Abbott Architect Research Articles

Association of D-dimer with estimated glomerular filtration rate in chronic kidney disease at different stages in Indian population

: Hyper-coagulability followed by cardiovascular disease is the most common cause of mortality in CKD (chronic kidney disease). Diagnostic usefulness of hypercoagulability marker at various stages of CKD needs to be assessed. : An observational cross-sectional study.: Dept of Biochemistry, Institute of Nephrourology, Bangalore, India from January 2022 to March 2022.Study population consists of CKD patients attending Nephrology outpatient for follow up. They were categorized into 5 stages using eGFR values. Laboratory test including D-Dimer was assayed in all the participants using Abbott Architect ci4100 analyzer. In our study, a peaked and statistically significant (P value = <0.0001) D-Dimer values were observed in stage 4&5 (5.4 ±2.5) in comparison with stage 1, 2 & 3 (0.9±0.2). D- Dimer had strong negative correlationR= - 0.79 with eGFR in stage 5 CKD. D-Dimer assay should be considered as a part of routine investigations in CKD patients especially in developing countries like India, where most of the patients reach hospital only at the later stages of the disease, in order to achieve a better follow-up and management of the disease.

Managing ethylenediaminetetraacetic acid (EDTA) interference in EDTA contaminated samples - selectivity in reporting analytes.

The widely accepted practice of not reporting any results from ethylenediaminetetraacetic acid (EDTA) contaminated samples necessitates repeat phlebotomy and could delay clinical management decisions. EDTA, however, interferes variably or not at all in assays. EDTA concentration in contaminated samples, like serum indices, therefore, could be used to selectively report the result of analytes not affected at measured EDTA concentration. A serum pool, level 1 and level 3 internal quality control materials were spiked with tripotassium-EDTA to create samples with EDTA concentration up to 6.0mmol/L. EDTA and 45 common and critically important analytes were measured on Abbott Architect to identify EDTA concentrations for analytes where the change in concentration exceeded their respective reference change value (RCV) for unidirectional change at 95% probability. Serum potassium increased and calcium decreased exceeding RCV at 0.17mmol/L EDTA. Alkaline phosphatase (ALP) decreased exceeding RCV at EDTA >1.86mmol/L. The decrease in iron did not exceed a wide RCV of 61.9% until maximum spiked EDTA but exceeded the desirable specification for allowable total error (30.7%) at EDTA >1.86mmol/L. The small decrease in magnesium did not exceed RCV. EDTA up to the concentration in blood collection tubes did not affect the results of any other measured analyte. Only serum potassium, calcium, ALP and iron studies, of the 45 analytes studied, should not be reported in EDTA contaminated samples. EDTA concentration cut-offs for selective reporting would further facilitate reporting of these analytes in EDTA contaminated samples.

Concomitant Use of Sutimlimab and COVID-19 Vaccines in Patients with Cold Agglutinin Disease from the Phase 3 Cardinal and Cadenza Studies

Background: Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia, characterized by chronic hemolysis mediated by classical complement pathway activation. The ongoing COVID-19 pandemic has posed an additional challenge in treating patients with CAD. Anti-CD20 therapies (commonly used off-label to treat CAD) increase the risk of serious COVID-19 infection and reduce the immune response to COVID-19 vaccines. Recent evidence has also shown a correlation between CAD exacerbations and both COVID-19 and COVID-19 vaccines; raising concern amongst clinicians as CAD patients are usually elderly with comorbidities and will likely require additional boosters during the ongoing pandemic. Sutimlimab (SUT), recently FDA approved for patients with CAD, is a first-in-class humanized monoclonal antibody which selectively targets C1s in the classical complement pathway; addressing the underlying mechanism of hemolysis in CAD. In the Phase 3 CARDINAL (NCT03347396) and CADENZA (NCT03347422) studies, SUT treatment led to rapid and sustained increases in hemoglobin and clinically meaningful improvements in fatigue and was generally well tolerated - reported adverse events (AE) were consistent with elderly populations. Both studies spanned the period before and during the pandemic; investigators were advised to vaccinate enrolled patients without stopping SUT treatment. However, the impact of SUT on immune response to COVID-19 vaccination is unknown. Objective: To explore concomitant use of COVID-19 vaccines and SUT in patients with CAD Methods: Post-hoc analysis from the open label extension (OLE) part of the CADENZA and CARDINAL studies. COVID-19 cases/diagnoses were collected via the regular AE reporting system. Data on tolerability to COVID-19 vaccine was collected through AE reports. Immunogenicity to COVID-19 vaccines was analyzed in a subset of patients fully vaccinated (2 doses) against COVID-19 and had consented to the use of stored samples (collected no later than 6 months after vaccination). Anti-Sars-CoV-2 Spike (EUROIMMUN Anti-SARS-CoV-2 ELISA) and anti-Sars-CoV-2 Nucleocapsid (Abbott Architect i2000 SR) IgG titers were measured. Three patients who tested positive for COVID-19 during Part A of both studies were excluded from the immunogenicity analysis. Results: Of the 61 completers from both studies, 47 received at least one dose of a COVID-19 vaccine; 14 received none; 11 had an additional booster. All participants, regardless of vaccination status, had similar demographic and clinical characteristics. Among those vaccinated, most (83%) received both doses during the studies; of these, mRNA vaccines were the most common (79%). The mean inter-dose interval for fully vaccinated patients (n=37) was 38 days; those who received 1 booster (n=11) had a mean of 165 days between the last dose and booster. No COVID-19 cases were reported during the OLE. Ten AEs were reported in 8 patients during the 7 days after any vaccine dose, but none more than once, and there were no serious AEs. SUT therapy was postponed/skipped twice due to vaccine administration, at the investigator's discretion. Anemia and hemolysis markers, including hemoglobin and total bilirubin, were measured after vaccination to assess its impact on hemolytic activity. No indications of hemolytic exacerbation were observed (Table 1). The immunogenicity analysis comprised 27 patients. All patients developed an immune response post-vaccination, measured via positive IgG anti-spike antibodies (Figure 1). The mean time between last dose and serum collection was 65 days (range: 25-137). Antibody titers were similar irrespective of gender or age. A further analysis performed on 6 patients with booster vaccinations demonstrated elevated immune responses pre to post booster (mean [95% CI] log10 titer change: 1.82 [0.79-2.85]). To rule out previous asymptomatic COVID-19 infection, anti-nucleocapsid SARS-Cov-2 IgG antibodies were assayed and were negative in all cases. Conclusions: COVID-19 vaccination response was not impaired in patients with CAD being treated with SUT. COVID-19 vaccines were well tolerated, and there were no signs of increased hemolytic marker activity following COVID-19 vaccination in patients receiving SUT. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

On-Cell Stability for Therapeutic Drug Monitoring

Abstract Introduction A common problem in many clinical laboratories and outpatient clinics is processing specimens rapidly to comply with specimen stability criteria. Labs receive thousands of samples a day and may face challenges with staffing, equipment malfunction, or workflow, which can prevent immediate processing of samples. Currently, for therapeutic drug monitoring, the lab is required to centrifuge specimens and remove the serum/plasma from cells within 2-hours (CLSI-GP44-A4). Many of these drugs are monitored in the outpatient setting, which may require longer transportation times to get specimens from the collection location to the laboratory. This creates challenges for the lab in processing samples within 2-hours and may result in unnecessary rejection of otherwise acceptable specimens. Not all clinical sites have the staffing or space to process the specimens on site. Our objective was to determine if the on-cell stability of therapeutic drugs can be extended to beyond two hours. Methods We performed spiking studies to determine the on-cell stability of phenytoin in whole blood that was collected from healthy donors in barrier-free red top tubes. Phenytoin was spiked into the whole blood at a final concentration of about 10 (therapeutic) or 40 (toxic) µg/mL. The spiked whole blood samples were mixed by inverting six times and then were left at ambient temperature for 30 minutes, 2-, 4-, 6-, or 12-hours, after which they were centrifuged, and the serum was removed for analysis of total phenytoin concentration on the Abbott Architect and free and total phenytoin on the Beckman AU (n=3 per time point and concentration). In vivo studies are ongoing for an extended list of therapeutic drugs, in which two extra red top tubes are collected from patients being monitored for phenytoin, valproic acid, digoxin, vancomycin, lithium, or carbamazepine therapy. The two study tubes are kept at ambient temperature for 6- or 12-hours after collection before being centrifuged and separated from cells. The 6- and 12-hour drug concentrations were compared to the patient’s standard of care tube that was processed within 2-hours, after clotting for 30 minutes. Results Spiking studies demonstrated phenytoin was stable on cells for at least 12-hours at both 10 and 40 µg/mL. The percent total phenytoin remaining at 12-hours relative to the 30-minute control was 104 ± 2% at 10 µg/mL and 99 ± 16% at 40 µg/mL. Furthermore, the fraction of free phenytoin did not change over the 12 hours (10 µg/mL: 8 ± 1% free; 40 µg/mL: 10 ± 1% free). Our preliminary in vivo studies have shown no change in vancomycin or lithium concentration in samples processed 6- and 12-hours post-collection. Conclusion We have demonstrated that phenytoin, vancomycin, and lithium collected in red-top tubes are stable on cells at ambient temperature for at least 12-hours.

ODP109 PARATHYROID HORMONE AND 25 OH VITAMINA D IN PREGNANCY: DATA FROM AN ARGENTINEAN COHORT SUPPORTING SUPPLEMENTATION.

Abstract Vitamin D (Vit D) deficiency has become a global health care issue, as it affects a great number of women during pregnancy and lactation. Vit D levels are critical during pregnancy, being the mother the only source of them for the developing fetus; an enzymatic system for conversion of 25OH VitD into 1-25(OH) 2 VitD is present in the placenta, thus reinforcing the importance of VitD during gestation. VitD deficiency has been associated with obstetric complications and adverse outcomes in offspring, affecting skeletal, immunological and respiratory systems. It is known that prenatal supplements available do not contain enough VitD to fulfil requirements. It is generally accepted that elevated PTH is an indicator of VitD deficiency, and Hysaj O et al (2021) showed that 25OH VitD is a statistically significant determinant of PTH levels in early and late pregnancy. Aim To evaluateVitD status and its relationship to parathyroid hormone (PTH) in a cohort of pregnant women representative of multiple Argentinian regions. Subjects and Methods Data from samples of 423 pregnant women in 1st and 2nd trimester were collected between 2016 and 2021. VitD was measured in different platforms: DiaSorin Liaison CLIA (n=184), Roche COBAS ECLIA (n=166), Abbott ARCHITECT CMIA (n=33), Biomérieux VIDAS ELFA (n=18) and Siemens CENTAUR CLIA (n=16). PTH (ng/L) was measured in 162 samples by SIEMENS IMMULITE CLIA and Roche COBAS ECLIA. As VitD is light-exposure dependent, we considered warm and high light-exposure season period from December to March and cold and low light season from April to September. VITD (ng/L) levels were classified as Deficient (<20), Insufficient (between 21 and 29) and Sufficient (>30) (Endocrine Society, 2014). Results From 423 data collected, 102 were excluded because of lacking information on VitD supplementation. From the remaining non supplemented 321 samples, 48% resulted insufficient, 30% deficient and 22% sufficient for VitD (groups comparison: p< 0. 05, Kruskal Wallis-Dunn test). The seasonal period and pregnancy trimester distributions didn't show significant differences. Similar results of VitD insufficiency were found in the major used platforms, regardless the seasonal period considered. PTH results expressed as median and interquartile range were (ng/L): 32. 0 (13.7-169. 0) in Deficient pregnancies (N=92), 23.7(13.3-88. 0) in Insufficient (n=50) and 18.7 (9.8-55.7) in Sufficient (n=20). Conclusions This study shows VitD inadequate levels in 78% in non-supplemented pregnancies, regardless season or measurement platform. Relative elevated levels of PTH were associated to pregnancies with VitD deficiency, evidenciating a regulatory role according to published data. To improve VitD status during pregnancy it would be advisable to pose new strategies for prenatal supplements developed by a multidisciplinary professional team. Presentation: No date and time listed

PSAT085 Monoclonal Cortisol Immunoassay Cut Off Point to Diagnose Adrenal Insufficiency (AI)

Abstract Objective Adrenal Insufficiency (AI) is diagnosed when the peak cortisol level after a cosyntropin stimulation test is <18 mg/dL using a standard reference (e.g. polyclonal antibody (pAb) immunoassay). However, in most laboratories the polyclonal assay is being replaced by a specific monoclonal antibody (mAb) immunoassay which yields lower cortisol levels, leading to the over diagnosis of AI and unnecessary steroid use. Methods/Study Population We obtained blood samples from 36 patients undergoing 1 mcg cosyntropin stimulation tests for diagnosis of AI. Samples were analyzed using pAb immunoassay (Abbott Architect Cortisol), mAb immunoassay (Roche Elecsys Cortisol II), and mass spectrometry (MS). AI was diagnosed if serum cortisol level was <18 using the pAb immunoassay. Measurements by MS and mAb immunoassay were individually used in simple logistic regression models to predict AI. For each model, we calculated a cortisol level corresponding to a 50% probability (median) of AI and used the delta method to determine the standard error and 95% confidence interval of the median. We used receiver operator characteristic (ROC) curve, area under the curve, sensitivity, and specificity to evaluate the potential of the median values as thresholds for each predictor. Results The ROC curve model indicated an area under the curve of 0.997 with a median value of 11.2 mcg/dL for the mAb immunoassay. This provides a sensitivity of 95%, specificity of 95%, positive predictive value of 95%, and negative predictive value of 94%. This new value has a Kappa coefficient of 0.89 when compared to the pAb immunoassay. When using all the data points throughout the stimulation test, data showed a mean difference in cortisol level between the mAb immunoassay and the pAb immunoassay of 5.12 mcg/dL (p-value <0.01) at any point during the test. Discussion/Significance New and highly specific mAb immunoassays are being used more widely but yield lower cortisol results. This reflects the need for further studies to determine new cut off points for highly specific cortisol immunoassays. A cut off level of 11.2 mcg/dL for the mAb immunoassay would provide a sensitivity of 95% and specificity of 95%. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Comparison between liquid chromatography-tandem mass spectrometry and immunoassay methods for measurement of plasma 25 (OH) vitamin D

Abstract Objectives Vitamin D is one of the major hormones involved in the metabolism of calcium (Ca) and phosphorus (P). In the present study, we aimed to determine the analytical performance of the immunoassay method used for determining plasma 25-hydroxyvitamin D [25(OH)D] levels in routine clinical practice in laboratories. Methods Venous blood samples were collected from 156 patients for the comparisons and were analyzed with Siemens ADVIA Centaur XPT, the Roche Cobas 6,000’s module e601, Abbott Architect i2000, and the liquid chromatography with tandem mass spectrometry (LC-MS/MS). Results The four methods were analyzed and compared through the Passing-Bablok regression for 25(OH)D, and the highest correlation was found at LC-MS/MS and Cobas 6,000’s module e601 (r=0.799), LC-MS/MS/Abbott Architect i2000, and LC-MS/MS/Siemens ADVIA Centaur XPT as r=0.736, 0.721, respectively. The correlation coefficient was found between Abbott Architect i2000 with Roche Cobas e601 and Siemens ADVIA Centaur XPT as r=0.934 and r=0.907, respectively. Also, the correlation coefficient was found between Roche Cobas e601 and Siemens ADVIA Centaur XPT as r=0.906. Conclusions The Roche Cobas assay showed better performance, compared with the other assays. Based on our findings, the chemiluminescence methods in automated systems seem to be expedient.

Clinical significance of undetectable high sensitivity cardiac troponin I (hs-TnI) in Thai individuals with low cardiovascular risk

Abstract Introduction The long term prognosis of individuals who has undetectable hs-TnI is poorly defined in low cardiovascular risk. We aim to examine whether undetectable hs-TnI individuals have better cardiovascular outcomes in low cardiovascular risk population. Methods Data of low cardiovascular risk population (<7.5%) who has no established of atherosclerosis cardiovascular disease (ASCVD) was derived from the Electricity Generating Authority of Thailand (EGAT) study in 2007–2009 survey. High sensitivity cardiac troponin I was measured by using the Abbott ARCHITECT i2000 SR assay. We categorized level of hs-TnI into undetectable hs-TnI (<1.9 ng/L), low hs-TnI, intermediate and more hsTnI by gendered specific cut-off. The low cardiovascular risk population was classified into extremely low risk (<5%) and low risk (5–7.5%). Major cardiovascular event (MACE) and all-cause mortality were collected until 31st December 2019. Survival analysis and subgroup analysis were performed. Results A total of 3,442 participants were eligible. Mean age was 43.6 years-old, 65.5% male, hs-TnI was detected 79.8%, median hs-cTnI was 2.6 ng/L (2,3.6). During median time followed-up 10.3 years, 52 events (1.5%) of MACE and 60 events (1.7%) of all-cause mortality occurred. After adjusted for conventional risk factors, hs-cTnI significantly associated with incidence of MACE (HR 1.03 95% CI 1.02–1.04, p-value <0.001). Compared with intermediate and more hs-TnI group, undetectable hs-TnI and low hs-TnI had 79% and 52% lower incidence of MACE (HR 0.21, 95% CI (0.05–0.79) and HR 0.48, 95% CI (0.23–1.0), p-value for trend 0.04. Subgroup analysis, incidence of MACE remained higher either extremely low or low CV risk compared with those undetectable hs-TnI. (P for interact 0.83) Conclusion Among individuals with low cardiovascular risk, hs-TnI testing can provide risk prognostication. Undetectable hs-TnI could be as a negative risk marker for adverse cardiovascular events. Funding Acknowledgement Type of funding sources: None.

Antibody response 6 months after the booster dose of Pfizer in previous recipients of CoronaVac.

The most widely used vaccines were messenger RNA (mRNA), viral vector, and inactivated virus with two‐dose schedules. In Brazil, the CoronaVac (Sinovac) was the first vaccine approved for emergency use, and the third dose was administered, preferably, with the BNT162b2 vaccine. We evaluated antibody levels after 6 months of the booster dose with BNT162B2 in previous recipients of CoronaVac and whether a subsequent severe acute respiratory syndrome coronavirus 2 (SARS‐COV‐2) infection enhances the antibody response. We analyze the humoral response (spike [S] IgM for the SARS‐CoV‐2 and IgG for the S and nucleocapsid [N] proteins) in samples collected before the third dose and 6 months after the third dose. The presence of antibodies was measured by using Abbott Architect i2000SR. The IgM and IgG antispikes were stimulated mainly 30 days after the third dose (30d/3D), with a decline over time. The IgG anti‐N was stimulated predominantly in 90d/3D and 180d/3D. The N IgG levels were 50 and 35 times higher in the positive polymerase chain reaction (PCR) group in 90d/3D and 180d/3D, respectively. The S IgG titers were 1.5 times elevated in the positive PCR group, in 180d/3D. The BNT162b2 boosted the S IgG levels, decreasing after 60 days. The booster shot induced IgM and IgG antibodies against spike protein. Infection after vaccination increased antibodies against protein N.

Role of serum hepcidin as a biochemical marker in children with Beta-thalassemia of iron status in Wasit Province Iraq

β-thalassemia is characterized by anemia and depending on the severity of the anemia. Hepcidin is a 25-amino-acid peptide generated by the liver, based on hypoxia, anemia, and iron storage. controls blood iron concentration and tissue distribution and regulates the body's iron hemostasis. To evaluate the usefulness of Serum Hepcidin level as a biochemical marker of iron status in children with β thalassemia major, β thalassemia Intermedia and its relation with serum ferritin level. A cross-section study which will involve 90 included 50 Thalassemia Major (TM) and 40 Thalassemia Intermedia (TI). Patients will be collected from the thalassemia center in Kut Hospital for Gynecology and Pediatrics, were randomly selected for this study. All patients child in both gender from (5-17 years). Enzyme-linked immunosorbent assay [ELISA] used for determination of Hepcidin, Abbott Architect C4000 And cobas c 111 analyzer used for the determination of Ferritin, Iron and Hemoglobin was measured by Sysmex XP-300. The study included both gender 62.2% were male and 37.8% were females, regarding male gender 57.1% had βTM and 42.9% had βTI while female gender 52.9% had B-thalassemia major and 47.1% had β-thalassemia Intermedia.

Quality control of total carbon dioxide (CO2) in serum or plasma using the Abbott Architect is affected by environmental pCO2 concentrations.

Introduction: Total CO2, or bicarbonate, is a parameter in clinical chemistry often applied to assess the metabolic status of a patient. This article discusses the observations and interventions during an episode of assay instability on an Abbott Architect routine chemistry analyser.Results: The Levey-Jennings plot of QC data showed a circadian pattern, having an overestimation of total CO2 during periods of high personnel attendance. A qualitative analysis revealed a correlation between atmospheric CO2 in the lab environment and the acquired total CO2 value in a quality control sample. Assessment of total CO2 is hence influenced by the equilibrium between atmospheric CO2, dissolved CO2 and bicarbonate. The effect is more pronounced on samples containing low concentrations of total CO2. The bias related to environmental CO2 is also noticeable on patient samples, patient means between periods with high and low atmospheric CO2 levels differed by 2mmol/L.Discussion: Passive ventilation of the laboratory environment is proven insufficient during weather conditions in which the lab is not exposed to wind. Consistent reduction of atmospheric CO2 could only be guaranteed with an active ventilation infrastructure. Systematic closure of analyser lids also reduced analyser variance.Conclusion: The lab environment is an important source of parameter variance. Both environmental and infrastructural aspects must be considered when assessing the potential cause of the instability.

A practical approach example to measurement uncertainty: Evaluation of 26 immunoassay parameters.

IntroductionMeasurement uncertainty is a non-negative parameter that characterizes the distribution of all values appropriate to the measured size and is associated with the measured result. In this study, we aimed to compare the results with various suggestions and produce more qualified results by calculating the measurement uncertainties of the immunoassays like fertility hormones, drug concentration tests, cardiac markers, thyroid function tests and tumour markers.Materials and methodsUncertainty calculation was made in accordance with the top-down approach according to Nordtest guide. The 12-month study of internal and external quality assessment results were used. The parameters of drug concentration tests were performed on the Abbott Architect c8000, other hormones/markers on the i2000 of the same brand.ResultsFactors that increased the measurement uncertainty of a test were due to external quality control data. The calculations showed that 13 of 26 parameters satisfied quality requirements. The highest uncertainty value, with 28% belonged to cancer antigen 19-9 test. The lowest value was calculated for prolactin with 8.3%. Dehydroepiandrosterone sulfate and phenytoin performed poorly in terms of measurement uncertainty, although internal and external quality control assessment results were considered favourable for both.ConclusionIt is recommended that the concept of measurement uncertainty, which plays an important role in the total quality performance of the laboratory, should be followed up by the clinical laboratory experts at certain time intervals and should be increased the awareness of clinicians about the subject.

Kastamonu İlinde Hepatit A Seroprevalansının Değerlendirilmesi i

Aim: Hepatitis A disease is a contagious liver infection caused by the hepatitis A virus (HAV). This study aimed to decide the hepatitis A seroprevalence in all age groups in Kastamonu province, Turkey.
 Material and Method: The current study analyzed the anti-HAV antibodies test results of the patients who applied to Kastamonu Training and Research Hospital for various reasons between 2018-2022. The most up-to-date test results of patients sent more than one serum sample were evaluated. The patients were separated into eight age groups: 0-10,11-20, 21-30, 31-40, 41-50, 51-60, 61-70, and ≥71. The anti-HAV IgM and anti-HAV IgG values were determined using the chemiluminescence microparticle immunoassay method in the Abbott Architect i2000SR. The results were evaluated based on the manufacturer’s instructions. 
 Results: There was positivity in 27 (1.3%) of 2083 patients in whom anti-HAV IgM was studied and in 837 (58.2%) of 1439 patients in whom anti-HAV IgG was studied. The anti-HAV IgG positivity in females and males was 55.9% and 61.0%, respectively; anti-HAV IgM positivity was 1.7% and 0.8%. The anti-HAV IgG positivity rate increased with increasing age (p

Pediatric reference interval verification for 17 specialized immunoassays and cancer markers on the Abbott Alinity i system in the CALIPER cohort of healthy children and adolescents.

Clinical laboratory investigation of autoimmune, metabolic, and oncologic disorders in children and adolescents relies on appropriateness of reference intervals (RIs). The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) previously established comprehensive pediatric RIs for specialized immunoassays on the Abbott ARCHITECT system. Herein, we aim to verify performance on new Alinity i assays by evaluating sera collected from healthy children as per Clinical andLaboratory Standards Institute (CLSI) EP-28A3C guidelines. Precision, linearity, and method comparison experiments were completed for 17 specialized Alinity immunoassays, including cancer antigens, autoimmune peptides, and hormones. Sera collected from healthy children and adolescents (birth-18 years, n=100) were evaluated. CLSI-based verification was completed using previously established CALIPER RIs for ARCHITECT assays as the reference. Of 17 specialized immunoassays assays, only anti-cyclic citrullinated peptides (anti-CCP) did not meet acceptable verification criterion (i.e.,≥90% of results within ARCHITECT reference CI). Anti-thyroglobulin, anti-thyroid peroxidase, and carcinoembryonic antigen did notrequire age-specific consideration beyond one year of age, with 63, 91, and 80% of samples equalling the limit ofdetection, respectively. Estimates were separated by sex for relevant assays (e.g., sex hormone binding globulin, total and free prostate specific antigen). Findings support transferability of pediatric RIs on ARCHITECT system to the Alinity system for 16 specialized immunoassays in the CALIPER cohort and willbe a useful resource for pediatric clinical laboratories using Alinity assays. Further work is needed to establish evidence-based interpretative recommendations for anti-CCP and continue to evaluate pediatric RI acceptability for newly available assay technologies.

HTLV-1/2 Infection in Blood Donors from a Non-Endemic Area (Catalonia, Spain) between 2008 and 2017: A 10-Year Experience.

Human T-cell lymphotropic virus type 1 and 2 (HTLV-1/2) screening is not mandatory in Spanish blood banks. In Catalonia, selective screening was introduced in 2008, followed by universal screening in 2011. We present herein a 10-year experience of HTLV testing in blood donors. HTLV-1/2 selective screening was performed using Ortho-Clinical Diagnostics HTLV-I/HTLV-II Ab-Capture ELISA between February 2008 and May 2009, then Abbott Prism HTLV-I/ HTLV-II assay until December 2010. Abbott Architect rHTLV-I/II assay was then used for HTLV-1/2 universal screening in pooled samples. INNO-LIA HTLV I/II Score (Fujirebio) and in-house HTLV-1/2 proviral DNA real-time PCR were used in reactive samples. Follow-up was offered to confirm HTLV-1/2 donors in Vall d’Hebron Hospital. Between 2008 and 2017, 51 blood donors were confirmed HTLV positive (46 HTLV-1, 4 HTLV-2 and 1 HTLV) out of 2,114,891 blood donations (1 in 41,468). Sixty-nine percent were female, median age was 40 years and most were born in Latin America (69%), followed by Europe (25%), Africa (4%) and Asia (2%). Screening of relatives and partners identified 12 additional HTLV-1 cases. Lookback studies did not show any HTLV-1/2 transmission. HTLV infections found in blood donors mirror epidemiological changes in the population of Spain. Consequently, HTLV should be considered a potential risk for recipients and calls for the design of optimal strategies to ensure transfusion safety.

Results of a sample-to-cutoff ratio using Abbott Architect rHTLV-I/II assay allow to predict detection of HTLV-1 and HTLV-2 proviral DNA by real-time PCR

The present study aims to correlate the sample-to-cutoff ratios (S/CO) distributions of reactive results for HTLV-1/2 antibodies with the detection of proviral DNA in a population of blood donor candidates. It was carried out a retrospective data search of 632 HTLV-1/2 reactive samples, submitted to confirmatory testing from January 2015 to December 2019. Serological screening was performed by chemiluminescent microparticle immunoassay Architect rHTLV-I/II, whereas confirmatory testing was performed by in-house real-time polymerase chain reaction method. 496 out of 632 samples (78%) had undetectable HTLV-1/2 proviral DNA and 136 (22%) had detectable proviral DNA. HTLV infection was not confirmed in any individual for whom the S/CO ratio value was <4, and proviral DNA detection rates gradually escalated as S/CO ratio values increased. The sensitivity and predictive positive value found for the Architect rHTLV-I/II was 100% and 22%, respectively. The receiver operating characteristic (ROC) curve analysis showed that the optimal S/CO ratio value for predicting the presence of HTLV-1/2 was 18.11. High S/CO ratios were more associated with the detection of proviral DNA. The S/CO ratio value <4 suggests excluding true HTLV infection and the risk of blood transmission.

Results of a sample-to-cutoff ratio using Abbott Architect rHTLV-I/II assay allow to predict detection of HTLV-1 and HTLV-2 proviral DNA by real-time PCR

The present study aims to correlate the sample-to-cutoff ratios (S/CO) distributions of reactive results for HTLV-1/2 antibodies with the detection of proviral DNA in a population of blood donor candidates. It was carried out a retrospective data search of 632 HTLV-1/2 reactive samples, submitted to confirmatory testing from January 2015 to December 2019. Serological screening was performed by chemiluminescent microparticle immunoassay Architect rHTLV-I/II, whereas confirmatory testing was performed by in-house real-time polymerase chain reaction method. 496 out of 632 samples (78%) had undetectable HTLV-1/2 proviral DNA and 136 (22%) had detectable proviral DNA. HTLV infection was not confirmed in any individual for whom the S/CO ratio value was <4, and proviral DNA detection rates gradually escalated as S/CO ratio values increased. The sensitivity and predictive positive value found for the Architect rHTLV-I/II was 100% and 22%, respectively. The receiver operating characteristic (ROC) curve analysis showed that the optimal S/CO ratio value for predicting the presence of HTLV-1/2 was 18.11. High S/CO ratios were more associated with the detection of proviral DNA. The S/CO ratio value <4 suggests excluding true HTLV infection and the risk of blood transmission.

Early identification of high-risk individuals for monoclonal antibody therapy and prophylaxis is feasible by SARS-CoV-2 anti-spike antibody specific lateral flow assay

Monoclonal antibody therapy has been approved for prophylaxis and treatment of severe COVID-19 infection. Greatest benefit appears limited to those yet to mount an effective immune response from natural infection or vaccination, but concern exists around ability to make timely assessment of immune status of community-based patients where laboratory-based serodiagnostics predominate. Participants were invited to undergo paired laboratory-based (Abbott Architect SARS-CoV-2 IgG Quant II chemiluminescent microparticle immunoassay) and lateral flow assays (LFA; a split SARS-CoV-2 IgM/IgG and total antibody test) able to detect SARS-CoV-2 anti-spike antibodies. LFA band strength was compared with CMIA titer by log-linear regression. Two hundred individuals (median age 43.5 years, IQR 30−59; 60.5% female) underwent testing, with a further 100 control sera tested. Both LFA band strengths correlated strongly with CMIA antibody titers (P < 0.001). LFAs have the potential to assist in early identification of seronegative patients who may demonstrate the greatest benefit from monoclonal antibody treatment.

Comparative evaluation of four commercial analyzers for the serological screening of hepatitis A, B, C and HIV.

Independent evaluations that deploy clinical patient samples are important in assessing the performance of commercial tests used for serological screening of viral hepatitis and HIV in clinical laboratories. We compared the analytical performance of Abbott Architect i2000SR, Abbott Alinity i, DiaSorin Liaison XL, and Siemens Atellica for the following analytes: anti-HAV IgG/anti-HAV total, anti-HAV IgM, HBsAg, anti-HBc IgM, Anti-HBc, HBeAg, anti-HBe, anti-HBs, anti-HCV, and HIV Ag/Ab. In addition, anti-HBc IgM, HBeAg, and anti-HBe were evaluated for Abbott Architect, Abbott Alinity and DiaSorin Liaison. Pseudonymized clinical serum specimens (N=98-200 for each analyte) were selected for the analysis according to their reactivity on the Abbott Architect. The results were compared against Abbott Architect and against consensus. A generally high agreement was observed between the tests. Abbott Alinity had the lowest anti-HAV IgG/total specificity (75.9% against Abbott Architect and 83.0% against consensus). The comparatively low sensitivity of Siemens Atellica (78.2%), Abbott Alinity (87.5%) and DiaSorin Liaison (89.3%) for anti-HAV IgM against Abbott Architect may reflect a higher false-positive rate of Abbott Architect. Particular variation was observed in the sensitivity values of anti-HBc, HBsAg and HIV Ag/Ab between the test methods. DiaSorin Liaison anti-HBs gave consistently higher values as compared to the other tests. The serodiagnostic methods for HIV and viral hepatitis of Abbott Architect, Abbott Alinity, DiaSorin Liaison, and Siemens Atellica performed well in comparison with each other. The observed differences between the tests will provide useful information for clinical laboratories in planning their workflows for screening and confirmation.

Investigation of SARS-CoV-2-Specific Humoral and Cellular Immunity Values in Health Care Workers with COVID-19 Disease and Administered with COVID-19 Vaccine

For limiting the coronavirus disease-2019 (COVID-19) pandemic, the effects on both humoral and cellular immune responses due to vaccines and previous infection should be taken into consideration. In some of the studies about the humoral immune response of the virus and different vaccines, it has been suggested that there can be a discordance between cellular and humoral immune responses during COVID-19 infection. The aim of this study was to determine the effects of humoral and cellular immune responses against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antigens in three groups of healthcare workers (HCWs) who were vaccinated with two doses of inactivated virus vaccine (CoronaVac), non-vaccinated and recovered COVID-19 infection and non-infected healthy controls by comparing the variables of gender and age and to examine the relationships between them. In this study, the antibody recognizing the receptor binding domain (RBD) of the spike (S) glycoprotein (IgG-S), nucleocapsid protein (IgG-N) of SARS CoV-2 and Interferon Gamma (IFN-γ) titres were determined among non-infected and vaccinated with two doses of inactivated virus vaccine (IVV) (n= 56, 1st group: 27 men, 29 women), non-vaccinated and COVID-19 convalescents (CG) (n= 41; 2nd group: 21 men, 20 women) and non-vaccinated and non-infected healthy controls (HCG) (n= 23, 3rd group: 10 men, 13 women) in 120 HCWs. Diagnosis of all the participants in COVID-19 CG was confirmed for SARS CoV2 infection with reverse transcription polymerase chain reaction (RT-PCR) test according to manufacturer's instruction (Bio-speedy® SARS CoV-2 Double Gene RT-qPCR, Bioeksen R and D Technologies, Turkey). IgG-S and IgG-N antibody levels were determined quantitatively by Abbott Architect i2000 (Abbott Laboratories, Abbott Park, IL, USA) system. (Qiagen, MD, USA). IFN-γ levels were determined by using the QuantiFERON SARS-CoV-2 Starter Blood Collection Tubes (Qiagen, MD, USA). All statistical data analysis were conducted using SPSS (version 22, IBM Corp., Armonk, NY, USA). Student's independent t-test or Mann-Whitney U test was used for the differences between bivariate groups and Spearman Rank correlation was used to evaluate the monotonic relationship between nonnormally distributed data sets. Spearman rho > 0.7 denotes high, 0.7 > rho > 0.5 moderate and rho > 0.05 was considered as significant. For each of the immunity parameters, there were no significant differences between males and females in the IVV group, as well as in the CG. In neither of the groups age and immunity parameters were found to be highly correlated. All three immunity parameters of males in CG and IVV groups significantly differed from each other. Although humoral immunity parameters of females between CG and IVV groups did not show any significant difference, the IFN-γ titres significantly differed from each other. There were no significant differences in the IgG-S titres between CG and IVV combined gender groups. However, IgG-N and IFN-γ titres significantly differed from each other between CG and IVV groups. Antibody and particularly IFN-γ levels in two dose CoronaVac vaccinated group were less pronounced in comparison to the observed responses in COVID-19 convalescents group, indicating that CoronaVac may induce substantially less robust and persistent cellular and humoral responses than natural SARS-CoV-2 infection.