Colonización rectal por Enterobacterales productores de múltiples carbapenemasas: Reporte de un caso de coproducción / Rectal colonization by Enterobacterales producing multiple carbapenemases: a co-production case report

Resumen El constante aumento de Enterobacterales productores de carbapenemasas (CPE) se constituye en un problema de salud pública a nivel mundial, por el impacto generado en la mortalidad de los pacientes. El tracto gastrointestinal es el principal reservorio de este tipo de microorganismos, por lo cual, la colonización rectal se convierte en un importante factor de riesgo para el desarrollo de posteriores infecciones. Una de las estrategias de vigilancia epidemiológica activa, es la búsqueda de pacientes colonizados, a través de cultivos de tamización para detectar estos microrganismos multirresistentes. Reportamos el caso de un paciente, con historia de sepsis de origen pulmonar, colonizado por Klebsiella pneumoniae con coproducción de carbapenemasas NDM + KPC y Escherichia coli con carbapenemasa NDM. Este hallazgo es cada vez más frecuente, lo cual implica un reto en su detección y diagnóstico. Se describen características del paciente, procedimientos realizados y hallazgos microbiológicos.

Abstract The constant increase in carbapenemase-producing Enterobacterales (CPE) constitutes a public health problem worldwide, due to the impact generated on the mortality of patients. The gastrointestinal tract is the main reservoir for this microorganism, which is why, rectal colonization becomes an important risk factor for the development of subsequent infections. One of the active epidemiological surveillance strategies is the search for colonized patients through screening cultures, to detect these multi-resistant microorganisms. We report the case of a patient, with a history of sepsis of pulmonary origin, colonized by Klebsiella pneumoniae with co-production of NDM + KPC carbapenemases and NDM carbapenemase-producing Escherichia coli. This finding is more and more frequent, which implies a challenge in its detection and diagnosis. Patient characteristics, procedures performed and microbiological findings are described.

Detección rápida de Enterobacterias productoras de carbapenemasas en hisopados rectales de pacientes neonatos colonizados / Rapid detection of carbapenemase-producing Enterobacteriaceae in rectal swabs of colonized neonatal patients

Resumen Objetivo: Detectar la presencia de Enterobacterias productoras de carbapenemasas en hisopados rectales de neonatos mediante técnica de nefelometría láser y caracterización del tipo de carbapenemasa mediante test inmunocromatográfico. Materiales y Métodos: Estudio descriptivo de corte transversal. Fueron incluidos 57 neonatos, tamizados al ingreso a UCI, mediante hisopado rectal, procesado por nefelometría laser HB&L Carbapenemase (Alifax®) y caracterización del tipo de carbapenemasa por inmunocromatografía rápida RESIST-3 (Coris BioConcept®). Resultados: Encontramos un alto porcentaje de colonización rectal (22.9%) correspondiente a 13 hisopados positivos y 44 (77.1%) fueron negativos por nefelometría láser. Por VITEK 2® se obtuvo identificación de Klebsiella pneumoniae resistente a carbapenémicos en los 13 aislamientos y el test inmunocromatográfico reveló la presencia de carbapenemasas blaKPC en estos aislamientos. Discusión: Estudios evidencian el aumento de la colonización por microorganismos productores de carbapenemasas en neonatos. Los resultados de este estudio demuestran que un porcentaje significativo de neonatos que ingresan a las Unidades de Cuidado Neonatal se encuentran colonizados con Enterobacterias productoras de carbapenemasas en tracto intestinal. Lo anterior constituye un riesgo potencial para su diseminación y posterior desarrollo de brotes, en donde surge la importancia de implementar estrategias de vigilancia activa como la tamización rectal para la detección oportuna de neonatos colonizados.

Abstract Objective: To detect the presence of carbapenemase-producing Enterobacteriaceae in rectal swabs of neonates by means of laser nephelometry technique and characterization of the type of carbapenemase by immunochromatographic test. Materials and Methods: Descriptive cross-sectional study. 57 neonatal patients were included; They underwent rectal screening upon admission to the ICU, using swabs which were processed by HB&L Carbapenemase laser nephelometry (Alifax®) and characterization of the type of carbapenemase by RESIST-3 rapid immu nochromatography (Coris BioConcept®). Results: We found a high percentage of rectal colonization (22.9%) corresponding to 13 positive swabs and 44 samples (77.1%) were negative by laser nephelome try. Identification of carbapenem-resistant Klebsiella pneumoniae was obtained by VITEK 2® in the 13 isolates and the immunochromatographic test revealed the presence of blaKPC carbapenemases in these isolates. Discussion: Studies show increased colonization by carbapenemase-producing microorganisms in neonates. The results of this study demonstrate that a significant percentage of neonates who enter Neonatal Care Units are colonized with Enterobacteriaceae that produce carbapenemases in the intestinal tract. This constitu tes a potential risk for its spread and subsequent development of outbreaks, where the importance of implementing active surveillance strategies such as rectal screening for the timely detection of colonized neonates arises.

The effect of lens opacity on the measurement of retinal oxygen saturation / 中华眼底病杂志

Objective To analysis the effect of lens opacity on the measurement of retinal vessel oxygen saturation.Methods This was a cross sectional study.Forty four eyes of 44 patients with different degrees of lens opacity were enrolled.There were 23 males and 21 females.The patients aged from 48 to 84 years,with the mean age of(71.8± 10.3) years.The mean best corrected visual acuity was 0.65±0.22.The mean intraocular pressure was (14.2± 4.3) mmHg (1 mmHg=0.133 kPa).The mean equivalent spherical degree was (-0.05 ± 2.10) D.The opitical quality analysis system was applied to measure intraocular objective scattering index (OSI) caused by lens opacity.According to the OSI,the opacity of lens was divided into four groups.Patients with OSI value ＜ 1.0 was grouped to level 1,which indicated that the lens were basically transparent;patients with OSI value between 1.0 and 3.0 was grouped to level 2,which indicated early cataract;patients with OSI value between 3.0 and 7.0 was grouped to level 3,which indicated progressive cataract;patients with OSI value ＞ 7.0 was grouped to level 4,which indicated the mature stage of cataract.The retinal oximeter Oxymap T1 was used to capture the fundus images under different wavelengths.Pearson correlation analysis was used to analyze the correlation between retinal oxygen saturation and age,intraocular pressure,equivalent spherical degree and OSI.One way ANOVA was used to analyze the difference of retinal oxygen saturation among groups.Results The mean retinal arterial oxygen saturation,venous oxygen saturation and arteriovenous difference was (90.70± 6.46)％,(47.34 ± 13.51)％,(43.36 ± 10.09)％,respectively.The correlations of retinal arterial oxygen saturation,venous oxygen saturation and arteriovenous difference with age,intraocular pressure,equivalent spherical degree was not statistically significant (all P＞0.05).The retinal arterial oxygen saturation and venous oxygen saturation was negatively correlated with OSI (r=-0.462,-0.500;P=0.002,0.001),the arteriovenous difference and OSI was positively correlated (r=0.373,P=0.013).According to lens opacity,there were 11 eyes in level 1,9 eyes in level 2,14 eyes in level 3,10 eyes in level 4.There were significant differences of retinal artery and venous oxygen saturation among different lens opacity levels (F=5.340,4.710;P=0.003,0.007);meanwhile,the arteriovenous difference was not significantly different (F=2.048,P=0.123).The retinal arterial oxygen saturation and venous oxygen saturation was significantly lower in the level 4 lens opacity group than any other three groups (all P＜0.05),but there was no statistically significant difference among level 1 to level 3 lens opacity group.Conclusion The effect of lens opacity of level 1 to level 3 is limited on the measurement of retinal oxygen saturation,but level 4 lens opacity will cause decrease of retinal artery and venous oxygen saturation.

Progress in laboratory diagnosis of heparin induced thrombocytopenia / 中华检验医学杂志

Heparin induced thrombocytopenia ( HIT ) is a severe side effect of heparin with antibody-mediation.Laboratory assays can be divided into two major categories, about functional assays and HIT antibodiesdetection.Thefunctional assays, such as the serotonin release assay ( SRA ) and heparin-induced platelet activationassay( HIPA) , are sensitive and specific for HIT.They arethe reference standard assays generally, but have thedeficiencies of complicated operation and time-consuming, and cannot be used as a routine examination. TheHIT antibodiesdetections, such as ELISA, immune turbidimetry assay, chemiluminescent assay and lateral flow immunoassay, have high diagnostic sensitivityandareavailable at routine laboratories.They can exclude the diagnosis of HIT or beused to diagnose HIT effectively combined with the pre-test probability score(4Ts score) of HIT.

Comparative analysis between HP-083/4 and rational used instrument on results of six items / 国际检验医学杂志

Objective To compare the performance of HP-083/4 and rational used instrument on detecting six items.Methods The rational instruments were used as contrast instrument,HP-083/4 was the verified instrument.A total of 100 blood specimens and 100 urine specimens were collected,and the levels of antistreptolysin O(ASO),hypersensitive C reactive protein (hsCRP),D-di-mer(D-D),glycosylated hemoglobin(HbA1c),rheumatoid factor(RF)and urine microalbumin(mAlb)were detected.The regression equation and correlation coefficient(r)of the two methods were calculated,and the Kappa values(κ)were analyzed to evaluate the performance of HP-083/4.Results There was a good linear correlation (r >0.950)for the two methods in detecting the serum ASO,hsCRP,D-D,HbA1c,RF and mAlb,r were 0.991,0.995,0.970,0.957,0.980 and 0.967 respectively.Besides,they had good concordance(κ>0.6),theκ values were 0.830,0.957,0.601,0.720,0.920 and 0.694 respectively.Conclusion HP-083/4 is effec-tive in detecting ASO,hsCRP,D-D,HbA1c,RF and mAlb,which should be suitable for clinical application.

Influences of hemoglobin variants on different HbA1c measurement systems / 中华检验医学杂志

Objective To assess influences of hemoglobin variants on different HbA 1c measurement systems.Methods HbA1c values of normal samples and samples with hemoglobin variants were measured respectively byenzymatic assay (Norudia N HbA1c,SEKISUI), immunity transmission turbidity (oneHbA1c FS,DiaSys), boronate affinity HPLC(Ultra2,Trinity Biotech), capillary electrophoresis(Capillary 2 Flex Piercing,Sebia)and ion exchange HPLC(HA8160,Arkary;Variant Ⅱ Turbo(VⅡ-T),Bio-Rad;Variant ⅡTurbo 2.0 (VⅡ-T 2.0), Bio-Rad).HbA1c values from different hemoglobin variants and HbA1c measurement systems were analyzed .Results The HbA1c values from the 7 HbA1c measurement systems were well correlatedin normal samples .For HbE heterozygote , the HbA1c values from VⅡ-T were divided into 2 groups comparing with CFP , and HbA1c differences between CFP and other measurement systems are minor except for HA8160 and VⅡ-T.The HbA1c values of homozygous HbE were given by Ultra 2 but CFP and VⅡ-T 2.0.The differences of HbA1c values from samples with J-Bangkok are much higher than those from the samples with other hemoglobin variants .The differences of HbA1c values from samples with all kinds of hemoglobin variants(Hb J-Bangkok, Hb J-Newyork, Hb G-Taipei and Hb G-Coushatta)are dramatic for VⅡ-T.For rare Kurosaki, CFP can give a hint that there existshemoglobin variant while measuring HbA 1c. Conclusions Capillary Flex 2 Piercingcan well recognize common hemoglobin variants . Different hemoglobin variants have different influences on different HbA 1c measurement systems.The influences of J-Bangkok among HbA1c measurement systems are more evident than the other common hemoglobin variants .

Performance Verification of Analyzing IgG by Immune Nephelometry Assay / 现代检验医学杂志

Objective To test and verify the performance of analyzing IgG using nephelometry assay,and discuss reasonable model of performance verification of this system.Methods According to related documents and standards,this study verified the precision,accuracy,assay measurement range(AMR)and reference interval.Results The within-run precision in low level was 2.24%,while it was 2.73% in high level.The overall precision in low level was 2.25%,while it was 2.68%.The relative bias between the results of analyzing the calibrator with a different lot from that used for calibrating and its concen-tration printed was 5.18%.The AMR of the original dilution was 2.44~33.5 g/L.The results of reference interval verifica-tion identified with what the manufactur declares.Conclusion The major performances of analyzing IgG by this system are identifies with the manufactur declares.The reference interval offered by the manufactur is acceptable.The verification and calculation methods are simple and convenient,with strong operability.

Assessment of the consistency of five standardized cystatin C measurement systems / 中华检验医学杂志

Objective To assess the consistency of four standardized cystatin C particle-enhanced turbidimetric assay (PETIA) and one particle-enhanced nephelometric immunoassay (PENIA) measurement systems Methods Performance verification test was conducted according to CLSI EP 15-A2 and EP9-A2. Fourty serum samples in comparative test were obtained from the remaining serum samples of outpatients in Peking Union Medical College Hospital in March 2013.Fourty serum samples were tested on Olympus AU5400 automatic biochemical analyzer ( four PETIA Cys C reagents:Shanghai Jingyuan Co ., Ltd, Beijing Leadman Biochemistry Co ., Ltd, Beijing Strong Biotechnologies , Maker Biotechnology in Sichuan , and labelled as A, B, C, D respectively) and PENIA N Latex Cys C measurement system on Siemens BNⅡ(labelled as E).Correlation analysis were performed among four PETIA methods one PENIA method Differences of each detection system were compared in the medical decision level 1,2,3,4 mg/L.The reference material ERM-DA471/IFCC was measured by five systems and bias ( percentage bias ) was calculate for each system.Results Results of systems A, B, C, D, E were 1.29(0.89-2.43), 1.30 (0.96-2.59), 1.22(0.90-2.44), 1.27(0.96-2.47), 1.14(0.82-2.05)mg/L.Chart shows bias among these five systems was small when Cys C concentration was less than 4mg/L.PETIA method A, B, C, D correlated with their mean value well , with the average deviation from their mean value ( percent deviation) at -0.017 -0.031 mg/L ( -3.1%-2.1%), and all were less than allowed bias from the biological variation (3.4%).The deviation of PETIA method A, B, C, D with their mean value in medical decision level at -0.176 -0.178 mg/L.Systems A, B, C, D correlated well with the result of PENIA method system E , and the mean deviation ( percent deviation ) was at 0.278 -0.326 mg/L ( 12.6%-18.5%) , and the deviation ( percent deviation ) in the medical decision level 0.055 -1.079 mg/L (5.51%-26.98%).Bias of PETIA method A, B, C, D Cys C system measuringERM -DA471/IFCC ranged from 0.22 to 0.39 mg/L ( 3.9%-7.0%) , which exceeded the allowable range of the reference material target value, and were larger than the allowable bias from biological variation (3.4%).Bias ( percent ) of PENIA method system E was -0.1 mg/L ( -1.7%) , within the allowable range of ERM-DA471/IFCC target value .Conclusions The consistency of four assesed PETIA Cys C reagents was relatively ideal, and improved markably after being traced to ERM-DA471/IFCC.Besides, the results of PETIA were higher than those of PENIA .Bias among these five systems was small when Cys C concentration was less than 4 mg/L, and the bias became larger in higher Cys C concentration.

Evaluation of quantitative detection limit and functional sensitivity of prealbumin and their clinical applications analysis / 国际检验医学杂志

Objective To evaluate the limit of blank (LoB),limit of detection (LoD),limit of quantitation(LoQ)and functional sensitivity (FS)of prealbumin (PA)detected by the Roche Modular P automatic biochemical analyzer.Methods According to the EP17A file of the American Clinical and Laboratory Standards Institute (CLSI),saline as the blank sample and a series of low con-centration samples were detected by the Roche Modular P automatic biochemical analyzer for determining LoB,LoD and LoQ.And FS was determined based on the domestic universal method .Results LoB of PA was 16.35 mg/L,LoD was 18.23 mg/L,LoQ was temporarily unable to evaluate and FS was 25.00 mg/L.The report scope and the report mode in clinic were affirmed by combi-ning with the low value of the reportable scope.Conclusion LoD of PA detected by the Roche Modular P automatic biochemical an-alyzer is established,which provides more valuable information for clinical diagnosis and treatment.Conducting the comparison of different evaluation methods determines the advantages and limitation of the practical application of different methods.

Study on the antigenicity of Streptococcus pneumonia polysaccharide, its derivatives and conjugates by three immunological assays / 中华微生物学和免疫学杂志

Objective To monitor and analyze the antigenicity of Streptococcus pneumonia polysac-charide, its derivatives and conjugates by three immunological assays .Methods Inhibition ELISA and rate nephelometry(RN) were established for this study.Antigenicity of serotype 23F pneumococcal conjugates and their intermediates were analyzed by double immunodiffusion assay , inhibition ELISA and RN .The re-sults derived from three assays were comparatively analyzed to evaluate the changes of antigenicity during the preparing process of serotype 23F conjugate.Results Double immunodiffusion assay, inhibition ELISA and RN were all applicable to antigenicity analysis during the process of conjugate preparation .Inhibition ELISA could quantitatively detect a slight difference of polysaccharide antigenicity during the preparing process . Conclusion The antigenicity of polysaccharide during the preparing process of pneumococcal conjugates could be analytically monitored by using three immunological assays .This study provided evidence for suc-cessfully using immunological assays as the quality control means during the preparing process of pneumococ -cal conjugates .

Análisis de concordancia entre el dosaje de inmunoglobulinas y la fracción gamma del proteinograma sérico / Analysis of agreement between the dosage of immunoglobulins and gamma fraction of serum protein electrophoresis / Análise de concordancia entre a dosagem de imunoglobulinas e a fragao gamma do proteinograma sérico

En este trabajo se proponen dos criterios que evalúan el acuerdo existente entre densitometría y nefelometría, en la evaluación de los niveles de inmunoglobulinas en suero, basados en la propia población de pacientes y su posible aplicación en un algoritmo de autoverificación. Se construyó la variable Diferencia GAMgamma = Suma Igs - gamma; se efectuó el análisis según el método de Bland y Altman. Se estimó el IC95% empleando como referencia una cohorte de 497 pacientes concurrentes al laboratorio del Hospital A. Posadas en octubre y noviembre de 2011 y que tenían un dosaje de inmunoglobulinas G, A y M normal para población adulta. Estos resultados fueron contrastados con 2 poblaciones: a) 977 sujetos concurrentes en el mismo período y b) 111 pacientes con presencia de componente monoclonal (CM). En la población de referencia el IC95% Diferencia (mg/dL) fue de 115-653 y el DE para los límites ± 21 mg/dL. Utilizando los criterios Valores de referencia seguido por Diferencia se obtuvieron los siguientes resultados: Población de pacientes: 470/977 (48,1%) pasaron las dos alarmas y serán autovalidados. Población con CM: el 75,6% dio al menos una alarma. No obstante, si bien se puede considerar aceptable esta sensibilidad, hubo 27 CM que pasaron las dos alarmas. Se concluye que luego de una inspección visual previa, casi el 50% de los resultados serán autovalidados.

Two criteria are proposed to evaluate the agreement between densitometry and nephelometry of serum immunoglobulin level, based on own patient population and its possible application in a self-validation algorithm. A difference GAMgamma = Sum Igs -gamma variable was constructed; analysis was performed according to the Bland and Altman method. CI 95% was estimated using as reference a cohort of 497 patients attending Posadas Hospital's laboratory in October and November 2011 who had a normal dosage of G, A and M immunoglobulins for an adult population. These results were compared with two populations: a) 977 patients attending the hospital in the same period and b) 111 patients with monoclonal component (MC). In the reference population, the CI 95% Difference (mg/dL) was 115-653 and the limits were ± 21 mg/dL. Using Reference Values criteria followed by Difference, the following results were obtained: in the patient population, 470/977 (48.1%) passed both alarms and will be validated. In the MC population, 75.6% gave at least one alarm. However, although this may be considered acceptable sensitivity, there were 27 MC who passed both alarms. It can be concluded that after a visual inspection, almost 50% of the results will be self-validated.

Neste trabalho sáo propostos dois critérios que avaliam o acordo existente entre densitometria e nefelometría, na avaliagáo dos níveis de imunoglobulinas em soro, com base na pròpria populagáo de doentes e a sua possível aplicagáo num algoritmo de autovalidagáo. Foi construida a variável Diferenga GAMgamma = Soma Igs - gama, a análise foi realizada de acordo com o método de Bland & Altman. IC95% foi estimada utilizando-se como referencia uma coorte com 497 doentes concorrentes ao laboratòrio do hospital Posadas em outubro e novembro de 2011 e que tinham uma dosagem normal de imunoglobulinas G, A e M para populagáo adulta. Estes resultados foram comparados com duas populagdes-. a) 977 doentes concorrentes no mesmo período e b) 111 doentes com presenga de componente monoclonal (CM). Na populagáo de referencia, IC95% Diferenga (mg/dL): (115-653) e o DE para os limites ± 21 mg/dL foram os resultados. Utilizando os critérios Valores de Referencia seguidos de Diferenga foram obtidos os seguintes resultados: A populagáo de doentes de 470/977 (48,1%) passou os dois alarmes e seráo autovalidados. A populagáo com CM que deu pelo menos um alarme foi de 75,6%. No entanto, embora esta sensibilidade possa ser considerada aceitável, houve 27 CM que passaram os dois alarmes. A conclusáo é que depois de uma inspegáo visual prévia, cerca de 50% dos resultados seráo autovalidados.

Validation and development of an immunonephelometric assay for the determination of alpha-1 antitrypsin levels in dried blood spots from patients with COPD / Desenvolvimento e validação de um método de imunonefelometria em amostras de sangue em papel-filtro para a dosagem da alfa-1 antitripsina em pacientes com DPOC

OBJECTIVE: To validate and develop an immunonephelometric assay for the determination of alpha-1 antitrypsin (AAT) levels in dried blood spots from COPD patients in Brazil. METHODS: We determined AAT levels in serum samples and dried blood spots from 192 COPD patients. For the preparation of dried blood spots, a disk (diameter, 6 mm) was placed into a tube, eluted with 200 µL of PBS, and stored overnight at 4ºC. All of the samples were analyzed by immunonephelometry in duplicate. We used the bootstrap resampling method in order to determine a cut-off point for AAT levels in dried blood spots. RESULTS: The correlation coefficient between the AAT levels in serum samples and those in dried blood spots was r = 0.45. For dried blood spots, the cut-off value was 2.02 mg/dL (97% CI: 1.45-2.64 mg/dL), with a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 95.7%, 27.2%, and 100%, respectively. CONCLUSIONS: This method for the determination of AAT levels in dried blood spots appears to be a reliable screening tool for patients with AAT deficiency. .

OBJETIVO: Validar e desenvolver um método de dosagem de alfa-1 antitripsina (AAT) por imunonefelometria em amostras de sangue em papel-filtro em pacientes com DPOC no Brasil. MÉTODOS: Amostras de soro e de sangue em papel-filtro de 192 pacientes com DPOC foram utilizadas para a dosagem de AAT. Para a preparação das amostras de sangue em papel-filtro, um disco do papel com diâmetro de 6 mm foi colocado em um tubo e eluído com 200 µL de PBS, permanecendo por toda a noite a 4ºC. Todas as amostras foram analisadas em duplicata por imunonefelometria. O método de reamostragem bootstrap foi utilizado para a determinação de um ponto de corte para o nível de AAT nas amostras de sangue em papel-filtro. RESULTADOS: O coeficiente de correlação entre os níveis de AAT em soro e em sangue em papel-filtro foi de r = 0,45. Para as amostras em papel-filtro, o ponto de corte foi de 2,02 mg/dL (IC97%: 1,45-2,64 mg/dL), com sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo de 100%, 95,7%, 27,2% e 100%, respectivamente. CONCLUSÕES: Este método de determinação dos níveis de AAT em sangue em papel-filtro se mostrou uma ferramenta confiável para o rastreamento de pacientes com deficiência de AAT. .

Light transmittance aggregometry with non-adjusted PRP is more suitable for clinical laboratory =monitoring antiplatelet therapy / 中华检验医学杂志

Objective In this study,maximum platelet aggregation rate of Light transmittance aggregometry (LTA) for coronary heart disease(CHD) patients taking antiplatelet drug and patients without antiplatelet therapy was measured in non-adjusted and platelet count-adjusted platelet-rich plasma (PRP).The aim of this study is to compare which method is superior in evaluation of antiplatelet drug effect.Methods This is a methodology comparative research.560 CHD outpatients and inpatients that visited Beijing Anzhen Hospital of the Capital University of Medical Sciences from May to June,2012 were chosen,who were treated with aspirin monotherapy,or patients on combination therapy with aspirin and clopidogrel,as well as patients without antiplatelet therapy.LTA was performed in non-adjusted (improved method) and platelet count (200 × 109/L)-adjusted PRP (original method),using 6 μmol/L adenosine diphosphate (ADP) and 0.5 mmol/L arachidonic acid (ARA) as agonists.The maximum aggregation rates in 5 min were detected,and consistency and differences of the two methods were compared.Results There is no statistically significant correlation between maximum aggregation rate and platelet count in PRP with 6 μmol/L ADP or 0.5 mmol/L ARA as agonists in all subgroups including aspirin monotherapy,combination therapy with aspirin and clopidogrel and patients without antiplatelet therapy (-0.21 ≤ r ≤0.111,P ＞ 0.05).The maximum aggregation rate using ADP as agonists in original method is decreased compared with improved method,there is statistically significant difference in all subgroups including patients without antiplatelet therapy,aspirin monotherapy,combination therapy with aspirin and clopidogrel less than one week and more than one week.The variability of platelet aggregation rate using ADP as agonists with improved method is lower than that with original method in all subgroups.Yet the maximum aggregation rates using ADP as agonists with improved method and original method correlate well with each other in all subgroups (r =0.78,0.73,0.40,0.71,P ＜0.01).In the subgroup of subjects without antiplatelet therapy using ARA as agonist,platelet aggregation rate is decreased in original method compared with improved method,there is statistically significant difference,and the variability of the aggregation rate with improved method is also lower than that with original method,ranging from 62％-98％ relative to 5％-89％.The decrease of aggregation rate using ARA as agonist for patients taking antiplatelet drug compared with patients without antiplatelet therapy can be detected both with improved method and original method.Conclusion Non-adjusted PRP in LTA is more convenient and time-saving,and it also means less effects on platelet in vitro.Therefore,non-adjusted PRP is more suitable for monitoring efficacy of antiplatelet therapy in clinical laboratory.

Performance evaluation of nine commonly used urine albumin assay systems / 中华检验医学杂志

Objective By investigating precision,linearity and accuracy of 9 commonly urine albumin assay systems (8 of immuno-turbidimetric assays and 1 of immuno-nephlometric assay),and comparing the concordance of measurement results,to elucidate the quality of the existing analytical systems.Methods Referring to Clinical and Laboratory Standards Institute (CLSI) EP15-A2,two mixed urines with U-Alb levels of 20 mg/L and 200 mg/L were made to validate precision; Referring to CLSI EP14-A2,fourty fresh urines were selected to evaluate matrix effect of saline diluted European Reference Materials (ERM) DA 470 and saline diluted urine,also to reflect the variation of measurement results among systems; Referring to EP6-A,saline diluted urines (10 levels) were made to validate linearity; Taking the theoretical concentration of precisely saline-diluted ERM-DA 470 as the target value,accuracy of each assay system was evaluated.Maximal allowable coefficient variation (CV) of ≤ 15％ was taken as the acceptable precision for each assay system,as rccommcnded by International Federation of Clinical Chemistry (IFCC)-and National Kidney Disease Education Program (NKDEP) ; maximum allowable bias of ≤25％ was taken as criteria for accuracy evaluation as used in Proficiency Test (PT) sponsored by College of American Pathologists (CAP).Results At level of micro-albuminuria(20-200 mg/L),all 9 systems total CVs were ≤ 15％ ; No matrix effect or interference were found in saline diluted ERM DA 470 and saline diluted urine.For A,B,E,F,G and I systems,validated linear regions were close to those stated in kit instruction;For C,D and H systems,the lower limits of validated linear region (18.7,3.6 and 12.0 mg/L,respectively) were higher than those stated in kits instruction (0,0.9 and 5.0 mg/L,respectively) ;For B and C systems,the lower limits of validated linear region were close to the upper limits of reference interval stated in kit instruction.When urine albumin was ≤ 12.6 mg/L,A,E,F,G and I systems showed good accuracy,absolute biases at all dilution were below 3 mg/L,D system showed higher positive bias (5.0-14.4 mg/L),B,C and H systems' biases were not evaluated because of high in-batch CV (the CV of B system≥ 18.1％,of C system ≥ 14.5％,of H system ≥ 39.1％); when U-Alb ranged in 25.2-201.0 mg/L,all 8 systems' relative biases were ≤25％,except D systems,which showed an un-acceptable positive bias (15.9％-44.3％).Good concordance among systems' results was present at level of microalbuminuria(20-200 mg/L),with CV among systems ＜ 15％ ;when urine albumin was ＜ 20 mg/L,CV among systems increased as allumin concentration decreased.The main contribution of variation came from B,C and H systems,which lower limits of linearity were relatively high.Conclusions At level of microalbuminuria(20-200 mg/L),except D system,the other 8 systems show good precision and accuracy;at low level of urine albumin(＜20 mg/L,especially ＜ 10 mg/L),precision and accuracy of some systems(B,C and H system) needs to be improved.

Analytical performance of three cysteine proteinase inhibitor c reagents applied in the automatic biochemistry analyzer / 中华检验医学杂志

Objective To validate the analytical performance of three Cys C reagents with particle-enhanced turbidimetric immunoassay(PETIA) method used on the automatic biochemistry analyzer for preliminary clinical application.Methods The performance of three Cys C reagents (labeled as A, B, C) with PETIA method from Shanghai Jing Yuan Co., Beijing Leadman Co. and Beijing Jiuqiang Co. on OlympusAU2700 automatic biochemistry analyzer were assessed.According to the standard of CLSI EP6-A, EP15-A and EP7-P, the precision, linearity range, disturbance (bilirubin, hemoglobin, chyle) were assessed, and compared with those of Cys C reagent based on particle-enhanced nephelometric immunoassay(PENIA) from Dade Behring Co.. The reference ranges for Cys C in serum of 120 healthy individual were evaluated.Results The within-run CVs of the three reagents (A, B and C) were 3.08%-3.2%, 2.3%-4.15% and 1.38%-1.53% respectively.The total CV in A, B and C were 3.29%-3.44%, 2.65%-5.18% and 1.67%-1.69% respectively, lower than the stated.Limits of quantitative determination (LOQ) of the three reagents were 0.41, 0.23 and 0.07 mg/L, basically meeting the testing requirement.The linearity range was 0.22-7.26 mg/L(r=0.996), 0.20-7.72 mg/L(r=0.999)and 0.20-7.62 mg/L(r=0.997)in the three reagents, which demonstrated a sound linear correlation. For interference tests, no remarkable interference (<±10%) of reagent C was detected when bilirubin≤684 μmol/L, hemoglobin≤9.7 g/L and Chyle turbidity≤6 200 FTU; and no significant interference of reagent B was found when bilirubin≤684 μmol/L, hemoglobin≤6.79 g/L and Chyle turbidity≤6 200 FTU; when bilirubin≤684 μmol/L, hemoglobin≤4.85 g/L and Chyle turbidity≤1 240 FTU reagent A was not interfered significantly. The comparison afte and before the high-speed centrifugation reveals that the average percentage of bias for reagents A, B, C measured Cys C in chylous serum samples of patients was -8.31%, 1.52%, 1.32%, respectively.In method comparison tests, the regression equations of the three reagents compared with Dade Behring PENIA Cys C reagent were as follows:Y=0.787X+0.492 (R2=0.976), Y=1.098X+0.137 (R2=0.982) and Y=1.037X+0.249 (R2=0.996), respectively. Agreement rates of the high Cys C in reagent A, B, C and Dade Behring Cys C reagent were 80% (Kappa=0.615,P=0.000), 100% (Kappa=1.000,P=0.000), 91.2% (Kappa=0.824,P=0.000); While for reference range of preliminary clinical assessment, diagnosis coincidence rate of reagent A increased to 98.8% (Kappa=0.974,P=0.000). Conclusions When used in automatic biochemical analyzer, the three Cys C reagent with PETIA showed high precision,sensitivity, and sound correlation with Dade Behring PENIA reagents.The three reagents are all able to meet clinical test requirements, nevertheless, anti-interference capability were diffierent and the reference range should be further validated.

Determinação de cistatina C como marcador de função renal / Cystatin C measurement as renal function marker

INTRODUÇÃO: A cistatina C sérica tem sido apontada como um marcador de filtração glomerular. OBJETIVO: Realizar a validação de um método específico e automatizado, a imunonefelometria, mensurando os níveis séricos de cistatina C por meio do nefelômetro da empresa Behring (BN II) e correlacionar resultados obtidos entre pacientes transplantados. O ensaio perfaz o intervalo de referência de 0,23-7,25 mg/l. A imprecisão intra e interensaio foi de 8,73 por cento e 5,38 por cento, respectivamente. A recuperação analítica da cistatina C após adição de controle foi entre 86,7 por cento e 98 por cento (média 92,3 por cento). A estabilidade da cistatina C à temperatura ambiente, sob refrigeração e sob congelamento foi testada. A perda mais significativa foi encontrada nas amostras armazenadas à temperatura ambiente, em que foram perdidos até 10 por cento da concentração inicial. Foi encontrado coeficiente de variação de 14,79 por cento para sensibilidade analítica. Durante todo o processo foram comparados os resultados com o controle de qualidade e obtivemos bons resultados. Depois desses testes, nós comparamos as correlações em três grupos de pacientes transplantados renais sob diferentes esquemas de imunossupressão (n = 197) - azatioprina (n = 36), micofenolato mofetil (n = 131) e sirolimus (n = 30) - entre as equações de estimativa de filtração glomerular (Cockroft Gault, Nankivell e Modification of Diet in Renal Disease) e cistatina C sérica ou creatinina sérica. CONCLUSÃO: O ensaio nefelométrico cistatina C pode perfeitamente ser adequado à nossa rotina laboratorial e as correlações entre creatinina sérica e as diferentes equações de estimativa de filtração glomerular são melhores do que quando comparamos as mesmas à cistatina C nos três grupos, independentemente da terapia imunossupressora utilizada.

INTRODUCTION: Serum cystatin C has been identified as a glomerular filtration marker. OBJECTIVE: To validate immunonephelometry, a specific and automated method, by measuring levels of serum cystatin C through Behring nephelometer (BN II) and correlate results among transplant patients. The assay comprises the reference range of 0:23 to 7:25 mg/l. The intra-assay and inter- assay imprecision rates were 8.73 percent and 5.38 percent, respectively. The analytical recovery of cystatin C after addition of control was between 86.7 percent and 98 percent (average 92.3 percent). The stability of cystatin C to room temperature, refrigerated or frozen was tested. The most significant loss was found in samples stored at room temperature, in which up to 10 percent of the initial concentration was lost. The coefficient of variation was 14.79 percent for analytical sensitivity. Throughout the process the results were compared with quality control and good results were achieved. After these tests, we compared the correlations between equations for estimating glomerular filtration rate (Cockroft Gault, Nankivell and MDRD) and serum cystatin C or serum creatinine in three groups of kidney transplant patients under different immunosuppressive regimens (n = 197) [azathioprine (n = 36), mycophenolate mofetil (n = 131) or sirolimus (n = 30)]. CONCLUSION: The nephelometric cystatin C assay may be perfectly suitable for our routine laboratory. The correlations between serum creatinine and the various equations for estimating glomerular filtration are better than those between cystatin C and equations for estimating glomerular filtration in the three groups irrespective of the immunosuppressive therapy used.

Comparative study of platelet aggregation by turbidimetric and impedance methods in patients under acetylsalicylic acid antiplatelet therapy

INTRODUÇÃO: A hiperagregação (agregação excessiva) das plaquetas pode causar a formação de um trombo e a posterior oclusão dos vasos sanguíneos levando à isquemia. Esse fenômeno é responsável por doenças isquêmicas cardiovasculares, como angina pectoris e aterosclerose, bem como outras formas de isquemia, como o acidente vascular cerebral. Visando diminuir a função das plaquetas para reduzir a formação de trombos, o ácido acetilsalicílico vem sendo utilizado para tratamento antitrombótico, com diversos estudos mostrando sua eficácia. Dessa forma faz-se mister o uso de uma ferramenta laboratorial para o monitoramento da efetividade do tratamento, o que é feito por meio do teste de agregação plaquetária. O objetivo desse estudo foi comparar duas metodologias para esse exame (impedância elétrica e turbidimetria) em relação a trinta pacientes adultos de ambos os sexos em uso do fármaco. CONCLUSÃO: Os resultados mostraram uma boa correlação entre os métodos, possibilitando o uso concomitante de ambas as técnicas em laboratórios clínicos de rotina.

INTRODUCTION: Hyperaggregation of platelets can cause the formation of thrombi and subsequent occlusion of blood vessels leading to ischemia. This phenomenon can be responsible for ischemic cardiovascular diseases such as angina pectoris and atherosclerosis as well as other forms of ischemia such as stroke. To decrease platelet function and reduce the formation of thrombi, acetylsalicylic acid has been used for antithrombotic treatment, with several studies showing its effectiveness. Therefore it is necessary to use a laboratory tool to monitor the effectiveness of treatment, which is achieved through laboratory testing of platelet aggregation. The aim of this study was to compare two different methods (impedance and turbidimetry) to test platelet aggregation in 30 adult patients of both genders taking acetylsalicylic acid. CONCLUSION: The results show that there is a good correlation between these two methods and so both these techniques can be used in the clinical routine.

Reference Values for Serum Cystatin C by Nephelometric Immunoassay in Healthy Young Korean Men / 대한신장학회지

PURPOSE: In recent years, cystatin C (CysC) was proposed as a new marker for evaluating the glomerular filtration rate due to a constant serum level. The aim of this study was to measure serum CysC values of healthy young Korean men in assessment of kidney function and compare it with other reports until now in male populations, using nephelometric immunoassay. METHODS: CysC and creatinine levels were measured by particle enhanced nephelometric immunoassay and Jaffe method, respectively, in 145 young Korean men without evidence of kidney disease. Medline was searched for CysC reference values in healthy male populations. RESULTS: CysC values showed a normal distribution (Kolmogorov-Smirnov, K-S, p=0.2). The CysC reference interval for healthy young Korean men (age 19-29) was 0.58 to 0.94 mg/L (0.76+/-0.09 mg/ L, X+/-2SD, range 0.60 to 1.25 mg/L). Reference intervals for creatinine was 0.79 to 1.27 mg/dL (1.03+/-0.12 mg/dL, X+/-2SD, range 0.8 to 1.3 mg/dL) in subjects. Creatinine serum values did not show a normal distribution (K-S, p=0.001). The correlation coefficient for CysC and creatinine was only 0.308. (p=0.0001) Nephelometric CysC reference intervals we determined were consistent among different male populations. CONCLUSION: We determined reference intervals for CysC values in healthy young Korean men, and CysC reference values established by nephelometric immunoassay were consistent among different men population. This information could be useful in assessing renal function in healthy young Korean men.

Relationship between C-Reactive Protein and Atrial Fibrillation / 天津医药

Objective: To investigate the relationship between C-reactive protein(CRP)and its-717MG polymorphismin atrial fibrillation(AD of the population of the city of Nantong.Methods:The relationships between AF and AF risk factors were analyzed by comparing genders,ages and body nlagS index(BWI)in 92 AF patients and 60 non-AF control subjects.The serum CRP levels were detected by immunoturbidimetry in of the two groups.The CRP-717MG polymorphism wa8 detected by polymerage chain reaction-restriction fragment-length polymorphism in patients and control subjects.Results:The sel3utm CRP level wag positively correlated with the left atrium internal diameter(LAD)in AF patient group(r=0.58,P＜0.01).The level of CRP Wag significantly higher in AF patient group compared with that of control group(P＜0.01).The serum CRP level Wag higher in patients with non-paroxysmal atrial fibrillation than that of patients with paroxysmal atrial fibrillation(P＜0.05).There Wag no significant difference in the frequency of CRP genotype between AF and control groups(P＞0.05).But the alleles frequency of the G Wag lower in AF group than that of control group(P＜0.05).Conclusion:The semm CRP level is associated with AF and its subgroups.The serum CRP level is positively correlated with LAD.The results suggest that the inflammation influences the AF though atrium reconstruction.The relationship between CRP-7 17A/G and AF stir needs further large-scale perspective studies.

The abnormal expressions of immunoglobulin light chains Kappa and Lambda in malignant tumors / 国际检验医学杂志

Objective To investigate the abnormal expressions of immunoglobulin light chains kappa(Igκ)and Lambda(Igλ)in malignant tumors.Methods The concentrations of the Igκ and Igλ in serum were measured by rat nephelometry in 60 cases of malignant tumors and 15 cases of healthy people.Results The liver tumor patients had a higher concentration of Igκ and Igλ in serum than normal people(P＜0.01).There wre not significant differences between the levels of Igκ,Igλ and κ/λ ratio in the stomach tumor,lung tumor,proctologic/colonic tumor,mammary tumor,oesophagus tumor and normal peoples(P＞0.05).Conclusion The measurment of Igκ,Igλ and κ/λ ratio in serum would be helpful for the diagnosis of the liver tumor.By continous observation with Igκ,Igλ and κ/λratio in serum could predict the development of disease.