不同检测系统常用血清酶测定结果对比及偏倚评估

目的通过对不同检测系统进行方法学比对分析,探讨各检测系统之间测定临床常用血清酶是否具有可比性。方法依据美国临床和实验室标准化研究所EP9-A2文件要求,每天随机从临床样本中抽取8份不同浓度的血清样本,分别用两种检测系统进行相关血清酶测定,共测定5d,记录检测结果,并进行相关回归分析。根据直线方程计算在某医学决定水平处的预期偏倚（Bc）和预期偏倚的95％可信区间,并判断偏倚性是否可以接受。结果除天门冬氨酸氨基转移酶在低值处的预期偏差（绝对值）大于1／4允许总误差外,不同检测系统对常用血清酶测定结果的偏差在允许误差范围内,其检测结果具有可比性。结论当用2个以上检测系统检测同一检验项目时,应进行方法学比对和偏倚评估,判断其临床可接受性能,以保证检验结果的可比性。     

CLSI-EP9-A2标准在两种不同尿素试剂间的应用

目的 通过对两种不同尿素试剂进行方法学比对分析,探讨各试剂测定血清尿素是否具有可比性.方法 依据美国临床和实验室标准研究所（CLSI）EP9-A2文件要求,每天随机从临床样本中抽取8份不同尿素浓度的血清样本,分别用两种试剂进行尿素的测定,共测定5天,记录检测结果,将结果进行相关回归分析.根据直线方程计算在医学决定水平处的预期偏倚（c）和预期偏倚的95%可信区间,并判断偏倚是否可以接受.结果 两种试剂对血清尿素测定结果的相关系数（r）=0.998,截距（a）=0.048,斜率（b）=0.987,回归方程：Y=0.987X＋0.048.无方法内、间的离群点,两者结果具有可比性.结论 当用两种或两种以上以上试剂检测同一检验项目时,应进行方法比对和偏倚评估,判断其临床可接受性能,以保证检验结果的可比性.     

EP9-A2文件在评价两种碱性磷酸酶试剂中的应用

目的 应用美国临床和实验室标准研究所（CLSI）EP9-A2评价文件对两种碱性磷酸酶（ALP）试剂进行方法学比对分析,探讨两种试剂测定ALP是否具有可比性.方法 依据EP9-A2文件要求,每天随机从临床样本中抽取8份不同浓度水平的血清样本,分别用两种试剂进行ALP测定,共测定5天,记录检测结果,将结果进行相关回归分析.根据直线方程计算在某医学决定水平处的预期偏倚（BAK^C）和预期偏倚的95%可信区间,并判断偏倚是否可以接受.结果 不同试剂对ALP测定结果的偏倚在允许误差范围内,两者结果具有可比性.结论 在实验室用两种以上试剂检测同一项目时,可参照EP9-A2文件进行方法学比对和偏倚分析,判断其临床可接受性能,以保证实验室检测结果的准确性和可比性.     

两种总胆红素试剂测定结果的偏倚分析

目的 探讨两种总胆红素试剂测定结果间是否具有可比性.方法 依据EP9-A2文件要求,每天随机从临床样本中抽取8份不同浓度水平的血清样本,分别用两种试剂进行总胆红素测定,共测定5天,记录检测结果,将结果进行相关回归分析.计算在其医学决定水平处的预期偏倚（c）和预期偏倚的95%可信区间,并判断偏倚是否可以接受.结果 相关系数（r）=0.999, r2=0.998,截距（a）=-0.079,斜率（b）=0.998,回归方程：Y=0.998X-0.079.无方法内、间的离群点,测定结果的偏差在允许误差范围内.结论 在实验室用一种试剂替代另一种试剂前,可参照EP9-A2文件进行方法学比对和偏倚分析,判断其临床可接受性能,以保证实验室检测结果的准确性和可比性.     

两台化学发光仪检测人生长激素的比对分析及偏倚评估

目的对Immulite 1000化学发光仪和DXI 800化学发光仪两种不同检测系统检测人生长激素(hGH)进行方法比对及偏倚评估,探讨不同检测系统间测定结果是否具有可比性。方法依据美国临床和实验室标准化协会(CLSI)EP9-A2文件要求,每天至少收集8份不同浓度的新鲜血清,分别用两种检测系统测定hGH,连续测定至少5d,每个标本均按正反序重复测定,记录测定结果,检查离群点,目测线性及数据分布,计算相关系数和直线回归方程,根据回归方程计算hGH在临界值处的预期偏倚和预期偏倚的95%可信区间并判断偏倚是否可以接受。结果两台仪器检测hGH的相关系数r=0.999,均值差异呈负偏倚,但这种偏差均在允许的误差范围内,临床均可接受。结论同一项目在不同检测系统检测时应进行方法比对和偏倚评估,以确保检测结果的可比性和连续性。     

两种生化仪血脂测定结果的比对研究和偏倚评估

目的通过对日立7600和雅培AEROSET生化仪进行比对和偏倚评估，探讨两种检测系统之间血脂测定结果是否具有一致性。方法按照美国临床实验室标准化委员会（NCCLS）EP9-A2文件的要求，以日立7600生化仪为比较仪器，雅培AEROSET生化仪为实验仪器，分别测定40例患者血清甘油三酯（TG）、总胆固醇（TC）、高密度脂蛋白胆固醇（HDL—C）及低密度脂蛋白胆固醇（LDL—C）的含量，分析两种生化仪测定结果之间的相关性和偏倚，评估测定结果之间的可比性。结果日立7600和雅培AEROSET生化仪测定的血脂结果之间具有较好的一致性,预期偏倚可以接受。结论不同生化仪检测同一项目时,需进行方法学比对和偏倚评估，确保检测结果的一致性。     

两种生化仪血脂测定结果的比对研究和偏倚评估

目的通过对日立7600和雅培AEROSET生化仪进行比对和偏倚评估，探讨两种检测系统之间血脂测定结果是否具有一致性。方法按照美国临床实验室标准化委员会（NCCLS）EP9-A2文件的要求，以日立7600生化仪为比较仪器，雅培AEROSET生化仪为实验仪器，分别测定40例患者血清甘油三酯（TG）、总胆固醇（TC）、高密度脂蛋白胆固醇（HDL—C）及低密度脂蛋白胆固醇（LDL—C）的含量，分析两种生化仪测定结果之间的相关性和偏倚，评估测定结果之间的可比性。结果日立7600和雅培AEROSET生化仪测定的血脂结果之间具有较好的一致性,预期偏倚可以接受。结论不同生化仪检测同一项目时,需进行方法学比对和偏倚评估，确保检测结果的一致性。     

不同生化分析仪测定结果比对分析及偏倚评估

目的 采用日立7600-020与7600-010两种不同检测系统对多个项目进行方法比对和偏倚评估,探讨同一医院不同检测系统间测定结果是否具有可比性.方法 依据美国国家临床实验室标准委员会(NCCLS)EP9-A2文件要求,每天收集8份不同浓度的患者新鲜血清,分别用两种检测系统测定TG、TC、HDL-C、LDL-C等4项生化指标,连续测定5 d,记录测定结果,计算相关系数和直线回归方程,根据回归方程计算各指标在医学决定水平上的预期偏倚和预期偏倚的95%可信区间,并判断偏倚是否可以接受.结果 HDL-C、LDL-C的预期偏倚的95%可信区间大于CLIA′88允许误差范围的1/2,不可接受,其余两个项目测定结果的预期偏倚均可接受.结论 不同检测系统应定期对相同检测指标进行方法比对和偏倚评估,以确保检测结果的可比性.     

不同生化检测系统间检测结果的可比性研究

目的通过对同一实验室不同生化检测系统进行方法比对和偏倚评估，探讨不同生化检测系统间丙氨酸氨基转移酶（ALT）、总蛋白等10个生化项目测定结果是否具有可比性，为实验室认可提供可靠的实验数据。方法按照美国临床和实验室标准化研究所的EP9-A2文件要求，以Vitros950全自动干化学生化分析仪法为参比方法（X），以Olympus AU640、两台Dimension Xpand-HM生化分析仪法为待比方法（Y1-3），用不同浓度水平的患者新鲜血清对上述生化项目分别进行检测，计算相关系数及直线回归方程，以临床实验室改进规范88（CLIA’88）规定的室间质量评价允许误差范围的1／2为标准，在不同医学决定水平判断不同检测系统的偏差临床是否可以接受。结果在所检测的项目中，除了Y1检测系统ALT测定结果的预期偏差不能被接受外，其余项目测定结果在不同医学决定水平上，3种待比方法测定结果的偏差临床均可接受。结论当使用2个以上检测系统检测同一检验项目时，应进行方法比对和偏倚评估，判断其临床可接受性能，以保证检验结果的可比性。     

两种总蛋白试剂测定结果的偏倚分析

目的探讨两种总蛋白(TP)试剂测定结果间是否具有可比性。方法依据EP9-A2文件要求,每天随机从临床样本中抽取8份不同浓度水平的血清样本,分别用两种试剂进行总蛋白测定,共测定5d,记录检测结果,将结果进行相关回归分析。计算在其医学决定水平处的预期偏倚(B^c)和预期偏倚的95%可信区间,并判断偏倚是否可以接受。结果相关系数(r)=0.993,r2=0.986,截距(a)=0.362,斜率(b)=0.991,回归方程:Y=0.991X+0.362。无方法内、间的离群点,测定结果的偏差在允许误差范围内。结论在实验室用两种以上试剂检测同一项目前,可参照EP9-A2文件进行方法学比对和偏倚分析,判断其临床可接受性能,以保证实验室检测结果的准确性和可比性。     

甘油内空白法与GPO-POD法检测血清三酰甘油

目的 探讨甘油内空白法与甘油磷酸氧化酶(GPO)-过氧化物酶(POD)法测定生化质控血清中三酰甘油(TG)的差异.方法 采用两种方法测定7个不同品牌共17个批号生化室内质控血清和卫生部2006年常规化学室间质评样本三酰甘油,比较两法测定结果的异同.结果 甘油内空白法与GPO-POD法测定不同品牌不同批次生化室内质控血清三酰甘油的结果无明显相关,Roche与Leadman的TG结果可相差1倍以上;而Aalto和Bio Rad的结果非常相近.不同批次的卫生部室间质评样本结果与此类似.结论 部分品牌的生化质控血清含大量的游离甘油,两法测定质控血清的结果可能出现明显差异.     

Comparison of the effects of guanabenz and hydrochlorothiazide on plasma lipids

The effects of hydrochlorothiazide (HCTZ) and guanabenz monotherapy on blood pressure and serum lipoprotein levels were compared in a 14-week, randomized, parallel, double-blind multicenter study of 218 outpatients with mild hypertension. Mean supine blood pressure decreased 13/9 mm Hg in the guanabenz group and 17/11 mm Hg in the HCTZ group, changes that were significantly (p less than 0.01) different from baseline but not significantly different between the two treatment groups. Significant (p less than 0.01) mean decreases in total cholesterol and low-density lipoprotein (LDL) cholesterol levels (of 9 mg/dl and 4 mg/dl from baseline values) occurred during guanabenz treatment; HDL cholesterol levels fell by an average of 4 mg/dl. In the HCTZ group, triglyceride levels were significantly (p less than 0.01) increased by 13 mg/dl, and HDL cholesterol levels fell by 2 mg/dl. The change in LDL cholesterol levels, but not HDL cholesterol levels, was significantly different between guanabenz and HCTZ periods. The results show that guanabez, although providing effective blood pressure control that is comparable to that of HCTZ, has more favorable effects on lipoproteins.     

高脂血对不同方法测定血清高密度脂蛋白胆固醇的影响

目的　观察不同浓度血清三酰甘油 (TG)对高密度脂蛋白胆固醇 (HDL C)测定的影响 ,在临床实验室内寻找可靠的HDL -C测定方法以满足临床诊治需求。方法　采用全自动生化分析仪检测血清TG、TC、HDL C以及LDL C并与沉淀法和电泳法测定HDL C进行分组比较。结果　当血清TG <1.6 9mmol/L时 ,3种方法测定值之间无差异 ;当血清TG为 1.6 9～ 4 .0mmol/L范围时 ,各方法测定HDL -C有显著差异 ,但相关性良好。当TG >4 .0mmol/L ,各方法之间的差异程度不一致。结论　对高TG标本HDL C的测定电泳法、沉淀法和直接法之间有显著差异 ,有条件的实验室应尽可能采用电泳法测定高TG标本HDL C。     

High-density lipoprotein cholesterol, hepatic lipase and lipoprotein lipase activities in thyroid dysfunction--effects of treatment

We have investigated the effects of hyper- and hypothyroidism (clinical and subclinical) on lipid metabolism, with special emphasis on serum high-density lipoprotein cholesterol, post-heparin plasma hepatic lipase and lipoprotein lipase activities. In 16 patients with hyperthyroidism, increased post-heparin plasma hepatic lipase activity, decreased serum total cholesterol and serum high-density lipoprotein cholesterol were found while lipoprotein lipase activity and serum triglyceride were normal. In six patients with overt hypothyroidism serum total cholesterol and triglyceride were increased, post-heparin plasma hepatic lipase and lipoprotein lipase were decreased while serum high-density lipoprotein cholesterol was normal. In six patients with subclinical hypothyroidism, serum total cholesterol was increased, serum high-density lipoprotein cholesterol was decreased, while serum triglyceride, post-heparin plasma hepatic lipase and lipoprotein lipase were normal. When the three groups of patients became euthyroid, serum total cholesterol, serum triglyceride, post-heparin plasma hepatic lipase, lipoprotein lipase, and serum high-density lipoprotein cholesterol reverted to normal except for serum high-density lipoprotein cholesterol in the hyperthyroid group which showed no significant change with treatment. A positive correlation was found between serum T3 and post-heparin plasma hepatic lipase while negative correlations were found between serum total cholesterol and serum T3, post-heparin plasma hepatic lipase and serum total cholesterol, lipoprotein lipase and serum triglyceride respectively. Thus in these patients with thyroid dysfunction, significant reversible alterations in serum total cholesterol, triglyceride and high-density lipoprotein cholesterol were found and could be correlated with the observed changes in the activities of hepatic lipase and lipoprotein lipase.     

Parameters of the three-pool model of the turnover of plasma cholesterol in normal and hyperlipidemic humans.

Long-term studies (32-49 wk) of the turnover of plasma cholesterol were conducted in 24 subjects. Eight subjects were normilipidemic, six had hypercholesterolemia, eight had hypercholesterolemia and hypertriglyceridemia, and two had hypertriglyceridemia alone. 10 of the hyperlipidemic patients had a definite familial disorder. In all subjects (except one for whom complete data were not available), the same three-pool model previously described gave the best fit for the data. The parameters of the three-pool model observed in the normal subjects were compared with the model parameters found in the patients with the different kinds of hyperlipidemia. In addition, single and multiple regression analyses were conducted to explore the relationships between the model parameters and various physiological variables, including age, body size, and serum lipid concentrations. Using this approach, significant differences between groups, or correlations with serum lipid levels were seen for several parameters of the three-pool model: the production rate (PR); the size of the rapidly exchanging pool 1 (M1); all estimates of the size of the most slowly equilibrating pool 3 (M3); and the rate constant k21. The PR in normal subjects (1.14 +/- 0.19 g/day, mean +/- SD) was not significantly different from that found in patients with hypercholesterolemia, with or without hypertriglyceridemia. The major determinant of cholesterol PR was overall body size, expressed either as total body weight or as surface area. The correlations between PR and indices of adiposity (percent ideal weight and excess weight), although statistically significant, were much weaker in this nonobese population. After adjustment for body size variation, cholesterol PR was not correlated with the serum cholesterol concentration but was probably (P less than 0.05) correlated with the triglyceride concentration. When the two patients with very high triglyceride concentrations were excluded, however, no correlation was observed between adjusted PR and triglyceride level. It is probable that hypertriglyceridemic patients represent a heterogeneous population, in which the majority do not show increased cholesterol PR. M1 was correlated with all body size variables, but most strongly with excess weight. After adjusting for the effects of body size, M1 was also correlated and triglyceride. Major differences were found in the relationships between the physiological variables and the sizes of pools 2 and 3. M2 was correlated neither with any of the indices of body size or adiposity, nor with the serum levels of either cholesterol or triglyceride. In contrast, all estimates of M3 were correlated with indices of adiposity (but not of overall body size) and with the serum cholesterol concentration. Thus, the amount of cholesterol in slowly equilibrating tissue sites appears to particularly increase with elevations of the serum cholesterol level. The results also confirm previous data that adipose tissue cholesterol is an important part of pool 3.     

Lipoprotein lipase in clinical and experimental nephrosis

Studies were done to elucidate the relationship between the lipid levels in serum and the activity of lipoprotein lipase in clinical and experimental nephrosis.

Cholesterol, phospholipid and triglyceride concentration in serum and in individual lipoprotein fractions were measured in 12 nephrotic and 10 control children after an overnight fast. Serum cholesterol, phospholipid and triglyceride were increased in all nephrotic children. The increases in cholesterol and phospholipid concentration were observed in all individual lipoprotein fractions, whereas the increase in serum triglycéride was mostly found in the very low density lipoprotein fraction alone. Nephrotic children exhibited significantly less post-heparin lipoprotein lipase activity than control children, but no significant difference was observed between those two groups in the disappearance rate of lipase activity.

There was a high negative correlation between log plasma lipoprotein lipase activity and log triglyceride concentration in very low density lipoproteins.

Lipoprotein lipase activity in rat perirenal adipose tissue was assayed five and fourteen days after induction of antiserum nephrosis. There was a considerable decrease in enzyme activity and a marked increase in serum triglycerides; a high negative correlation between these two parameters was again observed.     

Serum lipoprotein profile in patients with cancer. A comparison with non-cancer subjects

The association of cancer with low serum total cholesterol is well established. Less clear is the relationship of cancer with the cholesterol distribution among the different lipoprotein classes. Conflicting results have been reported on low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and serum triglyceride levels in different types of tumor. Total serum cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and serum triglycerides were analyzed in 530 patients with newly diagnosed cancer (97 with hematological malignancies, 92 with tumor of the lung, 108 of the upper digestive system, 103 of colon, 32 of breast, and 98 of the genitourinary system) and in 415 non-cancer subjects. Anthropometric (body mass index) and biochemical (serum albumin) indices of nutritional status were also determined in all subjects. Total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, serum albumin, and body mass index were significantly lower in cancer than in non cancer-subjects. The lowest values of total cholesterol, low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol were recorded in patients with hematological malignancies and the highest in patients with breast tumor. All the cancer groups, with the exception of women with breast cancer, showed significantly lower total cholesterol, low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol than age- and sex-matched non-cancer subjects. Multiple regression analysis with low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and triglycerides as dependent variables and sex, age, body mass index, albumin, and cancer (dummy variable) as independent variables, showed that cancer was independently associated with low levels of low-density lipoprotein-cholesterol and high-density lipoprotein-cholesterol and with high values of serum triglycerides. Total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, serum triglycerides, body mass index and serum albumin were significantly lower in patients with metastatic than in patients with non-metastatic solid tumor. The significant difference in low-density lipoprotein-cholesterol and serum triglycerides between patients with metastatic and non-metastatic cancer was lost when lipoprotein cholesterol and serum triglyceride levels were adjusted for nutritional variables. The lipid profile in cancer patients is characterized by low low-density lipoprotein-cholesterol, low high-density lipoprotein-cholesterol and relatively high serum triglycerides. The abnormality is a common feature of both hematological and solid tumors and is not entirely explained by poor nutrition.     

Positive Correlation of Serum Lecithin: Cholesterol Acyltransferase Activity with Relative Body Weight

Abstract. The activity of serum lecithin:cholesterol acyltransferase (LCAT) was measured in 33 subjects who had no apparent diseases except obesity in some cases. Their liver function tests were all within normal limits. The correlations of serum LCAT activity with sex, age, glucose tolerance, relative body weight, basal immunoreactive insulin, and fasting serum cholesterol and triglyceride were studied. – The results indicate that an increase in serum LCAT activity is significantly correlated with increases in relative body weight, serum total cholesterol, serum unesterified cholesterol, serum basal immunoreactive insulin, and serum triglyceride. – At present the physiological significance of serum cholesterol es-terification is not fully established. However, the present findings suggest an increased turnover of serum esterified cholesterol in obese subjects.     

Insulin resistance--a risk factor for coronary heart disease?

Fasting insulin secretion was assessed by measuring fasting serum C-peptide levels in 529 women and 399 men aged 18-90 years, to study the relationship between insulin secretion, insulin resistance and risk factors for coronary heart disease. Subjects with low serum high density lipoprotein (HDL) cholesterol levels showed higher mean serum insulin and C-peptide levels than subjects with normal HDL cholesterol levels. In male subjects these differences were significant for both serum insulin and serum C-peptide results (P less than 0.005). In female subjects serum insulin results differed significantly (P less than 0.0005) but for the difference in mean serum C-peptide levels P was equal to 0.012. Fasting serum C-peptide correlated negatively with serum HDL cholesterol. However, serum C-peptide also correlated with serum triglyceride and serum triglyceride correlated negatively with serum HDL cholesterol. Each correlation was statistically significant (P less than 0.001). Multiple regression analysis suggested that the apparent association of C-peptide with HDL cholesterol was a consequence of the interrelated association between C-peptide, triglyceride and HDL cholesterol. The analysis was consistent with the hypothesis that obesity and increased insulin resistance were associated with increased insulin secretion and in turn with high serum triglyceride levels and consequentially low levels of serum HDL cholesterol. The data were compatible with the suggestion that insulin resistance rather than fasting insulin concentration per se could be a risk factor for coronary heart disease.     

甘油三酯和总胆固醇试剂对总胆汁酸检测结果的影响

目的探讨甘油三酯（triglyceride,TG）和总胆固醇（total cholesterol,TC）试剂对血清总胆汁酸（total bile acid,TBA）检测结果的影响及解决办法。方法 2008年1月-2009年10月采用魅力2000全自动生化分析仪,首先单独检测20份血清标本的TBA含量。然后分别检测TC和TG后进行TBA含量检测。最后设定特殊检测程序和清洗程序后再按TC→TBA,TG→TBA顺序进行TBA含量检测。结果单独检测20份血清标本的TBA结果均值为7.2μmol/L;按TC→TBA,TG→TBA顺序检测结果均值分别为13.5μmol/L和14.3μmol/L,单独和组合测量方法测定TBA结果有统计学意义（P〈0.05）。设定特殊检测程序和清洗程序后按TC→TBA,TG→TBA顺序检测结果均值分别为7.4μmol/L和7.5μmol/L,与单独测量TBA结果相比,无统计学意义。结论 TG和TC试剂对TBA检测产生干扰的原因是试剂成分中含有浓度较高的TBA,在魅力2000全自动生化分析仪上,设定特殊检测程序和清洗程序,能有效消除TG、TC试剂对TBA检测的影响。