Liaison XL Research Articles

Analytical interference of Burosumab therapy on intact fibroblast growth factor 23 (iFGF23) measurements using an immunoassay: preliminary evaluation

ABSTRACT Our study evaluated the possible interference of Burosumab (human recombinant monoclonal antibody directed against N-terminal domain of FGF23) on the immunoassay of intact FGF23 (iFGF23) with the Liaison XL. The analytical method uses three different antibodies, one of which directed against the N-terminal portion of FGF23. The evaluation of the method accuracy involved the fully automated execution of a dilution test on EDTA plasma from 5 subjects who had not received any monoclonal antibody (mAb), 20 EDTA plasma from patients treated with Burosumab, and 2 EDTA plasma from subjects who had not received any mAb in witch an adequate volume of Burosumab had been added in vitro. One sample with specific diluent (LIAISON® FGF 23) with an adequate volume of Burosumab had been added in vitro. The dilution assay provided highly inaccurate iFGF23 results in samples with therapeutic concentrations of Burosumab and in samples with concentrations below the LoQ (6.5 pg/mL). The addition of Burosumab to the diluent did not produce any analytical interference. Dissociation of iFGF23 from the mAb-target complex in diluted sample could explain the loss of accuracy in the iFGF23 immunoassay using the Liaison XL analyzer. Burosumab could be an interferent in immunoassay procedures of iFGF23.

Fourth-Generation HIV Rapid Tests: Enhanced Sensitivity and Reduced Diagnostic Window for HIV-1 Primary Infection Screening.

As most HIV rapid tests (HRT) detect only HIV-1/2 antibodies, their performance during primary HIV infection is poor. Determine HIV Early detect (Abbott) (Determine) is the only HRT with an HIV-1 p24-antigen detection, but the impact of this addition in shortening the diagnostic window remains unclear. A total of 183 HIV-1 primary infection samples were tested using the HRTs Determine and ONE STEP anti-HIV (1&2) Test (InTec Products) (One-Step). The pre-seroconversion subgroup was defined as p24-antigen positivity without Western blot nor Liaison XL (fouth generation enzyme immunoassay with distinct signal for p24-antigen and HIV-1 antibody) HIV-1 antibodies. Global sensitivity (95% CI) was 95% (91-97) for Determine versus 80% (74%-85%) for One-Step (difference p = 1.38e-06). Pre-seroconversion subgroup sensitivity was lower, at 71.9 (54.6%-84.4%) for Determine and 9.7% (3.3%-24.9%) for One-Step. Among the 45 samples with an HIV-1 infection date, no HRT was reactive up to 2 weeks. Between 2 and 3 weeks, Determine sensitivity was 78% (45%-95%) versus 56% (27%-81%) for One-Step. From 3 weeks to 1 month Determine sensitivity was 90% (62%-98%) and One-Step 45% (21%-72%). The last negative sample occurred at 3 weeks for Determine versus 70-90 days for One-Step. HRT with p24-antigen detection significantly shortens the diagnostic window from approximatively 3 months to 1 month. HRTs should be used with caution in the first month after HIV infection.

Role of Serum Alpha-fetoprotein in Assessing the Resectability of Hepatocellular Carcinoma

Background: Serum AFP is a well-established tumor marker of hepatocellular carcinoma (HCC) which has already proved its acceptability in confirming the diagnosis and predicting the prognosis of HCC. Objective: The current study is aimed to evaluate the role of serum alpha-fetoprotein in assessing the resectability of HCC. Methods: This was a single-center, cross-sectional study done from September 2020 to August 2021 at the department of Hepatobiliary, pancreatic, and liver transplantation surgery at BSMMU. A total of 27 HCC patients who met the inclusion criteria were enrolled in the study. Clinical, laboratory, and imaging findings were obtained using a standardized data collecting sheet with the patients' informed agreement. AFP was measured by automated chemiluminescence analyzer (LIAISON XL, DiaSorin, Italy) in the Department of Biochemistry & Molecular Biology, BSMMU. Based on the ROC curve of this study, the patients were divided into group 1 with AFP levels 38.45 ng/ml and group 2 with AFP levels >38.45 ng/ml. According to the resectable criteria (TNM stage: I, II, BCLC stage: 0, A, B, CTP grade: A, B, ECOG PS: 0) established for the study, each AFP group was further subdivided into resectable and unresectable subgroups. Finally, the parameters (tumor size, number, location, CTP grade, fibrosis score, performance status, HBV positive, HBV DNA, BCLC and TNM stage) of the resectable and unresectable patients in each AFP group were evaluated. Statistical analyses were performed using SPSS version 22. Quantitative variables were expressed as mean±standard deviation and examined using an unpaired t-test. The qualitative data were represented by frequencies and percentages, and the Chi-Square test and Fisher exact test (where applicable) were used to determine any correlation. The statistical tests were conducted with a 95% confidence interval, and P0.05 was deemed statistically significant. Results: In this study, thirty seven percent (37%) patients ...........

B-015 Analytical Verification of MR-proADM Biomarker in Human EDTA Plasma on Immunoassay Analyzer LIAISON® XL of Diasorin

Abstract Background Adrenomedullin (ADM) is a potent vasodilator peptide of 52-aminoacid belonging to the calcitonin family of peptides. Midregional pro-ADM (MR-ProADM) is a precursor for ADM that circulates is in a 1:1 ratio with it, and proportionally represents its levels and activity. Increased ADM circulating concentrations have been described for several disease states, including dysfunction of the cardiovascular system and sepsis. However, reliable ADM quantification has been hampered by the short half-life, the existence of a binding protein, and its physical properties. Hence, quantificacion of MR-proADM represents a more suitable option. The biomarker MR-proADM has been shown to be an accurate prognostic marker for outcome prediction in patients with lower respiratory infections, sepsis, urinary tract infections, and kidney disease. The objective of this study was the verification of the metrological characteristics and the verification of the linearity of quantitative measurement range, as declared by the manufacturer, of the LIAISON® Brahms MR-proADMTM on Liaison® XL (DiaSorin). Methods The verification was performed with two levels of quality controls (QC) from the manufacturer (x̄L=1,19 nmol/L and x̄H=5,48 nmol/L), and residual EDTA plasma samples from patients with an active sepsis code. The evaluation included the assessment of: • Detection capability (including limit of quantification (LoQ) and limit of detection (LoD), measuring three samples at the manufacturer's stated concentration (0.21 nmol/L and 0.09 nmol/L, respectively) in duplicate within 4 runs). • Precision (CV, %) and accuracy (bias, %) within, measuring 10 replicates of each QC level; and between run, measuring 5 replicates for each QC level within 5 runs. • Linearity of the quantitative range of measurement (six intermediate samples prepared by mixing a high concentration sample- XH=9.64 nmol/L- and a low concentration sample, XL=0.59 nmol/L; measured in triplicate). All studies were performed in accordance with the recommendations of the Clinical Laboratory Standards Institute guidelines. Statistical analysis was performed using Microsoft Excel®, 2016. Results All results with diluted samples presented a signal (RLU) higher than that detected in samples without analyte, so the LoD was verified. The precision at the LoQ concentration was 26.7% (acceptance criteria was set as <20%). CV for within-run precision were 4.3% and 2.0% and for between-run precision 6.8% and 7.9% for low (L1) and high (L2) control level, respectively. The average bias was 3.60% for L1 and 4.23% for L2, meeting acceptance criteria (<8%). Linearity was confirmed between 0.59 and 9.64 nmol/L (R2 = 0.995). The biases between the expected and the obtained value were ≤7% through the quantitative range of measurement, except for the lowest concentration sample (close to the quantitation limit). Conclusions Our study showed good compliance with the metrological characteristics declared by the manufacturer for LoD, precision, bias and linearity range. Although the LoQ was not verified, it is outside the clinical decision value in septic patients (< 2.25 nmol/L) and it is not deemed a limitation for clinical practice. Additionally, the Liaison XL® platform permits us to configure an emergency protocol circuit (24/7) with a TAT of 35 min.

A-056 Investigating Iodine Contrast Contamination in Cortisol and Aldosterone Samples

Abstract Background Primary aldosteronism (PA) is a condition characterized by hypertension resulting from excess secretion of aldosterone. PA caused by a unilateral aldosterone-producing adenoma can be treated with adrenalectomy but requires diagnosis by adrenal vein sampling (AVS). In this procedure, intravenous cosyntropin is administered to stimulate adrenal cortical secretion, followed by obtaining samples from the right and left adrenal veins and IVC. Laterization index is calculated by obtaining the aldosterone:cortisol ratio for each side, with a ratio cutoff ≥3 is used for confirmation. Iodinated contrast media facilitates visualization of catheter positioning during AVS and sometimes results in contamination of samples, evidenced by abnormal gel separator flotation (i.e. gel above plasma). This study had two aims: 1) to determine at what concentration contrast dye causes gel flotation and 2) discern whether contrast media interferes with our cortisol or aldosterone assays. Methods Gel flotation studies were performed by spiking pooled plasma samples with iohexol contrast media (Omnipaque 240, GE Healthcare) at concentrations ranging from 3%-10% v/v and aliquoting into fresh lithium heparin plasma separator tubes (BD, PSTs). Samples were then centrifuged and visually inspected for abnormal gel flotation. Contrast interference studies were performed using three pools of low (5 µg/dL), medium, (30 µg/dL), and high (55 µg/dL) cortisol concentrations. Sample pools were diluted with 20% contrast media or saline (control) and subsequently mixed at different ratios to create a range of dye concentrations (0.5%-18% v/v). Each mixture was assayed in triplicate for cortisol and aldosterone on a cobas e602 (Roche Diagnostics) and LIAISON XL (DiaSorin) immunoanalyzer, respectively. The total allowable error (TEa) was ±0.4 μg/dL or ±20% for cortisol and ±2 ng/dL or ±20% for aldosterone. Results Flotation of the gel separator was observed at a dye concentration of 4.5% v/v and greater. For the cortisol interference study, the bias was <5% for the three pools at all contrast media concentrations. Aldosterone was also measured in these pools, as bias could affect ratios calculated for PA. Aldosterone interference occurred at contrast dye concentrations ranging from 12%-20% v/v. An average positive bias of 34% was observed in aldosterone samples spiked with contrast media relative to the saline control. Compared to sample pool controls without added saline or dye, measurements for cortisol and aldosterone were 19%-22% and 16-25% lower in media- and saline-spiked samples (20% v/v), respectively, indicating a logical dilution effect. Conclusions Contrast dye contamination of AVS specimens can cause gel flotation in lithium heparin PSTs, preventing their analysis. The presence of contrast media at certain concentrations interfered with the DiaSorin aldosterone assay, leading to falsely elevated results. No cortisol assay interference occurred in the presence of contrast media but results were falsely decreased due to sample dilution. Samples collected during AVS may be contaminated with contrast dye causing gel flotation to occur. This is indicative of a minimum contrast media concentration of 4.5% v/v. Aldosterone:cortisol ratios may be inaccurate due to the positive aldosterone immunoassay bias with contrast media contamination. Care should be taken when reporting and interpreting AVS results with suspected contamination.

A-057 Assessing Direct Renin Stability in EDTA Plasma Prior to Separation from Cells and Post-thaw

Abstract Background Renin is an enzyme secreted by the kidneys responsible for blood pressure regulation through the renin-angiotensin-aldosterone axis. Direct renin measurements are frequently used to investigate underlying causes of hypertension, including primary aldosteronism (PA), which is screened for using an aldosterone:renin ratio (ARR). Appropriate handling of renin samples in the preanalytical phase is critical, as cryoactivation of prorenin can occur when samples are refrigerated or cooled for extended periods of time, falsely elevating results. Manufacturer instructions for renin handling are often poorly defined and there is currently no consensus as to best handling practices. Two variables that frequently lead to renin sample rejections in our laboratory are time to centrifugation after collection and time kept at room temperature (RT). The objective of this study was to evaluate the stability of direct renin under ambient and freeze-thaw conditions in an effort to reduce test cancellations due to improper handling. Methods Plasma samples collected from five volunteers with consent in K2EDTA tubes were used for renin stability studies. Baseline renin samples were kept at RT for two hours after collection, centrifuged, measured, and subsequently frozen for post-thaw studies. To assess stability before separation from cells, samples kept at RT for two and four hours prior to centrifugation were assayed in triplicate for direct renin. For post-thaw stability studies, plasma samples were split into two aliquots each and frozen at -20⁰C for at least 24 hours, but no longer than 30 days. After removal from -20⁰C, one set of aliquots was thawed on the benchtop at RT and the second set was thawed in an RT water bath for up to one hour. Samples were centrifuged and assayed for direct renin in triplicate at baseline and six hours post-thaw. Direct renin was measured using the LIAISON XL chemiluminescent immunoassay (Diasorin). Bias was assessed after each treatment. The total allowable error (TEa) was ±2 pg/mL or ±20%. Results Measured renin concentrations ranged from 6.8-29.7 pg/mL. The percent bias in direct renin concentrations when comparing samples stored for two-hour and four-hour timepoints before centrifugation was 2.0% on average. Post-thaw studies comparing renin concentrations at the baseline and six-hour timepoints revealed an average percent bias of 13.1% and 12.2% for RT and water bath thawing methods, respectively. All samples tested were within the TEa. Conclusions Direct renin is stable in lavender K2EDTA tubes at RT for up to four hours, prior to centrifugation and separation from cells. Renin concentrations remained stable after storage at -20⁰C and thawing at RT for up to six hours, regardless of thawing method. By expanding direct renin stability criteria, we hope to reduce the number of cancellations due to preanalytical handling errors and prevent redundant phlebotomy for patients.

A-252 Evaluation of the Use of One-tube Blood Collection and Automated Specimen Processing System for LIAISON® QuantiFERON®-TB Gold Plus Testing at a Large Regional Reference Laboratory

Abstract Background LIAISON® QuantiFERON®-TB Gold Plus (QFT-Plus) is an in vitro diagnostic assay for the indirect detection of infection caused by Mycobacterium tuberculosis complex (MTBC). QFT-Plus testing consists of four tubes (controls and TB antigens) and detects interferon-γ (IFN-γ) released by host cells when exposed to MTBC peptide antigens using chemiluminescence immunoassay (CIA) technology. Patient’s blood can be collected directly into four QFT-Plus tubes or into a single lithium heparin tube. If the one-tube collection process is utilized, blood must be aliquoted into each of the four QFT-Plus tubes prior to testing. In this study, we evaluated the workflow and feasibility of lithium-heparin blood collection and pre-analytical processing using the Copan Universe system for QFT-Plus testing on the LIAISON XL analyzer. Methods Whole blood collected into a 6 mL lithium heparin tube was mixed using a tube rotator prior to processing on the Copan UniVerse, which aliquots 0.9 mL blood into each of four QFT-Plus tubes and label the tubes with patient information. The lithium heparin tube is mixed again immediately prior to aliquoting into each QFT-Plus tube. Different methods of mixing (vortexing vs pipetting) were assessed for efficiency and performance. Walkaway feasibility was also assessed by testing aliquoting efficiency when loading 6, 9, 12 and 18 blood samples at a time. Visual inspection of the QFT-Plus tubes to check accuracy of labels was performed prior to incubation and validation of readability of the barcode labels through the analyzer was performed. Results Of 44 blood samples that were pipet mixed, 26 (59.1%), 15 (34.1%) and 3 (6.8%) showed no, slight and moderate hemolysis, respectively. None were grossly hemolyzed. Vortex mixing showed similar results with 61.3% (19/31) and 38.7% (12/31) showed no or slight hemolysis. However, bubble formation, which may interfere with pipetting by the UniVerse, was observed in several tubes when the samples were vortex mixed. The UniVerse appropriately aliquoted 0.9 mL blood and labeled 280 tubes. Only 1 (0.4%) tube had <0.9 mL volume detected. It takes about 20 minutes to aliquot 12 patient samples into four QFT-Plus tubes. Walkaway was possible when loading 18 patients’ samples at a time without negative downstream impact on pipetting or appropriate mixing of samples for QFT-Plus testing. All QFT-Plus tubes were labeled accurately with barcodes and accession numbers which were all read and processed through the analyzer. Conclusions Implementation of lithium-heparin blood collection for centralized QFT-Plus testing was feasible when used in conjunction with the Copan UniVerse, which allowed for high throughput specimen processing and mitigated the risk of sample mislabeling.

Establishment of IGF-1 and IGFBP-3 continuous reference percentiles from data of healthy children using three kinds of immunoassay systems

Background and aimsAppropriate continuous reference intervals (RIs) for serum insulin-like growth factor 1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP-3) are important for diagnosing growth hormone deficiency or excess. Material and methodsWe retrospectively reviewed serum IGF-1 and IGFBP-3 levels in Korean children aged 0–17 years who were diagnosed as healthy during a short stature workup in the outpatient clinics of three hospitals. IGF-1 and IGFBP-3 levels were measured using various immunoassays, including Liaison XL for IGF-1, an immunoradiometric assay (IRMA) for IGFBP-3 (n = 5522), and Immulite 2000 (n = 3036) and cobas e801 (n = 314). We established RIs from the 2.5th to 97.5th percentile RI curves using the lambda–mu–sigma (LMS) method for each sex group. ResultsPediatric serum continuous IGF-1 and IGFBP-3 reference percentiles by LMS method were found to be immunoassay method-dependent, but aligned relatively well with the manufacturers’ RIs. IGFBP-3 levels displayed notable discrepancies among the different immunoassay methods. ConclusionAge- and sex-specific pediatric LMS based continuous reference intervals are method dependent and they should be calculated for dynamic parameters that show variations throughout childhood.

Impact of COVID-19 on pro- and antiatherogenic lipoproteins (cross-sectional population study)

Aim. The aim of this cross-sectional retrospective study was to study the effect of SARS-CoV-2 S1/S2 infection on population lipid parameters, which are leading risk factors for the development and progression of atherosclerosis, which can be significantly distorted in systemic inflammation and, in particular, during respiratory viral infections.Material and methods. We analyzed anonymized results of one-time, one-year studies of complete lipid profiles and related laboratory parameters performed in the Helix Laboratory Service from February 1, 2015 to December 30, 2020 in 238541 males and 384437 females aged from 22 to 83 years in 334 populated areas of the European Russia using Roche Cobas C502, C702 (Roche Diagnostics GmbH, Mannheim, Germany), LIAISON XL (DiaSorin S.p.A, Italy) analyzers.Statistical analysis included methods of descriptive statistics, distribution analysis, sample comparisons, and search for dependencies.Results. A dramatic change in the magnitude and nature of seasonal population fluctuations in low-density lipoprotein cholesterol and high-density lipoprotein cholesterol (HDL-C) during the COVID-19 spread has been identified.COVID-19 differentially affects the relationship between high-sensitivity C-reactive protein (hsCRP) and atherogenic and antiatherogenic lipoproteins. These relationships have sex differences, are nonlinear, and in relation to HDL-C are associated with the level of specific anti-SARS-CoV-2 S1/S2 antibodies.Up to a hsCRP level of 2,5 mg/l, there is a significant increase in population levels of low-density lipoprotein cholesterol with a correlation coefficient of 0,14 for women (p<0,001) and 0,10 for men (p<0,001). At hsCRP levels >2,5 mg/l, the trend reverses. At the same time, HDL-C levels sharply decrease with a negative correlation of -0,23 (p<0,001) in women and -0,22 (p<0,001) in men with hsCRP values <2,5 mg/l, followed by a less pronounced decline.Conclusion. The study results may be useful for optimal prevention development and adequate assessment of atherogenic dyslipidemia treatment effectiveness in patients after COVID-19.

Evaluation of a fully automated high-throughput serology assay for detection of Hepatitis D virus antibodies

BackgroundHDV antibody testing is recommended for universal screening and as the first line in an HDV double reflex testing strategy for effectively identifying patients with active infection for therapeutic treatments. ObjectiveThe aim of this study is to evaluate the performance of a newly developed ARCHITECT HDV Total Ig (ARCHITECT HDV Ig) prototype assay. Study designPerformance characteristics were determined for the ARCHITECT HDV Ig and a reference test, LIAISON XL Anti-HDV using a well-characterized specimen panel, comprising HDV RNA positive (n = 62) and negative (n = 70) samples, and healthy US blood donors. ResultsHealthy US blood donors (n=200) showed 99.5% (199/200, 95%CI=97.65–99.98) specificity with ARCHITECT HDV Ig and 98.5 % (197/200, 95 %CI = 96.10–99.64) with LIAISON Anti-HDV. Among known HDV RNA positive samples, ARCHITECT HDV Ig detected 59/62 demonstrating 95.2 % sensitivity while LIAISON Anti-HDV sensitivity was 90.3 % (56/62). Among 101 HBV positive samples, 70 were reactive in the ARCHITECT test, 59 of which tested positive for HDV RNA for a positive predictive value (PPV) for the presence of HDV RNA was 84.3 %. For LIAISON Anti-HDV, 79 specimens were reactive and 56 contained HDV RNA: PPV for HDV RNA was 70.9 %. Among 70 HDV RNA negative samples, 39 were HBV positive. ARCHITECT HDV Ig negative predictive value (NPV) was 71.8 % and LIAISON Anti-HDV NPV was 41 % for the HBV positive group, respectively. ConclusionWhen compared to the LIASON Anti-HDV test, the ARCHITECT HDV Ig assay demonstrated enhanced sensitivity and specificity and better NPV and PPV values for HDV RNA status. The ARCHITECT HDV Ig assay represents a promising tool for universal screening of all HBsAg-positive persons.

Confounding factors of the expression of mTBI biomarkers, S100B, GFAP and UCH-L1 in an aging population.

To evaluate some confounding factors that influence the concentrations of S100 calcium binding protein B (S100B), glial fibrillary acidic protein (GFAP), andubiquitin carboxyl-terminal hydrolase L-1 (UCH-L1) in older individuals. Indeed, recent guidelines have proposed the combined use of S100B and the "GFAP-UCH-L1" mTBI test to rule out mild traumatic brain injuries (mTBI). As older adults are the most at risk of mTBI, it is particularly important to understand the confounding factors of those mTBI rule-out biomarkers in aging population. The protein S100B and the "GFAP and UCH-L1" mTBI test were measured using Liaison XL (Diasorin) and Alinity I (Abbott), respectively, in 330 and 341 individuals with non-suspected mTBI from the SarcoPhAge cohort. S100B, GFAP and UCH-L1 were all significantly correlated with renal function whereas alcohol consumption, Geriatric Depression Score (GDS), smoking habits and anticoagulant intake were not associated with any of these three biomarkers. Body mass index (BMI) and age were associated with GFAP and UCH-L1 expression while sex and mini-mental state examination (MMSE) were only associated with GFAP. According to the manufacturer's cut-offs for mTBI rule-out, only 5.5 % of participants were positive for S100B whereas 66.9 % were positive for the "GFAP-UCH-L1" mTBI test. All positive "GFAP-UCH-L1" mTBI tests were GFAP+/UCH-L1-. Among individuals with cystatin C>1.55 mg/L, 25 % were positive for S100B while 90 % were positive for the mTBI test. Our data show that confounding factors have different impacts on the positivity rate of the "GFAP-UCH-L1" mTBI test compared to S100B.

Evaluation of the Comparability of Wantai Wan200+ Instrument with Routine Laboratory Assays for 21 Different Analytes.

Background: We compared the performance of 21 different assays performed by the Wantai Wan200+ (Wantai BioPharm, Beijing, China) with respect to other methods in use at the University Hospital of Padova (AOPD), Italy. Methods: The plasma (P) or serum (S) of 5027 leftover samples, collected from May to Sept 2023, was either analyzed or frozen at -20 °C. Beckman DXI800 (DXI), Roche Cobas 8000 e801 (RC), Snibe Maglumi 4000 plus (SM), DiaSorin Liaison XL (DL) and Binding Site Optilite (BS) equipment were used at the AOPD. P-procalcitonin (PCT), DXI; P-Troponin I (TnI), DXI; S-CA125, DXI; S-free PSA (f-PSA), DXI; S-total PSA (t-PSA), DXI; S-IL6, SM; P-Troponin T (TnT), RC; P-NT-proBNP, RC; P-Neuron-Specific Enolase (NSE), RC; S-CA15-3, DL; S-CA19-9, DL; S-AFP, DL; and S-CEA, DL were tested in fresh samples. P-Myoglobin (Myo), DXI; P-Cyfra21-1, RC; S-β2 microglobulin (B2MIC), BS; S-HE4, SM; S-PGI, SM; S-PGII, SM; S-CA72-4, SM; and S-CA50, SM were analyzed in frozen and thawed samples. Bland-Altman (BA), Passing-Bablok (PB) and Cohen's Kappa (CKa) metrics were used as statistics. Results: An excellent comparability profile was found for 11 analytes. For example, the t-PSA CKa was 0.94 (95%CI: 0.90 to 0.98), and the PB slope and intercept were 1.02 (95%CI: 0.99 to 1.03) and 0.02 (95%CI: 0.01 to 0.03), respectively; the BA bias was 2.25 (95%CI: -0.43 to 4.93). Ten tested measurands demonstrated a suboptimal comparability profile. Biological variation in EFLM (EuBIVAS) performance specifications was evaluated to assess the clinical relevance of measured biases. Conclusions: Evaluation of the Wantai Wan200+'s performance suggests that between-method differences did not exceed the calculated bias. Metrological traceability may influence the comparisons obtained for some measurands.

Comparable analysis of six immunoassays for carcinoembryonic antigen detection

ObjectiveThis study aimed to assess the current status of carcinoembryonic antigen (CEA) detection. We evaluated the correlation, consistency, and comparability of CEA results among six automated immunoassays, and combined with the results of CEA trueness verification of the Beijing Center for Clinical Laboratories (BCCL) for further analysis. MethodsAbbott Architect i2000, Beckman DxI800, Roche Cobas E601, Diasorin Liaison XL, Maccura IS1200, and Autolumo A2000 were used to detect 40 individual serum CEA samples. Taking the optimal analytical quality specifications calculated from data on biological variation as the evaluation criterion. Passing-Bablok regression and Bland-Altman analysis were performed between each assay and all-assays median values to evaluate the correlation and relative difference. The concordance correlation coefficient (CCC) was used for consistency analysis. Additionally, the trueness verification program used samples at three concentration levels to assess the bias, coefficient of variation (CV), and total error (TE) between the average measured values and the target value. ResultsThe Spearman's rank correlation coefficient (rs) was ≥0.996 and the CCC ranged between 0.9448 and 0.9990 for each assay vs. all-assays median. Considering the all-assays median value of each sample as a reference, there were proportional and systematic differences according to the Passing-bablok regression analysis. The relative difference of the four assays (Abbott Architect i2000, Autolumo A2000, Diasorin Liaison XL, and Maccura IS1200) met the optimal analytical quality specifications. On the other hand, Beckman DxI800 (13.2 %) and Roche Cobas E601 (−9.0 %) were only able to fulfill the desirable analytical quality specifications. The average pass rates for bias, CV, and TE of the trueness verification program were 80 %, 98 %, and 96 %, respectively. ConclusionsThe six automated immunoassays vs. all-assays median have a good correlation in CEA detection. However, there is a lack of comparability of CEA results. Further improvements are needed in harmonization among CEA detections.

Prevalence of FGF23 elevation in patients with hypophosphatemia

Background and aimsTo investigate the contribution of FGF23 in explaining the cases of hypophosphatemia observed in clinical practice, we aimed to determine for the first time the prevalence of FGF23 elevation in patients with hypophosphatemia and to describe the different mechanisms of FGF23-related hypophosphatemic disorders. Materials and methodsWe performed a prospective, observational, multicenter, cohort study of 260 patients with hypophosphatemia. Blood measurements (PTH, 1,25-dihydroxyvitamin D, bone alkaline phosphatase, 25-hydroxyvitamin D, and FGF23) were performed on a Liaison XL® (DiaSorin) analyzer. ResultsPrimary elevation of FGF23 (>95.4 pg/mL) was reported in 10.4% (95CI: 7.0–14.7) of patients (n = 27) with hypophosphatemia, suggesting that at least 1 in 10 cases of hypophosphatemia was erroneously attributed to an etiology other than FGF23 elevation. Patients with elevated blood FGF23 were grouped according to the etiology of the FGF23 elevation. Thus, 10 patients had a renal pathology, chronic kidney disease or post-renal transplantation condition. The remaining patients (n = 17) had the following etiologies: malignancies (n = 9), benign pancreatic tumor (n = 1), post-cardiac surgery (n = 4), cirrhosis (n = 2), and chronic obstructive pulmonary disease (n = 1). ConclusionIn order to improve patient management, it seems essential to better integrate plasma FGF23 measurement into the routine evaluation of hypophosphatemia.

Association of Serum Alpha-fetoprotein with the Tumor Characters and HBV Status of Hepatocellular Carcinoma to Assess its Resectability

Background: Serum alpha-fetoprotein (AFP) has long been used to complement imaging tests in the screening and diagnosis of hepatocellular carcinoma (HCC), its utility as a predictive marker of long-term risk for HCC in HBV patients is contentious. Objective: The current study is aimed to assess the serum alpha-fetoprotein with the tumor character and HBV status of HCC to assess its resectability. Methods: This was a single-center, cross-sectional study done from September 2020 to August 2021 at the department of Hepatobiliary, pancreatic, and liver transplantation surgery at BSMMU. A total of 27 HCC patients who met the inclusion criteria were enrolled in the study. Clinical, laboratory, and imaging findings were obtained using a standardized data collecting sheet with the patients' informed agreement. AFP was measured by automated chemiluminescence analyzer (LIAISON XL, DiaSorin, Italy) in the Department of Biochemistry & Molecular Biology, BSMMU. Statistical analyses were performed using SPSS version 22. Quantitative variables were expressed as mean standard deviation and examined using an unpaired t-test. The qualitative data were represented by frequencies and percentages, and the Chi-Square test and Fisher exact test (where applicable) were used to determine any association. The statistical tests were conducted with a 95% confidence interval, and P<0.05 was deemed statistically significant. Results: Majority of the tumors were single and located in the right lobe. Local extension and distant metastasis were preset in unresectable patients of group 2.Hepatitis B virus was positive in 16 (59.3%) patients and DNA was detectable in 8 (29.6%) patients. HBV positivity and detectable HBV DNA was significantly associated with poor resectable status in group 2 but insignificant in group 1. Conclusions: In this study, the overall resectability was 37%. HBV positive HCC patients are significantly associated with poor resectability when serum AFP is raised and it would be more indicative when HBV DNA is detected. TAJ 2023; 36: No-2: 111-119

Erratum for Buron and Banaei, "Inflated Gamma Interferon Response with QuantiFERON-TB Gold Plus Using the Automated Liaison XL Analyzer: a Testing Algorithm To Mitigate False-Positive Results in Low-Incidence Settings".

Erratum for Buron and Banaei, "Inflated Gamma Interferon Response with QuantiFERON-TB Gold Plus Using the Automated Liaison XL Analyzer: a Testing Algorithm To Mitigate False-Positive Results in Low-Incidence Settings".

A-264 Comparison of the ZEUS Scientific Lyme Assays to the DiaSorin Liaison Lyme Assays Using a Modified Two-Tiered Testing Algorithm for Lyme Disease

Abstract Background Lyme borreliosis is the most common vector-borne disease in the United States. Modified two-tiered testing (MTTT) strategies have recently been developed that use enzyme immunoassays as the second tier test in place of an immunoblot. We directly compared two sets of MTTT assays with samples obtained from the northeastern United States, a Lyme disease endemic area. Methods Remnant specimens from 120 patients initially tested by the ZEUS Scientific Lyme ELISAs in accordance with an MTTT algorithm were analyzed with the DiaSorin Lyme chemiluminescent immunoassays. The ZEUS assays were performed on a DYNEX DS2 and the DiaSorin assays were performed on the DiaSorin Liaison XL. Analytical concordance was evaluated. Results Of the 25 samples that were negative by the ZEUS VlsE1/pepC10 IgG/IgM assay, 100% (25/25) were negative by the DiaSorin Lyme Total Antibody Plus assay. Of the 95 samples that were presumptive positive or equivocal by the ZEUS IgG/IgM assay, 64% (61/95) were presumptive positive or equivocal and 36% (34/95) were negative by the DiaSorin Lyme Total assay. Samples that tested presumptive positive or equivocal on the ZEUS IgG/IgM or DiaSorin Lyme Total were evaluated by the respective IgG and IgM assays. Positive IgG results and negative IgM results demonstrated >90% agreement between the ZEUS and DiaSorin assays (Table 1). Overall clinical interpretation was concordant between the ZEUS and DiaSorin MTTTs in 57% (54/95) of patients who tested presumptive positive or equivocal on the ZEUS IgG/IgM. Twenty-four samples that tested positive for IgM by the ZEUS assay tested negative for DiaSorin Lyme Total or IgM assays. Conclusion Comparison of the DiaSorin Lyme assays to the ZEUS Lyme assays using an MTTT algorithm suggests that the DiaSorin assays would result in fewer positive screening tests, decreasing unnecessary secondary testing, and may result in fewer patients treated with antibiotics.

Pediatric reference intervals for endocrine markers in healthy children and adolescents on the Liaison XL (DiaSorin) immunoassay system

ObjectivesProminent physiological changes occurring throughout childhood and adolescence necessitate the consideration of age and sex in biomarker interpretation. Critical gaps exist in pediatric reference intervals (RIs) for specialized endocrine markers, despite expected influence of growth and development. The current study aimed to establish and/or verify RIs for six specialized endocrine markers on a specialized immunoassay system. MethodsSamples were collected from healthy children and adolescents (5 to <19 years) and apparently healthy outpatients (0 to <5 years) as part of the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER). Serum samples were analysed for aldosterone, renin (plasma), thyroglobulin, anti-thyroglobulin, growth hormone, and insulin-like growth factor-1 (IGF-1) on the Liaison XL (DiaSorin) immunoassay platform. RIs (2.5th and 97.5th percentiles) were established for aldosterone, renin, thyroglobulin, anti-thyroglobulin, and growth hormone. Manufacturer-recommended pediatric RIs for IGF-1 were verified. ResultsAge-specific RIs were established for aldosterone, renin, and thyroglobulin, while no age-specific differences were observed for anti-thyroglobulin or growth hormone. IGF-1 was the only endocrine marker studied that demonstrated significant sex-specific differences. Manufacturer-recommended IGF-1 RIs were verified for children aged 6 to <19 years, while those for children aged 0 to <6 years did not verify. ConclusionsThis study marks the first time that pediatric RIs for aldosterone and renin were established in the CALIPER cohort and highlights the dynamic changes that occur in water and sodium homeostasis during the first years of life. Overall, these data will assist pediatric clinical laboratories in test result interpretation and improve clinical decision-making for patients tested using Liaison immunoassays.

Insulin: Know what your immunoassay detects. Evaluation of two new immunoassays

BackgroundInsulin is essential for glycemic regulation but diseases can cause a default or an excess of insulin secretion leading to dysregulated glycemia. Hence, measurement of insulinemia is useful to investigate hypoglycemia, determine the pathogenesis of diabetes and evaluate β-cell function. Thus, diabetic patients need supplementation with recombinant human insulin and/or insulin analogues. Analogues have primary sequences different from native human insulin and may not be detected by some immunoassays. The objective of our study was to evaluate new insulin immunoassays by determining their ability to detect different types of human insulin or analogues. MethodsThis study compared the reactivity of two new insulin immunoassays with five well-established immunoassays on ten commercial insulins. We also measured insulin in blood samples from diabetic or pancreas transplant patients with known treatment. ResultsContrary to recombinant human insulin, there were differences in the specificity to insulin analogues. We distinguished three immunoassay categories: those recognizing all types of insulin such as the non-specific BI-INS-IRMA®, Architect® and Access® immunoassays; those recognizing human insulin only (Cobas®); and those recognizing human insulin and analogues in variable proportions (Liaison XL®, iFlash® and Maglumi®). ConclusionAn accurate biological interpretation of insulinemia relies on knowledge of the specificity of the immunoassay used.

Undisclosed interference in 25-OH-Vitamin D immunoassay on Liaison XL analyzer when using heparin plasma tubes

This study investigates the impact of sample type on the measurement of 25-OH-vitamin D using the Liaison XL (Diasorin) and Cobas e801 (Roche). This investigation was motivated by the need to optimize sample volume usage, which led us to adopt the use of heparin plasma, an alternative proposed by Diasorin in their specification. Discordant and unexplainable results were observed, prompting us to evaluate the effect of sample type on the accuracy of the 25-OH-vitamin D measurements. We collected 34 different paired samples from a randomly selected patients who had two types of tubes taken simultaneously: serum-gel and lithium-heparin plasma tubes. The 25-OH-vitamin D levels were measured using Cobas e801 and Liaison. Statistical analysis was performed using the Mann-Whitney test to calculate the p-value. Biases were also calculated. When comparing the heparin matrix with the serum matrix on the Liaison XL analyzer, a higher proportion (p < .0001; 79% versus 64%) of patients were classified in the ‘normal group’, while fewer were classified in the ‘insufficiency’ or ‘deficiency group’. The heparin tubes on the Liaison XL analyzer showed a mean bias of 57.5%) (p-value < .001; 95%CI: 37.6–77.4) compared to the serum tubes. On the other hand, the heparin tubes on the Cobas e801 analyzer showed a mean bias of −0.2% (95%CI: −4.8 to 4.5) compared to the serum tubes. It is imperative for laboratory professionals to be aware of this interference for an accurate measurement of 25-OH-vitamin D levels on the Liaison XL. Further research is needed to understand the mechanism of this interference.