Architect i2000SR Research Articles

Gentamicin and Vancomycin Interference on Results of Clinical Chemistry Parameters on Abbott Architect c8000.

Gentamicin and vancomycin are nephrotoxic antibiotics. Little is known about the influence of drug concentrations on results of clinical chemistry tests. To investigate gentamicin and vancomycin interference on results of 33 commonly measured biochemistry tests. The study was carried out in the University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice (Zagreb, Croatia). For each drug, 10 aliquots of pooled serum were prepared. In order to cover toxic concentrations, pool serum samples were spiked with drugs to obtain 0 to 50 μg/mL of gentamicin and 0 to 200 μg/mL of vancomycin. Biochemistry tests were measured in duplicate on the Architect c8000 analyzer, and drug concentrations were measured on Architect i2000 SR (both Abbott Laboratories, Abbott Park, Illinois). For each tested concentration, bias was calculated against the initial measurement. Acceptance criteria were defined as measurement uncertainty of the commercial control with the value close to the measured range of the pool sample. For gentamicin, all bias values were below established criteria. For vancomycin, significant changes were observed for potassium, direct bilirubin, and immunoglobulin A. Significant bias was already detected at low vancomycin concentration (2.98 μg/mL) for direct bilirubin (bias = 9.7%; acceptable = 8%). Potassium bias at the highest vancomycin concentration (204.4 μg/mL) exceeded acceptance criteria (bias = 4.5%; acceptable = 4%). For immunoglobulin A, no apparent trend was observed, and bias is attributed to increased method imprecision. Gentamicin did not interfere with the results of clinical chemistry tests. Direct bilirubin concentration is falsely increased in the presence of vancomycin, and potassium is affected at high concentrations.

Evaluating the Prevalence of HBV, HCV, and HIV in Hemodialysis Patients in North Cyprus

Background: Patients undergoing dialysis treatment and hemodialysis are at risk of viral infections due to inadequate cellular immunity. Objectives: The aim of the study was to determine the prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) in hemodialysis (HD) centers in North Cyprus. Methods: The present study reviewed the health records of 140 patients in two dialysis units that represented all HD units in North Cyprus. Serological markers for HBV, HCV, and HIV were determined by the immunoenzymatic assay using commercial diagnostic kits (Architect i2000 SR, Abbott, USA). HCV RNA, HBV DNA, and HIV RNA were determined quantitatively using polymerase chain reaction (PCR). Results: One hundred forty HD patients were included in the study, consisting of 39.3% (n = 55) female and 60.7% (n = 85) male patients. Five (3.6%) patients were anti-HCV positive, one (0.7%) patient was HBsAg positive, and one (0.7%) was anti-HIV positive. Anti-HCV and HBsAg were negative in all of the patients according to the PCR results. There were no significant differences between males (1.2%) and females (7.3%) in terms of anti-HCV positivity (P = 0.078), HBsAg seropositivity (P = 0.607), and anti-HIV seropositivity (P = 0.607). Conclusions: The prevalence of HBV, HCV, and HIV infection in hemodialysis patients in North Cyprus is moderate to low. The main reason for the significantly lower rates compared to other areas could be effective protective measures and national vaccination.

Comparison of chemiluminescent microparticle immunoassay (CMIA) with electrochemiluminescence immunoassay (ECLIA) for Carcinoembryonic antigen (CEA)

Introduction: Carcinoembryonic antigen (CEA) is used for monitoring of disease progression and treatment response in cancer patients. Our aim was to compare the performance of chemiluminescent microparticle immunoassay (CMIA) with electrochemiluminescence immunoassay (ECLIA) for CEA.
 Methods: A total of 115 samples were collected during routine diagnostic, prognostic and therapy monitoring procedures in patients with colorectal and pancreatic cancer. We used ARCHITECT i2000SR and Cobas E601 for CEA analysis in sera samples.
 Results: The correlation coefficient of 0.984 [95% CI: 0.972 to 0.991] for results obtained on both platforms was observed for CEA≤10 ng/mL group. Moreover, intercept of 0.9027 [95% CI: 0.705 to 1.099] and slope 0.8076 [95% CI: 0.765 to 0.8498] (p < 0.0001) was observed in this group. In CEA >10 ng/mL group we observed slope = 1.1986 [95%CI: 1.1474 to 1.2498] (p < 0.0001), intercept = -11.69 [-17.53 to - 5.84] and correlation coefficient of 0.985 [95% CI: 0.976 to 0.9914]. Mean differences between assays in group ≤10 ng/mL and >10 ng/mL were 0.2066 (95% CI: 0.0019 to 0.4113) and –2.66 (95% CI: -10.10 to 4.76) ng/mL, respectively.
 Conclusion: Although there were differences, based on 20 days precision tests, overall results showed a good analytical performance and correlation between CEA assays on ARCHITECT i2000SR and Cobas E601 platforms. Reference intervals appropriate for the method of CEA measurement should be used. The standardization and harmonization of serum CEA concentration assays are needed.

How low can you go? Analytical performance of five automated testosterone immunoassays

BackgroundTestosterone is commonly measured using immunoassays, yet concerns with the accuracy and quality of testing by these methods exist, particularly for low testosterone concentrations. Study objectives were to evaluate selective performance characteristics, including functional sensitivity (FS), of 5 automated immunoassays for total testosterone. MethodsFS, imprecision, assay interference, limit of blank, linearity, and accuracy were assessed using the Abbott ARCHITECT i2000SR, SIEMENS ADVIA Centaur and IMMULITE 2000, Beckman Coulter DxI 800, and Roche MODULAR E170. Comparisons to an in-house liquid chromatography-tandem mass spectrometry (LC-MS/MS) method were performed using patient samples from men, women, boys, and girls. ResultsFS at 20% coefficient of variation (CV) for the ARCHITECT, Centaur, DxI, E170 and IMMULITE assays were 0.14, 1.23, 0.36, 0.77, 3.49 nmol/L, respectively. Total CVs for the 5-day imprecision study were ≤ 9.0% for all methods. All assays met manufacturer's claims for hemolysis, icterus, and lipemia interference and limit of blank. Dilution linearity studies had deviations from the target recoveries ranging from 3.4% (ARCHITECT) to 14.3% (DxI). Using National Institute of Standards and Technology Standard Reference Material 971, recoveries ranged from 79.2–149.2% (DxI, male and female, respectively). When compared to LC-MS/MS, more immunoassays under-recovered in men and women and over-recovered in boys and girls. Slopes ranged from 0.71 (IMMULITE, women) to 1.35 (DxI, boys). The combined average for percent bias was higher in boys (28.0%) than men (11.6%), women (22.8%), and girls (25.7%). ConclusionsChallenges with accurately measuring testosterone appear to remain for some immunoassays, but not all. While most immunoassays remain optimized for concentrations observed in healthy men, some showed acceptable performance when challenged at lower concentrations.

Establishing normal values of total testosterone in adult healthy men by the use of four immunometric methods and liquid chromatography-mass spectrometry.

The total testosterone (T) cutoffs clinically adopted to define late-onset hypogonadism (LOH) do not consider the differences that exist between different analytical platforms, nor do they consider the body mass index (BMI) or age of the patient. We aimed at providing method, age and BMI-specific normal values for total T in European healthy men. A total of 351 eugonadal healthy men were recruited, and total T was measured with four automated immunometric assays (IMAs): ARCHITECT i1000SR (Abbott), UniCel DxI800 (Beckman Coulter), Cobas e601 (Roche), IMMULITE 2000 (Siemens) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Reference ranges (RRs) were calculated for each method. Passing and Bablok regression analysis and Bland-Altman plot showed an acceptable agreement between Abbott and LC-MS/MS, but a poor one between LC-MS/MS and the other IMAs. Age-specific T concentrations in non-obese (BMI <29.9 kg/m2) men were greater than in all men. The total T normal range, in non-obese men aged 18-39 years, measured with LC-MS/MS was 9.038-41.310 nmol/L. RRs calculated with LC-MS/MS statistically differed from the ones calculated with all individual IMAs, except Abbott and among all IMAs. Statistically significant differences for both upper and lower reference limits between our RRs and the ones provided by the manufacturers were also noticed. We calculated normal ranges in a non-obese cohort of European men, aged 18-39 years, with four commercially available IMAs and LC-MS/MS and found statistically significant differences according to the analytical method used. Method-specific reference values can increase the accuracy of LOH diagnosis and should be standardly used.

Accuracy of Two Progesterone Immunoassays for Monitoring In Vitro Fertilization.

Progesterone concentrations are routinely monitored during in vitro fertilization cycles. Immunoassay-based platforms are used most often in this setting because they are simple to use and amenable to same-day sample collection and result-reporting. However, immunoassay methods are subject to variation in specificity between different assay manufacturers. In this study, a set of unexpectedly high progesterone concentrations led to a method comparison between two in-house immunoassay platforms relative to the reference method. Progesterone was measured in 28 serum samples from women undergoing IVF cycles using the Siemens ADVIA Centaur Immunoassay system and the Abbott Architect i1000SR analyzer. A subset of these samples was selected for progesterone measurement by liquid chromatography-tandem mass spectrometry to define the accuracy of each immunoassay. The Siemens ADVIA Centaur immunoassay system overestimated progesterone concentrations by 19% and the Abbott Architect overestimated progesterone concentrations by 5%. The Abbott Architect progesterone immunoassay provides a more accurate measurement of serum progesterone than the Centaur immunoassay at concentrations relevant for monitoring in vitro fertilization populations.

An analysis of the predictive value of the HIV Ag/Ab screening assay within the performance characteristics of the DiaSorin LIAISON XL for the detection of blood-borne viruses

BackgroundCorrect identification of blood borne viral infections, such as hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) is crucial in detection and follow up of infection in patients. ObjectivesWe evaluated the diagnostic performance of the DiaSorin LIAISON XL (LIAISON XL) for screening of HBV, HCV and HIV infection. In addition, we investigated the variability of the signal-to-cuttoff ratio (S/CO) of the LIAISON XL HIV Ag/Ab assay and it’s predictive value in subsequent confirmation of HIV-1 infection. Study designWe analyzed 16,497 blood samples on which HBV, HCV and HIV screening was performed. We defined A) archived samples previously tested with an arbitrary result in the Abbott ARCHITECT i2000SR system; B) prospectively collected samples which were simultaneously tested on the LIAISON XL and ARCHITECT i2000SR; C) prospectively collected serum samples for HIV testing which were tested solely on the LIAISON XL. ResultsThe agreements of HBV-, HCV-, and HIV markers between the two compared systems are remarkably high. Among the samples which were prospectively tested for HIV Ab/Ag on the LIASON XL, 229 (1.6%) were reactive of which 141 (61.6%) could be confirmed. Increasing the signal-to-cutoff value to 4 could increase the positive predictive value (PPV) to 88.1% without decreasing sensitivity. ConclusionsThe LIAISON XL system proved to be an excellent system for diagnosing HBV, HCV, and HIV. Our data for the first time showed that increasing the HIV S/CO ratio was safe and increased the PPV for confirmed HIV infection in the tested population.

The Importance of Serial Time Point Quantitative Assessment of Cardiac Troponin I in the Diagnosis of Acute Myocardial Damage.

Objective:The present study was aimed to establish a threshold value for cardiac troponin I (cTnI) for nonacute coronary syndrome (ACS) participants from the local population and also to determine the importance of serial time point estimation of cTnI in acute myocardial infarction (AMI), non-ST-elevated MI (NSTEMI), and unstable angina cases.Methods:The present study included 194 cases, admitted in ICCU with the complaint of anginal pain; 31 were diagnosed with AMI with typical electrocardiography (ECG) changes; whereas, 48 cases were diagnosed with NSTEMI. The latter group of cases was selected for the time point study of cTnI release at 0–4 h, 6–12 h, 72 h, and 144 h of admission. cTnI levels were assessed using the Abbott ARCHITECT i1000SR system.Results:ACS was clinically ruled out in 98 cases, and cTnI level for them was used to decide cTnI threshold for the non-ACS group. cTnI level was checked in 17 cases of unstable angina. The threshold value of cTnI for non-ACS participants was 0.1 ng/ml and can be considered as cut-off value for the regional population. The data suggested that the peak of cTnI levels in most of the AMI cases reached during 6–12 h. The cTnI levels were lower than 0.1 ng/ml, and no significant change in ECG was noticed in 17 cases of unstable angina.Conclusion:The present study suggested that the repeat of cTnI assay after 4–6 h of admission is required if the initial value is <3 ng/ml.

Analytical performances of simultaneous detection of HIV-1, HIV-2 and hepatitis C- specific antibodies and hepatitis B surface antigen (HBsAg) by multiplex immunochromatographic rapid test with serum samples: A cross-sectional study

BackgroundThe HIV/HCV/HBsAg Triplex consists in manually performed, visually interpreted, lateral flow, immunochromatographic rapid diagnostic test simultaneously detecting in 15min human immunodeficiency virus (HIV)-1 and HIV-2 and hepatitis C virus (HCV)- specific antibodies (Ab) (IgG and IgM) and hepatitis B virus (HBV) surface antigen (HBsAg) in serum, plasma and whole blood. MethodsA hospital-based cross-sectional study was conducted on a prospective panel of serum samples from adult inpatients included from routine analysis irrespectively of age and sex, including 250 sera positive for HIV-1-specific Ab, 250 for HCV-specific Ab, 250 for HBsAg and 250 sera negative for HIV- and HCV- Ab and HBsAg, and from 110 HIV-2-infected patients living in Ivory Coast, according to the results obtained by the reference chemiluminiscent microparticle immunoassay (CMIA) Abbott Architect i2000SR analyzer (Abbott Diagnostic, Chicago, IL, USA). Among HCV-seropositive sera, 187 were positive for HCV RNA (chronic infection), whereas 63 were negative (resolved infection), respectively. Serum samples were further tested blindly by HIV/HCV/HBsAg Triplex according to manufacturers’ recommendations. ResultsHIV/HCV/HBsAg Triplex showed very high sensitivity and specificity, as well as excellent concordance with CMIA Abbott results, as shown in the Table. Lower sensitivity was observed only in individuals who had cleared their HCV infection (presence of HCV-specific Ab in absence of HCV RNA). The mean lower limit of HBsAg detection was 2.38±0.63 IU/ml. Erythrocytes-spiked serum samples gave similar results than serum samples. ConclusionsAdvantages of HIV/HCV/HBsAg Triplex for HIV-1, HIV-2, HCV and HBV include the requirement for less overall specimen volume, fewer finger-sticks if capillary whole blood is used, cost savings through lower cost per virus tested, improved patient flow with results for multiple viruses available at the same time, overall service delivery efficiencies with less time required per infected patient; and patient benefits from fewer visits and lower cost associated with each clinic attendance. The screening of chronic HIV, HCV and HBV by multiplex HIV-1/HIV-2/HCV/HBsAg Triplex may improve the “cascade of screening” and quite possibly linkage-to-care with reduced cost.

Comparison of two automated instruments for Epstein-Barr virus serology in a large adult hospital and implementation of an Epstein-Barr virus nuclear antigen-based testing algorithm.

Serology remains the mainstay for diagnosis of Epstein-Barr virus (EBV) infection. This study compared two automated platforms (BioPlex 2200 and Architect i2000SR) to test three EBV serological markers: viral capsid antigen (VCA) immunoglobulins of class M (IgM), VCA immunoglobulins of class G (IgG) and EBV nuclear antigen-1 (EBNA-1) IgG. Using sera from 65 patients at various stages of EBV disease, BioPlex demonstrated near-perfect agreement for all EBV markers compared to a consensus reference. The agreement for Architect was near-perfect for VCA IgG and EBNA-1 IgG, and substantial for VCA IgM despite five equivocal results. Since the majority of testing in our hospital was from adults with EBNA-1 IgG positive results, post-implementation analysis of an EBNA-based algorithm showed advantages over parallel testing of the three serologic markers. This small verification demonstrated that both automated systems for EBV serology had good performance for all EBV markers, and an EBNA-based testing algorithm is ideal for an adult hospital.

The validation and implementation of donor screening for hepatitis B virus, hepatitis C virus, human immunodeficiency virus 1/2 and syphilis by ultrio elite assay (Panther system) and chemiluminescence assay (Abbott Architect i2000SR system) in Namibia

Infectious disease screening of Namibia blood donations for infectious diseases was contracted to the South African National Blood Service (SANBS) since 2004 and needed to be relocated back to Namibia. A cost analysis conducted showed that by introducing certain strategies, it was cost‐effective to implement ID‐NAT in Namibia. NAMBTS chose Ultrio Elite assay/Panther System (Gen‐Probe and Novartis, USA) for ID‐NAT for HIV 1/2 RNA, HBV DNA and HCV RNA and Chemiluminescent immunoassay done on the Architect i2000SR system (Abbott, Delkenheim, Germany) for HIV 1/2 Ag/Ab, anti‐HCV, HBsAg and Syphilis. For performance evaluation, the Panther System was compared with the Procleix TIGRIS system—Ultrio Plus assay (Gen‐Probe and Novartis, USA) while the Architect system was compared with the Abbott PRISM. The results of this evaluation demonstrated a 100% sensitivity and 100% specificity of the Ultrio Elite assay while the Architect also demonstrated 100% sensitivity and specificity of above 99% for detecting viral markers for HBV, HIV and HCV, and 97% sensitivity and 99·7% specificity for detecting syphilis. We found both the Procleix Panther and Architect systems to be flexible, robust and effective in screening blood for transfusion in our setting. Donor screening for HIV 1/2, HBV, HCV and syphilis for ID‐NAT and serology using the Procleix Panther and Architect systems was successfully relocated from South Africa and implemented in February 2014 in Namibia.

Probability of cancer in high-risk patients predicted by the protein-based lung cancer biomarker panel in China: LCBP study.

The authors built a model for lung cancer diagnosis previously based on the blood biomarkers progastrin-releasing peptide (ProGRP), carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), and cytokeratin 19 fragment (CYFRA21-1). In the current study, they examined whether modification of the model to include relevant clinical information, risk factors, and low-dose chest computed tomography screening would improve the performance of the biomarker panel in large cohorts of Chinese adults. The current study was a large-scale multicenter study (ClinicalTrials.gov identifier NCT01928836) performed in a Chinese population. A total of 715 participants were enrolled from 5 regional centers in Beijing, Henan, Nanjing, Shanghai, and Chongqing between October 2012 and February 2014. Serum biomarkers ProGRP, CEA, SCC, and CYFRA21-1 were analyzed on the ARCHITECT i2000SR. Relevant clinical information was collected and used to develop a patient risk model and a nodule risk model. The resulting patient risk model had an area under the receiver operating characteristic (ROC) curve of 0.7037 in the training data set and 0.7190 in the validation data set. The resulting nodule risk model had an area under the ROC curve of 0.9151 in the training data set and 0.5836 in the validation data set. Moreover, the nodule risk model had a relatively higher area under the ROC curve (0.9151 vs 0.8360; P = 0.001) compared with the American College of Chest Physician model in patients with lung nodules. Both the patient risk model and the nodule risk model, developed for the early diagnosis of lung cancer, demonstrated excellent discrimination, allowing for the stratification of patients with different levels of lung cancer risk. These new models are applicable in high-risk Chinese populations. Cancer 2018;124:262-70. © 2017 American Cancer Society.

Assessing precision, bias and sigma-metrics of 53 measurands of the Alinity ci system

Assay performance is dependent on the accuracy and precision of a given method. These attributes can be combined into an analytical Sigma-metric, providing a simple value for laboratorians to use in evaluating a test method's capability to meet its analytical quality requirements. Sigma-metrics were determined for 37 clinical chemistry assays, 13 immunoassays, and 3 ICT methods on the Alinity ci system. MethodsAnalytical Performance Specifications were defined for the assays, following a rationale of using CLIA goals first, then Ricos Desirable goals when CLIA did not regulate the method, and then other sources if the Ricos Desirable goal was unrealistic. A precision study was conducted at Abbott on each assay using the Alinity ci system following the CLSI EP05-A2 protocol. Bias was estimated following the CLSI EP09-A3 protocol using samples with concentrations spanning the assay's measuring interval tested in duplicate on the Alinity ci system and ARCHITECT c8000 and i2000SR systems, where testing was also performed at Abbott. Using the regression model, the %bias was estimated at an important medical decisions point. Then the Sigma-metric was estimated for each assay and was plotted on a method decision chart. The Sigma-metric was calculated using the equation: Sigma-metric=(%TEa−|%bias|)/%CV. ResultsThe Sigma-metrics and Normalized Method Decision charts demonstrate that a majority of the Alinity assays perform at least at five Sigma or higher, at or near critical medical decision levels. ConclusionMore than 90% of the assays performed at Five and Six Sigma. None performed below Three Sigma. Sigma-metrics plotted on Normalized Method Decision charts provide useful evaluations of performance. The majority of Alinity ci system assays had sigma values >5 and thus laboratories can expect excellent or world class performance. Laboratorians can use these tools as aids in choosing high-quality products, further contributing to the delivery of excellent quality healthcare for patients.

Generating method-specific Reference Ranges – A harmonious outcome?

ObjectivesWhen laboratory Reference Ranges (RR) do not reflect analytical methodology, result interpretation can cause misclassification of patients and inappropriate management. This can be mitigated by determining and implementing method-specific RRs, which was the main objective of this study. Design and methodsSerum was obtained from healthy volunteers (Male + Female, n > 120) attending hospital health-check sessions during June and July 2011. Pseudo-anonymised aliquots were stored (at − 70°C) prior t° analysis on Abbott ARCHITECT c16000 chemistry and i2000SR immunoassay analysers. Data were stratified by gender where appropriate. Outliers were excluded statistically (Tukey method) to generate non-parametric RRs (2.5th + 97.5th percentiles). RRs were compared to those quoted by Abbott and UK Pathology Harmony (PH) where possible. For 7 selected tests, RRs were verified using a data mining approach. ResultsFor chemistry tests (n = 23), Upper or Lower Reference Limits (LRL or URL) were > 20% different from Abbott ranges in 25% of tests (11% from PH ranges) but in 38% for immunoassay tests (n = 13). RRs (mmol/L) for sodium (138−144), potassium (3.8–4.9) and chloride (102−110) were considerably narrower than PH ranges (133–146, 3.5–5.0 and 95–108, respectively). The gender difference for ferritin (M: 29–441, F: 8–193ng/mL) was more pronounced than reported by Abbott (M: 22–275, F: 5–204ng/mL). Verification studies showed good agreement for chemistry tests (mean [SD] difference = 0.4% [1.2%]) but less so for immunoassay tests (27% [29%]), particularly for TSH (LRL). ConclusionWhere resource permits, we advocate using method-specific RRs in preference to other sources, particularly where method bias and lack of standardisation limits RR transferability and harmonisation.

Comparison of the performance of three cancer antigen (CA) 15-3 immunoassays

Introduction: In the present study we investigated the performance, precision, and recovery of three different automated methods in determining cancer antigen (CA) 15-3 levels.Methods: Serum samples were obtained from 60 hospitalized female patients. As controls, commercially available samples were used. Cancer antigen (CA) 15-3 levels were measured using ARCHITECT CA 15-3, Elecsys® CA 15-3, and Vitros CA 15-3 immunoassays. A comparison of the results between the three methods was conducted, and the precision and recovery were analyzed.Results: Coefficient of variations (CVs), determined with low- and high-level-CA 15-3 control samples, and reproducibility values were: 2.56-2.80% and 3.10-4. 20% for ARCHITECT i2000SR immunoassay analyzer; 3.50-5.55% and 4.88-6.47% for Cobas E 601 analyzer; 3.30-4.0% and 4.30-4.80% for VITROS 5600 Integrated System, respectively. The percent recoveries were 95-98% for Elecsys® CA 15-3 assay, 93-105% for Vitros CA 15-3 assay, and 92-95% for ARCHITECT CA 15-3 assay. Method comparison results demonstrated correlation coefficient (r) in range from 0.994 to 1. The average CA 15-3 concentrations measured by Vitros, ARCHITECT, and Elecsys® were 157.24 +/- 329.75 U/mL, 100.91 +/-213.75 U/mL, and 80.93 +/- 173.29 U/mL, respectively.Conclusions: Tumor marker CA 15-3 in individual patients should be monitored using the same immunoassay method, reagents, and analyzer. Different immunoassays tested on different analyzers, often show large discrepancies in reported values for individual patients. Different immunoassay technologies quantify analytes of clinical interest using monoclonal or polyclonal antibodies. Thus, the usage of antibodies with different specificities could explain the differences in CA 15-3 serum values between different methods.

Alu-based cell-free DNA: a novel biomarker for screening of gastric cancer.

Gastric cancer (GC) is the fourth most common cancer and the second major cause of cancer-related deaths worldwide. In our previous study, a novel and sensitive method for quantifying cell-free DNA (CFD) in human blood was established and tested for its ability to predict patients with tumor. We want to investigate CFD expression in the sera of GC patients in an attempt to explore the clinical significance of CFD in improving the early screening of GC and monitoring GC progression by the branched DNA (bDNA)-based Alu assay. The concentration of CFD was quantitated by bDNA-based Alu assay. CEA, CA19-9, C72-4 and CA50 concentrations were determined by ABBOTT ARCHITECT I2000 SR. We found the CFD concentrations have significant differences between GC patients, benign gastric disease (BGD) patients and healthy controls (P < 0.05). CFD were weakly correlated with CEA (r = −0.197, P < 0.05) or CA50 (r = 0.206, P < 0.05), and no correlation with CA19-9 (r = −0.061, P > 0.05) or CA72-4 (r = 0.011, P > 0.05). In addition, CFD concentrations were significantly higher in stage I GC patients than BGD patients and healthy controls (P < 0.05), but there was no significant difference in CEA, CA19-9 and CA50 among the three traditional tumor markers (P > 0.05). Our analysis showed that CFD was more sensitive than CEA, CA19-9, CA72-4 or CA50 in early screening of GC. Compared with CEA, CA19-9, CA72-4 and CA50, CFD may prove to be a better biomarker for the screening of GC, thus providing a sensitive biomarker for screening and monitoring progression of GC.

Evaluation of Virological Microparticle Enzyme Immunoassay According to the ISO 15189: Real-Life Experience in a University Hospital

The International Standard ISO 15189 based on the ISO 9001:2008 emphasizes specific requirements for quality and ability of medical laboratories. The accreditation of medical laboratories according to ISO 15189 includes the validation of biological methods, which depends on collection of bibliographic data and experimental proofs. Moreover, these results must be compared to provider data sheets and independent scientific data. In the immunodiagnostic field, independent published data are deeply lacking. The aim of our work was to share experience of method validation for virological immune markers on the widely used Architect i2000sr. After risk analysis, intra- and inter-assay variability, and inter-sample contamination were evaluated for each method, and sensitivity was investigated for antigen detection tests. A comparison between the two Architect i2000sr available in our laboratory was also performed. All tested methods were consistent with the manufacturer data (from the data sheet). No inter-sample contamination was observed. Both devices are broadly equivalent and can be used indifferently or as a backup solution of the other. To our knowledge, those results are the first independent complete data on the reliability of the Architect i2000sr in real-life experience. These data are needed to the accreditation of our platform and potentially useful for the accreditation of other laboratories using the same equipment.

Gestation specific reference intervals for thyroid function tests in pregnancy.

Thyroid function tests are frequently assessed during pregnancy to evaluate thyroid dysfunction or to monitor pre-existing thyroid disease. However, using non-pregnant reference intervals can lead to misclassification. International guidelines recommended that institutions should calculate their own pregnancy-specific reference intervals for free thyroxine (FT4), free triiodothyronine (FT3) and thyroid-stimulating hormone (TSH). The objective of this study is to establish gestation-specific reference intervals (GRIs) for thyroid function tests in pregnant Turkish women and to compare these with the age-matched non-pregnant women. Serum samples were collected from 220 non-pregnant women (age: 18-48), and 2460 pregnant women (age: 18-45) with 945 (39%) in the first trimester, 1120 (45%) in the second trimester, and 395 (16%) in the third trimester. TSH, FT4 and FT3 were measured using the Abbott Architect i2000SR analyzer. GRIs of TSH, FT4 and FT3 for first trimester pregnancies were 0.49-2.33 mIU/L, 10.30-18.11 pmol/L and 3.80-5.81 pmol/L, respectively. GRIs for second trimester pregnancies were 0.51-3.44 mIU/L, 10.30-18.15 pmol/L and 3.69-5.90 pmol/L. GRIs for third trimester pregnancies were 0.58-4.31 mIU/L, 10.30-17.89 pmol/L and 3.67-5.81 pmol/L. GRIs for TSH, FT4 and FT3 were different from non-pregnant normal reference intervals. TSH levels showed an increasing trend from the first trimester to the third trimester, whereas both FT4 and FT3 levels were uniform throughout gestation. GRIs may help in the diagnosis and appropriate management of thyroid dysfunction during pregnancy which will prevent both maternal and fetal complications.

A long way to go for the harmonization of four immunoassays for carcinoembryonic antigen

BackgroundCarcinoembryonic antigen (CEA) is one of the most widely used tumor markers worldwide. CEA immunoassays often yield different results. The objective of the present study was to investigate the current state of harmonization among CEA tests. MethodsA total of 94 individual serum samples were divided into 3 subsets and measured in triplicate using 4 assays, Abbott Architect i2000SR, Beckman Access DXI800, Roche Cobas e601, and Siemens Advia Centaur XP. The standards from each manufacturer and the 1st International Reference Preparation (IRP) 73/601 of the World Health Organization were measured as unknowns in parallel with the patient samples using the 4 assays. The results of an external quality assessment (EQA) scheme for CEA were also analyzed. ResultsA perfect correlation was not observed between any 2 assays, and the values obtained using the 4 assays were different for the detection of 94 individual patient serum samples. No consistency was detected in the CEA results evaluated by various assays for EQA samples, individual patient samples, the standards from each manufacturer, and the WHO IRP 73/601. ConclusionsHarmonization of the CEA results obtained using the 4 immunoassays has not yet been achieved.

ARCHITECT STAT High Sensitive Troponin I Familiarization Study (FAM) in the Department of Laboratory Medicine, Collegium Medicum, Nicolaus Copernicus University in Bydgoszcz, Poland

Background. International guidelines recommend the use of cardiac troponin assays for early detection of acute myocardial infarction. New high-sensitivity assays along with improved precision and sensitivity, are now widely available, accelerating patient’s diagnosis, treatment and invasive therapy. In this study we evaluated analytical performance of the Abbott ARCHITECT STAT high-sensitive troponin-I immunoassay and its 99th percentile upper reference limit. Methods. We performed the analytical evaluation of the hs-cTnI assay using Abbott ARCHITECT i2000SR immunoanalyzers. Features of the assay including imprecision, detection limits, linearity of dilution, interferences and method comparisons were assessed, as well as the 99th percentile upper reference limits in a cohort of 427 presumably healthy individuals were established. Results. Total imprecision ranged from 3.1% to 4.7% and was lowest for the medium controls. The observed limit of blank, limit of detection and limit of quantitation assumed values of 0.1, 1.5 and 4.8 ng/L, respectively. Common interferences, sample dilution and carry over did not affect the hs-cTnI results. Hs-cTnI was detectable in 98% of presumably healthy individuals. The 99th percentile values were age and sex dependent in the presumably healthy, but not in the healthy individuals. Conclusion. The new high-sensitivity troponin-I assay has improved analytical features and may be a valuable diagnostic tool.