD-EPI)2021 equation,which is based on creatinine and combined creatinine with Cys C,and the CKD-EPI 2012 equation,which is based on Cys C alone,to estimate glomerular filtration rate(GFR).Then,we assessed the association between serum KIM-1 and GFR<90 mL per minute per 1.73 m2.We observed significantly higher serum Cys C levels in patients with the elevated serum creatinine,compared with those with normal serum creatinine.The estimated GFRs based on creatinine were significantly higher than those based on the other equations,while a significant positive correlation was observed among all equations.Serum KIM-1 levels were negatively correlated with the estimated GFRs by the CKD-EPI Cys C and the combined creatinine with Cys C equations.A serum KIM-1 level above 0.71 ng/mL is likely to indicate GFR<90 mL per minute per 1.73 m2.We observed a significant correlation between serum creatinine and Cys C in our renal transplant patients.Therefore,serum KIM-1 may be used to monitor renal function when using potentially nephrotoxic drugs in renal transplants.

Evaluating new biomarkers for diabetic nephropathy:Role ofα2-macroglobulin,podocalyxin,α-L-fucosidase,retinol-binding protein-4,and cystatin C

BACKGROUND The intricate relationship between type 2 diabetes mellitus(T2DM)and diabetic nephropathy(DN)presents a challenge in understanding the significance of various biomarkers in diagnosis.AIM To elucidate the roles and diagnostic values ofα2-macroglobulin(α2-MG),podocalyxin(PCX),α-L-fucosidase(AFU),retinol-binding protein-4(RBP-4),and cystatin C(CysC)in DN.METHODS From December 2018 to December 2020,203 T2DM patients were enrolled in the study.Of these,115 were diagnosed with DN(115 patients),while the remaining 88 patients were classified as non-DN.The urinary levels ofα2-MG,PCX,and AFU and the serum concentrations RBP-4 and CysC were measured in conjunction with other relevant clinical indicators to evaluate their potential correlations and diagnostic utility.RESULTS After adjustments for age and gender,significant positive correlations were observed between the biomarkers CysC,RBP-4,α2-MG/urinary creatinine(UCr),PCX/UCr,and AFU/UCr,and clinical indicators such as urinary albumin-to-creatinine ratio(UACR),serum creatinine,urea,24-h total urine protein,and neutrophil-to-lymphocyte ratio(NLR).Conversely,these biomarkers exhibited negative correlations with the estimated glomerular filtration rate(P<0.05).Receiver operating characteristic(ROC)curve analysis further demonstrated the diagnostic performance of these biomarkers,with UACR showcasing the highest area under the ROC curve(AUC^(ROC))at 0.97.CONCLUSION This study underscores the diagnostic significance ofα2-MG,PCX,and AFU in the development of DN.The biomarkers RBP-4,CysC,PCX,AFU,andα2-MG provide promising diagnostic insights,while UACR is the most potent diagnostic biomarker in assessing DN.

Correlation between serum markers and transjugular intrahepatic portosystemic shunt prognosis in patients with cirrhotic ascites

BACKGROUND Individuals with refractory ascites in the context of liver cirrhosis typically face an adverse prognosis.The transjugular intrahepatic portosystemic shunt(TIPS)is an efficacious intervention,but there is a lack of reliable tools for postoperative pro-gnosis assessment.Previously utilized clinical biochemical markers,such as the serum albumin concentration(Alb),sodium(Na+)concentration,and serum creatinine(Scr),have limited predictive value.Therefore,the quest for novel,specific biomarkers to evaluate the post-TIPS prognosis in patients with liver cirrhosis and refractory ascites holds significant practical importance.A retrospective analysis was conducted on 75 patients with liver cirrhosis and refractory ascites who underwent TIPS at our institution from August 2019 to August 2021.These patients were followed up regularly for two years,and the death toll was meticulously documented.The patients were allocated into a survival group(n=45 patients)or a deceased group(n=30 patients)based on their prognosis status.The clinical data of the two groups were collected,and Child-Pugh scores and MELD scores were calculated for analysis.Spearman correlation analysis was carried out to evaluate the correlation of prognosis with Child-Pugh grade,MELD score,and Cys C level.Additionally,a multiple-factor analysis utilizing the Cox proportional hazard model was used to identify independent risk factors affecting the post-TIPS prognosis of patients with liver cirrhosis and refractory ascites.The receiver operating characteristic curve(ROC)ascertained the predictive value of the Cys C concen-tration,Child-Pugh grade,and MELD score for the prognosis of liver cirrhosis with refractory ascites in post-TIPS patients.RESULTS During a 2-year follow-up period,among 75 patients with liver cirrhosis and refractory ascites who underwent TIPS treatment,30 patients(40.00%)passed away.The deceased cohort exhibited heightened aspartate aminotrans-ferase,alanine aminotransferase,total bilirubin,Scr,prothrombin time,Cys C,international normalized ratio,Child-Pugh,and MELD scores compared to those of the survival cohort,while Alb and Na+levels were attenuated in the deceased group(P<0.05).Spearman analysis revealed moderate to high positive correlations between prognosis and Child-Pugh score,MELD score,and Cys C level(r=0.709,0.749,0.671,P<0.05).Multivariate analysis using the Cox proportional hazard model demonstrated that the independent risk factors for post-TIPS prognosis in patients with liver cirrhosis and refractory ascites were Cys C(HR=3.802;95%CI:1.313-11.015),Child-Pugh(HR=3.030;95%CI:1.858-4.943),and MELD(HR=1.222;95%CI:1.073-1.393)scores.ROC analysis confirmed that,compared to those of the classic prognostic models for Child-Pugh and MELD scores,the predictive accuracy of Cys C for post-TIPS prognosis in patients with liver cirrhosis and refractory ascites was slightly lower.This analysis yielded sensitivity and specificity values of 83.33%and 82.22%,respectively.The area under the curve value at this juncture was 0.883,with an optimal cutoff value set at 1.95 mg/L.CONCLUSION Monitoring the serum Cys C concentration is valuable for assessing the post-TIPS prognosis in patients with liver cirrhosis and refractory ascites.Predictive models based on serum Cys C levels,as opposed to Scr levels,are more beneficial for evaluating the condition and prognosis of patients with ascites due to cirrhosis.

Exploring the Role of Serum Cystatin C in Early Detection of Acute Kidney Injury among On-Pump Cardiac Surgery Patients: A Single-Center Investigation in Bangladesh

Background: Acute Kidney Injury (AKI) stands as a prominent postoperative complication in on-pump cardiac surgery, with repercussions on morbidity, mortality, and hospitalization duration. Current diagnostic criteria relying on serum creatinine levels exhibit a delayed identification of AKI, prompting an exploration of alternative biomarkers. Aims and Objectives: This study is designed to overcome diagnostic constraints and explore the viability of serum Cystatin C as an early predictor of Acute Kidney Injury (AKI) in individuals undergoing on-pump cardiac surgery. The investigation aims to establish the relationship between serum Cystatin C levels and the onset of AKI in patients subjected to on-pump cardiac surgery. Primary objectives involve the assessment of the diagnostic effectiveness of serum Cystatin C, its comparison with serum creatinine, and the exploration of its potential for the early identification and treatment of AKI. Methodology: Conducted as a single-center study at the cardiac surgery department of BSMMU in Bangladesh from September 2020 to August 2022, a comparative cross-sectional analysis involved 31 participants categorized into No AKI and AKI groups based on Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Data collection encompassed preoperative, post-CBP (cardiopulmonary bypass) conclusion at 2 hours, postoperative day 1, and postoperative day 2 intervals. Statistical analyses included Chi-squared tests, independent Student’s t-tests, and one-sample t-tests. Significance was set at P Results: The study revealed no significant differences in baseline characteristics between the No AKI and AKI groups, except for CPB time and cross-clamp time. Serum Cystatin C levels in the AKI group exhibited statistical significance at various time points, highlighting its potential as an early detector. Conversely, Serum Creatinine levels in the AKI group showed no statistical significance. The Receiver Operating Characteristic (ROC) curve analysis further supported the efficacy of serum Cystatin C, with an Area under the ROC Curve of 0.864 and a cut-off value of 0.55 (p Conclusion: This study supports the superior utility of serum Cystatin C as an early detector of AKI in on-pump cardiac surgery patients compared to serum creatinine. Its ability to identify AKI several hours earlier may contribute to reduced morbidity, mortality, and healthcare costs. The findings underscore the significance of exploring novel biomarkers for improved post-cardiac surgery renal function assessment.

Detection of decline in estimated glomerular filtration rate in patients with type 2 diabetes by cystatin C-based equations

BACKGROUND Aging population is a significant issue in Viet Nam and across the globe.Elderly individuals are at higher risk of chronic kidney disease(CKD),especially those with diabetes.Several studies found that the estimated glomerular filtration rate(eGFR)determined using creatinine-based equations was not as accurate as that determined using cystatin C-based equations.Cystatin C-based equations may be beneficial in elderly patients with an age-associated decline in kidney function.Early determination of eGFR decline and associated factors would aid in appropriate interventions to improve kidney function in elderly patients with diabetes.AIM To determine the utility of cystatin C-based equations in early detection of eGFR decline and to explore factors associated with eGFR decline in elderly patients with diabetes.METHODS This cross-sectional study included 93 participants aged≥60 years evaluated in Can Tho University of Medicine and Pharmacy Hospital between October 2022 and July 2023,including 47 and 46 participants with and without diabetes respectively,according to the American Diabetes Association criteria for diabetes.The kappa coefficient,Student’s t,Mann-Whitney,χ2,Pearson’s correlation,multivariate logistic regression,and multiple linear regression analyses were employed.RESULTS The eGFRs were lower with the cystatin C-based equations than with the creatinine-based equations.Good agreement was found between the Modification of Diet in Renal Disease(MDRD)and CKD Epidemiology Collaboration(CKD-EPI)2021 creatinine-cystatin C equations(kappa=0.66).In the diabetes group,30%of the participants had low eGFR.Both plasma glucose and glycated hemoglobin were associated with an increased risk of eGFR decline(P<0.05)and negatively correlated with eGFR(P=0.001).By multivariate logistic regression,total cholesterol,and exercise were independently associated with low eGFR.By multiple linear regression,higher plasma glucose levels were correlated with lower eGFR(P=0.026,r=-0.366).CONCLUSION Cystatin C-based equations were superior in the early detection of a decline in eGFR,and the MDRD equation may be considered as an alternative to the CKD-EPI 2021 creatinine-cystatin C equation.Exercise,plasma glucose,and total cholesterol were independently associated with eGFR in patients with diabetes.

胱抑素C在糖尿病肾病早期诊断中的应用

临床上多用测定血清肌酐（SCr）和内生肌酐清除率（CCr）来分析肾小球滤过率（GFR），但影响它们的肾外因素很多。胱抑素C（Cystatin C）是一类小分子蛋白质，在体内由有核细胞产生，不受肾外因素的干扰，其产生速率恒定，且只通过肾小球滤过排泄，具备作为GFR理想标志物的条件，实验研究SCr、CCr、Cystatin C之间的相关性，以阐明Cystatin C在糖尿病肾病早期诊断中的应用价值。

原发性肾小球疾病患者血清、尿Cystatin C与肾脏病理变化的关系

目的探讨在不同病理类型原发性肾小球肾炎(PGN)患者血清、尿Cystatin C(CysC)水平的差异性及其与肾脏病理变化的关系。方法对行经皮肾穿刺患者检测血清和尿中的Cystatin C,分别与肾小球评分以及肾小管间质评分进行相关性分析。结果在不同病理类型PGN中发现,IgA肾病(IgAN)、局灶增生性肾小球病(FSGS)、膜性肾病(MN)患者的血清、尿Cys-tatin C浓度与正常对照组比较差异有统计学意义(P<0.05),血清Cystatin C与肾小球评分有高度相关性,尿Cystatin C与其相关性相对弱,而与肾小管间质评分的强相关性要优于血清Cystatin C。结论在肾脏病理评估中,任一检测血清Cystatin C或尿Cys-tatin C均能很好地反映慢性肾脏病(CKD)的病理情况,尤其对肾小管间质病变有很大的临床意义。

黄葵胶囊对慢性肾脏病患者血清Cystatin C、hs-CRP的影响

目的:观察黄葵胶囊对慢性肾脏病(CKD)患者血清半胱氨酸蛋白酶抑制剂C(Cystatin C)、超敏C反应蛋白(hs-CRP)的影响。方法:将60例明确诊断为CKD的患者随机分为对照组(30例)和治疗组(30例),同时选择20名健康成人作为正常对照组,在基础治疗上加用黄葵胶囊每天3次,每次5粒口服,治疗前、后8周分别检测Cystatin C、hs-CRP、肌酐(Scr)及尿素氮(BUN)。结果:CKD患者血Cystatin C、hs-CRP、Scr及BUN较正常对照组明显增高(P<0.05),常规治疗8周后其CystatinC、hs-CRP、Scr及BUN均有所降低,但差异无统计学意义(P﹥0.05),而加用黄葵胶囊治疗后其Cystatin C、hs-CRP、Scr及BUN明显降低(P<0.05);Cystatin C与GFR呈负相关,与hs-CRP呈正相关。结论:黄葵胶囊可改善早期CKD患者的肾功能和炎症状态,有利于延缓CKD的进展。

胱抑素C的检测与应用

胱抑素C(Cystatin C)是一种低分子量非糖化碱性蛋白质,自20世纪80年代中期以来,通过大量研究表明,其具有影响因素少,特异性高,准确性好,更能及时反映肾小球滤过率变化理想的内源性标志物,它存在于各种体液之中,对其检测有多种方法,在肾功能、肿瘤、肝硬化、类风湿、肾移植及儿科领域具有更广的临床价值,现作一综述。

Scys C和 Ucys C在危重患者急性肾损伤时的诊断价值及临床意义

目的：探讨危重患者急性肾损伤（AKI）时血清胱抑素C（Scys C）及尿胱抑素C （ Ucys C）的水平变化。方法收集2013－05～2014－05我院ICU 141例危重患者资料，选取出现AKI的患者32例作为AKI组，未出现AKI的患者109例作为非AKI组，比较两组患者SCys C及UCys C水平。采用Spearman’s相关分析Scys C、Ucys C、Scr及APACHEⅡ评分之间相关性，绘制受试者工作特征ROC曲线并计算曲线下面积，分析血尿胱抑素C（ cystation C）对危重患者AKI的诊断价值，根据AKI患者Scys C和Ucys C升高率，判断其对AKI诊断价值的差异。结果①AKI组与非AKI组患者Scys C、Ucys C、Scr和APACHEⅡ评分比较差异均有统计学意义（ P＜0．05）。②Spearman’s相关分析显示，Scys C和Ucys C无相关性（P＞0．05）。③危重患者AKI影响因素的ROC曲线分析显示，Scys C和Ucys C曲线下面积分别为0．848和0．810。④χ2检验显示，AKI组患者Scys C和Ucys C升高率比较差异无统计学意义（ P＞0．05）。结论血尿Cys C可以作为重症患者发生AKI的诊断指标。 Scys C及Ucys C作为重症患者发生AKI的诊断指标时差异无统计学意义。

Cystatin C的临床应用

Cystatin C(Cys C)称半胱氨酸蛋白酶抑制剂C,是一种非糖基化蛋白,分子量为13.359KDa,由有核细胞产生,在人体大部分组织中稳定表达,广泛存在于各种体液中,在脑脊液和精液中的浓度最高,尿液中最低.……

Cystatin C敲除诱导的长爪沙鼠抑郁模型

目的内源半胱氨酸蛋白酶抑制剂Cystatin C(CysC)由CST3基因编码,在脑中高表达,在多种神经病理过程中具有保护作用。本文旨在观察敲除(knock out,KO)长爪沙鼠CysC基因能否诱导动物的抑郁模型,并探讨模拟病理条件下CysC对内皮细胞和神经细胞的保护作用。方法使用qPCR验证CysC敲除(CysC-KO)沙鼠不同组织中CysC的转录水平;通过糖水偏好、社会互交、新物体识别、明暗箱和旷场实验,评估CysC-KO对长爪沙鼠行为的影响;分别在缺氧和饥饿(H&S)、氧糖剥夺/复氧(OGD/R)或炎症因子刺激(TNF-α/LPS)模拟的病理条件下,利用MTT法检测CysC或其抑制剂对人脐静脉内皮细胞(HUVEC)和小鼠神经母细胞瘤细胞(N2a)活力的影响。结果在CysC-KO长爪沙鼠的各种组织中CysC表达显著降低,尤其是大脑。长爪沙鼠的CysC缺失,可通过年龄依赖的方式诱导沙鼠的抑郁样行为,但其运动和探索行为未见异常。CysC在H&S、OGD/R和炎症条件下,能显著改善内皮细胞和神经细胞的增殖;而抑制CysC则具有相反作用。结论敲除CysC的长爪沙鼠表现出抑郁样行为,这可能是血管内皮细胞和神经元细胞失去CysC的保护作用引起。这些结果为研究CysC在抑郁发生中的作用机制提供了新的长爪沙鼠模型。

鲢鱼重组cystatin C的抑菌活性及抑菌机理初探

cystatins是一类天然抗菌蛋白,广泛分布于鱼类加工废弃组织。采用滤纸片扩散法和二倍稀释法,评价了鲢鱼(Hypophthalmichthys molitrix)重组cystatin C(HmCystatin C)对6株常见的水产品腐败菌的抑菌活性;并以铜绿假单胞菌和腐生葡萄球菌为典型受试菌,测定HmCystatin C与菌体及其细胞壁成分脂多糖(lipopolysaccharides,LPS)和肽聚糖(peptidoglycan,PGN)的结合情况,及对受试菌生长曲线、细胞壁、细胞质膜通透性的影响,初步探讨其抑菌机制。结果表明,HmCystatin C对除枯草芽孢杆菌外的5株腐败菌均具抑制作用,对典型受试菌的最低抑菌浓度(minimum inhibitory concentration,MIC)及最低杀菌浓度(minimal bactericide concentration,MBC)均为3.5 mg/mL;HmCystatin C能与典型受试菌结合,并且对LPS和PGN表现出亲和性。此外典型受试菌的细胞壁和细胞质膜被破坏,胞内物质渗出。因此推测HmCystatin C可能首先吸附到菌体表面并与细胞壁成分结合,进而破坏细胞完整性,导致内容物外泄后菌体死亡。该结果为阐明鱼类cystatins抑菌机制奠定实验基础,也为综合利用鱼源cystatins提供理论参考。

The Role of High-sensitivity C-reactive Protein, Interleukin-6 and Cystatin C in Ischemic Stroke Complicating Atrial Fibrillation

This study examined the role of high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and cystatin C in ischemic stroke complicating atrial fibrillation (AF) and the relationship of systemic inflammation with this disease in order to identify AF patients who are at high risk of stroke and need optimal anticoagulant therapy.A total of 103 AF patients, simple (n=75) or complicated by ischemic stroke (n=28), and 112 control subjects were recruited.IL-6 level was detected by using enzyme linked immunosorbent assay.Cystatin C and hsCRP levels were measured by means of a particle-enhanced immunonephelometric assay.The results showed that the AF patients had higher levels of hsCRP (P=0.004), IL-6 (P=0.000), and cystatin C (P=0.000) than control subjects.Plasma hsCRP level was increased in the AF patients with ischemic stroke as compared to the patients with simple AF (P=0.036).The AF patients who had the level of hsCRP exceeding 3.83 mg/L were at a higher risk than those with hsCRP level lower than 3.83 mg/L (P=0.030).After adjusting for other factors, cystatin C remained positively associated with IL-6 (r=0.613) and hsCRP (r=0.488).It was concluded that hsCRP is positively correlated with ischemic stroke complicating AF and may be a risk factor independent of other risk factors for AF.Elevated cystatin C level is also indicative of the increased risk of AF.

Association between high cystatin C levels and carotid atherosclerosis

AIM To investigate the association between carotid atherosclerosis and cystatin C(CysC) and to determine the optimal CysC cut-off value.METHODS One hundred twenty-eight subjects were included in this study. Atherosclerosis was defined as a maximum carotid plaque thickness(MCPT) of greater than 2 mm. A receiver operating characteristic curve analysis was used to determine the diagnostic value of serum CysC for atherosclerosis. The subjects were divided into two groups according to the CysC cut-off value. We screenedfor diabetes, hypertension, dyslipidemia, smoking status, alcohol consumption, and exercise behavior. The association between atherosclerosis and CysC levels was assessed using multivariate analysis.RESULTS The subjects were then divided into two groups according to the CysC cut-off value(0.73 mg/L). The median age of the high CysC group was 72 years(85% males), whereas that of the low CysC group was 61 years(63% males). The CysC levels were significantly correlated with Cr and estimated glomerular filtration rate(eGFR) values. Bodymass index, visceral fat area, hypertension, diabetes mellitus, and MCPT were significantly higher in the high CysC group than in the low CysC group. Furthermore, the eG FR was significantly lower in the high CysC group. Regarding lifestyle habits, only the exercise level was lower in the high CysC group than in the low CysC group. Multivariate analysis, adjusted for age and sex, revealed that high CysC levels were significantly associated with an MCPT of ≥ 2 mm(odds ratio: 2.92; 95%CI: 1.13-7.99).CONCLUSION Higher CysC levels were associated with an MCPT of ≥ 2 mm. The CysC cut-off value of 0.73 mg/L appears to aid in the diagnosis of atherosclerosis.

Evaluation of renal function in patients with cirrhosis:Where are we now?

In the clinical context of the patients with liver cirrhosis, accurate evaluation of the renal function is potentially crucial. Indeed, it can lead to early diagnosis of both acute kidney injury and chronic kidney disease and to reliable characterization of the renal status of the patient before performing a liver transplantation. Despite some limitations, the assay of serum creatinine (SCr) is universally used to estimate glomerular filtration rate (GFR) because of its wide availability, its simplicity and because it is inexpensive. Nevertheless, several reports show that the value of this assay to estimate GFR is strongly challenged in cirrhotic patients, especially in patients with liver failure and/or severely impaired renal function. This has led to seek new alternatives to estimate more reliably the GFR in these patients. Although the reference methods, based on the utilization of exogenous markers, allow measuring GFR and thereby constitute the &#x0201c;gold standard&#x0201d; to evaluate renal function, they are not feasible in routine clinical practice. Several studies have shown that a cystatin C (CysC) based formula perform better than the SCr-based estimates in cirrhotic patients and the estimation of GFR by these formulas could therefore lead to optimize the management of the patients. A new estimate based on CysC has been recently developed using a large number of patients and the first results regarding the evaluation of its performance are promising, making this new formula the best candidate for a reference estimate of the renal function in cirrhotic patients.

Cystatin C and serum creatinine in estimating acute kidney injury of shock patients

BACKGROUND： Serum creatinine （SCr） is the most commonly used parameter to estimate renal function impairement, but there are some shortcomings. Many factors including age, gender, drug, diet, muscle mass and metabolic rate can in？ uence SCr, leading to an inaccurate estimation of kidney impairment. Studies have shown that cystatin C （CysC） is not affected by factors such as muscle mass, age, gender, diet, in？ ammation or tumor. The present study was undertaken to compare the sensitivity of CysC and SCr in evaluating renal function impairment at early stage of shock.METHODS： Seventy-one patients aged 38.3±21.4 years, who had been treated at the Emergency Medicine Department of the First Affiliated Hospital, Sun Yat-sen University between February 2006 and June 2007, were studied. They were divided into groups A, B, C, and D according to the shock time. Serum sample was drawn from each patient at 1, 2, 3, 4 hours after shock to determine SCr and CysC. CysC and SCr were determined again at 72 hours and 7 days after shock.RESULTS： CysC increased earlier than SCr in the 71 patients, and CysC decreased slower than SCr when shock was corrected. CysC increased at 1 hour after shock. There was a negative correlationship between CysC, SCr and glomerular filtration rate （GFR）, especially at early stage of shock.CONCLUSIONS： There is renal injury at early stage of shock. CysC is more sensitive than SCr in assessing renal function at the early stage of shock.

Prognostic indicators of patients with acute kidney injury in intensive care unit

BACKGROUND： Acute kidney injury （AKI） is associated with a high mortality. This study was undertaken to detect the factors associated with the prognosis of AKI.METHODS： We retrospectively reviewed 98 patients with AKI treated from March 2008 to August 2009 at this hospital. In these patients, 60 were male and 38 female. Their age ranged from 19 to 89 years （mean 52.4±16.1 years）. The excluded patients were those who died within 24 hours after admission to ICU or those who had a history of chronic kidney disease or incomplete data. After 60 days of treatment, the patients were divided into a survival group and a death group. Clinical data including gender, age, history of chronic diseases, the worst laboratory values within 24 hours after diagnosis （values of routine blood tests, blood gas analysis, liver and renal function, levels of serum cystatin C, and blood electrolytes） were analyzed. Acute physiology, chronic health evaluation （APACHE） II scores and 60-day mortality were calculated. Univariate analysis was performed to find variables relevant to prognosis, odds ratio （OR） and 95% confidence interval （CI）. Multiple-factor analysis with logistic regression analysis was made to analyze the correlation between risk factors and mortality.RESULTS： The 60-day mortality was 34.7% （34/98）. The APACHE II score of the death group was higher than that of the survival group （17.4±4.3 vs. 14.2±4.8, P〈0.05）. The mortality of the patients with a high level of cystatin C〉1.3 mg/L was higher than that of the patients with a low level of cystatin C （〈1.3 mg/L） （50% vs. 20%, P〈0.05）. The univariate analysis indicated that organ failures≥2, oliguria, APACHE II〉15 scores, cystatin C〉1.3 mg/L, cystatin C〉1.3 mg/L＋APACHE II〉15 scores were the risk factors of AKI. Logistic regression analysis, however, showed that organ failures≥2, oliguria, cystatin C〉1.3 mg/L ＋APACHE II〉15 scores were the independent risk factors of AKI.CONCLUSION： Cystatin C〉1.3 mg/L＋APACHE II〉15 scores is useful in predicting adverseclinical outcomes in patients with AKI.

Association between cystatin C and diabetic retinopathy among type 2 diabetic patients in China: a Meta-analysis

AIM:To explore the correlation between cystatin C(Cys-C)and diabetic retinopathy(DR)in those patients with type 2 diabetes mellitus(DM)in China.METHODS:Articles were collected from China National Knowledge Infrastructure(CNKI),Wanfang,VIP,Pub Med,EMBASE,Cochrane Library,Clinical Trials.gov,and Google Scholar.Quality and risk of bias within included studies was assessed using the Newcastle-Ottawa scale(NOS).Heterogeneity was determined by using Cochran’s Q-test and Higgins I^(2) statistics.Mean differences(MDs)and 95%confidence intervals(CIs)of Cys-C within the diabetes without retinopathy(DWR)and DR,DWR and non-proliferative diabetic retinopathy(NPDR),NPDR and proliferative diabetic retinopathy(PDR)were collected by using random-effects model because of high heterogeneity.Meta-analysis was conducted based on 23 articles of 2331 DR including NPDR and PDR patients and 2023 DWR patients through Review Manager 5.3.Subgroup analyses were also performed according to DM duration,body mass index(BMI),total cholesterol(TC),total triglycerides(TG),low-density lipoprotein C(LDL-C),and high-density lipoprotein C(HDL-C),sample origins and methods.Publication bias was assessed by the funnel plot.RESULTS:Cys-C level in DR patients was increased compared with that of DWR(total MD:0.69,95%CI:0.41 to 0.97,Z=4.79,P<0.01).Besides,the synthesized results of the studies showed the similar findings in the DWR vs NPDR group(total MD:0.29,95%CI 0.20 to 0.39,Z=6.02,P<0.01)and the NPDR vs PDR group(total MD:0.63,95%CI 0.43 to 0.82,Z=6.33,P<0.01).Heterogeneity of most of the subgroup analyses was still obvious(I^(2)≥50%,P<0.1).Forest plots of different subgroups indicated that there was a slight increase of Cys-C during the period between DWR and DR,DWR and NPDR,NPDR and PDR.Funnel plot showed that there was no significant publication bias.CONCLUSION:The elevated Cys-C is closely related with DR and probably plays a critical role in its progression.