Serum free light chain reference intervals in an Optilite and their influence on clinical guidelines

BackgroundSerum free light chain (FLC) analysis has been incorporated into the International Myeloma Working Group guidelines for the diagnosis and management of all monoclonal gammopathies. These recommendations were solely based on a single assay method (Freelite assay) and instrument. Here, we establish new reference intervals (RIs) for kappa and lambda FLC and the kappa-lambda difference and sum and a new diagnostic range for kappa/lambda FLC ratio (K/L-FLC) in an Optilite turbidimeter (The Binding Site) with the Freelite assay.MethodsTo establish new RIs, the CLSI EP28-A3C protocol was applied to 249 sample blood donors from Fuenlabrada, Spain, and the central 95% and total range were estimated. Samples from patients with polyclonal hypo- and hypergammaglobulinemia were used for the evaluation of K/L-FLC as a monoclonal proliferation index.ResultsThe new RIs and the new K/L-FLC diagnostic range for the Optilite (0.65–2.56 mg/L) are very different from those in on the guidelines (0.26–1.65 mg/L). We propose new RIs for the K − L difference and the K + L sum. Diagnostic range validation as a monoclonal proliferation index with samples with hypo- and hypergammaglobulinemia confirms this new range.ConclusionsIn this study, we present the FLC RI for Freelite reagents measured on an Optilite turbidimeter. These ranges are different from those provided by the manufacturer and from those used in most studies in the literature, which may lead to patient misclassification. Manufacturers and clinical laboratories must strive to provide RIs for the technology they are using and for their population.     

临床化学检测的标准化现状

实验室的质量管理和检验结果标准化是临床化学检测项目实现结果互认的2个重要基础。开展标准化工作,建立检验项目的标准化体系可为检验质量提供准确性依据,是确保检验结果准确、具有可比性的最有效措施。实现检验结果准确、可比的重要方法之一是建立和保证检验结果的溯源性。国际组织一般通过建立参考测量程序、参考物质和一致性方案等来解决不同项目的量值溯源性问题。正确度验证计划和能力验证的开展为临床化学检验项目的结果互认提供了依据。文章对临床化学检测标准化的现状进行综述,以期为临床实验室质量管理提供参考。     

Accuracy of position of cutting and drilling guide for sagittal split guided surgery: a proof of concept study

The benefits of three-dimensional planning and guided surgery have been realised over the last few years in maxillofacial surgery. Reproducing the exact positioning of the cutting and drilling guides on the flat mandibular angles defined by the engineer is a challenge for the surgeon and for the reliability of guided bilateral sagittal split osteotomy. Reference screws positioned on the skeleton before the acquisition of medical computed tomographic data can provide a fixed landmark that can be used during surgery and by the engineer during the design phase. The objective of this proof of concept in vitro study is to calculate the accuracy obtained for guides positioned by inserting a reference screw. The precision obtained for 30 guides following the insertion of 30 reference screws on 15 mandibular models was analysed. The models were scanned using an optical scanner and compared to CAD-CAM projects. The mean (SD) absolute position (in)-inaccuracy is 0.1616 (0.1141) mm for the entire guide surface and 0.13143 (0.0835) mm for the rim surface. The results indicate that the use of reference screws is efficient, and so they can be used to position guides accurately during guided bilateral sagittal split osteotomy.     

IFCC参考方法对两种常规检测系统ALP结果正确度的验证

目的评价常规检测系统测定血清碱性磷酸酶(ALP)的正确度。方法以国际临床化学联合会(IFCC)参考方法和两种常规检测系统(简称A法、B法)同时测定20份新鲜单人份血清样品。按美国临床实验室标准化协会(CLSI)EP9-A2文件评价两种常规检测系统测定结果的正确度,并用改良Bland-Altman图形分析法进行验证,评价常规检测系统与参考方法测定结果的一致性,综合判断常规检测系统的测定结果。按CLSI EP14-A2文件评价A、B两种方法校准品的基质效应。结果 A法、B法与IFCC参考方法测定结果的直线回归方程分别为YA=0.982 9XIFCC+0.010 8,YB=0.938 3XIFCC+0.012 9,平均偏倚分别为-1.1%、-5.5%。A法和B法检测结果的相关方程为YB=0.955 2XA+0.001 36,R2=0.997 6。A法和B法的校准品均存在基质效应,其中A法校准品的基质效应更明显。结论 A法与IFCC参考方法正确度性能一致,B法与IFCC参考方法正确度性能不一致。     

六安地区健康成人超敏Ｃ反应蛋白参考区间研究

目的：建立六安地区成人超敏C反应蛋白（hs-CRP）的参考区间。方法按照CLSI文件C28-A3《临床实验室如何确定和建立生物参考区间》要求,于2014年1～8月筛选前来六安市第二人民医院进行健康体检者137名,采用颗粒增强免疫透射比浊法测定血清hs-CRP浓度。结果去除3例离群值后,134例六安地区健康成人血清hs-CRP明显呈偏态分布,经对数转换,男女之间无组间差别（Z＜Z*）,参考上限为2.0664 mg／L。结论本研究为六安地区健康成人血清hs-CRP参考区间的建立提供了科学依据。     

Serum Gamma-glutamyl Transferase Concentration Within the Reference Range is Related to the Coronary Heart Disease Risk Prediction in Korean Men: Analysis of the Korea National Health and Nutrition Examination Survey (V-1, 2010 and V-2, 2011)

Background:Limited data exist on the association of serum gamma-glutamyl transferase (GGT) level within the reference range with the increased risk of coronary heart disease (CHD) prediction in men.The...     

Percentiles for anthropometric measures in 11–18 years-old students of 73 developing countries

Background and aimsone of the health concerns for any society is to have its own standard of growth. The aim of this study was to provide the age- and sex-specific percentile values of anthropometric measures for adolescents of developing countries. The use of global percentiles in developing countries overestimates underweight and stunting while underestimates overweight and obesity.MethodsThe data were obtained from the Global School-based Student Health Survey (GSHS). This study was conducted on school students, selected by multistage random cluster sampling from 73 developing countries. A parametric method was used for constructing age-specific reference intervals (normal ranges).ResultsIn general, 210,045 11–18 years-old schoolchildren (14.38 ± 1.39) from 73 developing countries between 2003 and 2014 were included in this study, among which 103,080 (49.08%) were male and 106,965 (50.92%) were female. Calculation of body mass index (BMI) percentile showed that for all BMI percentile curves of both sexes, there was a gradual increase up to the age of around 15 years, and then remain stable (except for 95th percentile). Moreover in all weight percentile curves of boys, except 90th and above, there was a slight rise until the age of 18 years. In 10th height percentile curves and above in boys, there was a sharp increase up to the age of 17, followed by a decline. Similarly, this pattern was found for 50th height percentile and above in girls.ConclusionThe use of global percentiles in developing countries overestimates underweight and stunting while underestimates overweight and obesity.     

Methylenetetrahydrofolate Reductase 677 Genotype-Specific Reference Values for Plasma Homocysteine and Serum Folate Concentrations in Korean Population Aged 45 to 74 Years: The Namwon Study

The reference interval for plasma total homocysteine (tHcy) and serum folate concentrations were estimated. Total of 3,154 reference individuals (1,029 men and 2,125 women) were selected based on stringent exclusion criteria. For plasma tHcy concentration (µM/L), reference values (median [5-95 percentile]) were 7.72 (5.03 to 13.80) and 6.09 (3.95-10.19) in men and women, respectively. For serum folate concentration (nM/L), reference values were 23.71 (11.73-38.44) and 28.95 (15.23-40.44) in men and women, respectively. The tHcy levels of both genders in the present study were lower than those in previous reports from other countries and Korea.

Graphical Abstract

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Comparison between reference values for FVC,FEV1, and FEV1/FVC ratio in White adults in Brazil and those suggested by the Global Lung Function Initiative 2012

OBJECTIVE:

To evaluate the spirometry values predicted by the 2012 Global Lung Function Initiative (GLI) equations, which are recommended for international use, in comparison with those obtained for a sample of White adults used for the establishment of reference equations for spirometry in Brazil.

METHODS:

The sample comprised 270 and 373 healthy males and females, respectively. The mean differences between the values found in this sample and the predicted values calculated from the GLI equations for FVC, FEV₁, and VEF₁/FVC, as well as their lower limits, were compared by paired t-test. The predicted values by each pair of equations were compared in various combinations of age and height.

RESULTS:

For the males in our study sample, the values obtained for all of the variables studied were significantly higher than those predicted by the GLI equations (p < 0.01 for all). These differences become more evident in subjects who were shorter in stature and older. For the females in our study sample, only the lower limit of the FEV₁/FVC ratio was significantly higher than that predicted by the GLI equation.

CONCLUSIONS:

The predicted values suggested by the GLI equations for White adults were significantly lower than those used as reference values for males in Brazil. For both genders, the lower limit of the FEV₁/FVC ratio is significantly lower than that predicted by the GLI equations.     

功能性消化不良罗马Ⅲ和罗马Ⅱ标准的比较及精神心理状况调查

目的 分析罗马Ⅲ和罗马Ⅱ标准对功能性消化不良(FD)诊断的临床特点、分型的差异,以及FD患者精神心理状态.方法 随机选取2008年6月至2008年12月间1600例消化科门诊患者(均经胃镜检查)进行问卷调查,按罗马Ⅱ和罗马Ⅲ标准诊断分型并归纳分析.结果 符合罗马Ⅱ标准的FD患者215例(13.44％),符合罗马Ⅲ标准249例(15.56％),两种标准对FD的检出率差异无统计学意义(x2=2.176,P＞0.05).罗马Ⅱ标准诊断的FD患者中71.16％(153/215)同时符合罗马Ⅲ标准;23.26％(50/215)患者有早饱、餐后饱胀不适、上腹痛和上腹烧灼感中的至少一种,但不符合罗马Ⅲ标准.罗马Ⅲ标准诊断的FD中61.45％(153/249)同时符合罗马Ⅱ标准;28.92％(72/249)患者病程不符合罗马Ⅱ标准.按罗马Ⅱ标准分型,溃疡样型51例(23.72％),动力障碍型103例(47.91％),非特异型61例(28.37％).按罗马Ⅲ标准分型,餐后不适综合征(PDS) 190例(76.31％),上腹疼痛综合征(EPS)131例(52.61％),同时符合PDS和EPS诊断72例(28.92％).FD伴焦虑、抑郁者分别为17例(16.83％)和48例(47.52％).符合罗马Ⅲ标准FD患者同时合并焦虑和抑郁时,餐后饱胀不适、早饱、上腹痛和上腹烧灼感症状总积分最高(x2=49.637,P＜0.05).结论 罗马Ⅲ标准更易理解和运用.FD患者常合并精神心理异常,可能加重临床症状.