Interferencia generada por la lipemia en la medición de constituyentes bioquímicos

Introducción. La turbidez por lipemia en las muestras para diagnóstico es una de las principales causas de la aparición de sesgos clínicamente significativos en la medición de magnitudes bioquímicas. Objetivo. Valorar la interferencia por lipemia en la medición de 25 constituyentes bioquímicos en dos analizadores con tecnología de química seca (Vitros 7600®) y química liquida (Atellica® Solution). Métodos. Estudio pre-experimental con pre y posprueba. Se añadieron cantidades crecientes de una emulsión lipídica de nutrición parenteral a siete alícuotas de una mezcla de sueros y se determinó por duplicado la influencia del interferente en 25 constituyentes. Se calculó el porcentaje relativo de desviación de la concentración del constituyente por influencia de la turbidez con respecto a una muestra sin interferente. Se establecieron límites de tolerancia para la interferencia utilizando tres criterios: del distribuidor de reactivos, del error sistemático deseable y del error máximo admisible. Resultados. Los constituyentes que presentaron los mayores sesgos para el analizador de química liquida fueron: fósforo (-84,72%), ALT (+81,25%) y AST (-75,76%), mientras que para la plataforma de química seca los constituyentes: ALT (-79,41%), CK (-28,92%) y lipasa (+24,85%). Se detectó interferencia significativa en diferente número de los constituyentes de acuerdo con el criterio de límite tolerable utilizado. Conclusiones. Los distintos resultados encontrados según la metodología y el analizador utilizado, además de la falta de replicabilidad de los ensayos para la valoración de interferencia por lipemia, origina la necesidad de armonizar los procesos e instaurar límites idénticos de interferencia tolerables entre los laboratorios y proveedores de insumos.

Introduction. Turbidity due to lipemia in diagnostic samples is one of the main causes of the appearance of clinically significant biases in the measurement of biochemical magnitudes. Objective. To assess the interference by lipemia in the measurement of 25 biochemical constituents in two analyzers with dry chemistry technology (Vitros 7600®) and liquid chemistry (Atellica® Solution). Methods. Pre-experimental study with pre and post test. Increasing amounts of a parenteral nutrition lipid emulsion were added to seven aliquots of pooled sera and the influence of the interferent on 25 constituents was determined in duplicate. The relative percentage deviation of the concentration of the constituent due to the influence of turbidity with respect to a sample without interference, was calculated. Tolerance limits for interference were established using three criteria: reagent distributor, desirable systematic error, and maximum permissible error. Results. The constituents that presented the greatest biases for the liquid chemistry analyzer were: Phosphorus (-84.72%), ALT (+81.25%) and AST (-75.76%), while for the dry chemistry platform the constituents, ALT (-79.41%), CK (-28.92%) and lipase (+24.85%). Significant interference was detected in a different number of constituents according to the tolerable limit criteria used. Conclusions. The different results found according to the methodology and the analyzer used, in addition to the lack of replicability of the tests for the evaluation of interference by lipemia, originates the need to harmonize the processes and establish identical limits of tolerable interference between the laboratories and suppliers of inputs.

Validação de intervalos de referência de exames bioquímicos do laboratório de análises clínicas de um hospital universitário / Validation of reference intervals for biochemical tests at the clinical analysis laboratory of a university hospital

Introdução: Os intervalos de referência (IRs) disponibilizados em laudos de exames laboratoriais orientam a interpretação dos resultados, respaldando a avaliação clínica realizada por profissionais de saúde. Objetivo: Validar IRs de parâmetros bioquímicos, com base nas características da população local, bem como em informações disponíveis nas bulas dos reagentes e na literatura científica. Material e Métodos: Foi realizado um estudo observacional, descritivo e transversal para padronização de IRs de trinta e quatro parâmetros bioquímicos, executados pelo laboratório de análises clínicas de um hospital universitário. Participaram do estudo quarenta indivíduos adultos, pareados pelo sexo, que responderam um questionário sobre o estado geral de saúde. Uma amostra de sangue foi coletada de cada participante e analisada conforme os padrões do laboratório. Resultados: Os dados obtidos com os voluntários saudáveis permitiram a validação dos IRs de albumina, alanina aminotransferase, amilase, aspartato aminotransferase, bilirrubina direta, bilirrubina indireta, bilirrubina total, cálcio iônico, capacidade total e latente de fixação de ferro, creatinoquinase fração MB, cloro, ferro, fosfatase alcalina, fósforo, gama glutamiltransferase, glicose, lipoproteína de alta densidade, lactato, lactato desidrogenase, lipase, magnésio, potássio, proteínas totais, saturação da transferrina, sódio, triglicerídeos e ureia, de ambos os sexos. Ácido úrico foi validado apenas para o sexo masculino e creatinoquinase total (CK) foi validado apenas para o sexo feminino. Conclusão: Os IRs contidos nas bulas destes reagentes representam a população atendida pelo laboratório e podem continuar sendo utilizados. Em contrapartida, os IRs dos analitos colesterol total, lipoproteína de baixa densidade, cálcio, ácido úrico feminino e CK masculino não foram validados e necessitam de novos estudos para a validação dos intervalos de referência utilizados

Introduction: The reference intervals (RIs) provided in laboratory test reports orientate the interpretation of results, supporting the clinical evaluation performed by health professionals. Objective: Validate RIs of biochemical parameters, based on the characteristics of the local population, as well as on information available in the package inserts of the reagents and in the scientific literature. Material and Methods: An observational, descriptive, and cross-sectional study was carried out for the standardization of RIs of thirty-four biochemical parameters, performed by the Clinical Analysis laboratory of a university hospital. Forty adult individuals, matched by sex, participated in the study, who answered a questionnaire about their general health status. A blood sample was taken from each participant and analyzed according to laboratory standards. Results: Data obtained from healthy volunteers allowed the validation of the RIs of albumin, alanine aminotransferase, amylase, aspartate aminotransferase, direct bilirubin, indirect bilirubin, total bilirubin, ionic calcium, total and latent iron-binding capacity, creatine kinase MB fraction, chlorine, iron, alkaline phosphatase, phosphorus, gamma glutamyltransferase, glucose, high density lipoprotein, lactate, lactate dehydrogenase, lipase, magnesium, potassium, total proteins, transferrin saturation, sodium, triglycerides and urea, of both sexes. Uric acid has been validated for males only and total creatine kinase (CK) has been validated for females only. Conclusion: The RIs contained in the package inserts of these reagents represent the population assisted by laboratory and can continue to be used. The RIs of total cholesterol, low-density lipoprotein, calcium, female uric acid and male CK analytes were not validated and require further studies to validate the reference intervals used

The application of sigma metrics in the laboratory to assess quality control processes in South Africa

Objective: This study aimed to determine the sigma metrics of analytes when using different total allowable error guidelines.Methods: A retrospective analysis was performed on 19 general chemistry analytes at Charlotte Maxeke Johannesburg Academic Hospital in South Africa between January 2017 and December 2017. Sigma metrics were calculated on two identical analysers, using internal quality control data and total allowable error guidelines from the Ricos biological variation database and three alternative sources (the Royal College of Pathologists of Australasia, the Clinical Laboratory Improvements Amendment, and the European Federation of Clinical Chemistry and Laboratory Medicine). Results: The sigma performance was similar on both analysers but varied based on the guideline used, with the Clinical Laboratory Improvements Amendment guidelines resulting in the best sigma metrics (53% of analytes on one analyser and 46% on the other had acceptable sigma metrics) and the Royal College of Pathologists of Australia guidelines being the most stringent (21% and 23%). Sodium and chloride performed poorly across all guidelines (sigma < 3). There were also month-to-month variations that may result in acceptable sigma despite poor performance during certain months.Conclusion: The sigma varies greatly depending on the total allowable error, but could be a valuable tool to save time and decrease costs in high-volume laboratories. Sigma metrics calculations need to be standardised

The performance evaluation of unassayed biochemistry serum controls / 中华检验医学杂志

Objective@#To evaluate the inter-bottle variations, stability in consumption and interchangeability of unassayed biochemistry serum controls.@*Methods@#Comparison between unassayed serum controls from a domestic "Pretrol®" and an international "Bio-Rad" manufacturer was conducted in department of laboratory, in May 2016, with Roche Cobas 8000, Roche Hitachi 7600 and Siemens 2400 modular analyzer. The inter-bottle variation was determined by monitoring the inter-batch variation of 10 bottles of control samples after eliminating the intra-batch variation from the same bottle. Stability in consumption was determined as the precision after 7 days storage under 2 ℃ to 8 ℃ or 30 days of storage under -20 ℃ since reconstitution. The interchangeability was determined as the precisionbetween the controls from different manufacturers for the same test.@*Results@#The inter-bottle imprecision of controls from domestic manufacturer for 13 biochemistry tests (CV concentration 1/CV concentration 2) were potassium (0.26%/0.42%), sodium (0.26%/0.21%), phosphorus (0.00%/0.62%), cholesterol (0.56%/0.54%), total protein (0.52%/0.33%), albumin (0.44%/2.00%), alanine aminotransferase (1.72%/0.57%), γ-glutamylaminotransferase (0.52%/0.62%), aspartate aminotransferase (3.10%/1.09%), lactate dehydrogenase (0.76%/0.91%), alkaline phosphatase (1.13%/0.97%), amylase (0.30%/0.39%) and glucose (0.00%/0.40%). The stability in consumption of the controls from the domestic manufacturer (CV concentration 1/CV concentration 2 under 2 ℃ to 8 ℃storage; CV concentration 1/CV concentration 2 under -20 ℃ storage) were potassium (1.06%/0.36%; 0.74%/0.48%), sodium (0.49%/0.59%; 0.72%/0.65%), phosphorus (0.95%/0.80%; 1.43%/0.84%), cholesterol (1.49%/1.58%; 2.17%/1.80%), total protein (0.84%/0.75%; 1.60%/1.68%), albumin (1.33%/2.28%; 1.94%/2.43%), alanine aminotransferase (1.41%/0.51%; 3.24%/1.60%) γ-glutamylaminotransferase (1.16%/1.16%; 2.85%/2.49%), aspartate aminotransferase (4.37%/2.14%; 2.99%/1.31%), lactate dehydrogenase (2.70%/2.54%; 3.84%/2.97%), alkaline phosphatase (2.63%/1.96%; 2.31%/2.10%), amylase (0.95%/2.19%; 1.58%/1.38%) and glucose (0.60%/0.48%; 1.41%/1.55%). The Inter-bottle variation and stability in consumption of biochemistry test unassayed controls from the domestic manufacturer were compatible for clinical assay according to the CV% specification from the Clinical Biochemistry Test Quality Requirement (WS/T 403-2012). The imprecision of the controls from both the domestic and international manufacturers (CVp concentration 1/CVp concentration2; CVq concentration 1/CVq concentration 2) were potassium (0.52%/0.46%; 2.39%/0.47%), sodium (0.30%/0.17%; 0.81%/0.47%), phosphorus (2.72%/1.11%; 4.57%/2.07%), cholesterol (0.29%/1.38%; 2.94%/1.81%), total protein (0.66%/2.46%; 1.85%/2.54%), alkaline phosphatase (2.67%/4.66%; 3.58%/8.55%), total bilirubin (5.71%/5.09%; 9.55%/7.41%), albumin (1.10%/2.61%; 4.79%/1.93%), alanine aminotransferase (6.42%/1.25%; 5.74%/1.63%), γ-glutamylaminotransferase (2.27%/4.35%; 4.38%/0.74%), aspartate aminotransferase (0.56%/2.84%; 0.91%/2.11%) and lactate dehydrogenase (2.36%/2.47%; 3.10%/1.52%). The interchangeability of serum controls from domestic manufacturer was better than clinical serum samples.@*Conclusion@#The unassayed serum biochemistry test controls from domestic manufacturer are suitable for the intra-laboratory quality control and showed a promising compatibility for inter-laboratory quality control usage.

Patient data used in internal quality control / 中华检验医学杂志

Objective Quality control procedure based on the patient data in clinical chemistry was set up in laboratory information system (LIS). Methods Clinical chemistry tests results of outpatients and inpatients were collected from January 2016 to March 2017 in Zhejiang Provincial People's Hospital. Statistical results of daily patient data, including Xˉ, P2.5, P5, P10, P25, P50, P75, P90, P95 and P97.5 were calculated. Secondly, cumulative coefficients of variation (CV) of these statistical datawere calculated and compared to different criterions. Optimal analytes and related control concentrations were chosen. The minimum number of patient sample which use Xˉ as control point was calculated by PASS 11.0 software. Finally, the quality control procedure was set up base on the LIS and was verified by patient data. Results In outpatients, Xˉwas chosen as control point in AFU, APOA, APOB, CA, CL, HDL, K, MG, NA, NEFA, TP and URIC and the minimum number of sample needed were 23, 23, 30, 8, 10, 24, 34, 8, 8, 20, 13 and 22. P25 was chosen in ALP and TBIL. P50 was chosen in AST, GLU, GPDA and PHOS.P75 was chosen in ALB, CHE, CREA and DBIL. In inpatients, Xˉ was chosen as control point in AFU, ALB, APOA, APOB, CA, CL, HDL, K, Lpa, MG, NA, NEFA, TP and URIC and the minimum number of sample needed were 73, 19, 34, 18, 10, 30, 36, 21, 87, 12, 17, 51, 26 and 52;P25 was chosen in ALP, ALT, AST, CREA, DBIL, LDH, TBIL and TG. P50 in PHOS, P75 in GPDA, and P90 in CHE. 200 samples were needed in the tests which used percentiles as control points. Most CVs of these control points were higher than the commercial quality control used every day. Finally, a quality control procedure based on patient data were set up in LIS. L-J and Z score charts were used to find out systematic bias. Conclusion Patient data used in internal quality control was an economical and practical way, which can make up for the deficiency of traditional method.

The performance evaluation of unassayed biochemistry serum controls / 中华检验医学杂志

Objective To evaluate the inter-bottle variations, stability in consumption and interchangeability of unassayed biochemistry serum controls. Methods Comparison between unassayed serum controls from a domestic "Pretrol?" and an international "Bio-Rad" manufacturer was conducted in department of laboratory, in May 2016, with Roche Cobas 8000, Roche Hitachi 7600 and Siemens 2400 modular analyzer. The inter-bottle variation was determined by monitoring the inter-batch variation of 10 bottles of control samples after eliminating the intra-batch variation from the same bottle. Stability in consumption was determined as the precision after 7 days storage under 2℃ to 8℃ or 30 days of storage under -20 ℃ since reconstitution. The interchangeability was determined as the precisionbetween the controls from different manufacturers for the same test. Results The inter-bottle imprecision of controls from domestic manufacturer for 13 biochemistry tests (CV concentration 1/CV concentration 2) were potassium (0.26％/0.42％), sodium (0.26％/0.21％), phosphorus (0.00％/0.62％), cholesterol (0.56％/0.54％), total protein (0.52％/0.33％), albumin (0.44％/2.00％), alanine aminotransferase (1.72％/0.57％),γ-glutamylaminotransferase (0.52％/0.62％), aspartate aminotransferase (3.10％/1.09％), lactate dehydrogenase (0.76％/0.91％), alkaline phosphatase (1.13％/0.97％), amylase (0.30％/0.39％) and glucose (0.00％/0.40％). The stability in consumption of the controls from the domestic manufacturer (CV concentration 1/CV concentration 2 under 2℃to 8℃storage;CV concentration 1/CV concentration 2 under-20℃ storage) were potassium (1.06％/0.36％; 0.74％/0.48％), sodium (0.49％/0.59％; 0.72％/0.65％), phosphorus (0.95％/0.80％;1.43％/0.84％), cholesterol (1.49％/1.58％;2.17％/1.80％), total protein (0.84％/0.75％; 1.60％/1.68％), albumin (1.33％/2.28％; 1.94％/2.43％), alanine aminotransferase (1.41％/0.51％;3.24％/1.60％) γ-glutamylaminotransferase (1.16％/1.16％; 2.85％/2.49％), aspartate aminotransferase (4.37％/2.14％; 2.99％/1.31％), lactate dehydrogenase (2.70％/2.54％; 3.84％/2.97％), alkaline phosphatase (2.63％/1.96％; 2.31％/2.10％), amylase (0.95％/2.19％; 1.58％/1.38％) and glucose (0.60％/0.48％; 1.41％/1.55％). The Inter-bottle variation and stability in consumption of biochemistry test unassayed controls from the domestic manufacturer were compatible for clinical assay according to the CV％ specification from the Clinical Biochemistry Test Quality Requirement (WS/T 403-2012). The imprecision of the controls from both the domestic and international manufacturers (CVp concentration 1/CVp concentration2;CVq concentration 1/CVq concentration 2) were potassium (0.52％/0.46％; 2.39％/0.47％), sodium (0.30％/0.17％; 0.81％/0.47％), phosphorus (2.72％/1.11％;4.57％/2.07％), cholesterol (0.29％/1.38％;2.94％/1.81％), total protein (0.66％/2.46％;1.85％/2.54％), alkaline phosphatase (2.67％/4.66％;3.58％/8.55％), total bilirubin (5.71％/5.09％; 9.55％/7.41％), albumin (1.10％/2.61％; 4.79％/1.93％), alanine aminotransferase (6.42％/1.25％;5.74％/1.63％), γ-glutamylaminotransferase (2.27％/4.35％; 4.38％/0.74％), aspartate aminotransferase (0.56％/2.84％; 0.91％/2.11％) and lactate dehydrogenase (2.36％/2.47％; 3.10％/1.52％). The interchangeability of serum controls from domestic manufacturer was better than clinical serum samples. Conclusion The unassayed serum biochemistry test controls from domestic manufacturer are suitable for the intra-laboratory quality control and showed a promising compatibility for inter-laboratory quality control usage .

Establishment and application of autoverification procedure for clinical chemistry test results / 中华检验医学杂志

Objective@#To develop autoverification rules to assistant the verification of biochemical results, based on laboratory information management system. @*Methods@#Designed six kinds of autoverification logic rules according to the guidelines of Clinical and Laboratory Standards Institute (CLSI) AUTO-10A and Accreditation Criteria for the Quality and Competence of Medical Laboratories(ISO15189: 2012), based on in-control of the Internal Quality Control. Those rules inculds: logic disorder rules, critical value rules, warning value rules, delta check rules, relevant contradictions rules, abnormal mode rules, etc. Those rules was setted up in laboratory information management system of Dian Diagnostics. From October 2016 to April 2017, The status of autoverification was checked according to the items and bar code, and compared with clinical diagnostic and manual review. @*Results@#The passing rate of autoverification is over 65% when counted according to tests and is 45% when counted according to sample code, the coincidence rate is 92% with clinical diagnosis.In passing results of autoverification, the coincidence rate is 97.48% to 100% when campared with manual verification, and in not-passing results, the coincidence rate is 82.98% to 85.21%. @*Conclusion@#(1)Autoverification can verify half of routine biochemical test results by setting intelligent logics and rules. (2)Autoverification rules must be verified by a certain amount of test results before they can be formally applied. (3)Autoverification could improve the speed and efficiency of post-test steps.(Chin J Lab Med, 2018, 41: 547-553)

Development of measurement technology for glycated hemoglobin / 中华检验医学杂志

Hemoglobin A1c ( HbA1c ) is a glycated hemoglobin characterized by non-enzymatic binding of glucose to the N-terminal valine residue on the β-chain of the hemoglobin A , is widely utilized as a golden biomarker for diabetes mellitus management because it provides valuable information for long -term glycemic control and assessment of patient risk for chronic complications .In 2010 the American Diabetes Association (ADA) suggested a cut-off value of 6.5％ (48 mmol/mol) HbA1c to diagnose diabetes.The rapid development of measurement technology has led to the application of kits based on different principles to detect HbA1c .This review summarizes the common HbA 1c methods including high performance liquid chromatography, immunoassay, enzymatic, and electrophoresis, and briefly introduces the development of measurement technology for HbA1c.

The measurement of hemoglobin A1c and its application in diabetes mellitus diagnosis / 中华检验医学杂志

Although it has been widely used in the diagnosis and management of diabetes abroad , the application of hemoglobin A 1c ( HbA1c ) test is restricted due to the difference of test ability between various level laboratories in China.The methods, interference and standardization of HbA 1c are still worthy of continuous paying attention by laboratory physicians . How to choose the most economical and efficient method, and how to provide accurate and reliable results for patients are the priorities which can promote the application of HbA1c in diabetes diagnosis and management in China.

The application of sigma metrics quality models in quality management of clinical biochemistry laboratory / 中华检验医学杂志

Objective To improve the quality of clinical biochemistry laboratory by quality indicators of pre-analytical,analytical,post-analytical phase and the whole process.Methods Analytical Phase:The Sigma values of items were calculated,applying the equation Sigma =(TEa％-Bias％)/CV％.Total allowable error (TEa) is from analyticalal specification defined in WS/T403-2012 of China,Bias％ is from the evaluation results of National Center for Clinical Laboratory (NCCL) trueness verification PT series and CV％ is from internal quality control data during the last 6 months in our lab.Normalized Sigma metrics plot was made to evaluate the analysis performance and the quality control strategies were designed accordingly.The quality goal indexes (QGI) were also calculated to propose improvement measures for items below 6 Sigma.Quality indicators of pre-,post-analytical and whole analytical phase,such as quality of specimen,critical value notification,critical value notification in time,TAT of hs-cTnT,TAT of emergency biochemical items,rewrite of laboratory reports and unacceptable performance in EQA-PT were measured in Sigma metrics too.The Sigma metrics changes before and after taking improvement measures were compared to conform the effectiveness.Results The average Sigma value of 17 biochemical tests was 5.29,of which 8 items (UA,K,ALP,CK,AMY,AST,TG,Na) achieved excellent to world class level (≥ 5 Sigma),6 items (LDH,Cre,TC,ALT,Mg,Glu) achieved marginal to good level (5 ＞ Sigma ≥ 3),BUN performed poorly (3 ＞ Sigma ≥ 2),Ca,TP performed unacceptably (Sigma ＜ 2) with serious quality defects.The Sigma values of unacceptable specimen,critical value notification,critical value notification in time,unacceptable turn around time (TAT) of hs-cTnT,unacceptable turn around time (TAT) of emergency biochemical items,rewrite of laboratory reports,unacceptable performance in EQA-PT were 4.17,3.60,2.75,1.72,3.27,4.52,3.33 respectively,rising to 4.30,4.30,2.90,2.45,3.75,4.80,3.60 accordingly after improvement.Conclusions Sigma metrics is potentially an ideal approach for clinical biochemistry laboratories management,which is helpful to find out problems,put forward improvement measures,and confirm the effectiveness,so as to achieve the purpose of continuous quality improvement.

Free hormone analysis-current status and application of equilibrium dialysis/ultrafiltration-coupled liquid chromatography tandem mass spectrometry / 中华检验医学杂志

Improving the quality of free hormone test results which is called reliability can improve the diagnosis rates of a series of diseases.However,such a need has not yet been met by the commonly used immunoassay-based methods,partially due to existence of lack of assay accuracy and specificity.Advanced mass spectrometry instrumentation in a combination of equilibrium dialysis or ultrafiltration can avoid the shortage of immunological methods,which is the forefront of the development of hormone detection methods. Free hormone analysis using mass spectrometry may also become gradually adapted as routine testing in clinical laboratories.This review is focused at the related information of free hormone,form of free hormone in body circulating, clinical utility of free hormone analysis, methodologies used for analysis, issues or concerns in quality performance of the commonly used methods, key components of equilibrium dialysis/ultrafiltration coupled liquid chromatography tandem mass spectrometry procedure and of method validation.

The effect of hemolysis on 41 chemistry and immunology tests and determination of hemolysis alert index / 中华检验医学杂志

Objective To evaluate hemolyticinfluence on 41 chemistry and immunology tests and define the hemolysis alert index, which can be used as evidence for sample rejection and test report verification.Methods Method evaluation.As a pair, both hemolyzed and non-hemolyzed serum samples were collected from the same patient at the same time.Hemolysis index and 41 tests were analyzed.The effect of hemolysis in different hemolysis level was evaluated by comparing results of the paired samples.The alertindex were defined by senior laboratory techniciansand clinical professionals based on discussion of widely accepted quality requirements.Results The number of sample with hemolysis index of 1,2,3 and 4was 24, 17, 7 and 4 respectively.Of the 41 analytes, 6 analytes increased in hemolyzed samples comparing to non-hemolyzed samples, namelyaspartate aminotransferase(AST), creatine kinase(CK), potassium(K),lactate dehydrogenase(LD),inorganic phosphorus(iP)and total bilirubin(TBil).Another 9 analytesdecreased in hemolyzed samples comparing to non-hemolyzed samples.These analytes are alkaline phosphatase(ALP), chloride(Cl), creatinine(Cr), immunoglobin M(IgM), sodium(Na), prealbumin (PA),rheumatoid factor(RF),triglyceride(TG),uric acid(UA).Hemolysis alert index was defined as 1 for AST,K,Na and LD;2 for Cr;3 for CK,iP,PA and TBil; and 4 for the other 32 tests.Conclusions Hemolysisalertindex were defined based on the investigation of hemolyticinfluence on 41 chemistry and immunology tests in ourlaboratory.However, hemolytic influence on clinical laboratory tests are closely related to the assay systems.So clinical laboratory should evaluate the hemolytic influence on its own analysis system,and define assay specific hemolysis alert index.

Improvement of the turnaround times of STAT biochemistry test in clinical laboratory / 中华检验医学杂志

Objective To shorten the stat test turnaround time (TAT) and improve the quality of service in clinical laboratory.Method Stat test TAT related data of clinical laboratory in Tongji hospital in Wuhan from August 1st to September 30th were collected by laboratory information system and hospital information system.EXCEL and SPSS were used for data analysis.Median and the 90th percentile were calculated for TATs from order to collection, collection to transfer, transfer to reception, reception to inspection and inspection to report.Outlier rates were calculated for TAT from collection to reception, reception to report, and collection to report using 2 h, 2 h, and 4h as target TAT value, respectively.Meanwhile descriptive statistics were calculated for TAT from order to collection in different clinical department, TAT from collection to reception during different collection time frames, and TAT from reception to report during different reception time frames.Results 32 235 stat biochemistry test data were included in this survey.Among three periods cut by collection and reception time, TAT from order to collection were the longest (P50: 681 min,P90:1261 min), followed by TAT from collection to reception(P50:94 min,P90:169 min) and TAT from reception to report(P50:68 min,P90:111 min).TATs from order to collection were longer in gynecological tumor department and organ transplantation department while shorter in infection department and cardiac vascular department.The TATs from collection to reception of specimen collected during 2:00 to 3:59 were longer than other collection time.While the TATs from reception to report of specimen received during 6:00 to 7:29 were longer than other reception time.There was no significant correlation between the amount of emergency specimens collected and TAT from collection to reception in different collection time period.However, the amount of emergency specimens collected was significantly correlated with the TAT from reception to report in different reception time period.Conclusions Analysis of TAT data can be used to identify existing problems and provide improved directions to shorten TAT in clinical laboratories.

Attention should be paid to the measurement of cardiac troponin in emergency room / 中华检验医学杂志

Cardiac troponin (cTn) is currently the most sensitive and specific marker of myocardial injuryandhas been widely used in clinical practice.Measurement of cardiac troponin in emergency room is every important in the diagnosis of acute heart disease, attention should be paid to cTn specimen type, turnaroud time and rapid detection methods and other issues when use cTn in emergency settings, in order to provide rapid and accurate results.

The Advantage of Cyclosporine A and Methotrexate Rotational Therapy in Long-Term Systemic Treatment for Chronic Plaque Psoriasis in a Real World Practice

BACKGROUND: Psoriasis is a chronic inflammatory disease. In the treatment of psoriasis, cyclosporine is commonly prescribed systemic agents. However, long-term use of cyclosporine is not recommended because of side effects such as nephrotoxicity or hypertension. OBJECTIVE: To ascertain the improved safety of rotational therapy using cyclosporine and methotrexate, we investigated the frequency of abnormal results in laboratory test after long term rotational therapy using cyclosporine and methotrexate. METHODS: From January 2009 to June 2014, patients who were treated with cyclosporine or methotrexate were enrolled. The clinical data and usage of medications were reviewed. Laboratory tests were conducted before starting the treatment and regularly follow-up. The occurrences of any laboratory abnormalities during the treatments were investigated. RESULTS: A total of 21 psoriatic patients were enrolled. The mean of medication period and cumulative dose of cyclosporine and methotrexate were 497.81±512.06 days and 115.68±184.34 g in cyclosporine and 264.19±264.71 days and 448.71±448.63 mg in methotrexate. Laboratory abnormalities were found in total two patients after rotational therapy: two patients (9.5%) in aspartate aminotransferase/alanine aminotransferase and one patient (4.8%) in uric acid. No laboratory abnormalities were found in renal function test. CONCLUSION: We found that the rotational approaches using cyclosporine and methotrexate reduced the possibility of the development of nephrotoxicity. In addition to other advantage such as quick switching from one agent to another, the rotational therapy using cyclosporine and methotrexate can minimize the adverse events during the systemic treatment of chronic plaque psoriasis.

The Advantage of Cyclosporine A and Methotrexate Rotational Therapy in Long-Term Systemic Treatment for Chronic Plaque Psoriasis in a Real World Practice

BACKGROUND: Psoriasis is a chronic inflammatory disease. In the treatment of psoriasis, cyclosporine is commonly prescribed systemic agents. However, long-term use of cyclosporine is not recommended because of side effects such as nephrotoxicity or hypertension. OBJECTIVE: To ascertain the improved safety of rotational therapy using cyclosporine and methotrexate, we investigated the frequency of abnormal results in laboratory test after long term rotational therapy using cyclosporine and methotrexate. METHODS: From January 2009 to June 2014, patients who were treated with cyclosporine or methotrexate were enrolled. The clinical data and usage of medications were reviewed. Laboratory tests were conducted before starting the treatment and regularly follow-up. The occurrences of any laboratory abnormalities during the treatments were investigated. RESULTS: A total of 21 psoriatic patients were enrolled. The mean of medication period and cumulative dose of cyclosporine and methotrexate were 497.81±512.06 days and 115.68±184.34 g in cyclosporine and 264.19±264.71 days and 448.71±448.63 mg in methotrexate. Laboratory abnormalities were found in total two patients after rotational therapy: two patients (9.5%) in aspartate aminotransferase/alanine aminotransferase and one patient (4.8%) in uric acid. No laboratory abnormalities were found in renal function test. CONCLUSION: We found that the rotational approaches using cyclosporine and methotrexate reduced the possibility of the development of nephrotoxicity. In addition to other advantage such as quick switching from one agent to another, the rotational therapy using cyclosporine and methotrexate can minimize the adverse events during the systemic treatment of chronic plaque psoriasis.

Performance verification of laboratory-developed clinical chemistry system-Analytical measurement range and clinical reportable range / 中华检验医学杂志

Objective To estimate the methodology for evaluating the analytical measurement range ( AMR) and the clinically reportable range ( CRR) in lab-developed system in clinical chemistry .Methods Method evaluation .Take serum CK for instance , a series of samples were prepared from both a specimen with a high concentration of the analyte of interest and a specimen with a low concentration for the following assays.Average slope method , linear dilution recovery method and the method recommended by Clinical and Laboratory Standards Institute ( CLSI ) EP6-A were used to established AMR in the lab-developed clinical chemistry system.Based on the maximum valid dilution of the specimen and the results of AMR , CRR were determined.One-half of the total error allowance ( TEa) of Chinese health standard was set up as allowance error (7.5%).Results X-Y scatter plot was made by assigning sample numbers to the horizontal axis and actual measured values to the vertical axis , which determined the upper limit of AMR was approximate 1 651 U/L.The results analyzed by average slope method indicated that the linear correlation between expected values and actual measured values was determined , the correlation (r), the intercept (a) and the slope (b) met the linear standard, and AMR was 5-1 699 U/L.The results analyzed by EP6-A indicated that the best fitting curve was obtained by using cubic polynomial method , and the linearity deviation of the minimum concentration was -77.1%, which exceeded one-half of TEa.Followed by the deletion of the maximum concentration , the resumed experiment was done .The results showed that the nonlinear coefficient c of quadratic polynomial and the nonlinear coefficient c and d of cubic polynomial have no significant difference to 0, and AMR was 7.5-1 458.0 U/L.By linear dilution recovery method , the linear correlation between expected values and actual measured values was determined , the correlation ( r) , the intercept ( a) and the slope ( b) met the linear standard , the recovery rates was between 100.0%and 104.8%, and AMR is 5 -1 699 U/L.The CRR was determined to be 5 -33 880 U/L, which met the standard of TEa . Conclusions Average slope method, linear dilution recovery method and EP 6-A method were all used to established AMR in lab-developed clinical chemistry system .Without complicated statistical analysis , linear dilution recovery method was suitable for clinical use .The linearity deviation of the minimum concentration analyzed by EP6-A did not meet the standard of the quality objective system , suggesting defects in the statistical analysis of the results .CRR was feasibly determined by using linear dilution recovery method align with AMR.

Investigation and analysis of internal quality control on clinical chemistry, clinical immunology and clinical hematology of mutual recognition laboratories in 142 medical institutions in Beijing / 中华检验医学杂志

Objective To investigate the internal quality control ( IQC ) on clinical chemistry , clinical immunology and clinical hematology in mutual recognition laboratories in medical institutions in Beijing.Methods By means of questionnaire survey and on -site investigation, fresh frozen serum and whole blood samples with assigned values by reference method were measured to investigate the status of IQC on clinical chemistry , clinical immunology and clinical hematology in 142 mutual recognition laboratories in medical institutions of Beijing,and results were analyzed.Results 142 copies of questionnaireson clinical chemistry, clinical immunology and clinical hematology were send out and 120, 97, and 101 laboratories returned the questionnaires respectively .The information feedback rate was 84.5%, 68.3% and 71.1%respectively .All the questionnaires were effective .Questionnaires survey results showed that more than 50%laboratories set up quality control goals and the most of the goals were probability for error detection ( Ped) 95%, probability for false rejection(Pfr)5%;About 70% laboratories usecd the same quality control plan for different tests ;The most frequently used quality control rules are 12s/13s/22s.On-site investigation showed that ,take the results of clinical chemistry for example , based on the desirable biological variation and WS/T 403 -2012 , most of the tests can't meet the quality control goalsunder the existing quality controlcondition.Conclusion Clinical laboratories should consider their actual situations , assess their own qualitylevels that they can reach , set reasonable quality standards for themselves , and make appropriateindividualized quality control plan.

Investigation on the distribution of critical value limits in adult patients in Beijing / 中华检验医学杂志

Objective To investigate the distribution of critical values of adults in Beijing, to provide the evidence for the formulation of the Standardized Management Guideline in Critical Values, in order to promote the accurate management of critical values.Methods A total of 110 398 data of critical values from the tertiary and above medical institutions during January 1 to May 31 in 2015 in Beijing were collected by the way of on-site inspection, covering the disciplines of hematology, clinical chemistry, coagulation and blood gas analysis.Fristly, the selected critical values were classified by the factor of admission departments and disease types,then were analyzed by using Kruskal-Wallis test, to compare the differences in each group.Secondly,the combined groups were classified by the factor of gender then were analyzed by using Mann-Whithey U test, to compare the differences in each group.Finally, the stratification thresholds of critical values were established.Results Except for the upper limits of Ca, pH, pCO2, Hb and the lower limits of Glu, pH, the rest of thresholds of critical values had significant differences due to different admission departments and disease types and/or gender.Conclusion Depending on the different admission departmentsces disease types and/or gender, hierarchical limit values on each critical value were formulated.

Analysis of error sources for routine chemistry external quality assessment program in China / 中华检验医学杂志

Objective To investigate and analyze the reasons of fa0ilure in external quality assessment(EQA) for routine chemistry and provide the basis for the corrective and preventive actions.Methods Based on the network system of NCCL EQA the reasons of failure in 2013 national routine chemistry external quality assessment program were investigated,among which the reasons were classified and analyzed with seven sources of problems which were clerical errors,methodological problems,equipment problems,technical problems,EQA materials problems,EQA Evaluation problems and unable to explain after investigation.Results The return rate of this root cause investigation for each analyte ranged from 33.3％ to 80.0％.The major reason for unacceptable analyte included clerical errors (6.5％) (decimal point position error:70.1％;unit error:20.8％;instrument or method coding error:8.1％),methodological problems (45.1％)(calibration:54.2％;reagent:38.0％;EQA material:7.8％),equipment problems (28.5％) (no regular maintenance:98.0％;pipeline error:2.0％),technical problems (8.2％) (do not follow SOP:80.4％;EQA material redissolve error:10.6％;placing order error:9.0％) and unable to explain (11.7％) (system error:68.2％;random error:31.8％).There were no EQA materials problems or EQA Evaluation problems in this survey.Analysis systems' grouping statistics were implemented for seven analytes including sodium,chlorine,phosphorus,direct bilirubin,total iron binding capacity,copper,and zinc.Unsatisfied EQA proportions of mating system were lower than nonmatching ones for the majority of analytes.Conclutions Further work on EQA should be undertaken by clinical laboratories.Laboratories should use reagents with high quality as well as improve the operation technology and sense of responsibility.Only in this way,can the accuracy and reliability of testing results be guaranteed.