酶法测定糖化白蛋白及其临床意义

目的评价酶法检测糖化白蛋白(GA)及临床意义。方法检测56名健康者血清GA水平,建立参考范围;检测所有试验者血清丙氨酸转氨酶(ALT)、天门冬氨酸转氨酶(AST)、尿素(Urea)、肌酐(Cr)、血脂[总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)]、空腹血糖(FPG)、餐后2 h血糖(2hPG)、糖化血红蛋白(HbA1 c),统计GA与上述指标间的相关性。用GA高值血清和低值血清评估Luc ica GA-L试剂盒的精密度及其线性。结果健康人群GA值为(14.35±2.00)%;GA与血清ALT、AST、U-rea、Cr、TC、TG、HDL-C和LDL-C的相关系数(r)分别为0.010、0.012、0.003、0.061、-0.039、0.026、-0.038和-0.051,与FPG、2hPG、HbA1 c的r分别为0.818、0.803和0.854,HbA1 c与FPG、2hPG的r为0.845和0.820。健康者、临界者和糖尿病(DM)患者间GA差异有显著性(P<0.001)。该法批内变异系数(CV)<2%,批间CV<5%,线性测定r=0.999 6;结论酶法检测GA有良好的精密度和稀释直线性,且不受血清ALT、AST、Urea及血脂水平的影响,与HbA1 c一样能很好的反映FPG和2hPG水平,适用于监测高危人群和DM患者近期整体血糖水平。     

酶法测定糖化白蛋白的方法学评价及其与糖尿病诊断的相关性研究

目的对酶法测定糖化白蛋白(GA)进行方法学评价,验证其作为临床常规方法的各项性能指标。研究糖尿病患者糖化血红蛋白(HbA1c)和GA的相关性,为糖尿病早期诊断和治疗效果监测提供更好的方法。方法按美国临床实验室标准化协会(CLSI)EP10-A3文件对酶法测定GA的精密度、线性、偏差、互染率、漂移性进行评价。测定336例糖尿病患者GA和HbA1c浓度,研究其变化并进行相关性分析。根据美国糖尿病学会(ADA)标准(HbA1c7%为血糖控制良好、7%~8%为血糖控制一般、8%为血糖控制不佳),采用受试者工作特征(ROC)曲线确定GA/HbA1c比值评估血糖控制程度的临界值。结果酶法测定GA的总平均不精密度为1.62%,平均偏差为7.58%,截距、斜率、非线性、互染率、漂移性均可接受;非线性参数检测高值存在正向偏移,需要进行进一步观察以确认方法的线性性能,但对临床诊断不会带来影响。GA与HbA1c诊断糖尿病的一致性较好,为88.1%;两者相关系数(r)为0.879(P0.01)。ROC曲线显示GA/HbA1c比值评估血糖控制程度的最佳临界值为2.60,敏感性为86.8%、特异性为70.1%;如GA/HbA1c比值2.60,可认为血糖控制不佳。结论酶法测定GA的方法学性能符合常规检测质量标准。GA可用于糖尿病的诊断和疗效评估。GA/HbA1c比值可作为监测血糖控制的补充指标。     

酶法测定糖化血红蛋白的临床应用

目的对在全自动生化分析仪上用酶法测定糖化血红蛋白(HbAlc)进行临床应用评价。方法用高效液相色谱法(HPLC)和酶法测定HbAlc,对其精密度、线性范围、相关性、干扰试验进行分析,以探讨酶法测定HbAlc的可靠性。结果酶法的批内平均变异系数(CV%)为2.54%,批间平均CV%为2.75%(都在允许误差5%的范围内),均低于HPLC法的批内和批间的平均CV%值3.41%和3.55%。HbAlc在4%～16%的范围内线性良好(γ=0.9980),两种方法具有良好的相关性,y(HbAlc)=0.9957x+0.102,r=0.9965,两种方法测定结果差异无统计学意义(P>0.05),酶法测定HbAlc有较高的可靠性;当甘油三酯(TG)<8.9 mmol/L,胆固醇(TC)<8.1 mmol/L,胆红素(TBil)<824μmol/L时,使用酶法测定对结果无干扰。结论酶法比HPLC法具有更好的精密度,且快速、准确,能适用于各种自动化分析仪,易于推广使用。     

酶法测定糖化血红蛋白方法学性能的相关因素研究

目的研究酶法测定糖化血红蛋白(HbA1c)方法性能的相关因素。方法选取2013年5月至2015年5月于该院就诊的100例糖尿病患者作为研究对象,选取同期非糖尿病患者100例,标本选择患者的血清,各浓度均为0.2mL分装待用,将全血标本离心,离心速度800×g,5min。吸取25μL红细胞加入500μL前处理液,充分混匀后由自动生化分析仪进行检测。线性试验采取HbA1c高值标本,用稀释液稀释成1/10、2/10、3/10、4/10、5/10、6/10、7/10、8/10、9/10、10/10,10个梯度,用酶法进行测定。采用SPSS 19.0统计软件对影响酶法测定的基本因素进行单因素分析,并进行Logistic多因素回归分析。结果酶法线性范围是2.5%~15.5%,r=0.992 0;经计算得到酶法的批内精密度CV2.54%,批间精密度CV2.75%。患者在血红蛋白(Hb)、离心速度、抗凝剂种类、储存温度、储存时间方面差异有统计学意义(P0.05)。Logistic多因素回归分析发现,酶法测定HbA1c与Hb、离心速度、抗凝剂种类、储存温度、储存时间具有显著相关性(P0.01)。结论酶法测定HbA1c的方法精确度高,影响其性能的相关因素有Hb、离心速度、抗凝剂种类、储存温度、储存时间,在临床上使用酶法测定HbA1c时注意相关因素。     

酶法糖化血红蛋白试剂盒方法学比对评价

目的评估一种酶法测定糖化血红蛋白（HbAlc）试剂盒的性能。方法酶法测定HbAlc,评价的方法学指标为试剂盒的线性范围、不精密度、抗干扰性、回收率,并分别与免疫法和高效液相（HPLC）法进行相关及偏倚分析。结果该试剂盒的检测在4．3-12．9％呈线性;不精密度测定低、中、高值批内及批间CV在0．89％～1．43％之间,总CV在1．77-2．16％;HbAlc标准为5．5％和10．5％其回收率分别为99．0％、102．1％;干扰实验：维生素C〈500mg／L、胆红素〈400mg／L、溶血素〈5000mg／L、乳糜〈2％时,对结果无明显干扰（干扰率（±5％）。酶法HbAlc与免疫法和HPLC法的测定结果比较其回归方程分别是：Y=1．0417X-0．7187和Y=0．9881X-0．0944,相关系数均为r=0．99,P〈0．05,检验方法之间具有显著的统计学意义,经验证酶法测定HbAlc与免疫法和高效液相法的偏倚都在允许范围内。结论酶法HbAlc试剂盒在不精密度、抗干扰性、线性范围均符合临床要求,与常规方法比较相关良好偏差较小,可完全满足临床对HbAlc检测需求。     

糖化白蛋白、糖化血红蛋白与糖尿病微血管病变的关系及临床意义

目的:探讨糖化白蛋白(glycosylated albumin,GA)、糖化血红蛋白(glycosylated hemoglobin,HbA1c)在糖尿病微血管病变(microvascular complications of diabetes,MVCD)患者中的表达及临床意义。方法:选择辽宁省朝阳市中心医院2017年...     

糖化血红蛋白及糖化白蛋白在妊娠期糖尿病诊断中的价值

目的评估糖化血红蛋白(HbA1c)和血清糖化白蛋白(GA)在妊娠期糖尿病(GDM)患者早期监测中的作用。方法根据美国糖尿病协会(ADA)建议,以口服75 g葡萄糖耐量试验(OGTT)测定值作为诊断GDM的标准,将98例妊娠妇女(孕期22~24周)分为正常妊娠组50例、GDM组48例,同时测定2组的HbA1c和GA,并进行统计学分析及受试者工作特征(ROC)曲线分析。结果 GDM组的HbA1c和GA明显高于正常妊娠组(P0.01)。当HbA1c的Cut-off值为5.15%时,ROC曲线下面积为0.954±0.020,敏感性为87.5%,特异性为92.0%。当GA的Cut-off值12.50%时,ROC曲线下面积为0.910±0.029,敏感性为81.3%,特异性为84.0%。HbA1c和GA联合诊断GDM的敏感性为70.8%、特异性为98.0%。结论当HbA1c5.15%和GA12.50%时,诊断GDM的敏感度和特异性较高。HbA1c和GA联合检测对GDM有重要价值。     

酶法测定糖化血清蛋白浓度

目的：了解酶法测定糖化血清蛋白（GSP）的实验特点。方法：采用酶法测定GSP，并对其方法学进行初步研究及评价。结果：线性41．0－1829．0μmol/L，达正常值8倍；平均回收率98．2％；精密度：批内CV0．99％－1．89％，批间CV2．23％－3．41％；该法（Y）和NBT法（X）比较：Y＝0．395X＋20．7，r=0.953;干扰影响小。结论：该法线性宽，精密度好，所受干扰小，是理想的GSP测定方法。     

糖尿病患者糖化血红蛋白浓度与血浆白蛋白水平的相关性

目的 探讨2型糖尿病患者糖化血红蛋白浓度与血浆白蛋白之间的相关性。方法 用高效液相色谱法检测糖尿病患者糖化血红蛋白（HbAlc）浓度，同时检测血浆白蛋白、球蛋白、空腹血糖（FPC）、肌酐和血红蛋白等。并登记患者年龄、性别、患病年数。结果 患者血浆白蛋白越低，其HbAlc浓度越高。HbAlc浓度与血浆白蛋白水平之间存在显著的负相关性（P〈0.01）。结论 单纯HbAlc水平不能全面反映血浆白蛋白不正常患者的血糖控制水平，这些患者的HbAlc浓度与糖尿病并发症进展程度之间可能会存在一定的差异。     

糖化白蛋白检测在妊娠期血糖监测中的应用

目的 探讨糖化白蛋白（GA）在妊娠期糖尿病（GDM）血糖监测中的作用,为临床应用GA提供参考.方法 对研究对象进行口服葡萄糖50 g负荷试验筛选,结果异常的进一步行75 g葡萄糖耐量试验,同时进行GA以及糖化血红蛋白（HbA1c）检测,并对实验结果进行比较分析.结果 GDM的空腹血糖为（5.79＆#177;0.32）mmol/L,GA为（15.76土1.83）％,HbA1c为（6.1＆#177;0.59）％,均高于正常组（P＜0.05）.GDM组GA、HbA1c阳性率分别为86.7％、73.3％.结论 GA可以作为GDM血糖监测的指标.在对GDM治疗效果的判断上,GA优于HbA1c,且不受红细胞寿命影响.     

Study of glycated amino acid elimination reaction for an improved enzymatic glycated albumin measurement method

BACKGROUND: In order to improve enzymatic glycated albumin measurement, we studied the endogenous glycated amino acid elimination reaction and the new bromocresolpurple (BCP) method for albumin measurement. METHODS: In the assay, endogenous glycated amino acids are first eliminated by oxidation by ketoamine oxidase. Second, glycated albumin is hydrolyzed to glycated amino acids by proteinase digestion, and glycated amino acids are oxidized to produce hydrogen peroxide, which is quantitatively measured. Third, albumin is measured by the new BCP method. Finally, glycated albumin value is calculated as the percentage of glycated albumin in total albumin. RESULTS: Glycated amino acid concentrations in prepared total parenteral nutrition products were increased in direct proportion to storage time and temperature. The glycated amino acid elimination reaction using ketoamine oxidase may be able to eliminate more than 15 mmol/l glycated amino acids. The glycated albumin values of samples calculated from the albumin concentrations using the new BCP method accorded with those calculated with the HPLC method. Fundamental performances (linearity, dilution test, analytical recovery, within-run and between-run CVs, interference study) of the present method were good. Detection of glycated albumin by the present method was significantly correlated with detection of glycated albumin by the high-performance liquid chromatography method (r(p) = 0.995). CONCLUSIONS: This new improved method is free of interference by endogenous glycated amino acids and is unaffected by albumin concentration, and enables more accurate analysis of glycated albumin.     

糖化清蛋白酶法快速检测及其临床意义评价

目的评价糖化清蛋白(GA)的酶法快速检测及其临床应用的意义。方法检测147例2型糖尿病(T2DM)患者及78例健康者的空腹血糖(FPG)、餐后2h血糖(2hBG)、糖化血红蛋白(HbAlc)等指标;同时应用液态酶法测定GA,用GA高值血清和低值血清评估试剂盒的精密度及其线性,建立GA参考范围;分析GA与各检测指标的相关性。结果健康人群GA值为(14.48±2.12)%;对147例患者的相关性分析显示,GA与HbA1c具有良好的相关性(r=0.868 7,P<0.01);GA与FPG、2hBG呈正相关(r=0.854、0.836,P<0.01);HbA1c>7.0%、4.0%≤HbA1c≤7.0%以及HbA1c<4.0%患者GA与HbA1c的相关系数分别为0.823(P<0.01)、0.756(P<0.05)和0.187(P>0.05);健康者、临界者和T2DM患者间GA差异有统计学意义(P<0.001)。结论该法批内变异系数(CV)<2%,批间CV<5%,线性测定r=0.998 7。GA与HbA1c具有良好的相关性,尤其表现于长期血糖控制欠佳的患者。酶法检测GA有良好的精密度和线性。     

An enzymatic method for the measurement of glycated albumin in biological samples

BACKGROUND: In order to determine glycated albumin more easily and rapidly, we developed a new enzymatic method for glycated albumin in blood samples. METHODS: The method involves use of albumin-specific proteinase, ketoamine oxidase and serum albumin assay reagent. In the assay, glycated albumin is hydrolyzed to glycated amino acids by proteinase digestion, and ketoamine oxidase oxidizes the glycated amino acids to produce hydrogen peroxide, which is quantitatively measured. Glycated albumin is calculated as the percentage of glycated albumin in total albumin. RESULTS: The calibration curve for glycated albumin concentration was linear (r(p)=0.999) between 0.0 and 50.0 g/l and that for albumin concentration was linear (r(p)=0.999) between 0.0 and 60.0 g/l. The analytical recoveries of exogenous glycated albumin added to serum were 100-102.5%. The within-run and between-run CVs were 0.45-0.67% and 1.09-1.26%, respectively. This method was free from interference by bilirubin, chyle, glucose, globulins and labile intermediate. Weak interference by hemoglobin and ascorbic acid was observed. Glycated albumin detected by the present method was significantly correlated with glycated albumin detected by high-performance liquid-chromatographic (HPLC) method (serum: r(s)=0.989, plasma: r(p)=0.992). CONCLUSIONS: This new enzymatic method is simple, rapid, allows multiple determinations and enables quantitative analysis of glycated albumin.     

Performance characteristics and clinical utility of an enzymatic method for the measurement of glycated albumin in plasma

OBJECTIVE: The measurement of plasma glycated albumin is particularly useful in the short-middle term monitoring of glycometabolic control in diabetics. The aim of this work is to evaluate a new enzymatic method for the measurement of glycated albumin in plasma, with particular attention to some selected cases and comparison with other relevant tests (fasting plasma glucose, after glucose load, fructosamine, glycated hemoglobin). DESIGN AND METHODS: We have performed a multicenter study by which sample collection was performed in three different centers (Milano, Padova and Cagliari) and serum samples, frozen at -80 degrees C, were then delivered under dry ice to the centralized laboratory in Milano. Glycated plasma albumin was measured with reagents from Asahi Kasei Pharma (Lucica GA-L enzymatic assay; AKP, Tokyo, Japan) on a Modular P Roche system. Fructosamine was assessed by a Roche method and HbA(1c) (measured separately in the three centers on fresh EDTA blood) by DCCT-aligned HPLC systems. We have investigated 50 type 2 diabetics, 26 subjects with gestational diabetes, 35 subjects with thalassemia major, 10 subjects with cirrhosis, 23 patients with end-stage renal disease subjected to dialysis treatment and 32 healthy adult control subjects. RESULTS: The main analytical performance characteristics of the new GA test were the following: (a) the within-assay reproducibility was between 3.0 and 3.9% (in terms of GA% CV, measured on 2 serum pools and 2 control materials at normal and pathological glycated albumin levels); (b) the between-assays reproducibility was from 2.8 to 4.1%; (c) the linearity was tested in the interval between 13 and 36% and found acceptable (r(2)=0.9932). Concerning the clinical utility of the new test, we have evaluated the relationships between GA, HbA(1c), fructosamine and fasting and post-prandial glucose in several patients, as well as the changes in the above mentioned parameters in a sub-group of type 2 diabetic patients for 18 weeks as they progressed from severe hyperglycemia (HbA(1c) >or=10.0%) toward a better glycemic control. The correlations between glycated albumin and HbA(1c) were as follows: (a) type 2 diabetics: r(2)=0.483 (good glycemic control), r(2)=0.577 (poor control); (b) diabetic patients under dialysis: r(2)=0.480; (c) liver disease: r(2)=0.186; (d) transfused non-diabetics with thalassemia: r(2)=0.004. Glycated albumin, as well as HbA(1c) and fructosamine, was of little value in the study of women with gestational diabetes, mainly because of the very limited glucose fluctuations in this particular category of subjects. In 11 type 2 diabetic patients under poor metabolic control, GA was better correlated with fasting plasma glucose then HbA(1c) (r(2)=0.555 vs. 0.291, respectively), and decreased more rapidly than HbA(1c) during intensive insulin therapy. CONCLUSIONS: The experience we have acquired with the new enzymatic test demonstrates its reproducibility and robustness. We confirm that plasma glycated albumin is better related to fasting plasma glucose with respect to HbA(1c). Moreover, glycated albumin is more sensitive than HbA(1c) with regard to short-term variations of glycemic control during treatment of diabetic patients. This test is also very appropriate when the interpretation of HbA(1c) is critical.     

糖化白蛋白在肝硬化患者中的临床意义

目的探讨糖化白蛋白(GA)在肝硬化患者中的变化及其临床意义。方法采用酶法测定105例肝硬化患者及80名健康体检者血清中糖化白蛋白分值(GA%),同时采用己糖激酶法(HK)测定血糖(Glu)。根据Child-Pugh标准对105例肝硬化患者进行分级,其中A级86例,B+C级19例。比较GA%及Glu在各组中的差异。结果肝硬化组GA%水平及异常率明显高于正常对照组(P<0.01),而Glu水平及异常率2组间差异无统计学意义(P>0.05)。随着肝病病情的发展,GA%异常率明显上升;而Glu无明显差异。结论 GA%在血糖正常的肝硬化患者中异常增高,且与病情的发展密切相关。     

Precise measurement of glycated serum albumin by column affinity chromatography and immunoturbidimetry

A precise and easy method for measuring glycated serum albumin using affinity chromatography and immunoturbidimetry on a centrifugal analyser, ensuring complete recovery of serum albumin is described.     

Measurement of glycated albumin by the nitroblue tetrazolium colorimetric method.

A method has been developed for the measurement of glycated albumin (albumin-fructosamine) by the nitroblue tetrazolium (NBT) colorimetric method. In this method, polyethylene glycol was added to the serum and then the mixture was centrifuged to separate globulin proteins from albumin proteins. This made it possible to measure the glycated albumin in the supernatant by the NBT colorimetric method, without the interference of globulin proteins. This measurement method correlated with the measurement of glycated albumin using boronate affinity chromatography with an r value of 0.942 (P < 0.001). Our method using polyethylene glycol permits easy measurement of albumin fructosamine and is therefore useful as an index of diabetic control and for diabetic screening.