bluuebunny/crossref_metadata_2025_split huggingface dataset:
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
Authors: Cortez R , Perdido M , Muyrong M , Eberhard A , Melake S , Van T 
Published: October 2024

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 &lt;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.
A-261 Outcome of a survey on dengue lateral flow immunoassay test kit reading and interpretation by medical laboratory staff in a hospital laboratory
Authors: Cheng K , Yeow J , Heng P , Wee G , Wong M , Teo B 
Published: October 2024

Abstract

Background
Lateral flow immunoassay (LFIA) tests, first introduced in 1959, are now the mainstay of clinical laboratories. Khoo Teck Puat Hospital (KTPH) is a 795-bed acute care general hospital located in the north of Singapore. The Department of Laboratory Medicine has been using dengue LFIA test kits for the detection of dengue NS1 antigen, IgM antibodies and IgG antibodies. While kits are cost-effective, user-friendly and provide rapid results, there is subjectivity in reading and interpretation of results.

Methods
We conducted a survey to assess test reading and interpretation by medical laboratory staff. Six serum and plasma specimens were analysed using Bioline™ Dengue IgG/IgM WB test device. Test kits at the end-point of sample incubation were photographed in both well-lit and dim conditions. A survey questionnaire was prepared using an online form builder tool using the photographs. Staff were invited to participate in the survey. They were allowed to report the result as ‘Positive’, ‘Negative’ or ‘Equivocal’.

Results
A total of sixteen responses were received. Results were 100% concordant for all 6 specimens in both well-lit and dim conditions. For one case, under a well-lit condition, 15 staff reported the result as ‘Positive’ while one staff reported ‘Equivocal’. Most of the reported results for samples with no consensus is split between ‘Positive’ and ‘Equivocal’.

Conclusions
Dengue viruses of all 4 known serotypes are endemic in Singapore. Positive results are tracked on a national level to identify areas of high dengue infection for intensive environmental and vector control measures. Hence, accurate reporting and identification of patients with dengue infection is important. Our survey shows that lighting conditions do not affect the interpretation of LFIA results. Reading and interpretation of dengue LFIA test kits however, remain dependent on user interpretation and newer test kits with optical readers may be useful in mitigating this.
A-274 The Yield of the Limulus Amebocyte Lysate (LAL), Which is Used for Endotoxin Detection and Fungal Diagnosis is Increased by Caffeine Collection Buffer
Authors: Zhang S , Zhang M , Zhang J 
Published: October 2024

Abstract

Background
Limulus Amebocyte Lysate (LAL), which is a major component of Fungal infection diagnosis kit, is used for the adjunct diagnosis of invasive fungal infection. This study used different blood collection buffers to find the optimal blood collection buffer to maximize the yield of LAL. The PBS collection buffer was found to prevent degranulation during blood collection procedure and the PBS-derived Limulus Amebocyte Lysate (LAL) was observed to work in both the chromogenic test and the turbidimetric method assays. A similar phenomenon was observed with the caffeine collection buffer.

Methods
To further confirm this observation, we used a caffeine collection buffer to collect the blood of horseshoe crabs in the 2023 bleeding season (from July to October). Once a week, 3 crabs were bled for a total of 30 crabs. The blood of each crab was collected using the caffeine collection buffer and the 3% NaCl collection buffer, respectively. The cell pellets were resuspended into LAL reagent water (LRW) or 5 mM CaCl2. The final LAL activity was tested by both chromogenic and turbidimetric assay methods.

Results
The results showed that a caffeine collection buffer could prevent degranulation for over 1 hr and the activity yield of caffeine-derived LAL is much higher than that of the 3% NaCl solution. There was no discernible impact upon activity yield of crab size, period of the bleed season, or the vendors. Interestingly, caffeine-derived LAL was observed to work in both the chromogenic and turbidimetric assays. The enzyme characteristic of the LAL was also described.

Conclusions
Caffeine collection buffer prevents amebocyte degranulation during blood collection and processing. The activity of caffeine LAL is much higher than that of 3% NaCl. Caffeine LAL works in both chromogenic test and turbidimetric assay.
A-277 Viability of multi-drug resistant organisms in a fecal collection and transport system stored at ultra-low temperature
Authors: Cowden L , Kelly B J 
Published: October 2024

Abstract

Background
Epidemiological studies are constantly investigating new, easier ways to collect and store patient specimens that allow for flexible testing windows and long-term storage as well as accurate quantification of organisms of interest. The FecalSwabTM system (Copan, Brescia, Italy) is intended for the collection and preservation of rectal and fecal specimens. This system includes a preservation medium which serves to maintain the viability of enteric pathogens during transport to a clinical laboratory for up to 72 hours at 4oC. The objective of this study was to assess the continued viability of multi-drug resistant organisms (MDROs) suspended in the FecalSwab sample format when frozen at -80°C and the impact of freeze-thaw cycles.

Methods
A total of 40 organisms were chosen spanning methicillin-resistant Staphylococcus aureus (MRSA, n=10), carbapenem-resistant Pseudomonas aeruginosa (CRPA, n=5), carbapenem-resistant Enterobacterales (CRE, n=5), vancomycin-resistant Enterobacterales (VRE, n=10) and extended-spectrum beta-lactamase containing Enterobacterales (ESBL, n=10). Each organism was spiked into FecalSwab at standardized concentrations. At each time point, FecalSwab media was plated onto blood agar and colonies were quantified. Each of the 40 organisms were assessed one-week post-freeze and over the course of freeze-thaw cycles at days 3 and 5. The survival of each MDRO was evaluated by calculating a difference between the concentration of organisms recovered (CFU per 10uL media) at each time point and the concentration of organisms confirmed present at the time of inoculation. Percent recovery was calculated from this difference.

Results
One week after freezing, the percent recovery for MRSA, VRE, ESBL, CRE, and CRPA averaged to 102%, 201%, 17.8%, 7.6%, and 0.8%, respectively (Kruskal Wallis p &lt; 0.001), with significant differences noted between gram positive and gram negative organisms (Kruskal Wallis p &lt;0.001).

Conclusions
Epidemiological studies interested in MDRO surveillance rely on methodologies that allow for accurate quantification of viable organisms. In this study, we’ve evaluated the viability of several multi-drug resistant organisms when frozen at -80°C in the FecalSwab. The FecalSwab system is intended for the collection of rectal swab and fecal specimens and to preserve the viability of enteric pathogenic bacteria for testing in the clinical laboratory. Although it was not specifically designed to preserve MDROs, it performed well with MRSA and VRE, but less well with CRE, CRPA and ESBL organisms. When using the FecalSwab system, the observed gram-specific differences may inform the suitability of this system depending on the organism(s) of interest.
A-282 Purpura fulminans caused by Haemophilus influenzae: case report of unusual etiology
Authors: Levi J , Bandeira S P , Castelo M H , Cavalcante L L , Pereira M M , Amaral E S , Oliveira B L , Furtado G P , Ventura F M , Cury R C 
Published: October 2024

Abstract

Background
Fulminant purpura is a clinical syndrome characterized by a purplish, ischemic-looking skin rash, commonly accompanied by systemic symptoms ranging from acute febrile syndrome to septic shock. Due to high lethality of possible infectious etiologies, immediate recognition and early initiation of empirical antimicrobial therapy are crucial to ensure better outcomes. Interdisciplinary collaboration among healthcare teams, infectious disease specialists and microbiologists is essential to ensure accurate and early microbiological diagnosis.

Methods
This work aims to report a case of Haemophilus influenzae-induced purpura fulminans that occurred in Fortaleza-CE, a coastal city in northeastern Brazil, highlighting clinical recognition and microbiological identification, based on review of medical records.

Results
Case report A 59-year-old man, originally from Germany, was on vacation in Brazil. He presented to emergency medical service with an acute onset of fever, abdominal pain and diarrhea, progressing to decreased level of consciousness and purplish ischemic skin lesions with hemorrhagic bullae on trunk and extremities (Figure 1), with no history of trauma. Upon admission, the blood exams showed bicytopenia - 1900 leukocytes/µL (86% segmented) and 51,000 platelets/µL - and very high C-reactive protein (41.58 mg/dL). Although empirical antimicrobial therapy with vancomycin and piperacillin-tazobactam was initiated, patient progressed to septic shock, hepatic dysfunction, requiring mechanical ventilation, vasopressor support, and renal replacement therapy. Blood cultures from hospital admission were positive after about 14 hours and allowed isolation of small and translucent colonies in Chocolate PVX plate Agar (BioMerieux™). Maldi tof analysis by Vitek MS identified H. influenzae (99.9 % accuracy). Despite prolonged hospitalization due to multiple organ dysfunctions, patient had a positive outcome.

Conclusions
This case illustrates the importance of immediate recognition of the syndrome coupled with assertive empirical treatment and early microbiological diagnosis for a positive clinical outcome, even in a severe presentation. Multiprofessional approach is essential for accurate and early diagnosis.
A-324 Performance and Turnaround Time of Plasma Lactate Assay on POCT, Blood Gas Instrument, and Chemistry Analyzer
Authors: Lockart K , Jin M 
Published: October 2024

Abstract

Background
Time is a critical factor of plasma lactate testing in the management of patients with sepsis. To best serve these patients, we must optimize testing methods to provide a turnaround time (TAT) that guides efficient patient care. Point of care tests (POCTs) provide rapid results for emergency department and medical intensive care unit but are not feasible for all hospital settings. Laboratory testing methods on an automation line provide greater efficiency but result slowly due to need of specimen preparation and longer analytical time. The goal of this study is to provide detailed TATs of plasma lactate testing among the methods of POCT, chemistry analyzer in an automation line, and blood gas analyzer.

Methods
Plasma lactate testing was performed by three methods, GEM Premier ChemSTAT (POCT in ER only), Beckman AU5800 (chemistry analyzer), and Radiometer ABL800 (blood gas instrument). The TAT of lactate for each method was measured and include the time from specimen collection to laboratory receipt (except for POCT method), and time from specimen receipt to resulting (including specimen preparation for Beckman AU5800).

Results
The average TATs of lactate testing for each method in all hospital sites are detailed with respect to each event and subcategorized (Table 1). The average TAT of 12.0 min on Radiometer ABL800 is higher than the TAT of 2.5 on GEM Premier ChemSTAT method but is greatly reduced compared to the TAT of 35.4 min on Beckman AU5800.

Conclusions
Radiometer ABL800 method could be the optimal laboratory method for plasma lactate testing fulfilling the TAT (average 12 min), with less test cancellation due to specimen stability issue, and combines testing with blood gases. Using three Radiometer ABL800 instruments, we manage the performance of around 70 plasma lactate tests daily.
B-014 Performance evaluation of the automated cell image analyzer DI-60 for leukocyte differential count
Authors: Chang S , Kim E , Kim Y , Won D 
Published: October 2024

Abstract

Background
The Sysmex DI-60 system (Sysmex, kobe, Japan) is an automated cell image analyzer that captures cell images and analyzes them. The aim of this study was to evaluate the performance of DI-60 for leukocyte differential count in comparison with manual differential count or XN-20.

Methods
A total of 205 samples were analyzed. The agreement between DI-60 pre-classification and post-verification by medical technicians was determined. The correlation and ability to identify clinically important abnormal cells of DI-60 post-verification were evaluated.

Results
The overall agreement of DI-60 pre-classification was 84.7% (Table 1). The correlation between DI-60 post-verification and manual differential counts were exellent (r2 &gt; 0.85) for neutrophil, lymphocyte, monocyte and eosinophil, but was very low for basophil (r2 = 0.3759). The correlation between DI-60 post-verification and leukocyte differential counts by XN-20 were exellent (r2 &gt; 0.90) for neutrophil, lymphocyte and eosinophil. However, monocyte and basophil showed a relatively low correlation of r2 = 0.6343 and r2 = 0.3118, respectively but was very low for basophil (r2 0.3759). The ability of DI-60 post-verification to identify clinically important abnormal cells including blast, promyelocyte, myelocyte, metamyelocyte and NRBC demonstrated excellent efficiency (80.8 to 96.3%) except for NRBC (51.0%). Overall sensitivity was 63.7-88.2%, and specificity was 84.3-95.5% excluding NRBC (43.7%).

Conclusions
DI-60 showed excellent pre-classification and generally high correlation compared to manual leukocyte differential counts. Although additional verification with PBS review by experienced medical technician may still be required, the performance DI-60 makes it an efficient screening tool in clinical laboratories.
B-054 Performance Evaluation of the VITROS HIV Combo Assay on the Ortho VITROS 3600 system
Authors: cao x , Zhang B 
Published: October 2024

Abstract

Background
n 2014, the US CDC updated HIV screening algorithm, recommended any assay capable of reliably detecting p24 antigen and both IgG&IgM antibodies as starting point. In 2021 Chinese FDA approved VITROS HIV Combo assay as early detection of acute HIV infection with fourth-generation Ag/Ab combination test, with several declared earlier seroconversion panel reactivity than the third generation assay. This study records the experiment run to assess clinical performance using prospectively collected HIV-1 and HIV-2 antibody positive samples from Chinese CDC on the VITROS HIV Combo Assay on the VITROS 5600 Integrated System,

Methods
In total 450 serum/plasma samples, including 164 HIV antibody positive (162 HIV-1 antibody positive and 2 HIV-2 antibody positive) and 286 HIV negative. The HIV-2 antibody positive samples were purchased from Seracare (United States), and the remaining samples were prepared by the Chinese CDC reference laboratory. In the samples prepared in the reference laboratory, all HIV-1 antibody positive samples were tested by HIV antibody confirmation test, and the result was positive; The HIV negative samples were confirmed based on a comprehensive assessment of HIV antibodies, HIV-1 p24 antigen, HIV nucleic acid testing, and follow-up testing results, and window period has been ruled out. Ten linear and sensitivity reference samples were added to the HIV-1 p24 antigen national reference material (batch number 20190505, purchased from the China Academy of Food and Drug Control) . The antigen concentrations from L1 to L10 were 20, 10, 5, 2.5, 1.25, 0.625, 0.313, 0.156, 0.0781, and 0 IU/ml, respectively.

Results
The sensitivity for this positive population of samples in the VITROS Combo test was calculated as 100.00% (164/164) with an exact 95% confidence interval (Cl) of 99.26% to 100.00%. The specificity for this negative population was 99.58% (Cl 99.38%-99.73%).

Conclusions
The sensitivity and specificity of VITROS Combo assay are very high. With class leading antigen sensitivity doesn’t sacrifice specificity. This new assay delivers excellent confidence in results, and with more target (HIV-1 p24) being detected, can helps laboratory shortening HIV infection window, improve operators and technicians’ confidence in the outcome of HIV testing.
B-056 Clinical and Analytical Performance Evaluation of Two Immunoassays for the Detection of Mite Specific Serum IgE for Allergy Diagnosis
Authors: Ozaki B C , Aarestrup P F , Cheloni E C , Aarestrup M F , Aarestrup B V , Aarestrup F M 
Published: October 2024

Abstract

Background
IgE-mediated allergic diseases can be considered a modern epidemic, with exponential growth mainly in industrialized countries. Diagnosis is usually based on detailed medical history, physical examination, skin or challenge test and the determination of allergen-specific serum IgE - a laboratory test that has become a high-value tool in the allergy patient's journey over the last three decades. As the identification of specific immunoglobulin E (sIgE) for a given allergen is important to aid in the allergy diagnosis, several methods for detecting IgE in vitro are available worldwide and, in recent years, there have been several improvements in laboratory methodologies bringing greater advances in terms of clinical and analytical performance. The study aims to evaluate the clinical performance and correlation between two different sIgE assays (IMMULITE® 2000 3gAllergy™ and ImmunoCAP) and their concordance with Skin Prick Test (SPT) and clinical history.

Methods
This prospective study was conducted with approximately 130 consecutive patients who underwent evaluation of allergic diseases in different centers in Brazil. Clinical data, blood samples, and SPT results were collected. With the blood samples, the allergens D1, D2 and D201 were evaluated using both methods (IMMULITE® 2000 3gAllergy™ and ImmunoCAP) and the data were evaluated in a correlation study and clinical concordance analysis.

Results
Qualitatively evaluating the sIgE results between the two immunoassays, at the cutoff point considered clinically significant (≥ 0.35 KU/L), a total agreement of 95.2% (D1); 95.1% (D2), 91.7% (D201) and 96.8% (Derp2) was observed. Semi-quantitatively evaluating through reactive interpretation, an agreement of 89.5% (D1); 91.06% (D2); 87.60% (D201) and 93.33% (Derp2) was observed. Spearman's correlation between the analytical methods was 0.85 (D1), 0.93 (D2), 0.68 (D201) and 0.76 (Derp2). When compared with the SPT results, a total agreement of 78.7% and 80.1% was obtained for 3gAllergy and ImmunoCAP, respectively, with slightly higher positive agreement for both methods.

Conclusions
The two methods have good agreement with each other, with greater differences when evaluated quantitatively. However, when compared to clinical history and skin prick test results, both perform very similarly with a few differences that may be caused by the difference in the assay design.
B-078 Serodiagnosis of Rheumatoid Arthritis Using the New Accentis Chemiluminescence Immunoassay Platform for Anti-CCP Antibody Detection
Authors: Weiss J , Elleuche S , Saschenbrecker S , Dähnrich C 
Published: October 2024

Abstract

Background
Rheumatoid arthritis (RA) is one of the most common autoimmune diseases and the most frequent chronic inflammatory arthropathy. Reliable diagnosis at the earliest possible stage is indispensable to keep the disease under control with suitable therapy and to prevent irreversible joint damage. Autoantibodies against cyclic citrullinated peptides (CCP) are a highly specific marker for RA with relevance for (differential) diagnosis, prediction and prognosis. In this study, we investigated the clinical and analytical performance of a newly developed anti-CCP chemiluminescence immunoassay (ChLIA) system.

Methods
Serum samples from 170 patients with clinically confirmed RA and from a control panel of 274 patients with other diseases were analyzed using the EUROIMMUN Anti-CCP ChLIA (IgG), which was processed on the fully automated random-access system Accentis (EUROIMMUN). The results were compared with those obtained with the EUROIMMUN Anti-CCP ELISA (IgG) with regard to sensitivity, specificity and inter-assay concordance.

Results
The ChLIA achieved a sensitivity of 71.2% (121/170) and a specificity of 97.4% (267/274), while the ELISA was less sensitive (67.5%, 114/170) and specific (96.4%, 264/274). The qualitative results showed positive and negative agreement rates between the two assays of 92.7% (115/124) and 95.9% (307/320), respectively, resulting in 95.0% (422/444) overall agreement and a kappa score (0.878) indicating near perfect agreement.

Conclusions
The new Accentis ChLIA showed improved sensitivity and specificity for the detection of anti-CCP antibodies compared to the corresponding ELISA. Given the enhanced clinical performance and the practical benefits of using a random-access system, this ChLIA platform can effectively support the diagnosis of RA.